A Hop Extract Lifenol® Improves Postmenopausal Overweight, Osteoporosis, and Hot Flash in Ovariectomized Rats

Objective. In order to assess the effectiveness of a hop extract (HE) for postmenopausal symptoms, the effects of Lifenol on ovariectomy-induced osteoporosis, hyperlipidemia, body weight increase, and hot flash were investigated in rats. Methods. Female Sprague-Dawley rats were ovariectomized and subjected to a daily scheduled exercise training (15 min at 15 m/min) or treated with HE (30 or 100 mg/kg, oral) or 17 beta-estradiol (100 mu g/kg, intraperitoneal) for 12 weeks. Body and visceral fat weights, serum lipid profiles, osteoporotic parameters in serum, and femoral bones were analyzed. Separately, forced running-induced dermal and rectal temperatures and blood flow velocity were measured in ovariectomized rats. Results. Ovariectomy increased blood lipids including triglycerides, total cholesterol, and low-density lipoproteins, leading to visceral fat accumulation and overweight. Estrogen depletion caused osteoporosis, displaying decreased femoral bone weight, bone mineral density and content, and blood phosphorus level. The disturbances in lipid metabolism and bone resorption were recovered by treatment with HE in a dose-dependent manner. In addition, HE treatment shortened the duration of forced running-induced alterations in skin and rectal temperatures by reducing blood flow velocity. Conclusion. The results indicate that HE attenuated overweight, osteoporosis, and hot flash in estrogen-deficient animals by regulating blood lipid profile and fat accumulation, blood estrogen and bone resorption factors, and dermal blood flow.