The effects of estrogen and raloxifene treatment on the antioxidant enzymes and nitrite-nitrate levels in brain cortex of ovariectomized rats

Öge, Ayşin; Sezer, Ebru; Özgönül, Mert; Bayraktar, Fırat; Sözmen, Eser Yıldırım

doi:10.1016/s0304-3940(02)01416-7

Cited by 27 publications

(10 citation statements)

References 17 publications

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“…Such findings suggest that ovariectomy causes oxidative stress in the liver, thereby aligning with previous findings (Jeong et al, ; Li et al, ). Estrogen could decrease ROS levels by increasing the production of SOD and GSH‐PX (Oge, Sezer, Özgönül, Bayraktar, & Sözmen, ). Interestingly, our results showed that RJ treatment, similar to estrogen treatment, could reverse the detrimental oxidative stress by increasing the hepatic antioxidant enzymes.…”

Section: Discussionmentioning

confidence: 99%

Royal jelly attenuates nonalcoholic fatty liver disease by inhibiting oxidative stress and regulating the expression of circadian genes in ovariectomized rats

et al. 2020

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Nonalcoholic fatty liver disease (NAFLD) has a high incidence in postmenopausal women and is accompanied by insulin resistance, obesity, and dyslipidemia. Royal jelly (RJ), a natural substance derived from hive, possesses numerous health‐beneficial properties. Here, we evaluated the effects of RJ (150, 300, and 450 mg kg–1 day–1, 8 weeks) on NAFLD in ovariectomized (OVX) rats. Based on the results, RJ ameliorated the degree of anxiety, improved serum lipid profile, and attenuated the hepatic steatosis and liver injury in OVX rats. Furthermore, the protective effects of RJ could be attributed to its antioxidant properties, which enhance the levels of hepatic antioxidant enzymes. The qRT‐PCR results also suggest that RJ improves the disturbances of circadian genes by downregulating their expression, including that of Per1 and Per 2, in the liver of OVX rats. Altogether, our findings suggest that RJ may be a promising agent for the treatment of NAFLD. Practical applications Postmenopausal women are at an increased risk of NAFLD. Currently, there are no licensed therapies for NAFLD. Although hormone replacement therapy (HRT) is reported to inhibit the development of NAFLD, it causes unexpected adverse effects. As HRT is controversial, the use of natural supplements to counteract the detrimental effects of menopause has recently attracted more attention. RJ is a natural product secreted from the hypopharyngeal and mandibular glands of worker bees. The present study illustrates the protective effect of the natural product, RJ, and its underlying mechanisms on NAFLD. This is the first study to assess the effect of RJ on NAFLD under estrogen deficiency. Such findings contribute to the further utilization of RJ, which might serve as a promising therapeutic option and natural food for the treatment of NAFLD.

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Section: Discussionmentioning

confidence: 99%

Royal jelly attenuates nonalcoholic fatty liver disease by inhibiting oxidative stress and regulating the expression of circadian genes in ovariectomized rats

et al. 2020

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“…2). Interestingly, antioxidant and/or antiapoptotic genes, such as nitric oxide synthase (18,19), bcl-2 (19), thioredoxin (19,20), and manganese superoxide dismutase (19), have been found to be switched on by estrogen in neurons. However, one limitation of these studies is represented by the fact that they were mostly performed on animal models, which may not be representative of the human brain physiology.…”

Section: Discussionmentioning

confidence: 99%

Estrogen and Selective Estrogen Receptor Modulators Exert Neuroprotective Effects and Stimulate the Expression ofSelective Alzheimer’s Disease Indicator-1, a Recently Discovered Antiapoptotic Gene, in Human Neuroblast Long-Term Cell Cultures

Benvenuti

Luciani

Vannelli

et al. 2005

The Journal of Clinical Endocrinology & Metabolism

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According to the fact that Alzheimer's disease (AD) is more common in postmenopausal women, estrogen treatment has been proposed. Experimental studies, still mostly performed using animal models, demonstrated that estrogen exerts neuroprotective effects. We previously established neuroblast long-term cell cultures from human fetal olfactory epithelium. In the present study, we addressed the role of estrogen in these unique human cells, which express both the estrogen receptor (ER)-alpha and ERbeta. We found that 17beta-estradiol (17betaE(2)) and the selective estrogen receptor modulators (SERMs) raloxifene and tamoxifen exerted neuroprotective effects, which were independent of cell proliferation, by increasing resistance against beta-amyloid-induced toxicity, with the exception of the highest concentrations of raloxifene (10 and 100 nm). In addition, 17betaE(2) exposure protected from oxidative stress, reduced apoptosis, and increased the expression of the catalytic subunit of telomerase. Furthermore, we evaluated by quantitative real-time RT-PCR whether estrogen/SERMs modulate the expression of the recently discovered seladin-1 (selective AD indicator-1) gene, which exerts neuroprotective effects and is down-regulated in AD-vulnerable brain regions. 17betaE(2) (100 pm to 100 nm) and SERMs (1 nm) significantly increased the amount of seladin-1 mRNA. Conversely, 10 and 100 nm raloxifene reduced the expression of seladin-1. The effect of estrogen appears mainly mediated by ERalpha because the selective ERalpha agonist propylpyrazole-triol determined a much greater increase of seladin-1 expression than the ERbeta agonist diarylpropionitrile. Our results add new evidence, using human neuronal cells, for a beneficial effect of estrogen in preventing neurodegenerative diseases and suggest for the first time that seladin-1 may mediate this effect.

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“…Accumulating evidence has shown the antioxidant effects of RAL which has the most fundamental importance in the brain [51,52]; together with the fact that HO-1 is found to reduce oxidative stress and improve cognitive function in Alzheimer rat model [53], this supports RAL's possible effectiveness in the nervous system. RAL effectively reduces neuronal cell death by mitigating oxidative stress [54].…”

Section: Effects Of Ral In Neuroprotectionmentioning

confidence: 86%

Distinct Approaches of Raloxifene: Its Far-Reaching Beneficial Effects Implicating the HO-System

et al. 2020

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Selective estrogen receptor modulators (SERMs) were discovered in the mid-1900s in connection with estrogen-related pathological conditions. They were developed to antagonize the adverse effects of estrogen and have been shown to be effective against postmenopausal disorders manifested by estrogen deficiency. Raloxifene (RAL), one of the most widely used SERMs, expresses estrogen-like effects on bones, while it is found to be an antagonist on breast and uterus. RAL has multiple beneficial effects throughout the body, including antioxidant and anti-inflammatory properties, because of which it gains particular attention. Additionally, previous studies have revealed that RAL is an efficient modulator of heme-oxygenase (HO) expression. HO, through its general activity, participates in comprehensive cell defense processes, thus the induction of HO by RAL administration indicates a major role in its therapeutic efficacy. In this review, we compile the current knowledge about the overall metabolic, neurocognitive, and cardiovascular effects of RAL involving the cytoprotective HO-system.

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The effects of estrogen and raloxifene treatment on the antioxidant enzymes and nitrite-nitrate levels in brain cortex of ovariectomized rats

Cited by 27 publications

References 17 publications

Royal jelly attenuates nonalcoholic fatty liver disease by inhibiting oxidative stress and regulating the expression of circadian genes in ovariectomized rats

Royal jelly attenuates nonalcoholic fatty liver disease by inhibiting oxidative stress and regulating the expression of circadian genes in ovariectomized rats

Estrogen and Selective Estrogen Receptor Modulators Exert Neuroprotective Effects and Stimulate the Expression ofSelective Alzheimer’s Disease Indicator-1, a Recently Discovered Antiapoptotic Gene, in Human Neuroblast Long-Term Cell Cultures

Distinct Approaches of Raloxifene: Its Far-Reaching Beneficial Effects Implicating the HO-System

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