Toxic alkaloids

Schneider, D. J., Miles, C. O., Garthwaite, L, Vanttalderen, A., Wessels, J. C. and Lategan, H. J. 1996. First report of field outbreaks of ergot-alkaloid toxicity in South Africa. Onderstepoort Journal of Veterinary Research, 63(2) 97-108. 

Unlabeled Uses Treatment of ergot alkaloid toxicity, pheochromocytoma, Raynaud s phenomenon... 

CHEEKE, P.R., Pyrrolizidine alkaloid toxicity and metabolism in laboratory animals and livestock, in Toxicants of Plant Origin, Vol. 1, (P.R. Cheeke, ed.), CRS Press, Boca Raton. 1989, pp. 1-22. 

If insects have no choice or if they are very hungry, the deterrency threshold value is much reduced, and they often feed on a diet with alkaloids that they would normally avoid 15,32). In this case we have the chance to test the toxicity of an ingested alkaloid. If insects do not take up alkaloid-containing food, alkaloid toxicity can be assessed to some degree by topical application or by injection (Table I). 

In the West Indies especially, pyrrolizidine alkaloid toxicity is a continuing problem, as plants containing pyrrolizidine alkaloids such as Heliotropium, Senecio, and Crotolaria species are used in traditional medicine to make herbal teas. Chronic exposure to low doses of these alkaloids causes liver cirrhosis, and it is estimated that these alkaloids account for one-third of the cirrhosis cases detected at autopsy in Jamaica (see Chapter 6 for more details of these natural toxins). 

As we saw in Chapter 3, pyrrohzidine alkaloid toxicity is a continuing problem, as plants containing pyrrolizidine alkaloids are also used in traditional medicine to make herbal teas, especially in the West Indies. 

Rose described the toxicity of the senecio plant in 1972 [24]. It is the most common plant species to contain the pyrolizidine alkaloids. Toxicity includes hepatic necrosis and later intrahepatic veno-occlusion. A major secondary component is ATN. There are over 50 species of senecio plants in the south east of South Africa. The plants are used extensively as enemas and purgatives. Rose mentions that, despite the deaths resulting from the use of these plants, the local inhabitants are not aware of the danger these plants pose to their well-being. 

Australian workers have prepared a number of semisynthetic pyrrolizidine esters as part of a major investigation of pyrrolizidine alkaloid toxicity. 7,9-Diacetylheliotridine (52), 7-acetylheliotridine (53), 7,9-divalerylheliotridine (54), and 7-pivalyl-(55), 9-pivalyl-(56) and 7,9-dipivalylheliotridine (57) were prepared by acylation of heliotridine with the appropriate acid chloride. The three last-... 

EXPLOSION and FIRE CONCERNS flammable solid NFPA rating Health 3, Flammability 4, Reactivity 4 very unstable severe explosion hazard when shocked or exposed to heat can form salts of picric acid that are initiators and shock-sensitive forms unstable salts with concrete, ammonia, bases, and metals (e.g., lead, mercury, copper, and zinc) can form extremely explosive mixtures with uranium perchlorate mixtures with aluminum and water ignite after a delay period incompatible with all oxidizable substances, albumin, gelatin, and alkaloids toxic gases and vapors, such as carbon monoxide and oxides of nitrogen, may be released in a fire use flooding quantities of water for firefighting purposes. 

Alkaloid Toxic dose, mg./kg. Paralyzing dose, mg./kg. References... 

One aspect of Veratrum alkaloid toxicity, namely the activity of veratradine, has been exploited earlier as a pharmacological tool in studying the mechanism of action of ion channels [13]. Vemtridine is one of a group of four types of lipid-soluble polycyclic compounds that serve as agonists of the sodium ion channel receptors that mediate the excitability of heart, nerve, and skeletal muscle. This review focuses primarily on the potential... 

Table II. Susceptibility of Animals to Pyrrolizidlne Alkaloid Toxicity. ...

Other significant experiments have corroborated the metabolic pyrrole hypothesis. When cells other than those capable of microsomal oxidation (i.e., cells other than liver) were incubated with pyrrolizidine alkaloids toxicity was not observed. However when these cells were exposed to synthetically prepared necine pyrroles, severe mitotic inhibition was observed. The chemical stability of the pyrrolic alkaloids is much less than that of the corresponding necine pyrroles and the former have not been detected Ija vivo. However when synthetic monocrotaline pyrrole was injected into the mesenteric vein of rats it produced the lesions typical of pyrrolizidine alkaloid poisoning portal vascular degeneration, hepatic necrosis, and inhibition of hepatocyte mitosis (63,64). Injected into the jugular veins of rats and dogs... 

Pilocarpine is a tropane alkaloid. Toxic symptoms are characterized by muscarinic effects. Toxic effects include hypersecretion of saliva, sweat, and tears contraction of the pupils of the eyes and gastric pain accompanied with nausea, vomiting, and diarrhea. Other symptoms are excitability, twitching, and lowering of blood pressure. High doses may lead to death due to respiratory failure. A lethal dose in humans is estimated within the range of 150-200 mg. 

Mattocks, A. R. Mechanisms of pyrrolizidine alkaloid toxicity. "Proc. 5th Int. Congr. Pharmacology", vol. 2 S. Karger Basel, 1973 p. 114-123. 

Crawford L, Kocan RM. Steroidal alkaloid toxicity to fish embryos. Toxicol Lett 1993 66 175-81. 

---