Combined Antihypertensive Effect of Paeoniflorin Enriched Extract and Metoprolol in Spontaneously Hypertensive Rats

Bo Li; Zheng-Biao Yang; Shan-Sha Lei; Jie Su; Ze-Wu Jin; Su-Hong Chen; Gui-Yuan Lv

Articles

Abstract

Pharmacognosy Magazine,2018,14,53,44-52.

DOI:10.4103/pm.pm_483_16

Published:February 2018

Type:Original Article

Authors:

Author(s) affiliations:

Bo Li¹, Zheng-Biao Yang², Shan-Sha Lei¹, Jie Su³, Ze-Wu Jin⁴, Su-Hong Chen⁵, Gui-Yuan Lv¹
¹ Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology; College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, P. R China
² Center of Safety Evaluation, Zhejiang Academy of Medical Sciences, Hangzhou, P. R China
³ College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, P. R China
⁴ College of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, Zhejiang, P. R China
⁵ Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology; College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou; College of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, Zhejiang, P. R China

Abstract:

Background: Hypertension is a great global health challenge and it mostly requires drug combination therapy with the various advantages. Metoprolol (MP) and paeoniflorin are both commonly used for the treatment of hypertension. However, whether they exert synergistic effects on antihypertension or not remains unclear, especially on vascular endothelial function. Objective: The purpose of the study is to investigate the advantages of the combined antihypertensive effects of paeoniflorin enriched extract from Radix Paeoniae Alba (RE) and MP in spontaneously hypertensive rats (SHR). Materials and Methods: SHR divided into six groups (n = 8 each group), animals in each group were administrated orally with distilled water, MP (6 and 20 mg/kg), RE (30 and 90 mg/kg), and MP (6 mg/kg) combined with RE (30 mg/kg) (MP + RE), respectively, daily for 6 weeks. Blood pressure (BP) and microcirculation were assessed. The organ bath experiment and hematoxylin and eosin staining were, respectively, performed for the functional and pathological vascular function analysis. Immunohistochemistry was applied to detect endothelial nitric oxide synthase (eNOS) expression in aorta, heart, and kidney. Further, high-performance liquid chromatography was employed to quantitatively determine paeoniflorin in RE and MP + RE sample solvent, as well as in plasma of Sprague-Dawley rats (SD) after single-dose administration of them. Results: The results showed that MP + RE significantly reduced BP, increased microcirculation, improved vascular function and pathological changes, and upregulated eNOS expression. MP was also found to increase the blood concentration of paeoniflorin in SD. Conclusion: The combination of RE and MP could be used for the treatment of hypertension and could improve microcirculation, upregulate eNOS expression, and mitigate endothelial dysfunction in SHR.