Antimicrobial activity of the crude extract of Piper sarmentosum against methicilin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Vibrio cholera and Streptococcus pneumoniae

Abstract

Background and aims: The emergence of novel diseases caused by microbial pathogens and the undesirable side effects of certain antibiotics has been a recent dilemma in the medical arena. Consequently, it has stirred the discovery of many naturally occurring agents which could possibly provide important ramifications against various pharmacological targets and to combat various ailments. The main aim of the present study was to determine the antimicrobial activity of the crude methanolic extract of Piper (P.) sarmentosum against methicillin resistant Staphylococcus aureus (MRSA), Escherichia coli, Vibrio cholera and Streptococcus pneumoniae.

Materials and methods: The plant materials were extracted by percolation in 70% methanol. Only the leaves were used in this study. Initial antimicrobial screening using disc diffusion assay was conducted and further screening of the antimicrobial properties in the plant was performed using minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The phytochemical constituents in the plant were evaluated via phytochemical screening and thin layer chromatography (TLC).

Results: P. sarmentosum inhibited the growth of MRSA with an inhibition zone of 10.0 mm. There was no inhibition zone observed for the other microbes tested. MIC test showed a value of 50mg/ml and MBC results showed no Colony Forming Unit (CFU) at 100 mg/ml against MRSA. Phytochemical screening of the crude extract indicated the presence of tannins, flavonoids, alkaloids glycosides and anthraquinone. Thin-layer chromatography (TLC) further confirmed the presence of flavonoids and alkaloids in the extract.

Conclusion: P. sarmentosum has shown to have some antimicrobial properties against MRSA. Based on the MIC index (MBC/MIC), the extract exhibits bactericidal effects against MRSA. TLC analysis indicated the presence of flavonoids and alkaloids which could have contributed to the antimicrobial activity of the plant extract.