Effects of menopause and tibolone on antioxidants in postmenopausal women

Vural, Perin; Akgül, Cemil; Canbaz, Mukaddes

doi:10.1258/0004563053857941

Cited by 31 publications

(19 citation statements)

References 14 publications

(24 reference statements)

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“…In the present study, activity of GPx and GST have been found to significantly decrease in ovariectomized female rats, as compared to intact ones of the same age. Our findings are in accordance with previous studies, in which it has been shown that menopause is associated with an increase in oxidative stress and a decrease of some antioxidants, such as ascorbic acid, alphatocopherol, total thiols (Vural et al 2005) and antioxidant enzymes such as SOD, CAT and GPx (Ha 2004). Furthermore, the activities of GSH reductase and GSH peroxidase also diminish with age (Hazelton and Lang 1985).…”

Section: Discussionsupporting

confidence: 93%

Effect of chronic treatments with GH, melatonin, estrogens, and phytoestrogens on oxidative stress parameters in liver from aged female rats

et al. 2007

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The aging theory postulates that this process may be due to the accumulation of oxidative damage in cells and molecules. The present study has investigated the effect of castration in old female rats on various parameters related to the antioxidant properties of several cellular fractions obtained from the liver, and the influence of several chronic treatments on it, both in intact and castrated animals. Sixty-one 22-month-old Wistar female rats, were used. About 21 intact animals were divided into three groups and treated for 10 weeks with GH, melatonin or saline, and 40 ovariectomized (at 12 months of age) animals were divided into five groups and treated for the same time with GH, melatonin, estrogens (Eos), phytoestrogens (Phyt) or saline. All animals were sacrificed at 24 months of age by decapitation. The activity of glutathione peroxidase (GPx) in cytosolic fraction, glutathione-S-transferase (GST) in cytosol and microsomal fractions, and the levels of nitric oxide (NO) and cytochrome C in mitochondrial and cytosol fractions of liver were determined. A decrease in GST activity was detected in cytosol and in the microsomal fraction in ovariectomized animals as compared to intact rats. The activity of GPx was also decreased in ovariectomized as compared with the intact group. NO level was increased and cytochrome C decreased in the mitochondrial fraction of the liver in ovariectomized females as compared with the intact group, respectively. No significant changes after melatonin or GH treatments were found in GPx, GST activity and NO level in mitochondrial fraction in the intact group. Administration of GH, melatonin, Eos and Phyt in the ovariectomized groups significantly increased the GPx, and GST activity in the cytosol and microsomal fraction and decreased the level of NO in the mitochondrial fraction as compared with the untreated rats. A significant increase in the level of cytochrome C in the mitochondrial fraction and a decrease in the cytosol fraction were also found with all treatments. The administration of GH, melatonin, Eos and Phyt to castrated females seem to reduce oxidative changes in the liver from old ovariectomized rats.

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Section: Discussionsupporting

confidence: 93%

Effect of chronic treatments with GH, melatonin, estrogens, and phytoestrogens on oxidative stress parameters in liver from aged female rats

et al. 2007

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“…Differently, conventional HRT (estrogen alone or estrogen plus progesterone) has been found to increase the levels of CRP, suggesting a possible proinflammatory effect of this therapy [39]. There is much less information regarding whether the oxidant/antioxidant equilibrium may be modified in women taking tibolone [40]. Our data did not indicate adverse effect of such treatment on the oxidative stress status in postmenopausal healthy women.…”

Section: Discussioncontrasting

confidence: 50%

Effects of menopause and tibolone on different cardiovascular biomarkers in healthy women

Vassalle

Cicinelli

Lello

et al. 2010

Gynecological Endocrinology

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“…The interaction of ER with c-rel subunit of NFkB prevents the binding of NF-kB to IL-6 promoter resulting in the repression of IL-6 expression (Ray et al 1994). Elevation of pro-inflammatory cytokines (TNF-a and IL-1b) is probably related with the increased oxidative stress seen in postmenopause (Vural et al 2005). On the other hand, induced oxidative stress act via different mechanisms, such as increasing nitric oxide and oxyradical production, and also increasing TNF-a and IL-1b synthesis (Yagi 1997).…”

Section: Discussionmentioning

confidence: 99%

Hormonal regulation of pro-inflammatory and lipid peroxidation processes in liver of old ovariectomized female rats

et al. 2009

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There is now a large body of evidence suggesting that the decline in ovarian function with menopause is associated with spontaneous increases in pro-inflammatory cytokines. On the other hand, oxidative stress has been implicated in the pathogenesis of several alterations due to menopause, and can arise through the increased production of lipid peroxides (LPO) and/or a deficiency of antioxidant defense. The aim of the present study was to investigate the effect of aging and ovariectomy on various physiological parameters related to inflammation and oxidative stress in livers obtained from old female rats and the influence of chronic exogenous administration of estrogens, phytoestrogens and growth hormone on these. Thirty-six female Wistar rats of 22 months of age were used in the present study. Twelve of them remained intact, and the other 24 had been ovariectomized at 12 months of age. Intact animals were divided into two groups and treated for 10 weeks with GH or saline, and ovariectomized animals were divided into four groups and treated for the same time with GH, estrogens, phytoestrogens or saline. A group of 2 month old intact female rats was used as young control. Protein expression of iNOS, HO-1, IL-6, TNFalpha, and IL-1beta were determined by Western blot analysis. The levels of NO( x ), LPO, TNFalpha, IL-1beta, IL-6 and IL-10 were determined in different fractions of the liver. Levels of LPO in the liver homogenates as well as iNOS protein expression and NO( x ) levels were increased in old rats as compared to young animals; this effect was more evident in ovariectomized animals. Pro-inflammatory cytokines TNF-alpha, IL-1beta and IL-6 were significantly increased and anti-inflammatory IL-10 decreased during ageing and after ovariectomy. Aging also significantly increased expression of HO-1 protein and ovariectomized rats showed an additional increase. Hormonal administration to the ovariectomized groups decreased NO( x ), LPO levels and pro-inflammatory cytokines as compared with untreated rats. Significant rise in IL-10 and reductions in the iNOS, IL-6, TNFalpha and IL-1beta proteins expression were also found. Oxidative stress and inflammation induced during aging in the liver are more marked in castrated than in intact old females. Administration of the different hormonal replacement therapies was able to inhibit the induction of pro-inflammatory cytokines and iNOS, decreased the levels of oxidative stress markers and had therapeutic potential in the prevention of liver injury.

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Effects of menopause and tibolone on antioxidants in postmenopausal women

Abstract: AddressesDepartments of 1

Cited by 31 publications

References 14 publications

Effect of chronic treatments with GH, melatonin, estrogens, and phytoestrogens on oxidative stress parameters in liver from aged female rats

Effect of chronic treatments with GH, melatonin, estrogens, and phytoestrogens on oxidative stress parameters in liver from aged female rats

Effects of menopause and tibolone on different cardiovascular biomarkers in healthy women

Hormonal regulation of pro-inflammatory and lipid peroxidation processes in liver of old ovariectomized female rats

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