The Antihypertensive Effects and Mechanisms of Huotan Jiedu Tongluo Decoction in Rats with H-Type Hypertension

Summary

Here, we present a protocol to induce H-type hypertension and evaluate the antihypertensive effects of Huotan Jiedu Tongluo decoction (HTJDTLD) administered intragastrically. In rats with H-type hypertension, HTJDTLD had effective antihypertensive effects, possibly associated with inhibition of endoplasmic reticulum (ER) stress-induced apoptosis pathway activation.

Abstract

H-type hypertension, which is a specific form of hypertension characterized by elevated plasma homocysteine (Hcy) levels, has become a major public health challenge worldwide. This study investigated the hypotensive effects and underlying mechanisms of Huotan Jiedu Tongluo decoction (HTJDTLD), a highly effective traditional Chinese medicine formula commonly used to treat vascular stenosis. Methionine was used to induce H-type hypertension in rats, and HTJDTLD was administered intragastrically. Then, the systolic and diastolic blood pressures of the caudal artery of rats were measured by noninvasive rat caudal manometry. Histological assessment of the aorta was performed by hematoxylin-eosin (HE) staining. Enzyme-linked immunosorbent assay (ELISA) was used to measure Hcy levels, and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and western blotting were used to determine the mRNA and protein levels of Glucose regulatory protein 78 (GRP78), Tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2), c-Jun N-terminal kinases (JNK), and caspase-3. The results showed that HTJDTLD significantly lowered blood pressure, alleviated histopathological lesions, and decreased Hcy levels after methionine treatment. Moreover, HTJDTLD significantly inhibited the gene and protein expression of GRP78, JNK, TRAF2, and caspase 3, which are involved mainly in the endoplasmic reticulum (ER) stress-induced apoptosis pathway. Overall, the results indicated that HTJDTLD had effective antihypertensive effects in rats with H-type hypertension and revealed the antihypertensive mechanisms associated with inhibition of ER stress-induced apoptosis pathway activation.

Introduction

Hypertension, a major risk factor for heart attack, stroke, and renal failure, has become a significant public health challenge that affects 1 billion people worldwide¹. Homocysteine (Hcy), a thiol group-containing amino acid, is a vital metabolic intermediary of methionine metabolism. Hypertension with elevated plasma Hcy levels is defined as H-type hypertension, which could be a significant risk factor for the occurrence and recurrence of cardiocerebrovascular diseases such as stroke^2,3. Recent studies have reported that the co-residency of H-type hypertension could aggravate the side....

Protocol

All animal experiments were approved by the Institutional Animal Care and Use Committee (IACUC) of Changchun University of Chinese Medicine. The materials are listed in the Table of Materials.

1. Animals and treatment

1. Randomly divide a total of 50 adult spontaneously hypertensive rats (SHRs) (male, 50 days old) into five groups, including control (CON), methionine (MET), MET + HTJDTLD + Enalapril maleate (EM), MET + EM, and MET + HTJDTLD groups.

Discussion

Hypertension is one of the most common cardiovascular disorders that affects one-third of the adult population and increases the risk of stroke, coronary heart disease, and heart and renal failure⁸. H-type hypertension is a special type of hypertension that refers to the co-occurrence of primary hypertension and increased homocysteine levels and has attracted broad attention over the years⁹. In recent years, the use of oral EM combined with antihypertensive drugs has shown .......

Materials

Name	Company	Catalog Number	Comments
1st Strand cDNA Synthesis SuperMix for qPCR	Yeasen,China	11149ES	cDNA synthesis kit
Anti-beta-actin antibody	Bioss, China	bs-0061R
Anti-caspase-3 antibody	Bioss, China	bs-0081R
Anti-GPR78 antibody	Abcam, USA	ab108513
Anti-JNK antibody	Abcam, USA	ab76572
Anti-p-JNK antibody	Bioss, China	bsm-52462R
Anti-rabbit IgG antibody	Bioss, China	bs-0295G-HRP
Anti-TRAF2 antibody	Bioss, China	bs-22372R
Bio-Rad CFX96 Touch system	Bio-Rad	CFX96	real-time PCR detection system
ECL Western Blot Substrates	Merck, MA, USA	WBULP-10ML
Enalapril maleate folic acid tablets	Yangzijiang Pharmaceutical Company, China	20040991
FastStart SYBR Green Master	Sigma	FSSGMMRO
Fructus Trichosanthis	The First Affiliated Hospital of Changchun University of Traditional Chinese Medicine, China	No catalog number
Hirudo	The First Affiliated Hospital of Changchun University of Traditional Chinese Medicine, China	No catalog number
intelligent noninvasive sphygmomanometer	Beijing Softron Biotechnology company	BP-2010A
Lonicerae Japonicae Flos	The First Affiliated Hospital of Changchun University of Traditional Chinese Medicine, China	No catalog number
Methionine	Sigma, USA	M9500
Radix Angelicae Sinensis	The First Affiliated Hospital of Changchun University of Traditional Chinese Medicine, China	No catalog number
Radix et Rhizoma Glycyrrhizae	The First Affiliated Hospital of Changchun University of Traditional Chinese Medicine, China	No catalog number
Radix et Rhizoma Nardostachyos	The First Affiliated Hospital of Changchun University of Traditional Chinese Medicine, China	No catalog number
Radix et Rhizoma Rhodiolae Crenulatae	The First Affiliated Hospital of Changchun University of Traditional Chinese Medicine, China	No catalog number
Radix et Rhizoma Salviae Miltiorrhizae	The First Affiliated Hospital of Changchun University of Traditional Chinese Medicine, China	No catalog number
Radix Scrophulariae	The First Affiliated Hospital of Changchun University of Traditional Chinese Medicine, China	No catalog number
Rat Hcy ELISA Kits	Shanghai Meimian Industrial Company, China	MM-0293R2
RIPA buffer	Shanghai Beyotime Biotechnology company	P0013B