Experimental Study Of Maca(Lepidium Meyenii Walp.) On Menopause Syndrome And Osteoporosis

Maca is root of Lepidium meyenii Walp. , belongs to the plant family of Solanaceae and grows in Andean region of South America at an altitude of 3500-4000m, it looks like radish. Maca root is an important food source for Andean inhabitant, it was traditionally used as food and as a folk medicine. It has been used to enhance physical endurance, the fertility and sexual performance of men and women and to treat women with menopausal symptoms. More recently, the health food of Maca is welcomed extensively in the world, and the pharmacology of Maca has been investigated actively, these studies were focused on fertility-improving and aphrodisiacs effect. But, since now no experimental studies have been carried out to evaluate whether Maca has improved effect on menopause syndrome and osteoporosis. With aging world arriving, some aging disease, such as menopause syndrome and osteoporosis severely influence the health of middle-aged and old women. To further promote the development and utilization of Maca, and exert beneficial therapeutics efficacy of this traditional plant. Based on the mechanism of menopause syndrome, this paper was conducted to investigate the effect of Maca extract on menopause syndrome and osteoporosis, from endocrine hormone regulation, immunological function, and free radical metabolism, etc. The results will provide experimental evidences for Maca's application to improve and treat menopause syndrome and osteoporosis.The ovariectomized rats were used as menopause syndrome and osteoporosis model, rats were divided into five groups: Sham-operated and ovariectomized groups were fed with equivolume of distilled water, and the remaining ovariectomized groups were orally administrated with ethanol extract of Maca at 0.096,0.24 g/kg and Estrosyn 0.05mg/kg continually for 28 weeks. The following indexes were determined: Serum hormone level , triglyceride, Cholesterol level ,serum and urine biochemistry, bone mineral density, bone metabolism, bone biomechanical,histopathological parameters, etc. Estrosyn, a kind of estrogen, was used as positive medicine in this experiment. The results showed Maca ethanol extract have definite decreased effect on raised serum follicle-stimulating hormone (FSH) induced by ovariectomy (OVX), but have no remarkable influence on serum estradiol and testosterone. Maca extract were effective in prevention of postmenopausal osteoporosis induced by OVX, these beneficial effect on bone were presented on following aspects: Maca extract (high dose) significantly increased bone mineral density (BMD) of lumbar vertebrae and bone ash calcium content of femur, but there were no marked effect on BMD of midshaft femur. The histopathological study showed the restoration of trabecular network with less inter-trabecular spaces was observed in Maca-treated groups. Also, long-term administration of Maca protected against bone loss without significantly increasing uterine weights, and no obvious uterine endometrium proliferation were observed in Maca-treated groups. This effect is different from hormone replacement therapy (HRT) and has less risk of endometrial proliferation.The occurrence of menopause syndrome have closed relation with disorder of free radical metabolism, this paper used natural senescent female mice as experimental model, the effect of Maca extract on SOD, GSH-Px, MDA levels of serum and related organ homogenate were carried out, and the content of skin hydroxyproline were measured, the effects of Maca were compared with positive medicine ganoderma polysaccharides. The result demonstrated most Maca extract have significantly increased effect on SOD, GSH-Px activity in serum and organ homogenate and decrease MDA content in liver, the effect is similar with ganoderma polysaccharides.Menopause disorder also have related with the decline of physical immunological function. This paper was conducted to study the effect of Maca extract on normal mice immunological function, including non-specific immunity, cellular immunity and humoral immunity. The results showed Maca extract significantly enhance the rate of lymphocyte transformation induced by PHA, promoted serum hemolysin IgM production, and remarkably increase antibody-producting cell level, this implied Maca have enhancing effect on normal mice cellular immunity and humoral immunity functions. However, there was no significant influence on phagocytosis of mononuclear macrophage.As has been mentioned above, the findings from this study demonstrated that Maca extract have definitely improved effect on menopause syndrome and osteoporosis, and no obvious endometrial proliferation, the side effect of estrogen, was observed for long-term use of Maca. These effects of Maca may due to adjusting Hypothalamus endocrine function, enhancing immunological function, improving free radical metabolism, cleaning peroxylipid. The finding will provide experimental evidences for Maca to prevent and treat women with menopause syndrome and osteoporosis.