MTOR and osteoporosis: Kaempferol (derived from Herba Epimedii, Rhizoma Anemarrhenae and Radix et Rhizoma Salviae) has been shown to prevent osteoporosis-induced bone loss in vivo and in vitro, which results from its regulatory effect on the mammalian target of rapamycin (mTOR) pathway (Zhao, et al., 2019).