Health, safety and quality concerns of plant-based traditional medicines and herbal remedies

Plant-based medicines and herbal remedies are considered to be healthy, pure and safe as it is obtained from natural resources. The increased interest and use of plant-based traditional medicines and herbal remedies, however, requires that the knowledge of users regarding these medicines’ health, safety and quality are addressed. The majority of medicinal plant material are harvested from wild stocks, where intrinsic and extrinsic factors result in varied production of phytochemical constituents. Plant material with inconsistent concentrations of biologically active compounds may affect the efficacy and safety of the medicine. Additionally, plants produce secondary metabolites to deter, stun, poison or kill threatening species. Some biologically active secondary metabolites may thus be mutagenic, genotoxic or carcinogenic. The quality of traditional medicines and herbal remedies are often compromised by the presence of contaminants from either natural or anthropogenic sources, which may result in adverse effects and even death. This paper provides an overview of the abiotic and biotic factors that may contribute towards the variability of bioactive concentrations. Additionally, contaminants that may affect the quality of traditional medicines and which in turn, may result in adverse effects are reviewed while recorded statistics of poisoning after the use of traditional medicines raises serious concerns.