A STUDY OF ADLAY ON LOWERING SERUM AND LIVER LIPIDS IN HAMSTERS

ABSTRACT

The functional component of adlay responsible for lowering blood lipids was studied using an animal model. Forty male hamsters were randomly divided into four dietary groups, including control, whole grain adlay (WGA), oil-free adlay (OFA) and adlay oil (AO) groups. All groups were fed a high fat diet containing 11.8% oil and 0.2% cholesterol for 8 weeks. The results showed that the WGA, OFA and AO diets could decrease triacylglycerol (TAG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) concentrations in serum (P < 0.05). Specifically, all lipid levels were significantly lowered in the WGA and OFA groups as compared to the AO group (P < 0.05). Ingestion of WGA or OFA also reduced liver TAG and TC concentrations (P < 0.05). The data demonstrated that WGA, OFA and AO prolonged the lag phase of LDL oxidation (P < 0.05). Moreover, hamsters fed with WGA or OFA had lower activity of malic enzyme in liver than those fed with control or AO diet (P < 0.05). WGA, OFA and AO diets were also found to enhance the activity of glucose-6-phosphate dehydrogenase. Thus, the beneficial components of adlay were mainly in the OFA portion.

PRACTICAL APPLICATIONS

Adlay is one of the most common components used in Chinese herbal medicine for hypolipidemic effect and immunoregulation. Numerous studies had demonstrated that adlay can decrease serum total cholesterol, triacylglycerol and low-density lipoprotein cholesterol concentrations in animal models and human subjects. However, the shelf-life of processed adlay products is relatively short due to the easy oxidation of its oil. According to the results of this study, it seems reasonable to remove the oil component of adlay grains to prevent its peroxidation and the development of off-flavor in products while retaining most of the hypolipidemic effects of adlay.