To investigate the effects of coated liposome from Discorea rhizoma extract (DRE) in streptozotocin (STZ)-induced, we evaluated changes in body weight, fasting blood glucose, blood insulin and blood lipid concentrations in mice. Mice were divided into four groups: (DC), diabetic DRE at 10 ㎎/㎏ (DRE-1), diabetic DRE at 50 ㎎/㎏ (DRE-2), and diabetic DRE at 250 ㎎/㎏ (DRE-3). Mice had free access to water and diet (10 weeks). The DC group showed higher blood cholesterol than the DRE-1, DRE-2, DRE-3 groups. In glucose tolerance test, the DRE-1, DRE-2, and DRE-3 groups increased after 30 minutes in decremental glycemic response area under the curve. Fasting blood glucose levels in the DRE groups significantly decreased through 4 weeks. Plasma total cholesterol, triglyceride and LDL-cholesterol concentrations were also lower in the DRE groups. On the other hand, the DRE-1, DRE-2 and DRE-3 groups showed higher HDL-cholesterol and insulin levels than the DC group. Moreover, blood glucose and lipid levels significantly decreased in streptozotocin (STZ)-induced diabetic mice treated with DRE. These results indicate that DRE may reduce elevated blood glucose levels and serum lipid concentrations in hypoglycemic and diabetic mice, suggesting its usefulness as a functional food.

Selenium was initially considered toxic to humans, but it was then discovered that selenium is essential for normal life processes. Selenium plays important roles in antioxidants. It is expected that chitosan microcapsules containing nano-selenium will be able to be used as a key material in bio-medical and cosmetic applications. The high concentration of chitosan derivatives guaranteesincreased antioxidative activity. Both inorganic and organic forms of selenium can be nutritional sources. The antioxidant properties of selenoproteins help prevent cellular damage from free radicals. The objective of this experiment was to study the antioxidative activity of chitosan nano-selenium. Our experiments were divided into five groups, in the presence of various concentrations(0.1%, 0.3%, 0.5%, 0.7%, and 0.9%) of chitosan. We performed an assessment of the antioxidant properties and cytotoxicity of respective concentrations of chitosan nano-selenium. The antioxidant activity was examined by the free radical scavenging activity on 1, 1-diphenyl-2-picrylhydrazyl(DPPH) assay. The cytotoxicity effect was measured by means of 3-(4, 5-dimethylthiazole-2-yl)-2, 5-diphenyltetrazolium bromide(MTT) assay. As a result, the electron donating abilities of 0.1%, 0.3%, 0.5%, 0.7%, and 0.9% of chitosan nano-selenium exhibited effective andioxidant scavenging activity at 12.5 ㎍/㎖ against DPPH radicals. 0.3% chitosan nano-selenium did not show cytotoxicity on human keratinocytes. In general, the cytotoxicity of 0.1% and 0.9% chitosan nano-selenium showed the lowest effects. Though low cytotoxicity of 0.5% and 0.7% chitosan nano-selenium exhibited 29.67% and 38.4% against human keratinocytes on adding 100 ㎍/㎖ and 50 ㎍/㎖, respectively, cell vitality was recovered with 200 ㎍/㎖. These findings support the notion that chitosan nano-selenium may be useful as a new active ingredient source for bioactive compounds.