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 selectedherbal medicines sold in Enugu State, Nigeria. Specifically, the studyevaluated the presence of bacterial, parasitic, and fungal loads and heavymetals (mercury, lead, zinc, and iron) in herbal medicine samples. Tenbranded samples were purchased from Ogige and Ogbete main markets andlabelled A to J. These medicines were indicated for the treatment of malaria,typhoid fever, ulcers, sexually transmitted infections, worm infestations, andgeneral blood cleansers. Laboratory analysis, using standard methods, wasemployed to determine the microbial and heavy metal contents of thesamples. Culturing and microscopy methods were used for microbial analysiswhile heavy metal analysis was done using atomic absorptionspectrophotometry. The analyses were carried out in duplicates usingpercentages, means, and standard deviations. The results showed that 60% ofthe samples exceeded safety limits for microbial contamination, while allsamples 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 bacteriaand sample A contained Escherichia coli, Proteus mirabilis, and Bacillus polymyxaabove safety limits. No sample was found with fungal and parasitic loadabove safety limits. The study concludes that herbal medicines may not beassured of safety in terms of bacterial, and heavy metal (iron and mercury)contents. The findings underline the health risks associated with unregulatedlocally prepared herbal medicines.