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In vitro prolactin but not LH and FSH release is inhibited by compounds in extracts of Agnus castus: Direct evidence for a dopaminergic principle by the dopamine receptor assay

Dept. Clinical and Experimental Endocrinology, University of Göttingen, Germany.
Experimental and clinical endocrinology 02/1994; 102(6):448-54. DOI: 10.1055/s-0029-1211317
Source: PubMed

ABSTRACT

Women suffering from premenstrual mastodynia often respond to stimuli of prolactin (Prl) release with a hypersecretion of this hormone. Pharmacological reduction of Prl release by dopamine agonists or treatment with extracts of Agnus castus (AC) improve the clinical situation of patients with such premenstrual symptoms. Extracts of AC contain compounds which inhibit in vivo Prl release in women as well as in vitro from dispersed rat pituitary cells. It is yet unknown whether this inhibitory action of AC is only exerted on Prl release or whether release of other pituitary hormones like LH and FSH is also affected. The effects of AC on LH and FSH release were examined in vitro using rat pituitary cell cultures. To rule out that the Prl-inhibiting properties of AC are at least in part due to a cytotoxic component, pituitary cell cultures were subjected to the MTT test. To assess whether the Prl inhibitory effect of AC preparations is due to compounds acting as dopamine (DA) agonists, we used the corpus striatum membrane DA receptor binding assay. Our results demonstrate for the first time that AC extract contains an active principle that binds to the D2 receptor. Thus, it is very likely that it is this dopaminergic principle which inhibits Prl release in vitro from rat pituitary cells. Furthermore we give evidence for the specificity of action of AC on hormone release, since gonadotropin secretion remained unaffected. The findings of the present study support the therapeutical usefulness of AC extracts for treatment of premenstrual mastodynia which is associated with hypersecretion of Prl. Furthermore, the beneficial effects of AC appear to be due to the inhibition of pituitary Prl release.

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    • "In vitro studies showed binding to -opioid receptors (Webster et al. 2006) and to -estrogen receptors (Jarry et al. 2003). Maybe more important, binding to dopamine D 2 receptors and inhibition of prolactin release from pituitary cells could be demonstrated (Jarry et al. 1994). Characteristic constituents of VAC are, beside others, iridoid glycosides, bicyclic diterpenes, flavonoids and flavones (E/S/C/O/P 2003). "
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    ABSTRACT: Background: Preparations of Vitex agnus castus L. (VAC) have been shown to be effective to treat irregular menstrual cycles, cyclical mastalgia and symptoms of the premenstrual syndrome (PMS). However, the dose-effect relationship for the treatment of PMS has not yet been established. This study aimed to investigate the clinical effects of three different doses of the VAC extract Ze 440 in comparison to placebo in patients suffering from PMS. Methods: In a multicenter, double-blind, placebo-controlled, parallel-group study, 162 female patients with PMS (18-45 years) were randomized to either placebo or different doses of Ze 440 (8, 20 and 30 mg) over three menstrual cycles. PMS symptoms' severity was assessed by patients using visual analog scales (VAS) for the symptoms irritability, mood alteration, anger, headache, bloating and breast fullness. Results: Each of the treatments was well tolerated. Improvement in the total symptom score (TSS) in the 20mg group was significantly higher than in the placebo and 8 mg treatment group. The higher dose of 30 mg, on the other hand, did not significantly decrease symptom severity compared to the 20mg treatment, providing a rational for the usage of 20mg. Corresponding results were observed with the single PMS symptom scores. Conclusion: This study demonstrated that the VAC extract Ze 440 was effective in relieving symptoms of PMS, when applied in a dose of 20mg. Therefore, for patients suffering from PMS, 20mg Ze 440 should be the preferred daily dose.
    No preview · Article · Sep 2012 · Phytomedicine: international journal of phytotherapy and phytopharmacology
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    • "Many premenstrual syndromes, particularly premenstrual mastalgia (mastodynia), are associated with latent hyperprolactinemia23, 24, 25. In addition, casticin has been demonstrated to reduce abnormally high serum prolactin levels in vivo (Figure 2). "
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    ABSTRACT: to investigate the anti-hyperprolactinemia activity of casticin, a flavonoid isolated from Vitex rotundifolia, and elucidate its molecular mechanism. hyperprolactinemia (MIHP) was induced by administration of metoclopramide dihydrochloride (50 mg/kg, tid, ip, for 10 d) in SD rats and the primary pituitary cells were prepared from the pituitary glands of the SD rats. Prolactin concentrations were measured using a radioimmunoassay. Cell viability was measured using an MTT assay. The mRNA expression of estrogen receptor alpha and beta in rat pituitary cells was measured using semi-quantitative RT-PCR analysis. the level of serum prolactin in the MIHP model group was 2.1 fold higher than that in the untreated control group (P<0.01). Casticin (10, 20, and 40 mg/kg, ip, for 7 d) reduced serum prolactin levels by 33.9%, 54.3%, and 64.7%, respectively (P<0.01). The positive control drug bromocriptine 1 mg/kg decreased the serum prolactin concentration in MIHP rats by 44.9%. 17β-Estradiol (E2) significantly increased the proliferation of pituitary cells and casticin (1 and 10 micromol/L) markedly inhibited E2-induced pituitary cell proliferation by 27.7% and 42.1%, respectively. Stimulation of pituitary cells with E2 increased prolactin secretion into the cell culture supernatants, and casticin (0.1, 1, and 10 micromol/L) significantly inhibited the prolactin release stimulated by E2 in a concentration-dependent manner. Casticin (1 and 10 micromol/L) significantly inhibited ERα mRNA expression in pituitary cells stimulated with E2 (P<0.01) but increased ERβ mRNA expression at a concentration of 10 micromol/L (P<0.01). However, casticin had no effects on proliferation and prolectin release of the unstimulated primary pituitary cells in vitro. casticin inhibited the release of prolactin from pituitary cells of SD rats stimulated with E2 in vivo and in vitro. These effects might be related with inhibiting the ERα mRNA expression and increasing the ERβ mRNA expression.
    Preview · Article · Nov 2010 · Acta Pharmacologica Sinica
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    • "Authors suggested that because of its dopaminergic effect A. castus could be considered as an efficient alternative phytotherapeutic drug in the treatment of hyperprolactinemia. Other studies have demonstrated that inhibition of prolactin secretion by A. castus is dependent on the initial level of prolactin and the dose of A. castus and is independent of gonadotrophins (19,20). "
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    ABSTRACT: There have been many treatments suggested for the management of mastalgia; one of these is the fruit extract of Vitex Agnus castus L. commonly known as Agnus castus, an extract of a deciduous shrub native to Mediterranean Europe and Central Asia. It is postulated that A. castus suppresses the stress-induced latent hyperprolactinemia which is a release of supra-physiological levels of prolactin in some patients in response to stressful stimuli. It is postulated that A. castus could be effective in the treatment of cyclical mastalgia by inhibiting the release of excess prolactin by blocking Dopamine-2 receptor type on pituitary. The adverse events following A. castus treatment are mild and reversible. The aim of this review is assess the efficacy of A. castus in the treatment of mastalgia. Data from randomized and non-randomized studies regarding the efficacy and safety of A. castus is reviewed in a systematic fashion. It is concluded that A. castus can be considered as an efficient alternative phytotherapeutic agent in the treatment of mastalgia.
    Full-text · Article · Oct 2008 · Evidence-based Complementary and Alternative Medicine
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