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Primary Genera of Concern


Compounds and Compound

Classes Implicated in Toxicity






Isoquinoline alkaloids



Steroidal alkaloids

NOTE: The information in this table was developed by committee members knowledgeable in botanicals and phytochemicals who consulted the references listed at the end of the chapter as needed. A review of each of the genera and families on this list was not practical within the constraints of this report. The list should thus be considered as a general guideline for determining which warrant attention, not as an authoritative statement on any in particular.

a A = reports of adverse effects to the heart, liver, lungs, kidney, immune system, reproductive system, teratogenicity, carcinogenesis, central nervous system (convulsant), or death in animals or humans, or where well-known constituents with adverse effects on these same organs, that is, pyrrolizidine alkaloids (liver), cardiac glycosides (heart), methylazoxymethanol glycosides (cancer) are reported for the genus. B = reports of nonpotentially lethal effects in humans or animals, such as severe irritation, gastric upset, emesis, photosensitization, or allergenicity. C = reports of effects that cannot be explained on the basis of known chemistry of the genus or where exceptional amounts, especially in livestock, were required to elicit the effect.

providing a protective function within the plant, they tend to be concentrated in young, tender leaves, shoots, and roots, or in reproductive structures (e.g., flowers and seeds). For example, livestock poisoning episodes have shown that there is often a bimodal distribution of toxic hazard with very young plants and plants at the reproductive stage being toxic, whereas at other growth stages no problems occur. (For a more complete discussion, see Appendix C and resources listed.) Frequently, compounds are continuously biosynthesized in a particular part of the plant, such as mature leaves where photosynthesis is at a maximum, but then they are transported and accumulated in other organs where the protective function conferred by such substances is required (Harborne, 1993).

Although it is possible for plants to contain completely different chemical entities in different parts, it is generally more likely that they will contain the same compounds or compounds that have undergone relatively minor structural transformations. The situation with respect to structural types of constituents is often under a state of continuous flux in response to environmental conditions and ecological factors. It is therefore appropriate to assume, in the absence of other information to the contrary, that a plant part marketed as a dietary supplement ingredient contains toxins that are found in other parts of the plant. That is, if a toxic chemical is present in one part of the plant, it will generally be present in the other parts of the plants, even if at lower concentrations. Indeed, concentrations of toxins

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