Fecal Metabolomics Study of Radix Scutellariae’ s Effect on Treating Type 2 Diabetic Rats Based on Mass Spectrometry Technique

Radix Scutellariae is a traditional Chinese medicine contained flavones such as baicalin, baicalein. Radix Scutellariae was proved to have effects on regulating blood glucose, blood lipid and antioxidation. In this research, Radix Scutellariae’s effect on treating diabetes was studied. Three experimental rat groups were adopted, including healthy control group (HC), type 2 diabetic model group (DM) and Radix Scutellariae treated group (RS). DM and RS rats were type 2 diabetes rats induced by streptozocin. HC and DM rats were given conventional food, free drinking water, while RS rats were treated with Radix Scutellariae extracting solution by gavage. The treatment lasted 12 weeks in order to observe the long-term therapeutic effect. Based on detecting weights and fasting blood glucoses at different weeks, the physical conditions of rats from each group were evaluated. After 12 weeks treatment, the feces samples from three groups were collected for further study. Ultra-performance liquid chromatography quadruple time-of-flight mass spectrometry (UPLC-Q-TOF MS) technology was adopted to study the alterations of rats’ endogenous metabolites. Hence, the effects of Radix Scutellariae on rats’ metabolic pathways were roundly and systematically researched. Principal components analysis (PCA) was applied to analyze the metabolites and the PCA score plots showed the metabolites from HC, DM and RS were obviously separated. The above results revealed that type 2 diabetes and Radix Scutellariae both influenced the metabolism of rats. Orthogonal partial least-squares discriminant analysis (OPLS-DA) and its S-plots were used for further analysis and potential biomarkers searching. 11 biomarkers were finally detected including sphinganine, phytosphingosine, methyl 3-phenylpropanoate, sphingosine, 3-methyldioxyindole, tetracosanoylglycine, stearidonic acid, leukotriene E4, leucylproline, L-urobilinogen and estradiol. Relative intensities of 11 biomarkers in different groups suggested that Radix Scutellariae could regulate the sphingolipid metabolism and fatty acid metabolism. This research took feces samples as research object, rather than serum and urine samples in typical metabolomics research. The results obtained from feces samples could preferably reflect liver, intestinal flora and other organs closely related to feces. Hence, this paper provide a new biological sample choice for metabolomics research.