Persimmon (Diospyros kaki L.f.) leaves have traditionally been used as a phytomedicine, in health beverages to treat cardiovascular and respiratory disease and to promote maternal health in East Asia. In particular, polysaccharides from persimmon are known to have anti-coagulant, anti-oxidant, and immune-stimulatory activities. However, their beneficial effects against osteoporosis have not been reported. In the present study, we investigated the anti-osteoporotic effects of polysaccharides from persimmon leaves (PLE0) using an in vivo model of ovariectomy (OVX)-induced bone loss and an in vitro system of receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation. In the OVX mouse model, PLE0 remarkably improved OVX-induced trabecular bone loss by suppressing osteoclast activity. In primary bone marrow-derived macrophages (BMMs), PLE0 dose-dependently inhibited osteoclast differentiation. In addition, PLE0 down-regulated RANKL-induced activation of mitogen-activated protein kinases (MAPKs) such as p38, ERK, and JNK resulting in suppression of nuclear factor of activated T cells cytoplasmic 1 (NFATc1) expression. Our results indicate that PLE0 has anti-osteoporotic effects in OVX-induced bone loss via inhibition of osteoclast differentiation. Taken together, PLE0 from persimmon may prevent postmenopausal bone loss and osteoporotic bone fragility.

Polysaccharides isolated from various plants are considered precious bioactive materials owing to their potent biological activities. Previously, we prepared a polysaccharide fraction (BLE0) isolated from young barley leaves (Hordeum vulgare L.), demonstrating its anti-osteoporotic and immunostimulatory activities. However, data regarding BLE0 toxicity is lacking. To establish its safety, in vitro genotoxicity (chromosomal aberration and bacterial reverse mutation assays) and acute oral toxicity assays were conducted. In the in vitro genotoxicity assays, bacterial reverse mutation and chromosomal aberration assays showed that BLE0 possessed no mutagenicity or clastogenicity. Furthermore, the median lethal dose (LD₅₀) of BLE0 was higher than 5000 mg/kg in female and male Sprague-Dawley (SD) rats and no adverse effects were observed in terms of mortality and abnormal changes in clinical signs (body weight and necropsy). Based on these results, BLE0 was found to be safe with regards to genotoxicity under our test conditions, demonstrating no acute oral toxicity up to 5000 mg/kg in SD rats.

Opuntia humifusa is a type of cactus whose fruits have been used in folk medicine for the treatment of several diseases. In the present study, we aimed to determine whether O. humifusa fruit water extract (OHE) has inhibitory effects against solar ultraviolet (sUV)-induced matrix metalloproteinase-1 (MMP-1) expression. In ex vivo human skin, we found that OHE suppressed sUV radiation-induced MMP-1 expression. The inhibitory effect of OHE was confirmed in human dermal fibroblasts. OHE treatment reduced sUV-induced MMP-1 expression by suppressing reactive oxygen species (ROS) generation and phosphorylation of c-Jun, a component of transcription factor activator protein 1 (AP-1). On the other hand, OHE recovered the tissue inhibitor of matrix metalloproteinase 1 (TIMP-1) and type 1 collagen production attenuated by sUV. As upstream signaling pathways for AP-1, MKK4-JNK, MEK-ERK, and MKK3/6-p38 phosphorylation were downregulated by OHE treatment. In addition, OHE exhibited DPPH radical scavenging activity. These findings demonstrate that OHE has a preventive effect against sUV-induced skin damage via suppression of pathways triggered by ROS.