Abstract: This study was aimed to offer a possible pharmacological basis regarding the remedial utilization of Wrightia tinctoria in hypertension and dyslipidemia in certain South Asian traditional systems of medicine, using in vivo and in vitro assays. The aqueous methanolic extract of W. tinctoria seeds (Wt.Cr) caused a dose-dependent (1–10 mg/kg) decrease in arterial pressure in anesthetized rats. In the right atria of isolated guinea pigs, Wt.Cr equally inhibited force and rate of spontaneous atrial contractions. When tested on phenylephrine-, high K+-, and low K+-induced vasoconstrictions in isolated rat aorta, Wt.Cr produced a concentration-dependent vasorelaxation, the most potent being against low K+-induced contraction. It also created a rightward shift in the Ca++ concentration–response curves and suppressed phenylephrine control peaks in a Ca++-free environment. In the rat model of tyloxapol-induced dyslipidemia, Wt.Cr produced a decline in the serum levels of total cholesterol and triglycerides. In high fat diet–induced dyslipidemia, it decreased serum total cholesterol and low-density lipoprotein cholesterol, improved high-density lipoprotein cholesterol, and prevented the increase in average body weights by causing a decrease in diet consumption. These data suggest that Wt.Cr lowers blood pressure through a combination of K+-channel opening and Ca++-channel blocking effects along with antidyslipidemic and weight-reducing properties.
*Natural Product Research Division, Department of Biological and Biomedical Sciences, The Aga Khan University Medical College, Karachi, Pakistan;
†Department of Pharmacology, University of Karachi, Karachi, Pakistan; and
‡Department of Pharmacy, College of Health Sciences, Mekelle University, Mekelle, Ethiopia.
Reprints: Anwarul Hassan Gilani, PhD, Department of Biological and Biomedical Sciences, The Aga Khan University Medical College, Karachi 74800, Pakistan (e-mail: firstname.lastname@example.org).
Supported by the Higher Education Commission, Government of Pakistan, under the program “Indigenous PhD Fellowship” awarded to H. S. Siddiqi.
The authors report no conflicts of interest.
Received November 20, 2013
Accepted March 19, 2014