Absence of in-vitro antimicrobial activity of some antimicrobial herbal preparations in the Ghanaian market

Herbal preparations are formulated into various dosage forms that are used in treatment of diseases including infections. In Ghana, many herbal mixtures are advertised and sold for treatment of microbial infections. The current study sought to investigate the purported antimicrobial activities of four herbal mixtures in the Ghanaian market, using the Agar Diffusion method. The samples investigated did not exhibit any antimicrobial activity against both Gram-positive and Gram-negative bacteria, and Candida albicans used in the study. Most of the plants constituting the components of the herbal mixtures assessed, however, have been documented to have antimicrobial activities against the microbes used in the study. The inability of the samples to show antimicrobial activity may be attributed to low concentrations of the active compounds in the mixture. Water is the vehicle mostly used for extraction in such mixtures, and it is possible that larger volumes of the vehicle vis-A -vis the plant material resulted in low concentrations of the active compounds. It is also possible that water is not the solvent of choice for such preparations. The study has shown that some of the common herbal preparations sold in Ghana for management of infections such as Candidiasis do not have the claimed activity in-vitro.