Glycosides rehmannia

Catalpol. Zhang et al. [233] studied the neuroprotective effects of catalpol, an iridoid glycoside isolated from the fresh rehmannia roots, on the cholinergic system and inflammatory cytokines in the senescent mouse brain induced by D-galactose. Acetylcholinesterase (AChE) activity increased in senescent mouse brain and choline acetyltransferase (ChAT) decreased in the basal forebrain of senescent mouse. Muscarinic acetylcholine receptor Ml (mAChRl) expression declined and the levels of tumor necrosis factor (TNF-a), interleukin-ip (IL-ip), and advanced glycation end products... 

Fig. 6 System 1 The detection of the iridoid glycosides (e.g. aucubin) in Verbasci Bos (la) and Rehmanniae radix (6a) is achieved by n-biitanol extraction (enrichment see 3.1)...

Two forms of rehmannia tuber are used in traditional Chinese medicine, the dried tuber sheng di huang), which is the subject of this entry, and the processed tuber (shu di huang), which is the subject of a separate entry. Processing reduces the content of the compound catalpol (an iridoid glycoside) such that the catalpol content of prepared rehmannia root is only 1/20-1/30 that of fresh rehmannia (Wang et al. 

Several different extracts of rehmannia tuber, including an ethanol fraction of an aqueous extract, rehmannia oligosaccharide, and rehmannia glycoside D, showed hypoglycemic activity in healthy and diabetic rats and mice (Kiho et al. 1992 IQtagawa et al. 1971 Oshio and Inouye 1982). 

Oshio, H., and H. Inouye. 1982. Iridoid glycosides of Rehmannia glutinosa. Phytochemistry 21(1) 133-138. 

Lim JD, Yun SJ, Chung IM, Yu CY (2005) Resveratrol synthase transgene expression and accumulation of resveratrol glycoside in Rehmannia glutinosa. Mol Breed 16 219-233... 

Nishimura H, Sakai H, Morota T, Chin M, Mitsuhashi H (1989) Six iridoid glycosides from Rehmannia glutinosa. Phytochemistry 28 2705-2709... 

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