16. Antioxidant and hepatoprotective activity of some dimethoxy flavones

Liver is one of the most important organs of the body. Any untreated injury to the liver leads to progression to liver fibrosis and cirrhosis of the liver. Paracetamol in high doses is known to be hepatotoxic and this is mainly due to the release of free radicals. Hence compounds with antioxidant properties are considered to be potential hepatoprotective agents. Naturally occurring flavonoids are known to be potent antioxidants and by virtue of this activity are also known to possess hepatoprotective ability. The present study was undertaken to determine the antioxidant and hepatoprotective activity of 3 synthetic flavones namely 3,6-dimethoxy flavone (3,6-DMF), 6,2'-dimethoxy flavone (6,2'-DMF) and 6,3'-dimethoxy flavone (6,3'-DMF).The antioxidant activity was determined by testing their ability to scavenge DPPH and hydroxyl radicals. The acute toxicity studies were carried out to determine the safety of the compounds. For evaluating the hepatoprotective ability, Paracetamol induced hepatotoxic model was used. All the three compounds exhibited good antioxidant activity which was comparable to the standard compound Vitamin E. Of the three compounds, 6,3'-DMF showed the best activity. The acute toxicity studies revealed that all the 3 compounds were safe even at the dose level of 2000mg/kg. The compounds were tested for hepatoprotective ability at 2 dose levels of 50 and 100mg/kg s.c. and the activity was compared with the standard drug Silymarin at the dose of 50mg/kg p.o. All the three compounds showed hepatoprotection at both the dose levels tested but the activity was more significant at the higher dose level. Thus it can be concluded that the synthetic dimethoxy flavones 3,6-DMF, 6,2'-DMF and 6,3'-DMFare potential hepatoprotectants and this activity could be mediated by their antioxidant property.