Water Extract of Fructus Hordei Germinatus Shows Antihyperprolactinemia Activity via Dopamine D2 Receptor.

Xiong Wang,Ji-Li Zou,Hao Guo,Si-Wei Peng,Li Ma,Jin-Hu Wu,En-Jing Zhang

doi:10.1155/2014/579054

Xiong Wang, Ji-Li Zou + Show 5 more

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https://doi.org/10.1155/2014/579054

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Abstract

Objective. Fructus Hordei Germinatus is widely used in treating hyperprolactinemia (hyperPRL) as a kind of Chinese traditional herb in China. In this study, we investigated the anti-hyperPRL activity of water extract of Fructus Hordei Germinatus (WEFHG) and mechanism of action. Methods. Effect of WEFHG on serum prolactin (PRL), estradiol (E2), progesterone (P), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and hypothalamus protein kinase A (PKA) and cyclic adenosine monophosphate (cAMP) levels of hyperPRL rats were investigated. And effect of WEFHG on PRL secretion, D2 receptors, and dopamine transporters (DAT) was studied in MMQ, GH3, and PC12 cells, respectively. Results. WEFHG reduced the secretion of PRL in hyperPRL rats effectively. In MMQ cell, treatment with WEFHG at 1–5 mg/mL significantly suppressed PRL secretion and synthesis. Consistent with a D2-action, WEFHG did not affect PRL in rat pituitary lactotropic tumor-derived GH3 cells that lack the D2 receptor expression but significantly increased the expression of D2 receptors and DAT in PC12 cells. In addition, WEFHG reduced the cAMP and PKA levels of hypothalamus in hyperPRL rats significantly. Conclusions. WEFHG showed anti-hyperPRL activity via dopamine D2 receptor, which was related to the second messenger cAMP and PKA.

Highlights

Hyperprolactinemia, which is one of the most common endocrine disorders of the hypothalamus-pituitary axis (PRL > 25 ng/mL) in young women, is associated with galactorrhea and ovulatory dysfunction that results in menstrual irregularities and barren [1]
We examined the effects of water extract of Fructus Hordei Germinatus (WEFHG) on modulation of PRL, E2, P, follicle-stimulating hormone (FSH), and luteinizing hormone (LH), protein kinase A (PKA) and cyclic adenosine monophosphate (cAMP) levels in the rat model of hyperPRL, and D2 receptor- and dopamine transporters (DAT)-mediated responses and PRL secretion in cell-culture systems
The results suggest that WEFHG could inhibit the secretion of PRL and regulate other sex hormone levels in hyperPRL rats effectively

Summary

Introduction

Hyperprolactinemia, which is one of the most common endocrine disorders of the hypothalamus-pituitary axis (PRL > 25 ng/mL) in young women, is associated with galactorrhea and ovulatory dysfunction that results in menstrual irregularities and barren [1]. HyperPRL can occur at any age, and the prevalence varies from 0.4% in the normal adult population to as high as 9–17% in women with menstrual problems such as amenorrhea or polycystic ovarian syndrome [2, 3]. Typical examples which induce hyperPRL are hypothalamus-pituitary lesions, pituitary tumor, severe liver or kidney disease, neuritis or irritations of the spinal cord, depression, or other physiological factors such as pregnancy and lactation [4, 5]. Galactorrhea is a common kind of female disease induced by hyperPRL. Bromocriptine and cabergoline are effective in curing hyperPRL, but 12% of patients can not endure bromocriptine [6], and the expense of them is very expensive [7]

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