Microbial and Heavy Metal Contents of Selected Herbal Medicines Sold in Enugu State, Nigeria

Abstract

This study investigates the microbial and heavy metal contents of selected
herbal medicines sold in Enugu State, Nigeria. Specifically, the study
evaluated the presence of bacterial, parasitic, and fungal loads and heavy
metals (mercury, lead, zinc, and iron) in herbal medicine samples. Ten
branded samples were purchased from Ogige and Ogbete main markets and
labelled A to J. These medicines were indicated for the treatment of malaria,
typhoid fever, ulcers, sexually transmitted infections, worm infestations, and
general blood cleansers. Laboratory analysis, using standard methods, was
employed to determine the microbial and heavy metal contents of the
samples. Culturing and microscopy methods were used for microbial analysis
while heavy metal analysis was done using atomic absorption
spectrophotometry. The analyses were carried out in duplicates using
percentages, means, and standard deviations. The results showed that 60% of
the samples exceeded safety limits for microbial contamination, while all
samples had excessive iron levels. Sample (A) contained mercury
(0.161mg/100ml) above the safe standards established by the FAO/WHO.
Seven samples (A, B, C, D, E, G, and I) were found to contain coliform bacteria
and sample A contained Escherichia coli, Proteus mirabilis, and Bacillus polymyxa
above safety limits. No sample was found with fungal and parasitic load
above safety limits. The study concludes that herbal medicines may not be
assured of safety in terms of bacterial, and heavy metal (iron and mercury)
contents. The findings underline the health risks associated with unregulated
locally prepared herbal medicines.