Beneficial effects of low-level laser irradiation on senile osteoporosis in rats

Effect of laser acupuncture on pain and density of bone in osteoporotic postmenopausal women: a randomized controlled trial

OBJECTIVE

This study aimed to evaluate the value of laser acupuncture (LA) on forearm bone mineral density (BMD) and wrist pain in osteoporotic postmenopausal women.

METHODS

Sixty-eight postmenopausal women diagnosed with osteoporosis were randomly allocated equally to one of two sets. The drug-only group received calcium and vitamin D 3 supplement containing fluoride daily for 12 weeks, whereas the drug/LA group received LA therapy for 20 minutes per session, three sessions weekly, in addition to the same supplementation. The primary outcome parameter was assessment of BMD of the nondominant arm. Other outcomes included wrist pain.

RESULTS

There was a highly significant improvement in the T-score of forearm BMD in both groups (-2.844 ± 0.476 to -2.597 ± 0.478 and -2.944 ± 0.486 to -1.652 ± 0.728 in the drug-only and drug/LA groups, respectively; P < 0.0001) and visual analog scale score (7.50 ± 0.79 to 4.24 ± 1.07 and 7.24 ± 0.82 to 3.09 ± 0.75 in the drug-only and drug/LA group, respectively; P < 0.0001). The improvement of both BMD and pain score was significantly higher in the drug/LA group (-1.303 and 4.15) compared with the drug-only group (-0.247 and 3.26; P < 0.0001).

CONCLUSIONS

LA in combination with calcium and vitamin D supplementation containing fluoride is an effective modality in improving forearm BMD and reducing pain in osteoporotic postmenopausal women.

Effect of photobiomodulation therapy with different wavelengths on bone mineral density in osteoporotic rats

Osteoporosis is associated with severe pain, bone deformity, fracture, and bone loss. It is important to find strategies to prevent bone resorption and treat osteoporosis. This study sought to assess the effect of photobiomodulation therapy (PBMT) with different wavelengths on bone mineral density (BMD) in osteoporotic rats. This animal study evaluated 63 adult female rats. The rats underwent ovariectomy to induce osteoporosis. Ovariectomized rats were randomly divided into 9 groups of control (OC), treatment with zoledronic acid alone (0.02 mg/kg), and treatment with 660 nm, 810 nm, and 940 nm PBMT alone (3 times a week for 6 weeks, energy density of 4 J/cm2), and combined with zoledronic acid. The healthy control group (HC) only underwent sham surgery. The rats underwent cone-beam computed tomography (CBCT) 52 days after the first treatment session to measure their BMD according to the gray value (GV) of images. To assess the biomechanical properties of bone, the resected bones were subjected to 3-point bending test (3-PBT). The experimental groups had significant differences with the OC group regarding radiographic and biomechanical properties of bone (P < 0.05), indicating a healing course. No significant difference was noted between the experimental groups treated with different laser wavelengths and those treated with zoledronic acid (P > 0.05). In the condition of this study, it was found that PBMT at a constant energy density of 4 J/cm2 with 660-, 810-, and 940-nm wavelengths is effective for enhancement of bone mineral density and biomechanical properties. No significant difference was noted between different wavelengths of diode laser regarding radiographic and biomechanical properties of bone.

Systemic osteoprotective effects of Epimedii Folium and Ligustri Lucidi Fructus in senile osteoporosis rats by promoting the osteoblastogenesis and osteoclastogenesis based on MLP-ANN model

Background

Senile osteoporosis (SOP), which is caused by unbalanced bone remodeling, leads to significant economic and societal burdens globally. The combination of Epimedii Folium (EF) and Ligustri Lucidi Fructus (LLF) serves as a commonly-used prescription for SOP in Traditional Chinese Medicine (TCM). This study aimed to evaluate the osteoprotective effects of EF and LLF in combination on SOP rats based on the constructed multilayer perception (MLP)-artificial neural network (ANN) model.

Methods

15 month old male Sprague-Dawley rats were administrated with EF, LLF or the combination of EF and LLF (EF&LLF) for 2 months, while 17 month old rats were used as the aging control group. All the rats were anesthetized with 25% ethyl carbamate, then their serum liver and bone tissues were taken. We detected bone mass, bone mineral density (BMD), biomechanics and the microstructure of bone trabecula by micro-CT and H&E staining to evaluate the degree of osteoporosis. Blood lipids and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and γ-glutamyl transferase (GGT) and liver pathology were use to assess the side effects of drugs. Levels of alkaline phosphatase (ALP) and Tartrate-resistant acid phosphatase (TRACP) and the ratio of ALP to TRACP both in serum and bone were measured for the evaluation of bone turnover rate. The bone mRNA and protein expression of osteoprotegerin (OPG), nuclear factor-kappa B ligand (RANKL), macrophage colony-stimulating factor (M-CSF), d2 isoform of vacuolar (H⁺) ATPase (ATP6V0d2), insulin-like growth factor (IGF-1), bone morphogenetic protein-2 (BMP2), M-CSF, Wnt5a, transforming growth factor-β1 (TGF-β1) were detected for evaluating bone metabolism.

Results

The results showed that EF&LLF improved bone mass and bone quality by preventing bone loss, increasing maximal load as well as protecting the micro-structural retrogressive change of trabecular bone in SOP rats; ameliorated the steatosis in the liver and decreased blood lipids and serum ALT, AST and GGT; enhanced bone remodeling by stimulating the expression of ALP and TRACP. At the molecular levels, EF&LLF stimulated the osteoclastogenesis by upregulating the protein and mRNA expression of OPG, RANKL, M-CSF and ATP6V0d2; meanwhile, EF&LLF stimulated osteoblastogenesis by enhancing the expression of TGF-β1, BMP2, Wnt5a and IGF-1. According to our established MLP model, EF&LLF has a better effect on osteoclastogenesis or steoblastogenesis in SOP rats than EF or LLF.

Conclusions

These findings demonstrate that the systemic bone protective effects of EF&LLF by promoting bone remodeling in aging rats might be a substitute medicine for the treatment of SOP.

Bone marrow adipose amount influences vertebral bone strength

Association of bone marrow adipose and microstructure with bone strength in osteoporotic rats using MR Dixon analysis and micro-CT was evaluated. A total of 40 female Sprague-Dawley rats (6-month-old) were divided randomly into sham-operated (SHAM, n=20) group and ovariectomized (OVX, n=20) group. Fat fraction (FF) was measured by two-point Dixon method with MR imaging at the baseline, 4th, 8th and 12th week, respectively. After sacrifice by anesthesia, the fifth lumbar vertebrae bone was sampled for micro-CT scanning. The biomechanical analysis was also performed. FF in osteoporotic rats significantly increases with time, which correlates with bone microstructure parameters. Compared with biomechanical test, FF showed negative correlation with break stress and elastic modulus. It also suggested that loss of bone mass was accompanied with the increase of adipose tissue content in vertebrae bone marrow. The impairment of bone strength leads to the risk of brittle fracture. In conclusion, the bone marrow adipose amount obtained by MR Dixon and microstructure by micro-CT correlates to bone strength in osteoporotic rats.