Comparing the Effects of Tocotrienol-rich Fraction, Calcium and Estrogen on Bone Metabolism in Ovariectomized Rats

Previous studies showed the role of oxidative stress in the pathogenesis of osteoporosis. Thus antioxidant agents have the potential to be used in the treatment and prevention of osteoporosis. In this study, vitamin E in the form of tocotrienol-rich fraction (TRF) was used. Comparison of the effects of treatments was made among TRF, calcium and estrogen. A total of 48 female Sprague-Dawley rats were divided into six groups: baseline, sham-operated, ovariectomized control and ovariectomized given calcium, estrogen or TRF. The treatment agents were administered via oral gavage for two months. Bone histomorphometry showed that treatment with either calcium, estrogen or tocotrienol was able to increase the trabecular volume and reduce the distance between the trabecular bone significantly compared with the ovariectomy control group. Treatment with either estrogen or tocotrienol showed significant increase in the thickness of the trabecular compared with the control group. Based on the calcium content test, supplementation with calcium increased the levels of calcium content in the fourth vertebral lumbar significantly compared with the sham and ovariectomy group. In conclusion, calcium, estrogen and tocotrienol had positive effects on the trabecular bone. However, tocotrienol was more superior to calcium or estrogen in preventing bone loss in postmenopausal osteoporosis. Tocotrienol prevented bone thinning and loss of volume without the side effects as estrogen. Although calcium can improve the bone calcium content, still, it was unable to prevent bone thinning.