Effects of mushroom, Pleurotus eryngii, extracts on bone metabolism.

We performed the present study to investigate whether Pleurotus eryngii extracts (PEX) play a role in bone metabolism. PEX treatment showed increase in the alkaline phosphatase activity of the osteoblasts and in the osteocalcin mRNA expression from primary osteoblasts. PEX also increased the expression of the Runx2 gene, and the secretion of osteoprotegerin from the osteoblasts showed marked increases after treatment with PEX. In addition, PEX treatment decreased the number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells and resorption areas. In vivo studies, using rats with ovariectomy-induced osteoporosis revealed that PEX alleviated the decrease in the trabecular bond mineral density.