Protective effects of Scutellaria baicalensis Georgi extract on D-galactose induced aging rats

Scutellaria baicalensis Georgi (SBG), a traditional Chinese herb, has attracted considerable attention for its wide range of pharmacological activities. This study aimed to investigate the intervention effects of SBG ethanol extract on aging rats induced by D-galactose (D-gal) and to explore potential mechanisms by serum and liver metabolic profiles. The aging rats were induced by the D-gal (100 mg/kg) for 10 weeks continuously with subcutaneous injection, while the control rats received physiological saline. Two other groups of rats were administered with 100 mg/kg/day and 200 mg/kg/day of SBG by oral route following D-gal injections. The abilities of spatial and learning memory were evaluated by open-field test and Morris water maze test. Then, some biochemical indexes related to cognitive ability and aging were measured. Histopathological feature in hippocampal region was observed by Hematoxylin and eosin (HE) staining. The changes of metabolic profiles were evaluated using proton nuclear magnetic resonance (¹H NMR) spectroscopy coupled with multivariate data analysis. Results showed that SBG could significantly improve the learning and memory functions, reducing oxidative damage and histological abnormalities of hippocampus neurons. In addition, significant differences in the metabolic profiles were observed both in serum and liver between the model group and the control group. After the treatment using SBG, the levels of these metabolites are significantly changed back to their similar levels in the control group. These metabolic changes are related to the disturbance in amino acid metabolism, glycometabolism and choline metabolism. Hence, SBG may have the potential to improve neurodegeneration and provide brain protection. Graphical abstract A ¹H NMR-based metabonomic study was conducted to provide a global view of metabolites related to D-gal induced aging rats and assess the holistic efficacy of Scutellaria baicalensis Georgi.