Antibacterial Activity of Plant Extracts and Its Phytochemical Analysis

Abstract

Emergence of multi-drug resistance in human and animal pathogenic bacteria as well as undesirable side effects of certain antibiotics has triggered immense interest in the search for antimicrobial drug of plant origin since there is no resistance developed to the drugs that are of plant origin. The antibiotic resistance was observed by testing with commonly used antibiotics against test microorganisms and then diameter of zone of inhibition was compared to the range obtained from CLSI standard guidelines of susceptibility testing—zone interpretation chart. A total of 12 plant materials were used to prepare the extracts of some commonly used spices such as cardamom, cumin, ginger, yellow mustard, black mustard, chilli, pepper, cloves, leaves of mint and guava plant, bael fruit and pomegranate epicarp. The methodology of extraction was solvent (ethanol and methanol) extraction and aqueous for bael fruit. The antibacterial activity was observed by Kirby Bauer method.  Out of the 15 plant extracts prepared, six plant extracts had an inhibitory effect against all the test microorganisms while ethanolic extract of ginger had an effect on Escherichia coli and Micrococcus and ethanolic extract of cumin had antibacterial effect against Micrococcus. Among all the plant extracts that worked against the test micro-organism ethanolic and methanolic extract of pomegranate epicarp showed greater zone of inhibition. The ethanolic and methanolic extracts of cloves and guava leaves had lower antimicrobial effect than that of the extracts pomegranate epicarp. Multiple secondary metabolites were responsible for antibacterial activity. Phytochemical analysis revealed that each extract had more than one secondary metabolite.

Keywords: Antibacterial activity, plant materials, solvent extraction, Kirby Bauer method, phytochemicals

Cite this Article

Chaitra Sai K., Pratiksha P. Bhat, Tharani S., Dhamodhar P. Antibacterial Activity of Plant Extracts and Its Phytochemical Analysis. Research & Reviews: A Journal of Life Sciences. 2019; 9(Issue 1 Special): 1s–11s.