Antimicrobial and antioxidant potential of Tylophora indica (Burm. f.) Merrill and development of an efficient micropropagation system for its therapeautic use

Infectious diseases caused by pathogenic microorganisms are the leading cause of human mortality worldwide. Emergence of multidrug resistance in these pathogens and negative effects of available antibiotics have necessitated the search for new potent antimicrobial agents of plant origin. Tylophora indica commonly known as “Antamool” or “Asthama herb” is a valuable medicinal plant traditionally used as a folk remedy for the treatment of a variety of diseases and disorders. An efficient and reproducible in vitro protocol was established for the mass cloning of this valuable plant through de novo adventitious shoot formation directly from the leaf explant. The antimicrobial activity of different solvent extracts of leaves of both native and in vitro plants was tested against bacterial strains (Staphylococcus aureus, Escherichia coli) and fungal strains (Aspergillius niger, Penicillium chrysogenum) using agar well diffusion method. The leaf extracts prepared by Rao and Book's method and methanolic leaf extracts exhibited a significant microbial inhibition at all tested concentrations (25, 50, 100 μg/ml), whereas very less activity was observed with acetone extract. Likewise the methanolic root extract of in vitro plants exhibited significant antioxidant activity. The highest free radical scavenging activity i.e. 75% was seen at 1000 μg/ml concentration depicting strong antioxidant effect. The present study suggests that T. indica may prove to be a potential natural source of antimicrobial and antioxidant agents which needs to be further explored.