Estrogen-Like Effect of Bazi Bushen Capsule in Ovariectomized Rats

Summary

Presented here is a protocol to show that Bazi Bushen capsule (BZBS) can regulate the RANKL/OPG signaling pathway in the ovariectomized rodent model through its estrogen-like effect.

Abstract

This study aims to show the estrogen-like effect of Bazi Bushen capsule (BZBS), a Chinese herbal compound, in ovariectomized mice. Female Sprague-Dawley (SD) rats were randomly divided into six groups: a sham-operated group, a model group (OVX), a progynova group, and BZBS groups (1, 2, and 4 d/kg/d). An ovariectomy was performed on all rats except those in the sham-operated group. Micro-computed tomography (micro-CT) scanning, hematoxylin and eosin (H&E) staining, immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA) detection were performed after 4 months of BZBS treatment. As a result, compared with the OVX group, rats treated with BZBS showed an increased number and area of trabecular bone and bone marrow cells, and a decreased number of adipose cells. The bone volume, trabecular number, and trabecular thickness of the right tibia in the medication groups increased and the trabecular space decreased. The 17β-estradiol and serum calcium levels in the medication groups were elevated, but the levels of serum phosphorus, sclerostin, β-CTX, and TRACP-5b were decreased. In the medication groups, the RANKL and sclerostin levels were decreased, while the osteoprotegerin (OPG) level was increased. In conclusion, this protocol systematically evaluated the therapeutic effects and potential molecular mechanisms of Chinese herbal compounds in ovariectomized rats with a variety of techniques.

Introduction

Postmenopausal osteoporosis (PMOP) is a skeletal system disease caused by inadequate ovarian function, decreased estrogen, and enhanced osteoclast activity¹, characterized by low bone mass, microarchitectural degeneration of the bone tissue, and damage of the bone trabecula. PMOP prone to cause fractures and can have serious effects on patients' quality of life. Osteoporosis affects about 200 million people worldwide²; about 40% of postmenopausal women suffer from osteoporosis³, and fractures occur in 33% of patients with PMOP⁴. The reduction of estrogen could lead to a rel....

Protocol

The animal experiments were approved by the Committee on Animal Research and Ethics of the Hebei Yiling Medical Research Institute (approval number: N2020150). The 36 Sprague-Dawley (SD) female rats (3 months old, weighing 180-200 g) (see Table of Materials) were fed with normal food and clean water in the new drug evaluation center of Hebei Yiling Medical Research Institute and were exposed to artificial light for 12 h per day in rooms with controlled temperatures (20-26 °C) and relative humidity (.......

Discussion

After ovariectomy, estrogen levels decreased sharply due to the continuous reduction of cancellous bone and increased bone turnover. Essentially, decreased estrogen secretion after menopause could cause significant bone loss¹⁸, leading to Ca²⁺ loss in ovariectomized rats^19,20. It has been reported that taking estrogen can help the metaphyseal fracture recovery of ovariectomized rats, and estrogen replacement therapy can also be .......

Materials

Name	Company	Catalog Number	Comments
10% neutral buffered formalin	Proteintech Group, Inc.	23408-1AP-100
17-Beta-Estradiol ELISA kits	Proteintech Group, Inc.	21933-1-AP
3%H2O2	ShanDong LIRCON Medical Technology Incorporated Company	20221027
Anti-osteoprotegerin antibody	Abcam	ab203061
Bazibushen capsules	Shijiazhuang Yiling Pharmaceutical Co. Ltd.	XB2103001
Biotin goat anti-rabbit IgG	Abcam	ab207995
Calcium assay kits	Nanjing Jiancheng Bioengineering Institute	C004-2-1
Diaminobenzidine	ZSGB-BIO	ZLI-9018
Estradiol valerate tablets	Bayer AG	156A
Gene 1580R centrifuge	GENE Co. Ltd.	GZ422515090077
Image-Pro Plus	Media Cybernetics	IPP 6.0
Leica DM6000B Microscope (fully automated upright microscope system)	Leica	361715
Normal Goat Serum Blocking Solution	Vector Laboratories	S-1000-20
Phosphate assay kits	Nanjing Jiancheng Bioengineering Institute	C006-1-1
Phosphate buffered saline	Servicebio, Wuhan, China	CR10201M
Quantum GX2 microCT Imaging System	PerkinElmer	CLS149276
RANKL rabbit polyclonal antibody	Elabscience Biotechnology Co. Ltd.	E-EL-R3032-96T
Rat SOST (Sclerostin) ELISA kit	Elabscience Biotechnology Co. Ltd.	E-EL-R1405c-96T
Rat TRACP-5b (Tartrate Resistant Acid Phosphatase 5b) ELISA kit	Abcam	ab108667
Rat β-CTx (Beta Crosslaps) ELISA kit	Elabscience Biotechnology Co., Ltd.	E-EL-R0939c-96T
Sclerostin rabbit polyclonal antibody	Beijing Vital River Laboratory Animal Technology Co., Ltd.	SCXK(JING)2016-0006
Slide scanner	Hamamatsu Photonics K.K.	Nano Zoomer-SQ
Sprague Dawley female rats	Beijing Vital River Laboratory Animal Technology Co., Ltd.	ZLI-9381