Microbial quality of herbal preparations sold in some parts of Nigeria

The practice of using herbal drugs has become widespread in recent times without prior knowledge of their microbiological safety. In this context, this research was focused on assessing the microbial quality of different popular herbal preparations registered by the National Agency for Food and Drug Administration Control (NAFDAC) sold within South-West and South-South regions of Nigeria. The microbial diversity of some herbal drugs were examined by aerobic plate count method and microbial isolates were identified based on their morphological, cultural and biochemical characteristics. A total of sixty (60) herbal samples from six (6) herbal products (Kj cleanser, Ok Cleanser, Sk cleanser, Gk cleanser, Y-Bitters and Sw-Bitters) were analyzed and all were found to be free from pathogenic bacteria and indicator organisms of fecal contamination. However, Bacillus spp. was isolated from twenty six (26) of the herbal samples. Altogether four different Bacillus spp. were identified and the most predominant was Bacillus subtilis. The total heterotrophic bacterial count (THBC) of the herbal syrups ranged from 3.10 x10² cfu/ml to 2.65x10³ cfu/ml whereas in the herbal powder the THBC ranged from 9.0x10¹ cfu/g to 1.5x10² cfu/g. The fungal count of herbal syrups ranged from 2.0x10¹cfu/ml to 1.9x10² cfu/ml while that of the herbal powder ranged from 1.0x10¹ cfu/ml to 1.0x10² cfu/ml. However, the microbial load and organisms present in the herbal samples were within WHO standard, therefore, it is recommended that plants to be used in herbal preparations should be properly washed and heated as to reduce or eliminate the presence of Bacillus species.