The aim of this study was to evaluate the osteoprotective effect of aqueous Rhizoma Dioscoreae extract (RDE) on the alveolar bone of rats with
ovariectomy-induced bone loss. Female Wistar rats underwent either
ovariectomy or
sham operation (
SHAM). The ovariectomized (OVX) rats were treated with vehicle (OVX),
estradiol valerate (EV), or RDE.
After treatments, the bone mineral density (BMD) and the three-dimensional microarchitecture of the alveolar bone were analyzed to assess bone mass. Microarrays were used to evaluate
microRNA expression profiles in alveolar bone from RDE-treated and OVX rats. The differential expression of
microRNAs was validated using real-time quantitative RT-PCR (qRT-PCR), and the target genes of validated
microRNAs were predicted and further analyzed using Ingenuity Pathway Analysis (IPA). The key findings were verified using qRT-PCR. Our results show that RDE inhibits
alveolar bone loss in OVX rats. Compared to the OVX rats, the RDE-treated rats showed upregulated expression levels of 8
microRNAs and downregulated expression levels of 8
microRNAs in the alveolar bone in the microarray analysis. qRT-PCR helped validate 13 of 16 differentially expressed
microRNAs, and 114 putative target genes of the validated
microRNAs were retrieved. The IPA showed that these putative target genes had the potential to code for
proteins that were involved in the
transforming growth factor (TGF)-β/
bone morphogenetic proteins (BMPs)/Smad signaling pathway (
Tgfbr2/Bmpr2, Smad3/4/5, and Bcl-2) and
interleukin (IL)-6/
oncostatin M (OSM)/Jak1/STAT3 signaling pathway (Jak1, STAT3, and Il6r). These experiments revealed that RDE could inhibit
ovariectomy-induced
alveolar bone loss in rats. The mechanism of this anti-osteopenic effect in alveolar bone may involve the simultaneous inhibition of bone formation and
bone resorption, which is associated with modulation of the TGF-β/BMPs/Smad and the IL-6/OSM/Jak1/STAT3 signaling pathways via
microRNA regulation.