A comparison of the effects of estrogen and Cimicifuga racemosa on the lacrimal gland and submandibular gland in ovariectomized rats.

Yunmeng Da,Lihua Qin,Ke Wang,Wenjuan Wang,Guangxia Cui,Jing Jia,Kaiyu Niu,Biao Jin,Yu Sun,Wenpei Bai,Stephen L Clarke

doi:10.1371/journal.pone.0121470

Abstract

This study aims to observe the effects of estradiol and Cimicifuga racemosa on the lacrimal gland and submandibular gland of ovariectomized rats. We randomly divided 20 adult female SD rats into four groups—a sham-operated group (SHAM), ovariectomized (OVX) group, ovariectomized group treated with estradiol (OVX+ E), and ovariectomized group treated with the isopropanolic extract of Cimicifuga racemosa (OVX+ iCR). The SHAM group and OVX group used distilled water to instead the drugs. Two weeks after ovariectomy, the estradiol and iCR were administered for 4 weeks. Next, we used H&E staining and electron microscopy to observe any histological changes in the lacrimal and submandibular glands and immunohistochemical staining to observe the expressions of cleaved caspase-3 (Casp-3) and Cu-Zn SOD (superoxide dismutase). The H&E staining find that both drugs can prevent the cells of area from shrinkage in the two kinds of gland. But under the electron microscopy, estradiol and iCR have different efficacy. Estradiol is more effective at protecting mitochondria in lacrimal gland acinar cells than iCR, and iCR is more effective at suppressing endoplasmic reticulum expansion than estradiol. Both estradiol and iCR have a similar protective function on mitochondria in the submandibular gland. The protective function of the two glands may inhibit apoptosis by suppressing the expression of Casp-3. In addition, iCR increases the expression of Cu-Zn SOD in duct system of submandibular gland. The results suggest that both estradiol and iCR confer a protective effect on the lacrimal and submandibular glands of ovariectomized rats via different mechanisms.

Highlights

Menopause, which occurs at ages 45~55 years in women, is a physiological process defined by the cessation of menstruation for more than 6 months, caused by ovarian function diminishing naturally or after surgery [1]
The serum estrogen level is proportional to the level of anti-oxidase and anti-oxidative activity, yet has an inverse correlation with serum lipid peroxide [42, 43]. These findings indicate that lack of estrogen may be responsible for the reduction in anti-oxidase and the increasement in reactive oxygen species (ROS), and the structural and functional changes that occur after menopause may have a close relationship with the oxidative stress caused by estrogen withdrawal
Our results indicate that ovariectomy can cause changes to organelles, such as mitochondria crest fracture and endoplasmic reticulum enlargement

Summary

Introduction

Menopause, which occurs at ages 45~55 years in women, is a physiological process defined by the cessation of menstruation for more than 6 months, caused by ovarian function diminishing naturally or after surgery [1]. There was a marked increase in both the fundamental and stimulating tear secretion of menopausal women who had received hormone replacement therapy (HRT) for three months [2], and an increase in the labial gland saliva flow rate, total salivary gland secretory rate, and buffering capacity in menopausal women (aged 61–76 years) who had received HRT for one year [3]. These results clearly suggest that HRT can increase the secretion of tear and saliva

Objectives

Findings

Discussion

Conclusion