ABSTRACT
Naturally occurring toxins (natural toxicants) associated with plants are those synthesized or accumulated by plants or by the many fungi and microorganisms that invade or grow saprophytically on, or endophytically within the plants. Natural toxicants, which include low molecular weight secondary metabolites through to high molecular weight proteins, are amongst the most damaging and deadly chemicals known. They are capable of eliciting a spectrum of biological effects from sudden death to prolonged chronic disease in livestock and humans. The harmful effects on humans resulting from the ingestion of common household or garden plants have been reviewed[1] and will not be considered in this present review. The use of herbs and other plants by humans for health purposes can also result in poisoning episodes. Apart from simply collecting the wrong plant, the dangers of toxins associated with herbal and medicinal plant preparations are similar to those of foods, i.e. natural toxicants can be intrinsic to the medicinal plants or can be present as contaminants. The influence that developing regulations concerning human exposure to natural toxicants in herbal preparations may have on regulations concerning human exposure to natural toxicants in food is considered in Section V.
