S T Shukla’s scientific contributions

An attempt has been made to isolate, identify and screen the endophytic crude fractions of Periwinkle (Catharanthus roseus (L.) G.Don) leaves for antioxidant activity and also for 1, 2-Dimethylhydrazine (DMH) induced colon cancer. Endophytic fungi from Catharanthus roseus (L.) G.Don leaves were isolated and cultured aseptically in PDA media. The developed fungus cultures were fermented in potato dextrose broth and fractionated using chloroform. Isolated fungus was identified from Mucur Sp. in preliminary identification method. Chloroform extract-1 of Mucor sp. (CEM-1) was subjected to free radical scavenging activities against 2, 2-diphenyl-1-picrylhydrazyl, hydroxyl free radicals and reducing power assay. The fraction was further assessed against DMH induced colon cancer in rats. DMH was induced subcutaneous route twice a week for 2 weeks with 40mg /kg body weight. The crude fractions were administered to the rats five times a week for four weeks by gavages at doses of 100mg/kg and 150mg/kg body weight/day each, during and after DMH treatment. All animals were sacrificed in week 5 for the evaluation of ACF. The colons were dissected out for the histopathological study to find out aberrant crypt foci (ACF) % inhibition. The fraction was found to be potential free radical scavenger with IC50 values of 104.07µg/ml & 341.13µg/ml for DPPH and hydroxyl radical respectively. It also shows increasing order reducing power activity with significantly % inhibition in ACF. Therefore these data support the claim that endophytes are an alternative source for novel secondary metabolites.