Study of Antimicrobial and Antioxidant Potentiality of Anti-diabetic Drug Metformin

Metformin, an oral hypoglycemic drug was studied in vitro for possible antibacterial and antioxidant activity. Antimicrobial activity of metformin was evaluated against 9 Gram-positive, Gram-negative bacteria and 3 fungi using disk diffusion technique. Kanamycin (30?g/disc) was used as standard. Antioxidant potentiality of metformin was investigated by DPPH scavenging activity. Metformin active at 500 ?g/ml, showed very good antimicrobial activity against most of the bacterial strains with an average zone of inhibition of 12-15mm. Metformin demonstrated a pronounced inhibitory action against Pseudomonas aeruginosa, an organism which is known to be multidrug resistant. The tested fungi are Saccharromyces cerevaceae, Candida albicans and Aspergillus Niger. The tested drug showed very good antifungal activity with an average 13 -17 mm zone of inhibition. The percentage (%) scavenging of DPPH free radical of metformin was found to be concentration dependent with IC50 value 56.90± 0.83?g ?g/ml while IC50 value of standard ascorbic acid was found to be 51.89 ± 1.11?g/ml. The results of these studies indicated that metformin could be significantly protect animals from tested pathogenic bacteria as well as might be beneficial for diabetic patient more than a hypoglycemic drug