Effects of ovariectomy and ascorbic acid supplement on oxidative stress parameters and bone mineral density in rats
Objectives: The aim of this study is to investigate the effects of ovariectomy on bone mineral density (BMD) and oxidative state in rats, and the alterations in these effects that vitamin C supplementation may produce. Materials and methods: Twenty female Wistar albino rats were randomly divided into three groups: control (C, n=6); ovariectomy (O, n=7); and ovariectomy+vitamin C supplement (OV, n=7). Oxidative stress (OS) was assessed 100 days postovariectomy by measuring the activity of several enzymes, including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase, as well as the concentrations of malondialdehyde (MDA), nitric oxide (NO), and total sulfhydryl groups in plasma and bone homogenates. Results: A significant decrease in BMD was observed in O group compared with C group (p=0.015), and a significant increase was observed in OV compared with O group (p=0.003). When groups were compared with respect to parameters of OS, MDA and NO levels in bone tissue were significantly higher in O than in C (p=0.032, p=0.022) and were significantly lower in OV than in O (p=0.025, p=0.018). SOD activity was significantly higher in O than in C (p=0.032). In plasma, MDA activity was significantly higher in O than in C (p=0.022) and NO level was significantly higher in O than in C and OV (p=0.017, p=0.018). Conclusions: Our results suggest that ovariectomy may produce osteoporosis and OS in females, and vitamin C supplementation may provide alterations regarding improvement in OS and BMD values. We assume that studies including more subjects are needed to make a decisive conclusion about OS-BMD relation.
Keywords: rat; ovariectomy; osteoporosis; oxidative stress; vitamin C; ascorbic