Therapeutic Potential and Toxicological Risks of Selected Toxic Medicinal Plants: A Pharmacognostic and Ethnopharmacological Review

Toxic medicinal plants occupy a complex position at the interface of pharmacognosy, ethnopharmacology, clinical pharmacology, and toxicology because the same secondary metabolites that provide potentially useful biological activity may also cause severe or fatal poisoning. This narrative review evaluates seven toxic medicinal plants that represent different pathways from traditional use to contemporary pharmaceutical relevance: Hyoscyamus niger L., Veratrum album L. (syn. V. lobelianum Bernh.), Ricinus communis L., Rauvolfia serpentina (L.) Benth. ex Kurz, Physostigma venenosum Balf., Podophyllum peltatum L., and Rhododendron ponticum L. The review integrates six source books supplied for the study, including Georgian medicinal-plant, historical, and geobotanical literature together with major international herbal monographs, and supplements them with peer -reviewed pharmacological, clinical, and toxicological evidence. For each species, botanical and pharmacognostic characteristics, historical and ethnopharmacological use, principal active or toxic constituents, mechanisms of action, modern therapeutic development, and safety limitations were compared. The analysis demonstrates several distinct translational models: isolation of active alkaloids such as scopolamine, reserpine, and physostigmine; processing that separates a medicinal product from a hazardous plant constituent, as in castor oil and ricin; semisynthetic drug development from podophyllotoxin; and species such as Veratrum and Rhododendron whose contemporary significance is predominantly toxicological. The findings emphasize that historical use and pharmacological act ivity are not equivalent to clinical efficacy. Safe therapeutic translation requires authenticated botanical material, chemical characterization, standardization, controlled dosing, clinical evaluation, and toxicological surveillance.