Anti-hypercholesterolemic agent from Indonesian rice bran

Abstract

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 reflex 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.