Phytochemical analysis and antimicrobial screening of some local weeds from Kelantan, Malaysia

Introduction: Due to the increased prevalence of microbial infections followed by increase resistance of microorganisms is an alarming problem urging more research in development of neA‘, compounds for the treatment of microbial infections. Since ancient times plants are acting as a source of medicine in treatment of many diseases including microbial infections and they can be used as the prime source for production of newer compounds. Objective: To study the antimicrobial activities of Andrographis paniculata (Acanthaceae), Borreria exilis, Borreria laevicaulis, Borreria latifolia, Borreria remotifolia and Richardia brasiliensis (Rubiaceae) and against several gram positive (Staphylococcus aureus, Bacillus sublilis), gram negative bacteria (Escherichia coli, Salmonella tjphimurium, Klebsiella pneumoniae) and fungi (Aspergillus niger, Candida albicans) along with its phytochemical analysis. Method: Extracts of the plants were prepared with solvents of different polarity using soxhlet apparatus. Plants were screened for the presence of phytochemicals and evaluation of their antimicrobial activity was tested using disk diffusion assay and minimum inhibitory concentration (MIC) broth dilution method.

Results: The phytochemical analysis revealed the presence of bioactive compounds which mainly contained phenolic compounds, flavonoids and tannins ascertain the pharmacological properties of selected plants. In general, the best antibacterial activity was performed by hexane extract of Borreria laevicaulis (diameter zone of inhibition 22.15mm) at a concentration of 1000μg/disk against Staphylococcus aureus whereas all the extract of Richardia brasiliensis showing no activity against all of the tested microorganisms. In the case of fungi, highest diameter zone of inhibition (25.65mm) at 1000µg/disk was observed against Candida albicans by hexane extract of Borreria laevicaulis. Meanwhile the minimum inhibitory concentration of Borreria laevicaulis hexane extract was found to be lowest at 62.51.1.μg/m1 against Staph•lococcus aureus and 2501.1μg/m1 against Candida albicans.
Conclusion: This study supported the use of plants which has broad spectrum of antimicrobial activity in traditional remedies and as a potential source for antimicrobial drugs.