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The Epileptic Gerbil. Neuronal Networks and Actions of Antiepileptic Drugs
Published in Carl L. Faingold, Gerhard H. Fromm, Drugs for Control of Epilepsy:, 2019
As discussed above, there is strong evidence from neurochemical studies that GABAergic neurotransmission may be impaired in gerbil brain, especially in SN. This may explain the high anticonvulsant potency of GABAmimetic drugs in this species. Löscher et al.31 reported that GABAmimetics, such as the GABA pro-drug cetyl GABA, the GABA degradation inhibitors aminooxyacetic acid (AOAA), and gamma-acetylenic GABA (GAG), the GABA receptor agonist THIP, and the GABA uptake blocker (-)-nipecotic acid ethyl ester, were strikingly more potent to suppress seizures in gerbils than in other genetic animal models of epilepsy and in traditional electrical or chemical mouse or rat models of epilepsy, such as maximal electroshock seizures (MES) or seizures induced by pentylenetetrazol (PTZ). Subsequent studies showed that the same was true for other GABA uptake blockers, such as the novel N-4,4-diphenyl-3-butenyl derivatives of nipecotic acid and guvacine, SKF 89976-A and SKF 100330-A,30 the GABA receptor agonist muscimol,32 and the GABA aminotransferase (GABA-T) inhibitors ethanolamine-O-sulfate (EOS)32 and gamma-vinyl GABA (GVG).33 Interestingly, the effective doses of GVG in gerbils are in the range known to be effective in patients with epilepsy.34 With respect to seizure types in gerbils, the GABA receptor agonists THIP and progabide were almost equally effective to protect against minor and major seizures.35
Restricted and Banned Herbals
Published in Amritpal Singh Saroya, Reverse Pharmacology, 2018
Chemical composition: The major stimulant alkaloid of A. catechu is arecoline (up to 0.2%), the remainder of the alkaloid content (total about 0.45%) being composed of arecaidine, guvacine, and guvacoline. The seeds contain procyanidins known as arecatannins, which have been linked to carcinoma.
Abies Spectabilis (D. Don) G. Don (Syn. A. Webbiana Lindl.) Family: Coniferae
Published in L.D. Kapoor, Handbook of Ayurvedic Medicinal Plants, 2017
Chemical constituents — Ripe and semiripe areca nuts contain26 a large number of amino acids both in the free and combined state. The salient features of amino acid makeup are an insignificant quantity of tryptophan and methionin, presence of high percentage of proline both in free and combined forms, and relative increase of free tryosine and phenylalanine and of combined arginine in the semiripe and ripe nuts. Earlier investigations revealed the presence of five alkaloids, viz., arecoline, arecaidine, guvaoline, guvacine, and arecolidine, but a recently detailed analysis of young and mature nuts showed the presence of minor amounts of + catechin and high amounts of procyanidins.105 Arecoline, a substitute for pilocarpine, has been isolated from the nuts. They also contain β-sitosterol and leukocyanidins and tannins which exhibit antibacterial and antifungal properties.178
Metabolism of the areca alkaloids – toxic and psychoactive constituents of the areca (betel) nut
Published in Drug Metabolism Reviews, 2022
Guvacoline (norarecoline) is a N-demethylated congener of arecoline that retains a labile methyl ester functional group, but it remains to be determined if guvacoline hydrolysis to its carboxylic acid derivative guvacine occurs in vivo or in vitro by enzyme-facilitated mechanisms.