Evaluation of heavy metal and microbial content of a multicomponent herbal preparation

Abstract

Herbal mixtures are extensively consumed globally for medicinal use due to the belief that they are safe and readily accessible. The herbal preparation (SHM), evaluated in this study, is made up of 7 plants found in Nigeria and it is used internally and externally for varieties of disease conditions. The heavy metals and microbial content of SHM was evaluated. Three batches of the SMH were analyzed for presence of heavy metals using Atomic Absorption Spectrophotometer. The microbial load was also evaluated by determining the total viable yeast, mould and coliform bacteria count. The metal and microbial content of the samples were compared with WHO permissible limits and differences in concentration among the batches were determined. Fe (0.010-0.100 mg/L) and Zn (0.010-0.030 mg/L) detected were significantly (P<0.05) lower than the permissible limits while Cu, Pb and Cd were absent. A batch had total yeast and mould count (4.95 x 103Cfu/mL) above the permissible limit whereas the other batches were below the limit. Microorganisms (yeasts, mould like Aspergillus flavus and Rhizoctonia solani) were present in all the batches and hence SHM may not be safe for internal use.
 Keywords: Herbal mixtures, Heavy metals, Microbial load, Atomic absorption spectrophotometer