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 10
8 to 9.375 x 10
8cfu/ml and
3.45x10
8 to 1.6x10
9cfu/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.
