Inhibition of Aldose Reductase Activities by Kampo Medicines

Abstract

131itional medicine "Flachimi-Gan" act as insulin-like substances and, consequently, the above natural drugs may partly reduce the elevation of serum insulin levels without affecting glucose levels in rats fed the high sugar diet. Furthermore, cinnamic acid and cinnamic aldehyde were isolated as anti-lipolytic substances from Cinnamomi cortex. It was reported that cinnamic acid and cinnamic aldehyde inhibited the VLDL synthesis from acetate in rat hepatocytes (14). Therefore, these finding suggested that the cinnamic acid and cinnamic aldehyde content of Cinnamomi cortex may prevent the hyperlipemia caused by the high sugar diet. Moreover, in the present work, we fractionated the acetone extracts of Moutan cortex as antilipolytic substances and are now investigating the isolation and structure of these anti-lipolytic and lipogenic substances from the above extracts.Abstract: Four kampo medicines, Shu-Jing-Huo-Xie-Tang (SJHXT),

Inhibitory activities of selected Kampo formulations on human aldose reductase

“…The group of Kampo formulations that are clinically used for DN and for which AR inhibitory activities in the rat lens have been reported [19] exhibited significant hAR inhibiting effects in the present in vitro study. Moreover, Chotosan and Yokukansan exhibited greater AR inhibitory activities than this group of Kampo formulations.…”

“…Goshajinkigan, Sokeikakketuto, Keishikajutsubuto and Hachimijiogan are clinically used for the treatment of peripheral neuropathy and were used as controls because previous reports exist only for these four formulations [19]. Four Kampo formulations, namely, Chotosan, Shichimotsukokato, Yokukansan, Yokukansankachinpihange, which are used for cognitive disorders were also selected to determine their AR inhibitory activities in this study (Table 2).…”

“…Because AR reduces glucose in its role as an important enzyme in the polyol pathway, previous studies have reported that the inhibition of AR is involved in the action of Kampo medicines that are used for treatment of DN including Goshajinkigan, Hachimijiogan, Sokeikakketuto and Keishikajutsubuto [19]. In the present study, the bioactivities of eight selected Kampo formulations that are currently in clinical use for the treatment of diabetes complications were assessed using human AR (hAR) inhibitory activity as the primary parameter to explore their possible novel clinical applications in the treatment of diabetes complications.…”

Maintaining the Redox-Balance Intact: Gosha-Jinki-Gan but Not Insulin Activates Retinal Soluble Guanylate Cyclase in Diabetic Rats

“…The administration of aldose reductase inhibitors to prevent the development of diabetic microangiopathy and basement membrane thickening had previously been shown in animal models [20,21] . Kampo medicine but not insulin is effective in this context [31,32] .…”

“…Experimental research on the single herb ingredients as well as the 10-herb formula has revealed the following physiological activities: Antioxidative actions [27,28] , vasodilation, mediated through NO production [29] , anticoagulatory effects [30] , aldose reductase inhibition [31,32] and improvement of glucose utilization in both in vitro and animal models [33][34][35] .…”