Coriander (Coriandrum sativum L) is a spice obtained from the plant belonging to the family Umbelliferae (Apiaceae). The green, young coriander leaves are also known as cilantro and are used as a herbal flavoring in the preparation of salads, sauces, Mexican salsas, and chilies, poultry and seafood dishes, and a variety of ethnic foods. The aromatic coriander fruit or seed, either whole or ground, finds use in curry meat dishes, puddings, breads, soups, and stews. Interestingly human perception of cilantro’s taste can vary dramatically, on the one hand imparting a bittersweet, spicy taste, and, on the other hand, being described by some as soapy with a repugnant odor. The reason for this discrepancy in perception has been recently traced to individual differences in genes that control our sense of taste and response to pungent chemicals found in foods.1–3 Besides the Spanish name cilantro for the coriander leaves, the grass-like coriander plant is also known as Chinese parsley and in Sanskrit as dhanya. It is indigenous to the Middle East and Mediterranean region, although it has been cultivated in China for millennia. The essential oil constitutes approximately 1% of the coriander fruit and is among the world’s top 20 essential oils. It finds uses in perfumes, cosmetics, herbal medicines, and alcoholic liquor flavorings. In traditional remedies, coriander was used for relief of gastrointestinal maladies, although other historical uses included as an aphrodisiac, antibiotic, a remedy for respiratory ailments and pain, and a treatment for loss of appetite and memory.3–8 The aim of this overview is to highlight studies about potential antioxidant, antimicrobial, diabetes-modulating, and neurological health benefits of coriander and one of its major constituents, linalool.
”A search of the PubMed literature database was completed in order to identify relevant research publications. Search terms included Coriandrum sativum, coriander, cilantro, Chinese parsley, and linalool. More than 150 relevant reports published between 1952 and 2015 were identified. Linalool was selected for study, because it is a major component of coriander oil for which numerous biological actions have been identified. Full reports of English-language publications and English-language abstracts of foreign-language articles from peer-reviewed journals were primary sources of information. Commercial and governmental reports also were supplementary sources. In general, the quality of studies was assessed based on the soundness of experimental methodologies, adequate description of the composition of test samples, and thoroughness of data analyses. Despite variations in the quality of some studies, they were nonetheless included in this discussion so that the variety of information can be evaluated and issues for future research identified.
In vitro studies are included in this overview to provide insights into possible mechanisms of bioactivity of coriander constituents and identify avenues for future research. Animal studies using multiple doses provide in vivo substantiation of biological efficacy, bioavailability, and potential adverse effects of coriander. Findings from animal studies using different delivery systems (topical, oral, injection) may be included together in sections of this overview, but may not be directly comparable. These animal studies also can identify additional issues to pursue and provide guidance in the design of human studies, although translatability to humans is not necessarily straightforward. Human studies may differ in quality with regard to thoroughness of study design and data analyses. Strength of evidence for a potential health benefit is greatest when consistent findings from well-controlled human studies and animal experiments are available, and insights into possible mechanisms of biological activity have been elucidated.
The composition of extracts from the different parts of the coriander plant depends on the methods of extraction. The major constituent of the essential oil from coriander seeds is linalool (60%–80%) followed by other alcohols, ketones, and esters such as α-pinene (0.2%–8%), γ-terpinene (1%–8%), geranyl acetate (0.1%–4.7%), and camphor (0.9%–4.9%). The yield and composition of essential oils can vary according to cultivar, plant maturity, isolation procedures, and cultivation conditions.7,9–18 It has been noted that total oils extracted from coriander contain substantial amounts of the unusual fatty acid petroselenic acid.19 The water-soluble components of the seed include monoterpenoid alcohols and their glucosides, alkyl glucosides, and norcarotenoid glucosides. As far as the immature leaves are concerned, primary constituents include aldehydes and alcohols such as 2E-decenal, decanal, 2E-decen-1-ol, and decanol.8,9,20–26 Among spices, the leaves of coriander have been reported to be a rich source of folates,27,28 a good source of ascorbic acid, and to contain good amounts of caffeic, ferulic, gallic, and chlorogenic acids.29–32 A summary of the variety of compounds identified in several coriander plant parts is presented in Table 1.
The cumulative consumption of coriander seed oil as a spice and from use as a food additive is estimated to be 0.0714 mg/kg per day or 5.4 mg for a 75-kg male.8 The consumption of coriander among different populations has not been widely documented, although the daily intake of coriander among adult males in India was determined to be 1.37 g.48 Additional intake data are needed in light of likely regional variations in forms, quantities, and patterns of coriander consumption.
A summary of select biological activities of coriander extracts and linalool is provided in Table 2.
Inhibition of Oxidation
There is considerable interest in identifying foods with strong antioxidant capacity for use in food preservation and in enhancing health.89 Data from diverse in vitro antioxidant assay systems indicate that different portions and extracts of the coriander plant suppress oxidative stress by acting as reducing agents, suppressors of lipid peroxidation, free radical scavengers, or as singlet oxygen quenchers (see Appendix, Supplemental Digital Content 1, http://links.lww.com/NT/A16).
There also is accumulating evidence for an oxidation-suppressing action of coriander in vivo. In normal rats, administration (intragastric) of etheric and aqueous extracts of coriander powder (1 mL/d) for 60 days resulted in decreased thiobarbituric reactive substances in liver and plasma, compared with controls. Similarly, a diet supplemented with 10% coriander powder (12 g/100 g body weight for 90 days) suppressed malondialdehyde (MDA) and peroxide levels in heart and liver tissue of rats, which, in part, was due to increased antioxidant enzyme activities.49,50 In rats treated with the colon carcinogen dimethylhydrazine and provided a diet supplemented with 5% to 10% coriander powder, liver MDA levels decreased, and liver and colon antioxidant enzyme systems increased, compared with controls.51 Compared with controls, mice treated with lead and administered ethanolic or aqueous extracts of coriander seeds (250–600 mg/kg, orally [PO]) exhibited a decrease in lead-induced oxidative damage to kidney and liver, which was accompanied by increases in glutathione levels and the activities of several antioxidant enzymes.52 Likewise, for rodents treated with the hepatotoxic agents carbon tetrachloride or hexachlorocyclohexane, administration of ethanolic extracts of coriander leaves (100–300 mg/kg, intraperitoneally [IP]; 100-500 mg/kg, PO) or provision of diets supplemented with coriander seed powder (5%–10%) resulted in decreased hepatic damage and increased antioxidant enzyme activities, compared with controls.42,53,54 In one of these studies, the efficacy of an ethanolic extract of coriander was similar to that of the antioxidant drug silymarin. In contrast, oral dosing of CCl4-treated rats with coriander essential oil (0.03 g/kg per day, PO) yielded pro-oxidant effects in liver tissue and did not significantly alter antioxidant defense systems.33 Regarding the brain, rats were exposed to lead for 4 weeks followed by a 7-day administration of a hydroalcoholic extract of coriander (250 and 500 mg/kg, IP).55 Compared with controls, animals given the coriander extract showed a significant decrease in reactive oxygen species, total protein carbonyl content, and lipid peroxidation products in cerebellum, hippocampus, frontal cortex, and brain stem regions. Also for all brain regions, dosing with coriander resulted in significant decreases in lead concentrations and increases in copper and zinc concentrations, compared with controls. Thus, this extract suppressed lead-induced brain damage by its ability to suppress oxidative stress and chelate metals. In another brain study, a coriander hydroalcoholic extract was administered to rats (100 500 and 1000 mg/kg, IP) 30 minutes prior to injection with the seizure-inducing agent pentylenetetrazole.56 Compared with controls, extract treatment significantly delayed onset of first minimal clonic seizures. It also prevented the elevation of brain MDA and the reduction of total thiol groups accompanying pentylenetetrazole dosing. Linalool alone was tested in H2O2-dosed guinea pigs.57 Linalool administration (120 mg/kg, IP) counteracted the decrease in total brain lipids caused by H2O2 and suppressed H2O2-induced brain lipid peroxidation levels in a manner similar to vitamin E and lipoic acid treatments. In another study, rats were treated with linalool (12.5–100 mg/kg, IP) for 11 days concurrently with acrylamide, a neurotoxin and oxidant.58 Compared with controls, administration of linalool at doses between 12.5 and 50 mg/kg led to significant increases in glutathione content and decreases in lipid peroxidation in the cerebral cortex.
These data collectively suggest that coriander exhibits efficacy in suppressing oxidation in several tissues, when tested in various experimental models of oxidative stress and when administered by different protocols. Future studies should evaluate how chronic dietary exposure to culinary-relevant amounts of coriander oil or coriander powder affects biomarkers of oxidative stress–associated conditions. For example, antioxidant effects on vascular pathology and endothelial integrity associated with cardiovascular and lung diseases would be of interest. In this context, bioavailability of coriander phytochemicals and their disposition in target tissues after consumption will be essential to characterizing any health benefits. Determining measurable benefits following intakes of low levels of coriander in the diet would be instructive in light of the controversies90 surrounding excessive antioxidant consumption and considering the opinion of the European Food Safety Authority that for foods there is insufficient evidence to establish that having antioxidant activity/content and/or antioxidant properties is a beneficial physiological effect.91
Considerable data from in vitro investigations provide support for coriander’s broad-spectrum antimicrobial activity (see Appendix, Supplemental Digital Content 1, http://links.lww.com/NT/A16). In contrast, the capacity of coriander to counteract infections in vivo is not well studied. However, in an animal study, different levels of coriander seed powder (1.5%, 2.0%, 2.5% wt/wt in diet) or an aqueous extract (750–1250 ppm in drinking water) were provided to broiler chicks for 21 days.59 Compared with controls, all doses of coriander extract in the drinking water and specific amounts of coriander powder in the diet (1.5% and 2.0%) significantly decreased the Escherichia coli content of ileal microflora without affecting the population of Lactobacillus bacteria. A significant improvement in antibody titer against Newcastle disease and infectious bronchitis was also observed for those receiving coriander extract in the drinking water. Based on the reports of others,60 the authors speculated that coriander extract was likely stimulating peripheral blood mononuclear cells and increasing tumor necrosis factor γ secretion. In light of these findings, dietary coriander modulation of the gut microbiota in other animal models and humans should be further characterized and specifically whether it can alter the host immune response and the balance of beneficial microbes occupying the stomach and intestine. A randomized, placebo-controlled, intraindividual pilot study of coriander oil as a treatment for interdigital fungal infection was evaluated in 35 patients.61 Coriander oil (6%) in unguentum leniens was applied to individuals with symmetric, bilateral interdigital tinea pedis for 14 and 28 days. For the entire observation period of 28 days, the clinical signs of mycosis were significantly attenuated on the side treated with coriander oil, compared with the vehicle-treated side. Tolerability of the coriander oil was good, and reports of pruritus and burning sensations were rare. Assessing coriander preparations alone or as a pharmaceutical adjuvant on other skin infections and conditions would be worthwhile.
Management of Diabetes (Preclinical)
The use of spices and plants for management of diabetes mellitus has been considered for decades.92–95 In one of the earlier reports evaluating coriander and diabetes, administration (in drinking water) of a hydroalcoholic extract of coriander fruit for 10 days to alloxan-treated diabetic rats had no effect on fasting blood glucose levels.62 Since then, there is a growing body of preclinical evidence in support of diabetes-modulating benefits of coriander.
Two reports describe the effect of feeding diets containing coriander seed powder (6.25%) to streptozotocin (STZ)–treated diabetic mice.63,64 In one of the studies, mice also were given a hot water extract of coriander seed (2.5 g/L in drinking water). In both studies, provision of coriander corrected the hyperglycemia of the diabetic mice. One of the studies reported that coriander treatment corrected the weight reduction usually observed after STZ treatment,63 but the other did not.64 In both studies, test diets did not correct polydipsia associated with diabetes and, where measured, did not affect plasma insulin levels. Elsewhere 2 experiments were conducted with male rats provided diets supplemented with 10% coriander seed powder. In 1 report,65 STZ-treated diabetic mice fed coriander exhibited a significant decrease in blood glucose, an increase in plasma insulin, and a lowering of glycated hemoglobin, compared with controls. These beneficial effects along with the amelioration of pancreatic islet damage in the rats were purported to be due to the free radical–scavenging activity of powder constituents. Similarly, with nondiabetic male rats fed a high-fat diet supplemented with 10% coriander seed powder,66 the high-fat diet–induced hyperglycemia was corrected. Also, liver glycogen content increased; liver hexokinase, phosphoglucomutase, and glycogen synthase activities increased; and glycogen phosphorylase activity decreased. The authors suggested that the coriander seeds exerted hypoglycemic benefits by enhancing glycolysis and glycogenesis and by suppressing glycogenolysis and gluconeogenesis. In contrast, for alloxan-treated diabetic rats fed a diet supplemented with 6% coriander leaf powder, no hypoglycemic effect or improvement in pancreatic histopathology was observed, compared with controls.70 Thus, the diabetes-modulating actions of seed and leaf powders are not consistent, which is an issue that requires further evaluation.
Other coriander extracts have been evaluated in vivo. A combination feeding study was conducted in which alloxan-treated diabetic rats were provided a polyherbal diet containing wheat germ oil, the juice of coriander leaves, and aloe vera gel (2:2:1 ratio) for 30 days. Compared with controls, feeding this mixture decreased fasting blood glucose levels. At the highest polyherbal dose, this effect was comparable in magnitude to that for glibenclamide.67 The mixture was effective in both normal and diabetic rats, although the contribution of coriander alone to this action cannot be ascertained. A hot water extract of coriander seeds was given (20 mg/kg, PO) to Meriones shawi, rats which develop obesity and hyperglycemia when given hypercaloric diets and allowed only minimal physical activity.68 Compared with controls, after 30 days’ administration of the extract, significant decreases in plasma glucose and hyperinsulin levels were noted, and insulin resistance decreased. In another investigation, an ethanolic extract of coriander seeds (200 mg/kg, IP) was administered to STZ-treated diabetic rats.69 Compared with controls, 5 hours after extract injection, serum glucose dropped significantly, and in excised pancreatic tissue, there was an increase in beta cells actively releasing insulin. An ethyl acetate extract of leaves and stems when administered (200 mg/kg, intragastric) to alloxan-treated diabetic rats for 7 days resulted in substantial decreases in blood and urinary glucose levels, compared with controls.71 The authors hypothesized that the antioxidant phytochemicals in leaves and stems contributed to a regeneration of beta cells damaged by alloxan. Lastly, an aqueous extract prepared from the leaves and stems of coriander was tested (100, 300, 500 mg/kg) in normoglycemic rats for modulation of postprandial glycemia43 following an oral sucrose tolerance test. Compared with controls, the extract significantly inhibited the postprandial glycemic peak at all doses. Furthermore, separate evaluation of rutin (50 mg/kg), a major polyphenol constituent of aqueous extracts of coriander leaves,72 significantly suppressed postprandial glycemia. Based on a subsequent in vitro assay, the authors suggested that the extract possessed diabetes-suppressing properties by inhibiting α-glucosidase activity in the gastrointestinal tract.
It is apparent from these several in vivo studies that treatment of diabetic rodents with coriander in most cases corrects hyperglycemia and can normalize insulin levels. The mechanisms for this beneficial effect are not well characterized but may to be due to modulation of carbohydrate metabolism or amelioration of pancreatic damage or, as assessed in an in vitro investigation, by attenuating glucose absorption.96 These preclinical in vivo studies suggest that coriander alone or as an adjunct may have utility in the management of diabetes.
Future studies should evaluate whether long-term intake of culinary-relevant levels of coriander seed or cilantro can alter glucose and insulin regulation in different models of diabetes and improve multiple diabetic symptoms. Prior to any potential application to humans, several issues must be addressed. The composition of commercially available coriander seed or cilantro samples used in studies needs to be characterized, a clearer understanding of possible mechanisms of action is needed, potential toxicities and adverse effects must be identified, and in what dietary context the inclusion of coriander could be most beneficial should be assessed. The capacity of linalool to influence the development of diabetes and the metabolic syndrome is not well studied (see Appendix, Supplemental Digital Content 1, http://links.lww.com/NT/A16).
No human studies have evaluated the effects of coriander oil on stress reduction and mood enhancement. However, there are reports in humans investigating either the individual action of linalool, a major constituent of coriander, or of other essential oils in which linalool is a major component. For example, in a study examining the effects of linalool stereochemistry on human neurological responses, subjects were randomly assigned to 2 experimental groups and 1 control group, each consisting of 4 female and 4 male participants.73 Those in the treatment groups participated in a stress task in rooms containing either 2.7 mg R-(−)-linalool/m3 or 9.8 mg S-(+)-linalool/m3, which correspond to hundred-fold concentrations of each enantiomer’s odor threshold. Continuous electrocardiogram and electrodermal activities were monitored, and blood pressure (BP), skin conductance reactivity, and saliva samples (for cortisol determination) were obtained prior to, during, and after testing. Compared with controls, both odorant substances slightly attenuated hypothalamus-pituitary-adrenal activity as measured by salivary cortisol levels. S-(+)-linalool acted as a stimulant when BP and heart rate were assessed, but relieved stress when skin conductance reactivity was measured. R-(−)-linalool was a stress reliever as determined by heart rate measurements. Thus, the compounds differentially affected the physiological processes studied, making conclusions about any consistent benefits unclear. The authors acknowledged that it is not known whether the quality or intensity of odorants contributed to these differences and that topical application of the enantiomers without odor perception should be further evaluated. A prospective, randomized trial of thirteen 28-week-pregnant women was conducted to examine the physical and psychological effects of aromatherapy using essential oils with high content of linalool.74 The subjects inhaled the essential oils (lavender, petitgrain, bergamot) dispersed from a diffuser for 5 minutes, and a Profile of Mood States (POMS) was conducted before and after the intervention. Compared with controls, those inhaling the linalool-containing essential oils exhibited a significant improvement in the tension-anxiety and anger-hostility portions of POMS. This was associated with enhanced relaxation and an increase in parasympathetic nerve activity, as assessed by heart rate measurements. In contrast, in another study, inhalation of lavender oil had no effect on patients’ anxiety prior to colonoscopy or esophagogastroduodenoscopy.75 Changes in preoperative anxiety were examined in another investigation of 60 patients prior to anesthesia and surgery.97 A distillate of Citrus aurantium containing flavonoids, phenolics, and linalool was given orally (1 mL/kg body weight) to the treatment group 2 hours prior to surgery. Anxiety was measured before and after surgery using the Spielberger State-Trait Anxiety Inventory and the Amsterdam Preoperative Anxiety and Information Scale. Compared with placebo controls, those receiving the distillate showed a strong anxiolytic response with no changes in hemodynamic variables. Any specific contribution of linalool to these effects cannot be assessed because of the complex composition of this distillate. In another study, the odor of jasmine tea, in which linalool is a major constituent, was investigated for effects on autonomic nerve activity and mood states in 24 healthy subjects.76 Also, the effects from exposure to the odors of (R)-(−)-linalool and its isomer (S)-(+)-linalool were examined. Autonomic nervous system activity, as measured by temporal durations of electrocardiographic signals between each heartbeat (R-R intervals), and mood states, as measured by POMS, were evaluated before and after 5-minute inhalation of the odors. Compared with water controls, jasmine tea significantly decreased heart rate for more than 40 minutes after inhalation. Moreover, jasmine tea inhalation significantly decreased negative mood scores for tension-anxiety and anger-hostility. A nonsignificant increase in positive mood score for vigor also was detected. Similarly, inhalation of (R)-(−)-linalool, the major linalool isomer in the jasmine tea odor, also caused a significant decrease in heart rate and negative mood scores, compared with controls. In contrast to this, (S)-(+)-linalool had the opposite effects on heart rate and mood. The (−)-linalool isomer is typically present in jasmine odors at levels at least 9-fold greater than those of the (+)-isomer. Somewhat different results were observed in a trial in which (−)-linalool was applied to 14 healthy subjects by percutaneous administration (1 mL linalool solution applied to lower abdomen for 20 minutes) while preventing fragrance inhalation.77 Compared with the placebo controls, those exposed to (−)-linalool exhibited a decrease in systolic BP and skin temperature, indicators of physiological deactivation, but yet showed no effects on subjective evaluation of well-being, compared with controls. The authors suggested that the lack of effect of (−)-linalool on well-being in this study was due to the prevention of olfactory processing of odor information and the associated psychological responses,77 an issue discussed in another publication.73 The calming effect of linalool inhalation in humans as measured by electroencephalography and sensory analysis78 also was studied before and after hearing environmental sound. Compared with controls, (R)-(−)-linalool inhalation produced favorable sensory impressions following exposure to work-related environmental sounds, which were accompanied by a trend toward decreased electroencephalography beta waves. Yet, when evaluating responses associated with linalool inhalation, those sensory profiles observed after exposure to natural environmental sounds were the reverse of those observed after mental work. These response discrepancies were further studied in humans inhaling linalool for 10 minutes either before or after physical and mental tasks and hearing environmental sounds.79 Sensory perceptions of the odor and physiological responses, measured by portable forehead surface electroencephalography, were determined. The responses to linalool were found to depend on the task and when linalool was administered. For example, compared with inhalation before hearing environmental sounds, inhalation of R-(−)-linalool after hearing these sounds resulted in more favorable sensory scores and a stronger decrease in beta waves. In contrast, when evaluated in the context after mental work, linalool was associated with sensory agitation and increased beta waves. No significant interaction between linalool exposure and physical work was observed. Thus, in humans, there is no evidence that coriander alone has neurological effects. Rather, linalool exposure (both via inhalation and transdermally) can affect sensory and neurological responses, although the outcomes are mixed and difficult to interpret. Despite these mixed results, studies examining the impact of dietary coriander on modulation of mood in humans would be of interest.
There is considerable evidence in experimental animal models that coriander and linalool improve learning and memory. Young and aged mice were fed diets supplemented with coriander leaves (5%, 10%, and 15% wt/wt of diet) for 45 days.80 Memory was then evaluated by the elevated plus maze test and a passive avoidance paradigm. In addition, retention of a learned task was tested following induction of amnesia (by injection of scopolamine or diazepam) in young mice fed the supplemented diet. Compared with controls, a dose-dependent improvement in memory scores was observed for both young and aged mice fed the coriander diets. Moreover, coriander supplementation reversed memory deficits induced by both amnesia-inducing agents. These effects were accompanied by a reduction in brain cholinesterase activity and serum total cholesterol. Compared with controls, no noticeable coriander-associated toxicity occurred as measured by body weight, hematology parameters, biochemical indices, or histopathologic examination. In light of these dose-dependent effects, the lowest chronic dietary dose of coriander that could provide these benefits in this model needs to be determined. A second study81 was conducted to evaluate dosing with an ethanolic extract of coriander seed on learning in suckling offspring of mice treated with the extract. The extract was administered (100 mg/kg, IP) for 25 days at 5-day intervals to mother mice during breast-feeding of the litter. After termination of breast-feeding, the learning behavior of newborn mice was evaluated by a passive avoidance training test. Those fed the coriander extract and tested 1 hour after feeding performed worse than did the controls. However, when tested at 24 hours and 1 week after feeding, learning was significantly improved, compared with controls. The reason(s) for the coriander-induced impairment of memory in the short-term (1 hour) and its subsequent improvement in the long term was not determined, although the authors speculated that metabolism of coriander constituents in newborns may be contributing to its later benefits. This study underscores the need to better understand how timing, amount, and method of exposure to coriander affect the nervous system.
Several studies examined the antianxiety actions of coriander. An aqueous extract of coriander seeds was administered to mice (10, 25, 50, or 100 mg/kg, IP) 30 or 45 minutes prior to the plus maze test.82 Only the 100-mg/kg dose was anxiolytic in this test, compared with controls. In the same report, animals were given the extract (10, 50, 100, and 500 mg/kg, IP) prior to testing for spontaneous activity and neuromuscular coordination. Compared with controls, the administration of the 50- to 500-mg/kg amounts dose dependently suppressed anxiety-associated spontaneous activity and motor coordination. The anxiolytic mechanisms and specific phytochemicals contributing to these effects were not determined. In another investigation in mice involving chronic dosing of an aqueous extract of coriander seed (25, 50, and 100 mg/kg, IP), the 25- and 50-mg/kg doses showed anxiolytic-like effects in the plus maze test.83 In a third study, mice were administered an ethanolic extract of coriander (50, 100, and 200 mg/kg, IP) 30 minutes prior to measuring their behavior in 4 anxiety tests.84 Compared with controls, mice receiving the 100- and 200-mg/kg doses of extract showed less anxiety-like behavior in the elevated plus maze, light and dark box, open field, and social interactions tests. These antianxiety responses were almost equivalent to that observed following dosing with diazepam. The active constituents in the extract and potential mechanisms of action were not determined. An ethanolic extract of coriander seed (50, 100, and 200 mg/kg, IP) also was administered to mice, but only the highest dose significantly demonstrated an anxiolytic-like effect in the plus maze test, compared with controls.85 In a recent study,86 an aqueous extract of coriander leaves was given to mice (50, 100, and 200 mg/kg, IP) 30 minutes prior to the elevated plus maze test. Compared with controls, all doses of the extract significantly enhanced anxiolytic responses, and the 200-mg/kg dose was similar in effectiveness to mice receiving diazepam.
Neurological Disease Management
Two studies34,87 characterized the capacity of coriander volatile oil to counteract symptoms in models of Alzheimer disease (AD). Rats were administered β-amyloid peptide 1–42 (Aβ(1–42)) 20 days prior to inhalation of coriander oil (69% linalool) preparations (200 μL of either 1% or 3% oil) for 60 min/d for 21 days. Compared with controls, Aβ(1–42)–injected rats exposed to coriander oil showed improved spatial memory in Y-maze and radial arm-maze tasks.85 Examination of hippocampus tissue revealed that in coriander-treated rats, compared with controls, markers of Aβ(1–42)–induced oxidative stress were suppressed. Moreover, exposure to coriander oil significantly enhanced anxiolytic- and antidepressant-like behaviors of rats. The authors suggested that further evaluation of coriander oil for treatment of AD-associated cognitive deficits is warranted. In a related study, an ethanolic extract of coriander seed was evaluated for amelioration of the adverse effects of the drug tacrine, an anticholinesterase inhibitor used in the therapy of AD patients.37 The tacrine-associated adverse effects also mimic some symptoms of human Parkinson disease. Rats were administered the coriander extract (100 or 200 mg/kg per day, PO) for 15 days prior to dosing with tacrine and then assessed for frequency of aberrant behaviors (vacuous chewing movements, tongue protrusions, orofacial bursts) and cognitive capacity (assessed in plus maze test). Compared with controls, coriander-treated rats exhibited significant, dose-dependent decreases in tacrine-induced locomotor changes and cognitive dysfunction. Coriander also counteracted tacrine-associated oxidative stress measured in brain homogenates. The quantitative composition of the extract was not provided, although flavonoids, alkaloids, tannins, saponins, steroids, and glycosides were present. The authors suggested that coriander extract could be considered for alleviation of adverse effects from Parkinson disease and AD drug treatments.
To determine antinociceptive effects in mice, a water extract of coriander seeds was administered (125–1000 mg/kg, IP) prior to testing in chemical- and thermal-induced pain models.88 Dose-dependent antinociceptive actions were observed in all the tests, compared with controls. The capacity of linalool to influence neurobehavioral responses in animals is discussed in the Appendix (Supplemental Digital Content1, http://links.lww.com/NT/A16).
Coriander used as a spice and seasoning is considered GRAS (generally recognized as safe) by the US Food and Drug Administration. Safety assessments of coriander essential oil and linalool have been published.8,98–100 Linalool is not mutagenic, but evaluations of the mutagenicity of the spice, coriander oil, and some coriander extracts have yielded inconsistent results.8,101 Coriander oil and pure linalool are not skin irritants, although products of linalool auto-oxidation can be.8,102 Coriander oil and linalool lack toxicity, which has led to the assessment that the essential oil is considered safe as a food additive at levels currently approved for use.8 There is limited information regarding the safety of coriander when taken orally for traditional medicine purposes. The quantities of coriander routinely used in traditional medicines are not well characterized, although consumption estimates of 2 to 5 g/d of seed powder and of tea prepared from 4 to 30 g seed in 100 mL water have been reported.45,68 Adverse effects associated with any historical use of coriander seeds and leaves in traditional medicines have not been documented,8,68 although a case report from Iran described endocrinotoxicity in a woman who had taken approximately 200 mL of a 10% leaf extract for 7 consecutive days.103
Coriander powder and its extracts can suppress oxidative stress in vivo in a variety of tissues and can modify numerous biomarkers of antioxidant activity. Because oral dosing of coriander is effective in this regard, future studies should focus on characterizing the effects of low dietary intakes of coriander on the progress of chronic conditions exacerbated by oxidative stress. There are only preliminary in vivo data supporting an antimicrobial efficacy of coriander. Nonetheless, the ability of topical administration of coriander to resolve skin irritations and infections should be further clarified, and characterizing the ability of dietary coriander to modify the gut microbiota would be important. There is emerging evidence that coriander seed powder in the diet of experimental animals has diabetes-modulating actions, but more studies are needed using lower dietary amounts of coriander powder (<1% wt/wt) for longer periods in several experimental models of diabetes before its relevance to culinary use of this spice by humans can be determined. In vivo studies using inhalation of coriander volatile oil and oral and systemic administration of coriander or its extracts strongly suggest that this spice can elicit neurobehavioral benefits. However, any potential relevance of these changes to human consumption of coriander first needs to be assessed in experimental models testing culinary-relevant levels of seed powder or oil on a variety of behavioral responses. Future investigations of potential health benefits of coriander should include data on the composition of samples used, any adverse effects, and the bioavailability and disposition of key phytochemical constituents in the target tissue(s) studied.
1. Hayes JE, Feeney EL, Allen AL. Do polymorphisms in chemosensory genes matter for human ingestive behavior? Food Qual Prefer
2. Eriksson N, Wu S, Do C, et al. A genetic variant near olfactory receptor genes influences cilantro preference. Flavour
3. Knaapila A, Hwang LD, Lysenko A, et al. Genetic analysis of chemosensory traits in human twins. Chem Senses
4. Sahib NG, Anwar F, Gilani AH, Hamid AA, Saari N, Alkharfy KM. Coriander (Coriandrum sativum
L.): a potential source of high-value components for functional foods and nutraceuticals—a review. Phytother Res
5. Nematy M, Kamgar M, Mohajeri SM, et al. The effect of hydroalcoholic extract of Coriandrum sativum
on rat appetite. Avicenna J Phytomed
6. Pieroni A, Gray C. Herbal and food folk medicines of the Russlanddeutschen living in Künzelsau/Taläcker, South-Western Germany. Phytother Res
7. Lawrence B. A planning scheme to evaluate new aromatic plants for the flavor and fragrance industries. In: Janick J, Simon E, eds, New Crops
, New York: Wiley; 1993:620–627.
8. Burdock GA, Carabin IG. Safety assessment of coriander (Coriandrum sativum
L.) essential oil as a food ingredient. Food Chem Toxicol
9. Nejad Ebrahimi S, Hadian J, Ranjbar H. Essential oil compositions of different accessions of Coriandrum sativum
L. from Iran. Nat Prod Res
10. To Quynh CT, Iijima Y, Kubota K. Influence of the isolation procedure on coriander leaf volatiles with some correlation to the enzymatic activity. J Agric Food Chem
11. Acimovic M, Oljaca S, Jacimovic G, Drazic S, Tasic S. Benefits of environmental conditions for growing coriander in Banat Region, Serbia. Nat Prod Commun
12. Dias MI, Barros L, Sousa MJ, Ferriera IC. Comparative study of lipophilic and hydrophilic antioxidants from in vivo and in vitro grown Coriandrum sativum
. Plant Foods Hum Nutr
13. Adam M, Dobiás P, Eisner A, Ventura K. Extraction of antioxidants from plants using ultrasonic methods and their antioxidant capacity. J Sep Sci
14. Gil A, De La Fuente EB, Lanardis AE, et al. Coriander essential oil composition from two genotypes grown in different environmental conditions. J Agric Food Chem
15. Smallfield BM, Van Klink JW, Perry NB, Dodds KG. Coriander spice oil: effects of fruit crushing and distillation time on yield and composition. J Agric Food Chem
16. Smallfield B, Perry N, Beauregard D, Foster L, Dodds K. Effects of postharvest treatments on yield and composition of coriander herb oil. J Agric Food Chem
17. Sriti J, Msaada K, Talou T, Faye M, Vilarem G, Marzouk B. Coupled extruder-headspace, a new method for analysis of the essential oil components of Coriandrum sativum
fruits. Food Chem
18. Neffati M, Marzouk B. Changes in essential oil and fatty acid composition in coriander (Coriandrum sativum
L.) leaves under saline conditions. Ind Crop Prod
19. Weber N, Klein E, Mukherjee K. Stereospecific incorporation of palmitoyl, oleoyl and linoleoyl moieties into adipose tissue triacylglycerols of rats results in constant sn-1:sn-2:sn-3 in rats fed rapeseed, olive, conventional or high oleic sunflower seed oils, but not in those fed coriander oil. J Nutr
20. Zhou ZF, Cehn LY, Shen M, Ma AD, Yang XM, Zou F. Analysis of the essential oils of Coriandrum sativum
using GC-MS coupled with chemometric resolution methods. Chem Pharm Bull (Tokyo)
21. Soares BV, Morais SM, dos Santos Fontenelle RO, et al. Antifungal activity, toxicity and chemical composition of the essential oil of Coriandrum sativum
L. fruits. Molecules
22. Eyres G, Marriott PJ, Dufour JP. The combination of gas chromatography-olfactometry and multidimensional gas chromatography for the characterisation of essential oils. J Chromatogr A
23. Stashenko EE, Puertas MA, Martínez JR. SPME determination of volatile aldehydes for evaluation of in-vitro antioxidant activity. Anal Bioanal Chem
24. Ishikawa T, Kondo K, Kitajima J. Water-soluble constituents of coriander. Chem Pharm Bull (Tokyo)
25. Salzer UJ, Furia T. The analysis of essential oils and extracts (oleoresins) from seasonings—a critical review. CRC Crit Rev Food Sci Nutr
26. Shrivashankara K, Roy T, Varalakshmi B, Venkateshwarlu G, Selvaraj Y. Leaf essential oils of coriander (Coriandrum sativum
L.) cultivars. Ind Perfum
27. Puthusseri B, Divya P, Lokesh V, Neelwarne B. Enhancement of folate content and its stability using food grade elicitors in coriander (Coriandrum sativum
L.). Plant Foods Hum Nutr
28. Puthusseri B, Divya P, Lokesh V, Neelwarne B. Salicylic acid–induced elicitation of folates in coriander (Coriandrum sativum
L.) improves bioaccessibility and reduces pro-oxidant status. Food Chem
29. Daly T, Jiwan M, O’Brien N, Aherne SA. Carotenoid content of commonly consumed herbs and assessment of their bioaccessibility using an in vitro digestion model. Plant Foods Hum Nutr
30. Singh G, Kawatra A, Sehgal S. Nutritional composition of selected green leafy vegetables, herbs and carrots. Plant Foods Hum Nutr
31. Kobori CN, Amaya DB. Uncultivated Brazilian green leaves are richer sources of carotenoids than are commercially produced leafy vegetables. Food Nutr Bull
32. Xiao Z, Lester GE, Luo Y, Wang Q. Assessment of vitamin and carotenoid concentrations of emerging food products: edible microgreens. J Agric Food Chem
33. Samojlik I, Lakić N, Mimica-Dukić N, Daković-Svajcer K, Bozin B. Antioxidant and hepatoprotective potential of essential oils of coriander (Coriandrum sativum
L.) and caraway (Carum carvi
L.) (Apiaceae). J Agric Food Chem
34. Cioanca O, Hritcu L, Mihasan M, Hancianu M. Cognitive-enhancing and antioxidant activities of inhaled coriander volatile oil in amyloid β(1-42) rat model of Alzheimer’s disease. Physiol Behav
35. Ramadan MF, Kroh LW, Mörsel JT. Radical scavenging activity of black cumin (Nigella sativa
L.), coriander (Coriandrum sativum
L.), and niger (Guizotia abyssinica
Cass.) crude seed oils and oil fractions. J Agric Food Chem
36. Duman AD, Telci I, Dayisoylu KS, Digrak M, Demirtas I, Alma M. Evaluation of bioactivity of linalool-rich essential oils from Ocimum basilucum and Coriandrum sativum varieties. Nat Prod Commun. 2010;5:969–974.
37. Mohan M, Yarlagadda S, Chintala S. Effect of ethanolic extract of Coriandrum sativum
L. on tacrine induced orofacial dyskinesia. Indian J Exp Biol
38. Laribi B, M’Hamdi M, Kouki K, Bettaieb T. Coriander (Coriandrum sativum
L.) and its bioactive constituents. Fitoterapia
39. Bajpal M, Mishra A, Prakash D. Antioxidant and free radical scavenging activities of some leafy vegetables. Int J Food Sci Nutr
40. Guera N, Melo E, Filho J. Antioxidant compounds from coriander (Coriandrum sativum
L.) etheric extract. J Food Compos Anal
41. Tang EL, Rajarajeswaran J, Fung SY, Kanthimathi MS. Antioxidant activity of Coriandrum sativum
and protection against DNA damage and cancer cell migration. BMC Complement Altern Med
42. Pandey A, Bigoniya P, Raj V, Patel K. Pharmacological screening of Coriandrum sativum
Linn. for hepatoprotective activity. J Pharm Bioallied Sci
43. Brindis F, González-Andrade M, González-Trujano M, Estrada-Soto S, Villalobos-Molina R. Postprandial glycaemia and inhibition of α-glucosidase activity by aqueous extract from Coriandrum sativum
. Nat Prod Res
. 2014;28(22):2021–2025. doi.org/10.1080/14786419.2014.917414.
44. Wong P, Kitts D. Studies on the antioxidant and antibacterial properties of parsley (Petroselinum crispum
) and cilantro (Coriandrum sativum
) extracts. Food Chem
45. Fan X, Sokorai KJ. Changes in volatile compounds of gamma-irradiated fresh cilantro leaves during cold storage. J Agric Food Chem
46. Msaada K, Hosni K, Taarit MB, Chahed T, Marzouk B. Variations in the essential oil composition from different parts of Coriandrum sativum
L. cultivated in Tunisia. Ital J Biochem
47. Matasyoh J, Maiyo Z, Ngure R. Chepkorir. Chemical composition and antimicrobial activity of the essential oil of Coriandrum sativum
. Food Chem
48. Uma Pradeep K, Geervani P, Eggum BO. Common Indian spices: nutrient composition, consumption and contribution to dietary value. Plant Foods Hum Nutr
49. Melo E, Bion F, Filho J, Guerra N. In vivo antioxidant effect of aqueous and etheric coriander (Coriandrum sativum
L.) extracts. Eur J Lipid Sci Technol
50. Chitra V, Leelamma S. Coriandrum sativum
changes the levels of lipid peroxides and activity of antioxidant enzymes in experimental animals. Ind J Biochem Biophys
51. Anilakumar KR, Khanum F, Bawa A. Effect of coriander seed powder (CSP) on 1, 2-dimethyl hydrazine-induced changes in antioxidant enzyme system and lipid peroxide formation in rats. J Diet Suppl
52. Kansal L, Sharma V, Sharma A, Lodi S, Sharma S. Protective role of Coriandrum sativum
(coriander) extracts against lead nitrate induced oxidative stress and tissue damage in the liver and kidney in male mice. Int J Appl Biol Pharmaceut Technol
53. Anilakumar K, Nagaraj N, Santhanam K. Effect of coriander seeds on hexachlorocyclohexane induced lipid peroxidation in rat liver. Nutr Res
54. Sreelatha S, Padma PR, Umadevi M. Protective effects of Coriandrum sativum
extracts on carbon tetrachloride-induced hepatotoxicity in rats. Food Chem Toxicol
55. Velaga MK, Yallapragada PR, Williams D, Rajanna S, Bettaiya R. Hydroalcoholic seed extract of Coriandrum sativum
(Coriander) alleviates lead-induced oxidative stress in different regions of rat brain. Biol Trace Elem Res
56. Karami R, Hosseini M, Mohammadpour T, et al. Effects of hydroalcoholic extract of Coriandrum sativum
on oxidative damage in pentylenetetrazole-induced seizures in rats. Iran J Neurol
57. Celik S, Ozkaya A. Effects of intraperitoneally administered lipoic acid, vitamin E, and linalool on the level of total lipid and fatty acids in guinea pig brain with oxidative stress induced by H2
. J Biochem Mol Biol
58. Mehri S, Meshki MA, Hosseinzadeh H. Linalool as a neuroprotective agent against acrylamide-induced neurotoxicity in Wistar rats. Drug Chem Toxicol
59. Hosseinzadeh H, Alaw Qotbi AA, Seidavi A, Norris D, Brown D. Effects of different levels of coriander (Coriandrum sativum) seed powder and extract on serum biochemical parameters, microbiota, and immunity in broiler chicks. Sci World J
60. Cherng J, Chiang W, Chaing L. Immunomodulatory activities of common vegetables and spices of Umbelliferae and its related coumarins and flavonoids. Food Chem
61. Beikert FC, Anastasiadou Z, Fritzen B, Frank U, Augustin M. Topical treatment of tinea pedis using 6% coriander oil in unguentum leniens: a randomized, controlled, comparative pilot study. Dermatology
62. Sharaf A, Hussein A, Mansour M. Studies on the antidiabetic effect of some plants. Planta Med
63. Swanston-Flatt SK, Day C, Bailey CJ, Flatt PR. Traditional plant treatments for diabetes. Studies in normal and streptozotocin diabetic mice. Diabetologia
64. Gray AM, Flatt PR. Insulin-releasing and insulin-like activity of the traditional anti-diabetic plant Coriandrum sativum
(coriander). Br J Nutr
65. Deepa B, Anuradha CV. Antioxidant potential of Coriandrum sativum
L. seed extract. Indian J Exp Biol
66. Chithra V, Leelamma S. Coriandrum sativum
—mechanism of hypoglycemic action. Food Chem
67. Srivastava N, Tiwari G, Tiwari R. Polyherbal preparation for anti-diabetic activity: a screening study. Indian J Med Sci
68. Aissaoui A, Zizi S, Israili Z, Lyoussi B. Hypoglycemic and hypolipidemic effects of Coriandrum sativum
L. in Meriones shawi
rats. J Ethnopharmacol
69. Eidi M, Eidi A, Saeidi A, et al. Effect of coriander seed (Coriandrum sativum
L.) ethanol extract on insulin release from pancreatic beta cells in streptozotocin-induced diabetic rats. Phytother Res
70. Jelodar G, Mohsen M, Shahram S. Effect of walnut leaf, coriander and pomegranate on blood glucose and histopathology of pancreas of alloxan induced diabetic rats. Afr J Tradit Complement Altern Med
71. Sreelatha S, Inbavalli R. Antioxidant, antihyperglycemic, and antihyperlipidemic effects of Coriandrum sativum
leaf and stem in alloxan-induced diabetic rats. J Food Sci
72. Barros L, Duenas M, Dias M, et al. Phenolic profiles of in vivo and in vitro grown Coriandrum sativum
L. Food Chem
73. Höferl M, Krist S, Buchbauer G. Chirality influences the effects of linalool on physiological parameters of stress. Plant Med
74. Igarashi T. Physical and psychologic effects of aromatherapy inhalation on pregnant women: a randomized controlled trial. J Altern Complement Med
75. Muzzarelli L, Force M, Sebold M. Aromatherapy and reducing preprocedural anxiety: a controlled prospective study. Gastroenterol Nurs
76. Kuroda K, Inoue N, Ito Y, et al. Sedative effects of the jasmine tea odor and (R)-(−)-linalool, one of its major odor components, on autonomic nerve activity and mood states. Eur J Appl Physiol
77. Heuberger E, Redhammer S, Buchbauer G. Transdermal absorption of (-)-linalool induces autonomic deactivation but has no impact on ratings of well-being in humans. Neuropsychopharmacology
78. Sugawara Y, Hara C, Tamura K, et al. Sedative effect on humans of inhalation of essential oil of linalool: sensory evaluation and physiological measurements using optically active linalools. Anal Chim Acta
79. Sugawara Y, Hara C, Aoki T, Sugimoto N, Masujima T. Odor distinctiveness between enantiomers of linalool: difference in perception and responses elicited by sensory test and forehead surface potential wave measurement. Chem Senses
80. Mani V, Parle M, Ramasamy K, Abdul Majeed AB. Reversal of memory deficits by Coriandrum sativum
leaves in mice. J Sci Food Agric
81. Zargar-Nattaj SS, Tayyebi P, Zangoori V, et al. The effect of Coriandrum sativum
seed extract on the learning of newborn mice by electric shock: interaction with caffeine and diazepam. Psych Res Behav Manag
82. Emamghoreishi M, Khasaki M, Aazam MF. Coriandrum sativum
: evaluation of its anxiolytic effect in the elevated plus-maze. J Ethnopharmacol
83. Ravindran A, Rai M, Raveendran N, Naik H, et al. Chronic anxiolytic-like activity of aqueous extract of Coriandrum sativum
seeds using elevated plus maze test in Swiss albino mice. Int J Pharm Pharmaceut Sci
84. Mahendra P, Bisht S. Anti-anxiety activity of Coriandrum sativum
assessed using different experimental anxiety models. Indian J Pharmacol
85. Pathan A, Kothawade K, Logade M. Anxiolytic and analgesic effect of seeds of Coriandrum sativum
L. Int J Res Pharm Chem
86. Latha K, Rammohan B, Sunanda BP, Maheswari MS, Mohan SK. Evaluation of anxiolytic activity of aqueous extract of Coriandrum sativum
Linn. in mice: a preliminary experimental study. Pharmacognosy Res
87. Cioanca O, Hritcu L, Mihasan M, Trifan A, Hancianu M. Inhalation of coriander volatile oil increased anxiolytic-antidepressant–like behaviors and decreased oxidative status in beta-amyloid (1-42) rat model of Alzheimer’s disease. Physiol Behav
88. Taherian AA, Vafaei AA, Ameri J. Opiate system mediate the antinociceptive effects of Coriandrum sativum
in mice. Iran J Pharmaceut Res
89. Prior RL, Cao G, Prior RL, Cao G. Analysis of botanicals and dietary supplements for antioxidant capacity: a review. J AOAC Int
90. Gostner JM, Becker K, Ueberall F, Fuchs D. The good and bad of antioxidant foods: an immunological perspective. Food Chem Toxicol
91. European Food Safety Authority (EFSA). Scientific opinion on the substantiation of health claims related to various food(s)/food constituents and protection of cells from premature aging, antioxidant activity, antioxidant content and antioxidant properties, and protection of DNA, proteins, and lipids from oxidative damage pursuant to Article 13(1) of Regulation (EC) no 1924/2006. EFSA J
92. Srinivasan K. Plant foods in the management of diabetes mellitus: spices as beneficial antidiabetic food adjuncts. Int J Food Sci Nutr
93. Yeh GY, Eisenberg DM, Kaptchuk TJ, Philips RS. Systematic review of herbs and dietary supplements for glycemic control in diabetes. Diabetes Care
94. Bailey CJ, Day C. Traditional plant medicines as treatments for diabetes. Diabetes Care
95. Swanston-Flatt SK, Flatt PR, Day C, Bailey CJ. Traditional dietary adjuncts for the treatment of diabetes mellitus. Proc Nutr Soc
96. Gallagher A, Flatt P, Duffy G, Abdel-Wahab Y. The effects of traditional antidiabetic plants on in vitro glucose diffusion. Nutr Res
97. Akhlaghi M, Shabanian G, Rafieian-Kopaei M, Parvin N, Saadat M, Akhlaghi M. Citrus aurantium
blossom and preoperative anxiety. Rev Bras Anestesiol
98. Bickers D, Calow P, Greim H, et al. A toxicologic and dermatologic assessment of linalool and related esters when used as fragrance ingredients. Food Chem Toxicol
99. Letizia CS, Cocchiara J, Lalko J, Api AM. Fragrance material review on linalool. Food Chem Toxicol
100. Lapczynski A, Letizia CS, Api AM. Addendum to fragrance material review on linalool. Food Chem Toxicol
101. Reyes MR, Reyes-Esparza J, Angeles OT, Rodríguez-Fragoso L. Mutagenicity and safety evaluation of water extract of Coriander sativum
leaves. J Food Sci
102. Christensson JB, Matura M, Gruvberger B, Bruze M, Karlberg AT. Linalool—a significant contact sensitizer after air exposure. Contact Dermatitis
103. World Health Organization. Endocrinotoxicity induced by Coriandrum sativa
: a case report. WHO Drug Info