Acupuncture at Taichong and Zusanli points exerts hypotensive effect in spontaneously hypertensive rats by metabolomic analysis.

Background: The development of hypertension affects several target organs, the kidneys being one of them. Acupuncture has been used to treat hypertension for a long time. Several mechanisms of acupuncture on hypotensive effect have been reveled, while the effects of acupuncture on the alterations in renal cortex from a metabolomic perspective are still unclear.

Methods: Twelve male Wistar rats served as the control group (Wistar Group). Twenty-four male spontaneously hypertensive rats (SHR) were randomly divided into two groups: the model group (SHR Group) and the acupuncture group (AC Group). In the AC Group, milli-needle acupuncture was used to puncture the bilateral Taichong (LR3) and Zusanli (ST36) points. Blood pressure values were measured weekly and the rats were euthanized after three weeks. Renal cortical tissues were collected for non-targeted and targeted metabolomic analyses.

Results: Acupuncture reduced blood pressure values in rats (Compared with the SHR Group, P < 0.001). Thirteen metabolites with significant differences and three metabolic pathways were screened by untargeted metabolomics. The SHR Group was compared with the Wistar Group and AC Group both involving metabolites and pathways related to bile acid metabolism. Furthermore, targeted metabolomics quantification of four bile acids, Cholic acid (CA), Allocholic acid (ACA), Deoxycholic acid (DCA) and Chenodeoxycholic acid (CDCA), revealed that all bile acid concentrations were relatively high in the SHR Group, except for ACA.

Conclusion: This study indicate that abnormal bile acid metabolism may be an independent risk factor the development of hypertension. Acupuncture at Taichong and at Zusanli points effectively modulated bile acids metabolism in SHR renal cortex tissues to exert a hypotensive effect, and CA may be able to be a new target for the treatment of hypertension.