Role of antioxidant systems, lipid peroxidation, and nitric oxide in postmenopausal osteoporosis

Abstract

In this study we assessed activities of antioxidant enzymes, lipid peroxidation end-products, and nitric oxide (NO) levels in women with postmenopausal osteoporosis (PMO). Relationship between oxidative stress parameters and NO levels with bone mineral density (BMD) and clinical variables influencing bone mass and health related quality of life measures was also investigated in women with PMO. Postmenopausal women (n=87), aged 40-65, without previous diagnosis or treatment for osteoporosis and independent in daily living activities were included. BMD was measured at the lumbar spine and proximal femur using dual-X-ray absorptiometry (DXA). Erythrocyte catalase (CATe) enzyme activity, erythrocyte and plasma enzyme activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and lipid peroxidation end-product malondialdehyde (MDA) and nitrite/nitrate levels, by product of NO were studied. A total of 23 healthy non-porotic women were included as controls. Women with PMO had significantly lower erythrocyte CATe enzyme activity and higher erythrocyte malondialdehyde (MDAe) and erythrocyte nitric oxide (NOe) levels in comparison to controls whereas erythrocyte SODe and GSH-Px enzyme activity was similar. In plasma, osteoporotic women had significantly higher SOD enzyme activity and higher MDA levels whereas similar GSH-Px enzyme activity and NO levels compared to non-porotic controls. Significant correlation was found between erythrocyte SODe, CATe enzyme activity and NOe levels with proximal femur BMD. Some of the quality of life scores as pain, mental, and social functions correlated with antioxidant enzyme activities and NO levels.Consequently, oxidative stress markers may be an important indicator for bone loss in postmenopausal women. Further researches assessing the oxidative stress markers and NO in bone tissue and changes with anti-osteoporotic drugs would be valuable to better understand the role of free radicals, antioxidants, and NO in the regulation of bone mass.

Protective Effect of Vanillic Acid on Ovariectomy-Induced Osteoporosis in Rats

“…Previously, VA has been reported to exhibit estrogenic activity, and hence we hypothesize that VA may favor the anti-osteoporotic property by acting as estrogen analog (Xiao et al, 2014). Since, estrogen plays a critical role in maintaining bone mineralization and remodeling (turnover) process via regulating the balance between osteoclast and osteoblast (Ozgocmen et al, 2007). Hence, the present experiment was designed to evaluate the anti-osteoporotic property of VA in ovariectomy-induced rat model which mimic postmenopausal osteoporosis.…”

Detection of significant pathways in osteoporosis based on graph clustering

“…Previous studies have revealed that SOD2 is significantly upregulated in circulating monocytes at the mRNA and protein level in vivo in Chinese patients with low versus high hip BMD levels (49). Women with postmenopausal osteoporosis have significantly higher plasma SOD enzyme activity levels than those in controls (50). This indicates that SOD2 is significant in the pathogenesis of osteoporosis, promoting osteoclast differentiation, formation and activity (51).…”

Relationships between endothelial nitric oxide synthase gene polymorphisms and osteoporosis in postmenopausal women

“…The impact of NO on bone metabolism is two-way directional, affecting not only the function of osteoclasts, but also the differentiation and proliferation of osteoblasts (Brennan et al, 2003;van't Hof et al, 2004). It has been found that NO is related with osteoporosis development in postmenopausal women (Ozgocmen et al, 2007;Rosselli et al, 1995). During menstrual cycle, blood NO metabolite concentrations correlate with estrogen levels, being higher in the follicular phase than in the secretory phase (Cicinelli et al, 1996).…”