Microbial and heavy metal contaminants in herbal preparations sold in Maseru, Lesotho

Abstract

The majority of the populations, both from developed and developing countries, use herbal preparations for primary healthcare purposes. In particular, the use of herbal preparations in Lesotho is high due to inadequate healthcare facilities and inaccessibility of healthcare services. Herbal preparations are inexpensive, easily accessible and culturally accepted than conventional medicines. Although herbal preparations are popularly used, they could be contaminated with pathogenic microbes, toxic heavy metals and non-metals, agrochemical residues, mycotoxins and endotoxins and, thus World Health Organization (WHO) recommends that herbal preparations should be evaluated for safety, efficacy and potency so as to protect the consumers. This study was, therefore, designed to evaluate heavy metals and microbial contaminants in some of the commercially available herbal preparations in Maseru, Lesotho. A total of five herbal preparations were randomly purchased from different areas of Maseru at market price and were subjected to toxic heavy metals and microbial load analysis in accordance to International pharmacopeia and European pharmacopeia. Antimicrobial sensitivity test was performed to the isolated microorganisms. Our results revealed that all of the five herbal preparations were found to be contaminated with fungi beyond WHO limit, 103 CFU/ml. Pseudomonas aeruginosa was also isolated in all the five herbal preparations. The isolated P. aeruginosa was found to be susceptible to ciprofloxacin and ceftriaxone, clinically used antibiotics. There was no growth of Staphylococcus aureus, Escherichia coli and Klebsiella pneumonia from all the five herbal preparations. Again, total coliform count in three samples exceeded 103 CFU/ml, WHO safety limits. Finally, all herbal preparations complied with the limit test for chlorides; however, only two herbal preparations complied with the limit tests for total heavy metals, less than 20ppm. Therefore, this study reports and concludes that herbal preparations sold in Maseru could be contaminated with pathogenic microorganisms, acid radical’s impurities and toxic heavy metal metals. The testing of herbal preparations for microbial and heavy metal contaminants is highly recommended and, may become mandatory.