Effects of Gengnianchun on learning and memory ability, neurotransmitter, cytokines, and leptin in ovariectomized rats.

This study aimed to evaluate the beneficial effects of a traditional Chinese medicine named Gengnianchun (GNC) in ovariectomized Sprague-Dawley rats. The rats were randomly categorized into sham-operated group (Sham), saline-treated ovariectomized group (OVX), GNC-treated ovariectomized group (OVX+GNC), estradiol valerate-treated ovariectomized group (OVX+E). GNC and estradiol was administered for 1 month at dosages of 125 and 0.1 mg/day, respectively. Ovariectomy caused deterioration of learning and memory ability (P < 0.05), which was restored by treatment with GNC and estradiol (P < 0.05). Estrogen level and endometrial thickness significantly decreased in the OVX group (P < 0.05). These parameters significantly increased in the OVX+E group (P < 0.05) but did not change in the OVX+GNC group (P > 0.05). GNC and estradiol significantly increased the levels of norepinephrine (NE) and dopamine (DA) and decreased the levels of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in the hypothalamus (P < 0.05). The levels of interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) significantly decreased and the levels of interleukin-2 (IL-2) and interferon-gamma (IFN-γ) increased in the OVX+GNC and OVX+E groups compared with those in the OVX group (P < 0.05). OVX rats treated with GNC and estradiol further exhibited reversed ovariectomy-induced weight gain and leptin resistance (P < 0.05). These results indicated that GNC demonstrated phytoestrogen-like properties without the side effects of estradiol valerate. Thus, GNC may confer protective and beneficial effects for management of menopausal syndrome.