Anti-hypercholesterolemic agent from Indonesian rice bran

This research was conducted to determine the total oryzanol content of various extracts and bioassay-guided isolation of active anti-hypercholesterolemic agent from Indonesian rice bran. Hot solvent extraction was done by reflux method using single and binary solvents, namely hexane, chloroform, ethyl acetate, dichloromethane, isopropanol, acetone, hexane-ethyl acetate (1:1, v/v), hexane-isopropanol (1:1, v/v), and chloroform-ethyl acetate (1:1, v/v). TLC densitometric was used to quantitatively analyze the total oryzanol content in various extracts. The hexane extract was selected for fractionation and evaluated for their anti-hypercholesterolemic activity. The structure of an isolated compound was determined on the basis of NMR and Mass spectroscopy. The total oryzanol content was obtained using various solvents ranging from 27.92 to 43.59 mg/100g rice bran, in which hexane extract showed the highest amount (43.59 ± 3.36 mg/100g rice bran). β-sitosterol has been isolated from rice bran hexane extract, which shows a significant decrease in serum total cholesterol level. In summary, hexane is the best solvent to extract oryzanol compound using reflux method, and β-sitosterol was suspected to be responsible for anti-hypercholesterolemic activity in addition to existing compound such as oryzanol that contained in the rice bran.

Vitamin B6 Supplementation Improves Oxidative Stress and Enhances Serum Paraoxonase/Arylesterase Activities in Streptozotocin-Induced Diabetic Rats

The purpose of this study was to investigate the effects of vitamin B6 (Vit B6) on oxidant and antioxidant status in streptozotocin-induced diabetic rats. Thirty-two Wistar rats were divided into four groups: control (C), control + Vit B6 group (C + Vit B6), diabetes (D), and diabetes + Vit B6 group (D + Vit B6). Vit B6 (4 mg/kg body weight) was administered in drinking water for 4 weeks after the induction of diabetes. Vitamin B6 reduced serum total cholesterol level in the C + Vit B6 (P< 0.01) and D + Vit B6 (P< 0.05) groups. Plasma and tissue malondialdehyde levels were reduced in the C + Vit B6 and D + Vit B6 groups. Whole blood glutathione peroxidase (GSH-Px) and erythrocyte superoxide dismutase (SOD) activities were higher in the D group (P< 0.05). GSH-Px and SOD activities were increased in C + Vit B6 group while these parameters decreased in the D + Vit B6 group. Paraoxonase and arylesterase activities were decreased in the D group while they were increased in C + Vit B6 and D + Vit B6 groups. The results of present study suggest that vitamin B6 supplementation might be a promising adjunctive agent for improving oxidative stress and metabolic disturbances and for preventing diabetic complications including atherogenesis.