Anthraquinones from the Seeds of Cassia tora with Inhibitory Activity on Protein Glycation and Aldose Reductase

Abstract

Nine anthraquinones, aurantio-obtusin (1), chryso-obtusin (2), obtusin (3), chryso-obtusin-2-O-b b-D-glucoside (4), physcion (5), emodin (6), chrysophanol (7), obtusifolin (8), and obtusifolin-2-O-b b-D-glucoside (9), isolated from an EtOAc-soluble extract of the seeds of Cassia tora, were subjected to in vitro bioassays to evaluate their inhibitory activity against advanced glycation end products (AGEs) formation and rat lens aldose reductase (RLAR). Among the isolates, compounds 6 and 8 exhibited a significant inhibitory activity on AGEs formation with observed IC 50 values of 118 and 28.9 m mM, respectively, in an AGEs-bovine serum albumin (BSA) assay by specific fluorescence. Furthermore, compounds 6 and 8 inhibited AGEs-BSA formation more effectively than aminoguanidine, an AGEs inhibitor, by indirect AGEs-ELISA. N e e -Carboxymethyllysine (CML)-BSA formation was also inhibited by compounds 6 and 8. Whereas compounds 1, 4, and 6 showed a significant inhibitory activity on RLAR with IC 50 values of 13.6, 8.8, and 15.9 m mM, respectively.

Anthraquinones from the Roots of Knoxia valerianoides inhibit the formation of advanced glycation end products and rat lens aldose reductase in vitro

“…3). The present biological data and our previous results on anthraquinones from Cassia tora and Rumex japonicus (Jang et al, 2007;Kim et al, 2008) demonstrated that anthraquinones having 6-hydroxyl group show strong AR inhibitory activity, and 6-hydroxyl and/or 1-hyroxyl groups of anthraquinones contribute to inhibitory activity on AGEs formation. This is the first report of compounds 1, 2, 5, 7, and 8 having inhibitory activity on AGEs formation or RLAR.…”

“…In our ongoing project directed toward the discovery of preventive agents for diabetic complications from herbal medicines (Yoo et al, 2008;Jang et al, 2007), the roots of Knoxia valerianoides Thovel ex Pitards (Rubiaceae) were chosen for more detailed investigation, since the EtOAc-and n-BuOH-soluble fractions of the MeOH extract showed significant in vitro inhibitory activities on both AGEs formation and rat lens aldose reductase (RLAR). The roots of K. valerianoides (Radix Euphorbiae seu Knoxiae) are famous in traditional medicine in Asia, and have been used for relatively moderate fluid accumulation in the chest and flanks with such symptoms as labored breathing, dull pain in the lateral aspect of the chest, expectoration of thick sputum, and a thick, greasy tongue moss (Bensky and Gamble, 1986).…”

Constituents of the flowers of Erigeron annuus with inhibitory activity on the formation of advanced glycation end products (AGEs) and aldose reductase

“…In our ongoing project directed toward the discovery of preventive agents for diabetic complications from herbal medicines (Jang et al, 2007), the flowers of E. annuus were chosen for more detailed investigation. The ethyl acetate-soluble extract was found to inhibit both the formation of AGEs and rat lens aldose reductase (RLAR) in vitro.…”

Screening System of Blocking Agents of the Receptor for Advanced Glycation Endproducts in Cells Using Fluorescence

“…Our previous studies identified several single compounds and extracts from natural products that inhibited AGE formation. 18,[20][21][22] To identify agents that disrupt AGE-induced protein crosslinking in vitro, candidate compounds were added to a collagen-coated surface that had been pretreated with AGE-BSA; AGE-collagen cross linking was detected using specific anti-AGE and horseradish peroxidase-linked antibodies. The AGE cross-linking disruptor N-phenacylthiazolium bromide (PTB) reacts with and cleaves covalent AGE-derived protein crosslinks.…”