Assessment of Microbiological Contamination and Metal Toxicity in Anti-Diabetic Herbal Medicines Available in Local Markets of Dhaka City, Bangladesh
Use of anti-diabetic herbal medicines (ADHMs) is in rise all over the world due to the availability and low cost of its raw materials. To analyze the quality of ADHMs, our present study was conducted to evaluate the level and types of microbiological and metal contamination in eight ADHMs samples collected from different local markets of Dhaka City, Bangladesh. No ADHMs were found to be contaminated with coliform or even other pathogens like E. coli, Salmonella spp., and Listeria spp. However, aerobic bacterial count of the samples fails to satisfy safe limits set by different regulatory standards, in addition with the yeasts and molds contamination for some samples. Metal analysis results showed that, among nine toxic metals such as Copper (Cu), Zinc (Zn), Lead (Pb), Manganese (Mn), Chromium (Cr), Iron (Fe), Cadmium (Cd), Nickel (Ni), and Arsenic (As), Cu, Zn, Pb, Cr, Ni content was in safe limit according to different pharmacopoeia and WHO guidelines. Among all the regulatory authorities, only the Health Sciences Authority (HSA), Singapore claims the Cd content is above the permissible limit in all the samples except ADHM-4. Chinese pharmacopoeia restricts the use of ADHM-1, ADHM-2 and ADHm-8 because of unacceptable As contamination. All the target anti diabetic herbal preparations (ADHPs) were found to retain unacceptable level of Mn, ranging from 0.44 to 4.17 ppm. Metals contamination poses potential risks in human health and regulatory authorities not only should impose restriction on the use of the medicines but also direct guidelines to keep the drugs safe.
Keywords - Raw Materials, Coliform Bacteria, Pathogens, Safe Limit, And Human Health.