Osteoporosis Prevention by Adlay (薏苡 Yì Yǐ: The Seeds of Coix Lachryma-Jobi L. var. ma-yuen Stapf) in a Mouse Model

ABSTRACTOsteoporosis is characterized by reduced bone mass and quality due to an imbalanced bone remodeling. A grass crop, adlay (Coix lachryma-jobi), is a kind of nourishing food, which has also been used in traditional Chinese medicine. In this study, we investigated the effect of adlay (C. lachryma-jobi L. var. ma-yuen Stapf) on osteoporosis using an ovariectomized mouse model. The adlay diet (10% and 30% adlay in mouse diet) or water extract of adlay (0.3 g/kg/day) was given to ovariectomized mice for 4 weeks. In some experiments, the primary rat osteoblast cells were used to test the possible mechanism of adlay on osteoporosis. The body weight was slightly increased and uterus weight was markedly decreased in ovariectomized mice, which were not affected by adlay treatment. Adlay diet (30%) and adlay extract feedings significantly reversed the decreased bone alkaline phosphatase activity and calcium contents and bone mineral density in ovariectomized mice. Moreover, adlay extracts increased the osteoblast cell proliferation in a dose-dependent manner. Adlay extracts also increased the protein expressions of proliferating cell nuclear antigen and phosphorylated extracellular signal-regulated kinase (ERK) 1/2 in osteoblast cells. ERK inhibitor PD98059 significantly reversed the increased osteoblast cell proliferation by adlay extracts. Taken together, these findings indicate that adlay effectively alleviates the osteoporotic status in ovariectomized mice. Adlay is capable of increasing the proliferation of osteoblast cells via an ERK-regulated signaling pathway. Adlay may be a helpful healthy food for osteoporosis prevention.