ABSTRACT
ObjectiveTo explore the effect and possible mechanism of Shenqi Pills （肾气丸） on cognitive impairment and hippocampal glucose energy metabolism in type 2 diabetes mellitus （T2DM）. MethodsSixty C57BL/6 mice were randomly divided into control group， model group， rosiglitazone group and Shenqi Pills low-， medium- and high-dose groups， with 10 mice in each group. T2DM model was induced by a high-fat diet combined with intraperitoneal injection of streptozotocin in all the groups except for the control group. After successful modeling， the high-， medium-， and low-dose Shenqi Pills groups were given 2.08， 1.04， and 0.52 g/（kg·d） of Shenqi Pills granules by gavage respectively， while the rosiglitazone group was given 3 mg/（kg·d） of rosiglitazone tablets by gavage， and the control group and model group were gavaged with 10 ml/（kg·d） of distilled water， all for 8 consecutive weeks. The body weight and fasting blood glucose （FBG） level were recorded every two weeks. The Morris water maze test was performed on the 8th week of medication. After 8-week medication， oral glucose tolerance test （OGTT） and fasting insulin level were measured， hippocampal glucose energy metabolism-related products were quantitatively detected by liquid chromatography tandem mass spectrometry， and KEGG annotation analysis was performed. ResultsCompared to those measured at the same timepoints in the control group， the body mass on week 6 and 8， as well as the FBG level on week 2， 4， 6 and 8 in the model group increased； the blood glucose level at 0， 30， 60 and 120 minutes of the OGTT test increased， while fasting insulin level after 8-week medication decreased. The escape latency of the model group was significantly prolonged on the 3rd and 4th days， and the escape latency time increased， while the total swimming distance， platform quadrant residence time and the number of platform crossings decreased （P＜0.05 or P＜0.01）. Compared to those measured at the same timepoints in the model group， the body mass on week 6 in the low-dose Shenqi Pills group， on week 6 and 8 in the medium- and high-dose groups， and on week 8 in the rosiglitazone group were significantly reduced； the FBG levels in all the Shenqi Pills groups and rosiglitazone group on week 6 and 8 decreased， while fasting insulin levels increased. In the OGTT test， blood glucose in the medium-dose group of Shenqi Pills at all timepoints decreased； in the Morris water maze test， the escape latency period of the medium- and high-dose Shenqi Pills groups was shortened on the 3rd and 4th days， while the escape latency time was reduced， and the total swimming distance， platform quadrant residence time， and number of platform crossings increased in the medium-dose Shenqi Pills group （P＜0.05 or P＜0.01）.The medium-dose Shenqi Pills showed best effect， therefore it was selected for the targeted quantitative detection of metabolites. The medium-dose Shenqi Pills group could regulate the disorder of glucose metabolism in the hippocampus of T2DM mice， and 13 differential metabolites were found，up-regulating α-ketoglutarate and 3-phosphoglyceric acid， and down-regulating fumaric acid， glutamatic acid， lactatic acid， inosine， malic acid， adenine， fructose 1,6-diphosphate and others. KEGG annotation of differential metabolites suggested that Shenqi Pills was closely related to the regulation of glucose metabolism disorder and insulin resistance in the hippocampus region of T2DM model mice， as well as neurodegenerative diseases and ABC transport， hypoxia-inducible factor 1 （HIF）， forkhead transcription factor （FoXO） and cyclic adenosine monophosphate （cAMP） signaling pathways. ConclusionShenqi Pills can improve learning and memory abilities and cognitive impairment in T2DM mice， and may act its role by regulating glucose energy metabolism in the hippocampus of T2DM.