Antibacterial and anti HIV 1 reverse transcriptase activity of selected medicinal plants from Phalaborwa, South Africa

Abstract

Background and Objective: For years mankind has depended on medicinal plants for treatment of infectious diseases. Many medicinal plants are reported to possess antimicrobial and antiviral activity. Use of these plants as antimicrobials suggests that these plants might be potential source of antimicrobial and antiviral agents for the future. This study focused on medicinal plants collected in Mashishimale village (Phalaborwa) for treatment of infectious diseases. The aim of the study was to investigate the minimal inhibitory concentration and the presence of HIV 1 reverse transcriptase of the selected plants. Materials and Methods: Five solvents with different polarities (n-hexane, chloroform, ethyl acetate, water and acetone) were used for extraction of plant materials. Antimicrobial activity was screened against two Gram positive and two Gram negative test bacteria. The HIV reverse transcriptase colorimetric assay was performed according to the manufacturer's instructions. Results: Enterococcusfaecalis and Escherichiacoii were most sensitive to plant extracts with average MIC values below 0.5 mg mL-1, while Staphylococcus aureus was the most resistant. The polar extracts of Terminalia sericea had good inhibitory activity against HIV reverse transcriptase, recording IC50 values of about 0.08 mg mL-1 for acetone and water extracts. Conclusion: The findings of the study indicate that studies of this nature are useful and may lead to for discovery of more plant-derived compounds with activities against bacterial and viral strains. Furthermore, the identity of the active ingredients may be important to establish the mechanisms used by some of these plants.