Antiaflatoxigenic and antioxidant activities of Garcinia extracts.

The effect of hexane and chloroform extracts from the fruit rinds of Garcinia cowa and Garcinia pedunculata on the growth and aflatoxin production in Aspergillus flavus was studied using peanut powder as a model food system. The growth of A. flavus was completely inhibited by the hexane and chloroform extracts from G. cowa and chloroform extract from G. pedunculata at 3000 ppm concentration, which was considered as the minimum inhibitory concentration (MIC). The MIC for the hexane extract of G. pedunculata was at 4000 ppm. Both the extracts from G. cowa inhibited aflatoxin B1 production upto 100% at a lower concentration of 2000 ppm. It was observed that, at lower concentration of the extracts from G. cowa and G. pedunculata, the degree of inhibition of aflatoxin production was much higher than the inhibition of fungal growth. The hexane and chloroform extracts from G. cowa and G. pedunculata were also studied for their antioxidant capacity by the formation of phosphomolybdenum complex at 100 ppm concentration and reducing power by potassium ferricyanide reduction method at various concentrations. Hexane and chloroform extracts from G. cowa showed higher antioxidant capacity than G. pedunculata extracts. Similarly, both the extracts from G. cowa showed higher reducing power than the extracts from G. pedunculata. The antiaflatoxigenic activities of the extracts from G. cowa and G. pedunculata may be due to their effective antioxidative properties, which could suppress the biosynthesis of aflatoxin.