This study evaluated the in vitro and in vivo antiresorptive effects of astilbin, isolated from Smilax glabra Roxb roots, on RANKL‐induced osteoclastogenesis using RAW 264.7 cell culture and a transgenic medaka ( Oryzias latipes ) fish model of osteoporosis. RAW 264.7 cells were treated with varying concentrations of astilbin, then cytotoxicity and RANKL‐induced osteoclast differentiation were assessed. Phosphorylation of targeted proteins PI3K and Akt and the expression levels of osteoclast differentiation‐related genes were analyzed using Western blot and quantitative real‐time PCR, respectively. The in vivo bone antiresorptive effects of astilbin were assessed using the index of bone mineralization ( I M ) method. As a result, astilbin showed no toxicity toward RAW 264.7 cells at concentrations ≤ 100 μg/mL. At 100 μg/mL, the compound inhibited osteoclast number up to 48% in comparison to control. It suppressed the phosphorylation of PI3K and Akt proteins and downregulated the expression levels of genes, Nfatc1, Mmp-9, Cstk , and Trap , involved in osteoclastogenesis. In addition, astilbin reduced RANKL‐induced bone loss in the in vivo osteoporotic medaka fish model. These findings suggest that astilbin inhibits osteoclastogenesis via the PI3K/Akt pathway and may serve as a potential antiosteoporotic agent.
Nguyen et al. (Thu,) studied this question.