A-41 Free Communication/Poster - Immunology-Supplements Wednesday, May 28, 2014, 7:30 AM - 12:30 PM Room: WB1
PURPOSE: Exercise and targeted dietary supplementation are separately known to impact both muscle function and inflammation in the elderly. Beta-alanine (BA) improves muscle function, while epigallocatechin gallate (EGCG) is an antioxidant and is anti-inflammatory. However, there is limited information on the interactions between diet and exercise on outcomes related to function and inflammation. Therefore, we examined the impact of voluntary wheel running (VWR) and/or dietary supplementation with BA and EGCG on muscle function and inflammation in aged mice.
METHODS: Control diet or diet supplemented with 1.5 mg/g EGCG and 3.43 mg/g BA was given ad libitum to 17 month old male Balb/c mice for 4 weeks, during which they either ran on a wheel or remained sedentary (SED). Mice were then given muscle function tests over 11 days, and were euthanized 24 hours after the final test for tissue collection. Mice were maintained on diet and exercise interventions during the 11 day period.
RESULTS: Diet and VWR did not differ in their affect on body weight or food intake during the study, and neither differentially impacted body composition. VWR maintained grip strength (p=.027) and improved time to exhaustion on a treadmill test to fatigue (p=.001). As expected, VWR increased gastrocnemius expression of interleukin (IL)-6 (p=.001), although diet had no effect. Neither VWR nor diet affected gene expression levels of IL-1beta, IL-10, or tumor necrosis factor-alpha. Interestingly, dietary intervention with BA and EGCG increased gene expression of Itgam, the gene responsible for macrophage marker CD11b expression, in the gastrocnemius (p=.015). We also demonstrated a significant diet effect on gene expression of insulin-like growth factor 1 (p=.007), which is known to be produced by macrophages.
CONCLUSIONS: VWR and dietary supplementation with BA and EGCG differentially affect gene expression of inflammation markers in aged gastrocnemius muscle. VWR increased gene expression of IL-6, while dietary intervention increased a marker of macrophage number as well as expression of IGF-1. Our dietary intervention was not successful at improving muscle function in several tests, although VWR did improve function as expected. Supported by a grant from Abbott Nutrition.