Effect of vitamin E supplementation on bone metabolism in nicotine-treated rats

Norazline M, Kee PL, Lukman HI, Nazrun AS, Ima-Nirwana S
Correspondence: Dr Norazlina Mohamed, azlina@medic.ukm.my

ABSTRACT
Introduction Nicotine has been shown to exert negative effects on bone. This study determined whether vitamin E supplementation is able to repair the nicotine-induced adverse effects in bone.
Methods 24 male rats were divided into three groups. The first group was the baseline control and killed untreated at the beginning of the study. Groups 2 and 3 received nicotine at 7 mg per kg for three months but during the second and third months, group 2 was supplemented with alpha-tocopherol (N+ATF) while group 3 was given palm tocotrienol mixture (N+TT). Serum interleukin-1 (IL-1), serum interleukin-6 (IL-6), serum osteocalcin, urine deoxypyridinoline (DPD) and bone calcium content were measured.
Results Palm tocotrienol mixture was able to prevent the increment of IL-1 and IL- 6 due to nicotine treatment. No changes were seen in the osteocalcin levels, but the N+ATF group had lower urine DPD levels after treatment. However, bone-remodelling index revealed no significant changes. No significant differences were seen in the femoral bone calcium content results, although the fourth lumbar bone calcium content was reduced in both groups with 66.5 percent reduction in the N+ATF group and 59.6 percent reduction in the N+TT group.
Conclusion Palm tocotrienol mixture was better than alpha-tocopherol in reversing the effects of nicotine on IL-1 and IL-6. Both forms of vitamin E were not able to restore the nicotine-induced bone calcium loss, but the N+ATF group suffered a greater loss. Tocotrienol seemed to be superior to alpha-tocopherol in combating against the adverse effect of nicotine.

Keywords: alpha-tocopherol, bone remodelling, nicotine, tocotrienols, vitamin E
Singapore Med J 2007; 48(3): 195–199