著者

和田 啓爾

出版者

日本生薬学会

雑誌

生薬學雜誌 (ISSN:13403443)

巻号頁・発行日

vol.50, no.3, pp.195-203, 1996-06-20

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From edible and medicinal plants, several active principles that affected the metabolizing enzyme systems were isolated. A toxic substance, 4-0-methylpyridoxine (MPN), responsible for "gin-nan food poisoning" was isolated from the seeds of Ginkgo biloba L. (Ginkgoaceae). MPN causes food poisoning through not only antagonizing vitamin B_6 (in the body) but also inhibiting the formation of 4-aminobutanoic acid (GABA) from glutamate in the brain. The MPN levels in the sera of the patients with gin-nan food poisoning may be determined by HPLC, which may be used for chemical diagnosis of gin-nan food poisoning. Two characteristic terpenoids, bilobalide and ginkgolide A in G. biloba, shortened the anesthetics (hexobarbital and urethane, i.p.) induced sleeping time in mice. Bilobalide has an anticonvulsant effect, especially on the MPN-induced convulsions. Those effects are considered to be due to induction of the hepatic drug metabolizing enzyme (cytochrome P450), by repeated oral administration of bilobalide. Several limonoids from the citrus plants shortened the sleeping time induced in mice by urethane, and induced the liver glutathione S-transferase (GST) in mice. The relationship between the structures and the effects of limonoids on both sleeping time and induction of liver GST was discussed. Columbin from columbo root and β-caryophyllene and α-humulene from Pinus densiflora also affected the sleeping time induced in mice by anesthetics. Their effects on hepatic drug metabolizing enzymes were also studied.