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The probable positive effects of photobiomodulation therapy (PBMT) and oxytocin (OT) treatments together or alone were evaluated on cell viability along with the changes in the gene expression of Osteocalcin (OC), Osteoprotegerin (OPG), and Runt-related transcription factor 2 (Runx2) levels of sham (healthy)-Bone marrow mesenchymal stem cell(BMMSC) and ovariectomy-induced osteoporosis (OVX)-BMMSC. BMMSC was harvested from healthy and OVX rats and was cultured in osteogenic induction medium (OIM). There were five groups of BMMSCs: (1) sham -BMMSCs; (2) control -OVX-BMMSCs; (3) OT-treated-OVX-BMMSCs; (4) PBMT-treated-OVX-BMMSCs, and (5) OT + PBMT-OVX-BMMSCs. In all 5 groups, BMMSC viability and proliferation as well as gene expression of OC, OPG, and RUNX2 were evaluated. PBMT and PBMT + OT treatments showed a promising effect on the increased viability of OVX-BMMSC (ANOVA test; LSD test, p = 0.01, p = 0.002). The results of gene expression analysis revealed that the sham- BMMSCs responded optimally to OT treatment. It was also found that OVX-BMMSCs responded optimally to PBMT + OT and PBMT treatments at early and middle stages of osteogenic induction process. Nevertheless, they responded optimally to PBMT + OT and OT especially at the late stage of osteogenic induction process. PBMT and PBMT + OT treatments significantly increased viability of OVX-BMMSC in OIM in vitro. Both PBMT and PBMT + OT treatments could promote mineralization of OVX-BMMSC in the culture medium at early and middle stages of osteogenic induction process. Both OT and PBMT + OT treatments could promote mineralization of OVX-BMMSC in vitro at late stages of osteogenic induction process.

Osteoporosis (OP) and osteoporotic fracture are major public health issues for society; the burden for the affected individual is also high. Previous studies have shown that pulsed wave low-level laser therapy (PW LLLT) has osteogenic effects. This study intended to evaluate the impacts of PW LLLT on the cortical bone of osteoporotic rats' tibias in two experimental models, ovariectomized and dexamethasone-treated. We divided the rats into four ovariectomized induced OP (OVX-d) and four dexamethasone-treated (glucocorticoid-induced OP, GIOP) groups. A healthy (H) group of rats was considered for baseline evaluations. At 14 weeks following ovariectomy, we subdivided the OVX-d rats into the following groups: (i) control which had OP, (ii) OVX-d rats treated with alendronate (1 mg/kg), (iii) OVX-d rats treated with LLLT, and (iv) OVX-d rats treated with alendronate and PW LLLT. The remaining rats received dexamethasone over a 5-week period and were also subdivided into four groups: (i) control rats treated with intramuscular (i.m.) injections of distilled water (vehicle), (ii) rats treated with subcutaneous alendronate injections (1 mg/kg), (iii) laser-treated rats, and (iv) rats simultaneously treated with laser and alendronate. The rats received alendronate for 30 days and underwent PW LLLT (890 nm, 80 Hz, 0.972 J/cm(2)) three times per week during 8 weeks. Then, the right tibias were extracted and underwent a stereological analysis of histological parameters and real-time polymerase chain reaction (RT-PCR). A significant increase in cortical bone volume (mm(3)) existed in all study groups compared to the healthy rats. There were significant decreases in trabecular bone volume (mm(3)) in all study groups compared to the group of healthy rats. The control rats with OP and rats from the vehicle group showed significantly increased osteoclast numbers compared to most other groups. Alendronate significantly decreased osteoclast numbers in osteoporotic rats. Concurrent treatments (compounded by PW LLLT and alendronate) produce the same effect on osteoporotic bone.