Tocotrienols are needed for normal bone calcification in growing female rats

Abstract

In this study the effects of vitamin E deficiency and supplementation on bone calcification were determined using 4-month-old female Sprague-Dawley rats. The rats weighed between 180 and 200 g. The study was divided in three parts. In experiment I the rats were given normal rat chow (RC, control group), a vitamin E deficient (VED) diet or a 50% vitamin E deficient (50%VED) diet. In experiment 2 the rats were given VED supplemented with 30 mg/kg palm vitamin E (PVE30), 60 mg/kg palm vitamin E (PVE60) or 30 mg/kg pure alpha-tocopherol (ATF). In experiment 3 the rats were fed RC and given the same supplements as in experiment 2. The treatment lasted 8 months. Vitamin E derived from palm oil contained a mixture of ATF and tocotrienols. Rats on the VED and 50%VED diets had lower bone calcium content in the left femur compared to the RC group (91.6 +/- 13.3 mg and 118.3 +/- 26.0 mg cf 165.7 +/- 15.2 mg; P < 0.05) and L5 vertebra (28.3 +/- 4.0 mg and 39.5 +/- 6.2 mg compared with 51.4 +/- 5.8 mg; P < 0.05). Supplementing the VED group with PVE60 improved bone calcification in the left femur (133.6 +/- 5.0 mg compared with 91.6 +/- 13.3 mg; P < 0.05) and L5 vertebra (41.3 +/- 3.3 mg compared with 28.3 +/- 4.0 mg; P < 0.05) while supplementation with PVE30 improved bone calcium content in the L5 vertebra (35.6 +/- 3.1 mg compared with 28.3 +/- 4.0 mg; P < 0.05). However, supplementation with ATF did not change the lumbar and femoral bone calcium content compared to the VED group. Supplementing the RC group with PVE30, PVE60 or ATF did not cause any significant changes in bone calcium content. In conclusion, vitamin E deficiency impaired bone calcification. Supplementation with the higher dose of palm vitamin E improved bone calcium content, but supplementation with pure ATF alone did not. This effect may be attributed to the tocotrienol content of palm vitamin E. Therefore, tocotrienols play an important role in bone calcification.

The Effects of Annatto Tocotrienol on Bone Biomechanical Strength and Bone Calcium Content in an Animal Model of Osteoporosis Due to Testosterone Deficiency

“…Norazlina et al indicated that vitamin E was essential for normal calcium metabolism. Rats receiving vitamin E-deficient diet suffered from increased parathyroid level, impaired calcium absorption and low calcium content in the lumbar spine [35,36]. Supplementation with gamma-tocotrienol could preserve the calcium content in rats fed with vitamin E-deficient diet [37].…”

Mevalonate-suppressive dietary isoprenoids for bone health

“…Tocotrienol mixture at 60-and 100-mg/kg body weight restored free radical-induced reduction in serum level of osteocalcin, the number of osteoblasts, and bone formation in male Wistar rats while reducing the level of bone-resorbing cytokines [82]. Oral intake of γ-tocotrienol [91,166] and a mixture of tocotrienols [91,92] increased bone calcification in Sprague-Dawley rats. A tocotrienol-enhanced fraction and γ-tocotrienol also counteracted the nicotine effect on bone resorption in rats [83].…”

“…In all the comparison studies, α-tocopherol [91,92,166,169], tocopherols [169] and tocopheryl esters [82,91] with no mevalonate suppressive activity [63] offer either no protection or less-thantocotrienol effects [83,170,171]. γ-Tocotrienol at 60 mg/kg decreased trabecular separation and increased trabecular bone volume and thickness, trabecular number, load value, displacement, stress value, strain value, viscoelasticity and stiffness in male rats to significantly greater extent than did equal dose of α-tocopherol [88].…”

The 21st Century Form of Vitamin E - Tocotrienol

“…Gamma tocotrienols, shown to prevent the loss of bone mineral density, reduce osteoporosis, reduce body fat mass and improve the bone calcium content of rats [108,109]. Both tocotrienol and tocopherol have the potential to be developed as an antiosteoporotic agent.However, tocotrienol has been shown to be superior than tocopherol and is a better candidate for human studies [110].…”