Plants Teratogens PDF

Plants Teratogens Gustav Komlaga What are teratogens? Teratogens are defined as any environmental factor that can produce a permanent abnormality in structure or function of a foetus or embryo. This could be restriction of growth, or death of an embryo or a foetu...

Plants Teratogens Gustav Komlaga What are teratogens? Teratogens are defined as any environmental factor that can produce a permanent abnormality in structure or function of a foetus or embryo. This could be restriction of growth, or death of an embryo or a foetus. A teratogen can be chemical, physical, or biologic agent that causes an abnormality following fetal exposure during pregnancy in animals  Plant Teratogens Many phytoconstituents are known to be teratogenic in laboratory animals, However, only a few phytoconstituents have been shown by feeding trials to produce foetal abnormality in livestock.  Categories of teratogens There are 3 categories of plant teratogens: 1. known teratogens in known teratogenic plants e.g. Lupinus, Veratrum, Conium, Senecio genera and Leucaena genera 2. known teratogenic plants with unidentified teratogens e.g. Astragalus, Nicotiana and Trachymene genera 3. suspected teratogenic plants. e.g. Datura, Prunus, Sorghum and Senecio genera  Characteristic of teratogene Teratogens often act during a short, relatively early period of gestation cycle. Usually, the teratogenic effectof teratogens is undetected at the time of their use. The causative plant may disappear from the food source when the abnormalities become apparent  Some phytoconstituents groups known to have teratogen effect. alkaloids coumarins Lignans macrolides nitriles terpenoids toxic amino acids other unidentified compounds of some plants. The majority of plant teratogens contain nitrogen  Plants teratogenicity in man/animals Teratogenic effects only demonstrated in laboratory animal by incorporating certain suspected plants into animal fodder Often in larger doses not normally experience in humans. No plant species has been shown to be teratogenic in man. Teratogenic effects of plant teratogens is rarely notice in man because man consumes teratogens in quantities not enough to induce teratogenicity.  Teratogenic Mechanisms Teratogens may act by inducing the following effects in foetus. necrosis trigger apoptosis (programmed cell death). Changes in the patterns of gene expression Inhibition of cell interactions, Blockage of morphogenetic cell movements.  The teratogenic effects Teratogens can cause fetal death or gross abnormalities. Based on their mechanisms, they can cause vascular disruption, oxidative stress, can target specific receptors and enzymatic sites endocrine and central nervous system (CNS) disruption may affect a single anatomical feature or an entire system.  Factors influencing teratogenicity The ff conditions would affect the ability of a teratogen to exerts it effect: the dosage: in a high enough doses or in large doses. delivery into the embryo/fetus when it crosses the placenta/ nature of the teratogenic agent/chemical compound duration and frequency of exposure. Teratogens sometimes could be present in the maternal body even before conception.  Some useful plants with teratogenic potentials Malus domestica (Apple) seeds and Prunus cerasus (Cherry) seeds: contain cyanogenic glycosides that’s fatal to even adults. Solanum tuberosum (potato), Solanum melongena (eggplant), Lycopersicon esculentum (tomato) : contain solanidanes and spirosolanes that are suspected teratogens present in the edible plant parts. Cassava: contains cyanogenic glycosides especially concentrated in the peels.  Medicinal plants with teratogenic potentials Astragalus spp – used in herbal medicine and also in traditional Chinese and Persian medicine Asparagus racemosus : methanolic extracts can cause gross malformations in fetus  Medicinal plants with teratogenic potentials Datura stramonium – used for asthma treatment due to presence of atropine Senecio (genera)- contains biocides in the form of alkaloids Some potential teratogens and their plant sources Some potential teratogens and their plant sources Some teratogens and their plant sources  reference 1. Richard F. Keeler (1984). Teratogens in plants. Journal of Animal Science. 58 (4) pp 1029-1239. https://doi.org/10.2527/jas1984.5841029x 2. Treas and Evans. Textbook of Pharmacognosy.  Thank you!!!!!!!!!