Microbial and heavy metals contamination of herbal medicines

Abstract

This study was conducted to evaluate the microbial contaminants and presence of toxic heavy metals on some herbal medicines. Twenty-seven samples (3 kg each) of well-known herbs and 5 kinds of henna available in herb markets around Riyadh, Saudi Arabia were collected for microbial and toxic metal contamination. Twenty-one (60%) of the samples showed the presence of fungi. Aspergillus flavus and Aspergillus fumigatus were the most common isolates (9/35, 35%). Astralagus sarcocolla had the highest TPC count; Matricaria chamomilia had the highest total coliform count and fecal coliform count. Two henna samples showed more than 1 ppm lead content. Mercury was the highest in Lepidium sativum, aluminum in Zingiber officinale, calcium in Artemisia herba alba, cadmium in Lepidium sativum, Vigna radiata and Zingiber officinale. Copper was the highest in Cinnamomum zeylanicum, iron in Zingiber officinale, zinc in Salvia officinalis, potassium in Matricaria chamomilia, whereas sodium was the highest in Pimpinella anisum. Microbial determination showed that Bacillus species was seen in 3 (9.7%) of the isolated microorganisms with the predominance of Bacillus cereus (14/31, 45.2%). Other microbial isolates were Aeromonas hydrophilia, Shigella spp., Enterobacter agglomerans, Enterobacter spp., Vibrio fluvialis, Escherichia coli, Pasteurella multocida, Enterobacter cloacae, Staphylococcus hyicus, Staphylococcus epidermidis, Acinetobacter iwoffii and Klebsiella. Tests showed the sensitivity of most isolated bacteria to amoxicillin, gentamicin, imipinem, tobramycin and trimethoprim- sulfamethoxazole. © 2008 Academic Journals Inc.