Effects of nicotine on markers of bone turnover in ovariectomized rats

Abstract

Introduction Osteoporosis is characterized by low bone mass and density, as well as change in microarchitecture of bone tissue leading to decreased bone strength. In vitro research shows nicotine can increase osteoblast activity and proliferation, also suppress osteoclast activity. Therefore we explore nicotine anti-resorptive property by in vivo true experimental and randomized posttest only controlled group research that was conducted in 18-20 weeks old Rattus norvegicus . Methods Twenty-five female rats were divided into five groups, with 5 rats per group. The first group represented normal rats (Sham), while the second to fifth group underwent bilateral ovariectomy. The second group serves as positive control group (ovariectomy-only/OVX). The third to fifth group serve as dose 1 (P1-0.25mg/kg), dose 2 (P2-0.5 mg/kg), and Dose 3 (P3-0.75 mg/kg) treatment group receiving daily per-oral nicotine for 28 days, started 3 weeks post- ovariectomy. After 28 days treatment, the serum was checked. Results Nicotine has dose-dependent manner on serum osteocalcin and serum DPD level. Level of osteocalcin in P2 group was significantly lower (Mann-Whitney, p = 0.008) compared to OVX group (59.4% lower). Level of DPD in all group was not significantly different (ANOVA, p < 0.05) but shows lowest level in P2 group. For serum calcitonin level, there's no significant different between groups. Conclusion Nicotine at right low-dose might be able to inhibit osteoclast activity, thus open a possibility of anti-resorptive property of nicotine.

The Effects of Nicotine- and Cigarette-Related Products on Osteogenesis, Bone Formation, and Bone Mineralization: A Systematic Review

“…Eight studies observed a decreased quantity of exocytotic products and/or gene expression, whereas one noted an increase in proteoglycan deposition (Table 1). 5,8-35…”

“…Interestingly, of the remaining studies, eight showed an increase in these mechanisms. For example, Sananta et al 12 in a ovariectomized rat biological study noted decreased osteoclast activity with the addition of low-dose nicotine 8 weeks postoophorectomy. These results likely correlated with the chronicity of the oophorectomy and the inhibiting gene expression effect of nicotine on osteocalcin.…”