Antihypertensive Activity of Eucommia Ulmoides Oliv: Male Flower Extract in Spontaneously Hypertensive Rats

Ruo-Han Yang,Chao Liang,Hong-Yan Du,Xin Yao,Jin-Jin He,Zhen-Jiang Ding,Qin Li,Dong Fang,Zhan-Sheng Zhang,Xiao Wang

doi:10.1155/2020/6432173

Abstract

Eucommia ulmoides Oliv. is a traditional medical plant in Asia; however, it is still unknown whether Eucommia male flowers have an antihypertensive activity. In this study, we found that the aqueous extract of Eucommia ulmoides Oliv. male flowers can lower the blood pressure of SHR in a dose-dependent manner. Mechanistic studies suggested that the aqueous extract of male flowers can promote the mRNA and protein expressions of ACE2 in the kidney of SHR. ELISA assay showed that the plasma levels of ANG II was decreased, while ANG-(1–7) was increased in SHR treated with the aqueous extract of male flowers. ACE2 inhibitor DX600 can reverse the aqueous extract of Eucommia ulmoides Oliv. male flower-induced downregulation of Ang II and upregulation of Ang-(1–7), as well as the reduction of blood pressure in SHR. Moreover, Ang-(1–7)-Mas receptor antagonist A-779 abolished the antihypertensive effects of the aqueous extract of Eucommia ulmoides Oliv. male flower in SHR. The aqueous extract of Eucommia ulmoides Oliv. male flowers exhibited an antihypertensive action through the activation of ACE2-Ang-(1–7)-Mas signaling pathways in spontaneously hypertensive rats.

Highlights

Hypertension is a major risk factor that can lead to cardiac failure, coronary artery disease, stroke, renal injury, and even mortality [1, 2]
To investigate whether the aqueous extract of Eucommia ulmoides Oliv. male flowers exhibit antihypertensive activity in spontaneously hypertensive rats, we administrated the aqueous extract of Eucommia ulmoides Oliv. male flowers to spontaneously hypertensive rats and measured its effect on blood pressure
After 1 week administration, the blood pressure of SHR rats was decreased to 149.54 ± 6.28 mmHg at low dose, 142.04 ± 4.60 mmHg at medium dose, and 135.50 ± 3.56 mmHg at high dose; After 2 weeks administration, the blood pressure was decreased to 145.25 ± 5.43 mmHg at low dose, 139.39 ± 8.36 mmHg at medium dose, and 126.38 ± 4.88 mmHg at high dose; after 3 weeks administration, the blood pressure was decreased to 132.40 ± 5.24 mmHg at low dose, 125.19 ± 4.29 mmHg at medium dose, and 121.60 ± 4.29 mmHg at high dose. en, after 4 weeks to 7 weeks’ administration, the values of blood pressure were nearly reduced to the same degree among the three groups

Summary

Introduction

Hypertension is a major risk factor that can lead to cardiac failure, coronary artery disease, stroke, renal injury, and even mortality [1, 2]. Many effective synthesis drugs have been employed in hypertension treatment, undesirable adverse drug reactions usually appear after longterm administration. Erefore, there is a great deal of interest in using natural plant extracts as an alternative treatment for hypertension. Eucommia ulmoides Oliv., called Du-Zhong, is a traditional medical plant in China, Korea, and Japan [6, 7]. The annual yield of Eucommiae Cortex is rather low, which greatly limits its application as a traditional tonic medicine against hypertension. Unlike Eucommiae Cortex, Eucommia male flowers are available in relatively large yields and can be harvested every year [6]. Previous researches have demonstrated that Eucommia male flowers provide a range of beneflts, including anti-inflammatory, analgesic, and antibacterial effects. To the best of our knowledge, there is no pharmacological study conducted for testing the antihypertensive ability of Eucommia male flowers until now

Objectives

Methods

Results

Conclusion