Prophylactic effect of the constituent of Lyonia ovalifolia against high fat diet-induced obesity rats

Lyoniside (Ly) is a phenyltetralin lignan isolated from Lyonia ovalifolia (Ericaceae) wood as a major component (1). In the course of our research on the pharmacological effects of Ly, we recently found a prophylactic effect against 35% high fat diet-induced obesity rats. In the test, rats were fed a diet containing 5% (normal diet, ND) or 35% (high fat diet, HFD) beef tallow with or without Ly (0.02% w/w and 0.06% w/w) for 3 months. Three month-administration of Ly (0.02%) demonstrated a 48.9% and 22.8% protective effect against an increase in the renal or testicular white adipose tissues (WATr and WATt, respectively) of rats. The protective effects were not dose-dependent. The administration of Ly (0.02%) decreased the circulating total cholesterol (T-CHO) and free fatty acid (FFA) levels, while the circulating level of triglyceride (TG) was unaffected, whereas 0.06% Ly maintained the effect on the circulating T-CHO levels and decreased the circulating TG levels. The circulating FFA levels were deteriorated oppositely. The circulating levels of low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were unaffected by the 3-month administration of Ly. These results suggest that an improvement of blood lipid parameters by Ly markedly prevents the visceral fat accumulation in rats under HFD conditions. Furthermore, 12 known compounds were newly isolated from Lyonia ovalifolia wood.

Reference: 1. Yasue M. et al. (1960) Yakugaku Zasshi, 80: 1013.