Antimycobacterial, anti-inflammatory and genotoxicity evaluation of plants used for the treatment of tuberculosis and related symptoms in South Africa

Ethnopharmacological relevance: Emergence of drug-resistant tuberculosis strains and long duration of treatment has established an urgent need to search for new effective agents. The great floral diversity of South Africa has potential for producing new bioactive compounds, therefore pharmacological screening of plant extracts within this region offers much potential. To assess the in vitro antimycobacterial, antiinflammatory and genotoxicity activity of selected plants that are used for the treatment of TB and related symptoms in South Africa. Materials and methods: Ground plant materials from 10 plants were extracted sequentially with four solvents (petroleum ether, dichloromethane, 80% ethanol and water) and a total of 68 extracts were produced. A broth microdilution method was used to screen extracts against Mycobacterium tuberculosis H37Ra. The cyclooxygenase-2 (COX-2) enzyme was used to evaluate the anti-inflammatory activity of the extracts and the Salmonella microsome assay using two Salmonella typhimurium strains (TA98 and TA100) to establish genotoxicity. Results: Six out of 68 extracts showed good antimycobacterial activity. Three extracts showed good inhibition ( > 70%) of COX-2 enzyme. All the extracts tested were non-genotoxic against the tested Salmonella strains. Conclusion: The results observed in this study indicate that some of the plants such as Abrus precatorius subsp. africarius, Ficus sur, Pentanisia prunelloides and Terminalia phanerophlebia could be investigated further against drug-resistant TB strains. (C) 2014 Elsevier Ireland Ltd. All rights reserved.