Inhibition of Aldose Reductase Activities by Kampo Medicines

Abstract

Four kampo medicines, Shu-Jing-Huo-Xie-Tang (SJHXT), Gui-Zhi-Jia-Shu-Fu-Tang (GZJSFT), Niu-Che-Shen-Qi-Wan (NCSQW), and Ba-Wei-Di-Huang-Wan (BWDHW), traditional oriental herb prescriptions, exhibited potent inhibitory activities on rat lens aldose reductase in vitro at the concentration of 0.1 mg/ml using either glucose or DL-glyceraldehyde as a substrate. Four crude drugs, constituents of GZJSFT, Shakuyaku (Paeoniae radix), Kanzo (Glycyrrhizae radix), Sojutsu (Atractyloidis Lanceae rhizoma) and Keihi (Cinnamomi cortex) also inhibited rat lens aldose reductase activities at the concentration of 0.1 mg/ml in vitro. When these kampo medicines and crude drugs were incubated with human red blood cells, two kampo medicines (SJHXT, GZJSFT) and two crude drugs (Shakuyaku, Kanzo), significantly inhibited the accumulation of sorbitol within human red blood cells. These results suggest that the effectiveness of these kampo medicines to some of the chronic diabetic complications may be due to the inhibition of aldose reductase activities.