ANTITUMOR AND ANTIOXIDANT ACTIVITY OF NATURAL CURCUMINOIDS

Matural curcuminoids, curcumin, I, II and III isolated from turmeric ( Curcuma longa) were compared for their cytotoxic, tumour reducing and antioxidant activities, Curcumin III was found to be more active than the other two as a cytotoxic agent and in the inhibition of Ehrlich as cites tumour in mice (ILS 74.1%), These compounds were also checked fo r their antioxidant activity which possibly indicates their potential use as anti-promoters. The amount of curcuminoids (I, II and III) need ed for 50% inhibition of lipid peroxidation was 20, 14 and 11 g/ml. Co ncentrations needed for 50% inhibition of superoxides were 6.25, 4.25 and 1.9 mu g/ml and those for hydroxyl radical were 2.3, 1.8 and 1.8 m u g/ml, respectively. The ability of these compounds to suppress the s uperoxide production by macrophages activated with phorbol-12-myristat e-13-acetate (PMA) indicated that all the three curcuminoids inhibited superoxide production and curcumin III produced maximum effect. These results indicate that curcumin III is the most active of the curcumin oids present in turmeric. Synthetic curcumin I and III had similar act ivity to natural curcumins.