Protective effects of dietary kaempferol glycoside components from unripe soybean (Edamame, Glycine max L. Merrill. 'Jindai') leaves and their serous metabolite on carbon tetrachloride-induced liver injury mice.

The study investigated the protective effects of kaempferol galactoside (KG) components in mice, which were separated from Jindai soybean leaves (JDL) and mainly composed by two kaempferol galactosides. Further, KG-related metabolites in serum of mice were identified by Tof-MS. Results showed that both JDL and KG prevented the CCl4-induced increases in serum aspartate aminotransferase and serum alanine aminotransferase. Additionally, mice treated with KG had significantly decreased TBARS and TNF-alpha levels, compared to CCl4-treated mice. Serous analysis showed that kaempferol, glucuronidated kaempferol and methylated kaempferol with a glucuronic acid moiety were identified in the serum of mice fed unripe soybean leaves or kaempferol galactosides isolated from the leaves. The results indicated that kaempferol 3-O-galactoside connected to other glycosides via galactose might be hydrolyzed in the gastro-intestinal tract and/or epithelium cells to release kaempferol, followed by glucuronidation and/or methylation in the liver to contribute to a reduction in liver injury. The use of raw leaves containing kaempferol galactosides as food materials may contribute to a reduction in oxidation-related diseases.