Anti-Hyperprolactinemic Effect of Formula Malt Decoction, a Chinese Herbal Cocktail

Purpose: To investigate the anti-hyperprolactinemic activity of Formula Malt Decoction (FMD), a Chinese herbal mixture.
Methods: The effect of FMD on serum prolactin (PRL), estradiol (E2), progesterone (PGN), follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels were investigated in hyperprolactinemic (hyperPRL) rats. The effect of FMD on PRL secretion, dopamine D2 receptor and dopamine transporters (DAT) were studied in MMQ cells derived from rat pituitary adenoma cells, GH3 cells derived from rat pituitary lactotropic tumoral cells and PC12 cells from rat pheochromocytoma, respectively.
Results: Compared with the model group, a high dose of FMD (11.6 g/kg body weight) and medium dose of FMD (5.8 g/kg body weight) reduced PRL level of hyperPRL rats effectively. In MMQ cells, treatment with 5 mg/ml FMD (p < 0.01) or 10 mg/mL FMD (p < 0.01) significantly suppressed PRL secretion and synthesis at 24 h compared with controls (p < 0.01). Consistent with D2- action, FMD did not affect PRL in rat pituitary lactotropic tumor-derived GH3 cells that lack the D2 receptor expression compared with controls, but 8 mg/mL FMD significantly increased the expression of D2 receptors (p < 0.01) and DAT (p < 0.01) in PC12 cells.
Conclusion: FMD shows anti-hyperprolactinemia activity via dopamine D2 receptor.

Keywords
Formula Malt Decoction; Hyperprolactinemia; Dopamine D2 Receptor; Prolactin; Estradiol; Progesterone follicle stimulating hormone; Luteinizing hormone