Research PaperSome Nigerian anti-tuberculosis ethnomedicines: A preliminary efficacy assessment

Ethnopharmacological significanceNigerian herbalists possess indigenous ethnomedicinal recipes for the management of tuberculosis and related ailments. A collaborative preliminary modern scientific evaluation of the efficacy of some Nigerian ethnomedicines used by traditional medicine practitioners (TMPs) in the management of tuberculosis and related ailments has been carried out.Materials and methodsEthnomedicinal recipes (ETMs) were collected from TMPs from locations in various ecological zones of Nigeria under a collaborative understanding. The aqueous methanolic extracts of the ETMs were screened against Mycobacterium bovis, BCG and Mycobacterium tuberculosis strain H37Rv using the broth microdilution method.ResultsExtracts of ETMs screened against BCG showed 69% activity against the organism. The activities varied from weak, ≤2500 µg/mL to highly active, 33 µg/mL 64% of the extracts were active against Mycobacterium tuberculosis The activities of the extracts against Mycobacterium tuberculosis varied from weak,≤ 2500 µg/mL to highly active, 128 µg/mL. There was 77% agreement in results obtained using BCG or Mycobacterium tuberculosis as test organisms.ConclusionThe results show clear evidence for the efficacy of the majority of indigenous Nigerian herbal recipes in the ethnomedicinal management of tuberculosis and related ailments. BCG may be effectively used, to a great extent, as the organism for screening for potential anti-Mycobacterium tuberculosis agents. A set of prioritization criteria for the selection of plants for initial further studies for the purpose of antituberculosis drug discovery research is proposed.

Graphical abstractDespite the availability of conventional chemotherapy, many patients suffering from tuberculosis (TB) in sub-Saharan Africa continue to depend on traditional medicines to treat their diseases. In this study we interviewed 73 practitioners of traditional medicine (TMPs) from all seven major ecological zones throughout Nigeria and obtained 86 samples of remedies (ETMs) they utilized to treat TB. These remedies were primarily plant-based and subsequent collection of type specimens was used to identify and corroborate the plant species used by the TMPs for their respective ETMs. Extraction of the ETMs followed by determination of the minimum inhibitory concentration against Mycobacterium tuberculosis revealed that 69% (anti-BCG screen) and 64% (anti-Mycobacterium tuberculosis) of these extracts displayed antitubercular activity in vitro with 22% (BCG) and 15% (Mycobacterium tuberculosis) having a potent inhibitory effect at <500 µg/mL as crude extracts. These results support the utility of traditional remedies for TB management. Subsequent isolation and identification of the active principles, may provide useful starting points for the development of new antitubercular agents. Download high-res image (101KB)Download full-size image