INTRODUCTION

Tuberculosis continues to be a devastating public health problem. Many communities in Uganda use medicinal plants to treat various infections, including respiratory tract infections. There are claims that some can treat tuberculosis. Verifying some of these claims could lead to discovery of lead compounds for development of a TB drug.

METHODS

Chloroform and methanol extracts of L. camara collected from South-western Uganda were screened against three strains of Mycobacterium tuberculosis using the agar-well diffusion method. H37Rv, the rifampicin-resistant TMC-331 and a non-resistant wild strain (28-25271). The MIC and MBC were determined using the Agar dilution method on Middle brook 7H11.

RESULTS

The methanol extract showed the highest activity against all the three strains used, with zones of inhibition of 18.0-22.5 mm and MIC values of 20 µg/ml for H37Rv and 15 µg/ml for both TMC-331 and wild stain. The values for rifampicin were 1.0 µg/ml for both H37Rv and wild strain but rifampicin hardly showed any activity on TMC-331. The MBC value for the methanol extract of L. camara was 30µg/ml for the H37Rv, and 20µg/ml for both the TMC-331 and wild strains of M. tuberculosis. The MBC for rifampicin was 2.0µg/ml for both H37Rv and the wild strain.

CONCLUSION

We conclude that L. camara contains principles active against M. tuberculosis, which merit further research.