Antioxidant activity of AO-8, a herbal formulation in vitro and in vivo experimental models

The effect of AO-8, a herbal formulation was evaluated for free radical scavenging activity using in vitro and in vivo experimental models. AO-8 dose dependently inhibited ferric ion induced lipid peroxidation in vitro at 125-1000 micrograms. AO-8 was investigated at dose levels of 250, 500 and 750 mg/kg p.o. in isoproterenol-induced myocardial infarction and CCl4-induced hepatotoxicity in rats. The levels of serum GOT and LDH, cardiac glutathione, SOD and catalase were estimated following induction of myocardial infarction with isoproterenol. The estimation of parameters such as SGOT, SGPT, liver glycogen and lipid peroxidation were carried out in CCl4-induced hepatotoxicity. Treatment with AO-8 for 15 days at a dose of 500 and 750 mg/kg offered marked protection in both in vivo models. The reversal of increased serum enzymes in both the models may be due to the prevention of leakage of the intracellular enzymes by its membrane stabilizing activity. The inhibition of lipid peroxidation and enhancement of antioxidant enzymes by AO-8 may be due to the direct free radical scavenging activity which could be attributed to the antioxidant potential of various ingredients present in the formulation. Thus it can be concluded that AO-8 is an effective free radical scavenger and could prove beneficial in the treatment of various disorders associated with the involvement of free radicals.