Effects of low doses of quercetin and genistein on oxidation and carbonylation in hemoglobin and myoglobin

Study on the neuroprotective effects of Genistein on Alzheimer's disease

Along with the aging of the world population, the incidence rate of Alzheimer's disease (AD) has been increasing. At present, AD has become one of the most serious problems faced by modern medicine. Studies have shown that estrogen has a positive effect on AD, but estrogen has the side effect of leading to tumors. Recent in vivo studies have shown that genistein, one of the selective estrogen receptor modulators (SERMs), can improve brain function through the blood-brain barrier (BBB), antagonize the toxicity of amyloid β-protein (Aβ), that is, to inhibit neurotoxicity due to aggregation of beta amyloid protein, and have neuroprotective effects. In addition, the use of Gen can avoid the risk of endometrial cancer and breast cancer caused by estrogen therapy while exerting an estrogen-like effect, which has some potential for the delay and treatment of AD.

Molecular Mechanisms Underlying Protective Role of Quercetin on Copper Sulfate-Induced Nephrotoxicity in Mice

Copper overload is an established cause of nephrotoxicity, but the precise molecular mechanism remains unknown. Our study aimed to investigate the molecular mechanism of copper sulfate (CuSO₄)-induced nephrotoxicity and the protective effect of the natural compound quercetin using a mouse model. Mice were orally administered CuSO₄ only (200 mg/kg per day), or co-administered CuSO₄ (200 mg/kg per day) plus quercetin (25, 50, or 100 mg/kg per day), or quercetin only (100 mg/kg per day), or vehicle for 28 days. The blood and kidneys were collected for the examination of serum biomarkers, oxidative stress biomarkers, changes in histopathology and gene and protein expression. Our results show that quercetin supplementation attenuates CuSO₄-induced renal dysfunction and tubular necrosis in a dose-dependent manner. Quercetin supplementation at 50 and 100 mg/kg significantly attenuated CuSO₄-induced oxidative damage. Quercetin supplementation also inhibited the activities of caspases-9 and-3, and the expression of p53 and Bax mRNAs. Furthermore, quercetin supplementation markedly activated the expression of Nrf2 and HO-1 mRNAs, but inhibited the expression of NF-κB, IL-1β, IL-6, and TNF-α mRNAs. In conclusion, our results revealed that quercetin supplementation could inhibit CuSO₄-induced nephrotoxicity in mice via the inhibition of mitochondrial apoptotic and NF-κB pathways and the activation of Nrf2/HO-1 pathway. Our study highlights quercetin as a potential candidate in treating copper overload-induced nephrotoxicity.

Effect of Genistein on the Transgenic Drosophila Model of Parkinson's Disease

Parkinson's disease (PD) is the second-most common neurodegenerative disorder and is characterized by the degeneration of dopaminergic neurons in the substantia nigra pars compacta. Oxidative stress has also been linked with the progression of PD, hence the involvement of a natural plant product could offer neuroprotection. The present study deals with the effect of genistein on the transgenic flies expressing normal human alpha synuclein panneurally. The PD flies were exposed to 10, 20, 30, and 40 µM of genistein (mixed in diet) for 24 days. A significant dose-dependent increase in the life span and delay in the loss of climbing ability were observed in the PD flies exposed to genistein (p < .05). A significant dose-dependent decrease in oxidative stress markers and increase in dopamine content were observed in PD flies exposed to genistein. However, the exposure of genistein did not inhibit the expression of α-synuclein in the brains of PD flies.

Genistein attenuates di‑(2‑ethylhexyl) phthalate-induced testicular injuries via activation of Nrf2/HO‑1 following prepubertal exposure

Di-(2-ethylhexyl) phthalate (DEHP) and genistein (GEN) are of the most common endocrine disrupting chemicals (EDCs) present in the environment or the diet. However, investigation of the effects of acute exposure to these two EDCs during prepuberty has been lacking. In this study, DEHP and GEN were administrated to prepubertal male Sprague-Dawley rats by gavage from PND22 to PND35 with vehicle control, GEN 50 mg/kg body weight (bw)/day, DEHP50, 150 and 450 mg/kg bw/day, and combined treatment. Reproductive parameters including testis weight, anogenital distance and organ coefficient were evaluated on PND36. Enzyme activity involved in the regulation of testicular redox state as well as expression of genes and proteins related to anti-oxidative ability and apoptosis were also investigated. The results revealed that by PND36, DEHP treatment had significantly decreased the testis weight, organ coefficient, testicular anti-oxidative enzyme activities and caused tubular vacuolation; however, co-administration of GEN partially alleviated DEHP-induced testicular injuries and enhanced testicular anti-oxidative enzyme activities and upregulated the expression of NF-E2 related factor 2 and heme oxygenase-1, which indicated that GEN partially attenuated DEHP-induced male reproductive system damage through anti-oxidative action following acute prepubertal exposure to DEHP. Thus, GEN may have use in attenuating the damaging effects of other EDCs that lead to reproductive disorders.

Protective Effects of Genistein against Mono-(2-ethylhexyl) Phthalate-Induced Oxidative Damage in Prepubertal Sertoli Cells

Mono-(2-ethylhexyl) phthalate (MEHP) and genistein are two of the most prevalent endocrine-disrupting chemicals (EDCs) that present in the environment and food. However, how these two EDCs would affect prepubertal Sertoli cells development was rarely studied. In this study, primary prepubertal Sertoli cells were isolated from 22-day-old Sprague Dawley rats and exposed to MEHP at 1 μmol/L, 10 μmol/L, and 100 μmol/L (M1, M10, and M100), genistein at 10 μmol/L (G), and their combination (G + M1, G + M10, and G + M100). Cell proliferation inhibition rate, apoptosis and necrosis rate, and cellular redox state were evaluated. Our results revealed that MEHP could significantly increase cell proliferation inhibition rate, apoptosis rate, necrosis rate, and intracellular reactive oxidative species level. However, coadministration of genistein could partially alleviate MEHP-induced prepubertal Sertoli cells oxidative injuries via enhancement of testicular antioxidative enzymes activities and upregulation of Nrf2 and HO-1, indicating that genistein could partially attenuate MEHP-induced prepubertal Sertoli cells damage through antioxidative action and may have promising future on its curative role for attenuating other EDCs-induced reproductive disorders.

Prepubertal exposure to genistein alleviates di-(2-ethylhexyl) phthalate induced testicular oxidative stress in adult rats

Di-(2-ethylhexyl) phthalate (DEHP) is the most widely used plastizer in the world and can suppress testosterone production via activation of oxidative stress. Genistein (GEN) is one of the isoflavones ingredients exhibiting weak estrogenic and potentially antioxidative effects. However, study on reproductive effects following prepubertal multiple endocrine disrupters exposure has been lacking. In this study, DEHP and GEN were administrated to prepubertal male Sprague-Dawley rats by gavage from postnatal day 22 (PND22) to PND35 with vehicle control, GEN at 50 mg/kg body weight (bw)/day (G), DEHP at 50, 150, 450 mg/kg bw/day (D50, D150, D450) and their mixture (G + D50, G + D150, G + D450). On PND90, general morphometry (body weight, AGD, organ weight, and organ coefficient), testicular redox state, and testicular histology were studied. Our results indicated that DEHP could significantly decrease sex organs weight, organ coefficient, and testicular antioxidative ability, which largely depended on the dose of DEHP. However, coadministration of GEN could partially alleviate DEHP-induced reproductive injuries via enhancement of testicular antioxidative enzymes activities, which indicates that GEN has protective effects on DEHP-induced male reproductive system damage after prepubertal exposure and GEN may have promising future in its curative antioxidative role for reproductive disorders caused by other environmental endocrine disruptors.