The organoleptic and microbial quality of some herbal medicinal products marketed in Freetown, Sierra Leone.
Background: The WHO has advocated for the integration of herbal medicinal products into the primary health care system of developing countries. Safety, however, is a concern to the drug regulatory bodies. This study was carried out to determine the organoleptic properties and the microbial quality of herbal products available to consumers in the Freetown metropolis of Sierra Leone.
Materials and Methods: Twenty herbal preparations purchased within the Freetown metropolis were assessed for taste, colour, odour, and pH. The microbial load and the presence of pathogens were determined. The residual antibacterial activity of two of the preparations that showed no microbial contamination was determined using the cup plate method. The ability of a combination of methyl- and propyl-parabens to prevent growth in some of the herbal products was studied.
Results: It was found that 80% of the samples contained mean bacterial and fungal counts ranging from 1.47 x 108 to 9.375 x 108cfu/ml and 3.45x108 to 1.6x109cfu/ml, respectively. The bacterial contaminants were predominantly Gram-positive organisms of the genera Bacillus and Staphylococcus. Escherichia coli, Salmonella spp. and Shigella spp. were among the isolated pathogens. Aspergillus spp., Trichoderma harzianum, Candida albicans and Cryptococcus neoformans were the predominant fungal contaminants. Two of the herbal samples from which no contaminants were recovered inhibited test organisms while the tested preservative system consisting of a mixture of methyl- and propyl-para hydroxyl benzoic acid in the ratio 2:1 and a use concentration of 0.2%w/v completely inhibited growth in tested samples.
Conclusion: The findings of the study suggest that many of the herbal medicinal preparations marketed in Freetown are likely to be contaminated with potentially pathogenic microorganisms. The microbial quality of these herbal products may however be improved by the incorporation of appropriate preservatives.
Key words: Herbal products, Sierra Leone, organoleptic properties, microbial quality, preservatives