Suppression of high bone remodelling by E'Jiao in ovariectomised rats

Ejiao as a preventive agent for osteoporosis - a scoping review of current evidence

Ejiao, a traditional Chinese medicinal product derived from donkey's hide, has long been used to promote blood formation and treat various ailments. Recently, growing pharmacological evidence has suggested that Ejiao and its formulations may also possess bone-protecting properties, making it a potential candidate for preventing and treating osteoporosis. This scoping review aims to summarise the current scientific evidence on the anti-osteoporosis potential of Ejiao and its formulations in osteoporosis prevention. A comprehensive literature search was conducted using PubMed, Web of Science, Scopus, and China National Knowledge Infrastructure up to October 2024. Primary studies published in English or Mandarin, regardless of study design, that investigated the effects of Ejiao on bone in vivo or bone cells in vitro were included. A total of 22 studies were included, comprising five studies on Ejiao alone and 17 studies on Ejiao-based formulations. The findings indicated that Ejiao alone enhanced osteoblast differentiation by increasing alkaline phosphatase synthesis and reducing bone remodelling markers in ovariectomised rats. However, its direct effect on bone mineralisation and density remains uncertain due to the absence of an exogenous mineral source. In contrast, Ejiao-based formulations, such as calcium-Ejiao oral liquid and Donkey-hide glue reinforcing bone oral solution, demonstrated more pronounced bone-protective effects, including improving bone density, enhancing bone repair, and supporting vitamin D metabolism in both animal models and clinical studies. These findings suggest that while Ejiao alone may promote osteoblast activity, its role in osteoporosis management may be more effective when combined with essential minerals. Further long-term studies and human clinical trials are needed to clarify its therapeutic potential and underlying molecular mechanisms.

Effects of emulsified and non-emulsified palm tocotrienol on bone and joint health in ovariectomised rats with monosodium iodoacetate-induced osteoarthritis

Postmenopausal women are susceptible to osteoporosis and osteoarthritis. Tocotrienol, a bone-protective nutraceutical, is reported to prevent osteoarthritis in male rats. However, its efficacy on joint health in oestrogen deficiency has not been validated. Besides, data on the use of emulsification systems in enhancing bioavailability and protective effects of tocotrienol are limited. Ovariectomised adult female Sprague-Dawley rats (3 months old) were treated with refined olive oil, emulsified (EPT, 100 mg/kg/day with 25% vitamin E content), non-emulsified palm tocotrienol (NEPT, 100 mg/kg/day with 50% vitamin E content) and calcium carbonate (1% w/v in drinking water) plus glucosamine sulphate (250 mg/kg/day) for 10 weeks. Osteoarthritis was induced with monosodium iodoacetate four weeks after ovariectomy. Baseline control was sacrificed upon receipt, while the sham group was not ovariectomised and treated with refined olive oil. EPT and NEPT prevented femoral metaphyseal and subchondral bone volume decline caused by ovariectomy. EPT decreased subchondral trabecular separation compared to the negative control. EPT preserved stiffness and Young's Modulus at the femoral mid-shaft of the rats. Circulating RANKL was reduced post-treatment in the EPT group. Joint width was reduced in all the treatment groups vs the negative control. The EPT group's grip strength was significantly improved over the negative control and NEPT group. EPT also preserved cartilage histology based on several Mankin's subscores. EPT performed as effectively as NEPT in preventing osteoporosis and osteoarthritis in ovariectomised rats despite containing less vitamin E content. This study justifies clinical trials for the use of EPT in postmenopausal women with both conditions.

Effects of E'Jiao on Skeletal Mineralisation, Osteocyte and WNT Signalling Inhibitors in Ovariectomised Rats

E'Jiao is a traditional Chinese medicine derived from donkey skin. E'Jiao is reported to suppress elevated bone remodelling in ovariectomised rats but its mechanism of action is not known. To bridge this research gap, the current study aims to investigate the effects of E'Jiao on skeletal mineralisation, osteocyte and WNT signalling inhibitors in ovariectomised rats. Female Sprague-Dawley rats (3 months old) were ovariectomised and supplemented with E'Jiao at 0.26 g/kg, 0.53 g/kg and 1.06 g/kg, or 1% calcium carbonate (w/v) in drinking water. The rats were euthanised after two months of supplementation and their bones were collected for Fourier-transform infrared spectroscopy, histomorphometry and protein analysis. Neither ovariectomy nor treatment affected the skeletal mineral/matrix ratio, osteocyte number, empty lacunar number, and Dickkopf-1 and sclerostin protein levels (p > 0.05). Rats treated with calcium carbonate had a higher Dickkopf-1 level than baseline (p = 0.002) and E'Jiao at 0.53 g/kg (p = 0.002). In conclusion, E'Jiao has no significant effect on skeletal mineralisation, osteocyte and WNT signalling inhibitors in ovariectomised rats. The skeletal effect of E'Jiao might not be mediated through osteocytes.