Quercetin both partially attenuates hydrogen peroxide-induced toxicity and decreases viability of rat glial cells

Quercetin inhibits human microvascular endothelial cells viability, migration and tube-formation in vitro through restraining microRNA-216a

Background: Quercetin belongs to the flavonoids family, which has been proven to have extensive pharmacological effects. Nevertheless, the function of quercetin in peripheral arterial disease (PAD) has not yet been reported. In the research, we purposed to disclose the effectiveness of quercetin in the pathogenesis of PAD.Methods: HMEC-1 cells were cultivated in Matrigel for 24 h to observe the tube-formation. Detections of cell viability, migration and apoptosis were through implementing CCK-8, Transwell and flow cytometry methods. Western blot was utilised for measuring angiogenesis-, migration- and apoptosis-correlative factors. MiR-216a expression was examined via qRT-PCR, and its functions in HMEC-1 cells were uncovered after miR-216a mimic transfection. Assessment of JAK2/STAT3 and PI3K/AKT pathways was via implementing western blot.Results: HMEC-1 cells were spontaneously vascularised under Matrigel condition. Quercetin predominantly repressed cell viability, migration, VEGF expression and facilitated apoptosis in HMEC-1 cells. Additionally, suppression of miR-216a was discovered in HMEC-1 cells after quercetin stimulation, meanwhile miR-216a overexpression annulled the functions of quercetin in HMEC-1 cells. Besides, quercetin deactivated PI3K/AKT and JAK/STAT pathways through adjusting miR-216a.Conclusion: The above-mentioned consequences exhibited that quercetin suppressed HMEC-1 cell viability, migration and tube-formation through hindering JAK2/STAT3 and PI3K/AKT pathway via declination of miR-216a.

Protective effect of curcumin on fertility in cyclophosphamide exposed rats: Involvement of multiple pathways

This study assesses the effect of curcumin on cyclophosphamide (CPA)-induced functional alterations of the testicular, brain, and pituitary axis in common rodents, rats. Only CPA was given at 150 mg/kg body weight only on Day 1 or orally pre and posttreated with curcumin at 20 mg/kg body weight successively for 14 days. The outcomes showed that curcumin pre and posttreatments significantly affected the elevation of biomarkers of oxidative stress in CPA-induced rats, moreover, it increased nonenzymatic antioxidant levels in the epididymis, testes, and brain of the treated rats used in this study. In addition, followed by the preservation of histo-architectures of the epididymis, testes, and brain in the rats treated with CPA, curcumin helped in increasing the sperm quality and quantity and suppressing both the inflammatory indices and the activities of caspase-3, while pretreatment with curcumin gave a better result than posttreatment with curcumin. This may, therefore, represent a prospective adjuvant against CPA-induced spermatogenic deficits in humans. PRACTICAL APPLICATIONS: Jointly, through the antiapoptotic, antioxidant, and anti-inflammatory activities of curcumin, it instigated the toxicity of CPA-induced to be modulated along the testicular, brain, and pituitary axis in the rats. This may, therefore, represent a prospective therapeutic adjuvant against CPA-induced spermatogenic deficits in humans.

Chemoprotective role of quercetin in manganese-induced toxicity along the brain-pituitary-testicular axis in rats

Reproductive dysfunction in response to manganese exposure has been reported in humans and animals. Quercetin, a bioflavonoid widely distributed in fruits, vegetables and beverages has been shown to possess antioxidant, anti-inflammatory and anti-apoptotic activities in different experimental model systems. However, there is dearth of scientific information on the influence of quercetin on manganese-induced reproductive toxicity. This study was designed to evaluate the influence of quercetin on manganese-induced functional alterations along the brain-pituitary- testicular axis in rats. Manganese was administered alone at 15 mg/kg body weight or orally co-treated with quercetin at 10 and 20 mg/kg body weight for 45 consecutive days. Results indicated that quercetin co-treatment significantly (p < 0.05) inhibited manganese-induced elevation in biomarkers of oxidative stress whereas it increased antioxidant enzymes activities and glutathione level in the brain, testes and epididymis of the treated rats. Furthermore, quercetin mediated suppression of inflammatory indices and caspase-3 activity was accompanied by preservation of histo-architectures of the brain, testes and epididymis in manganese-treated rats. The significant reversal of manganese-induced decreases in reproductive hormones (i.e. luteinizing hormone, follicle-stimulating hormone and testosterone) and testicular activities of acid phosphatase, alkaline phosphatase and lactate dehydrogenase by quercetin was complemented by an increase in sperm quality and quantity in the treated rats. Collectively, quercetin modulated manganese-induced toxicity along the brain-pituitary-testicular axis in rats via its intrinsic antioxidant, anti-inflammatory and anti-apoptotic activities, and may thus represent a potential pharmacological agent against manganese-induced male reproductive deficits in humans.

Impact of Plant-Derived Flavonoids on Neurodegenerative Diseases

Neurodegenerative disorders have a common characteristic that is the involvement of different cell types, typically the reactivity of astrocytes and microglia, characterizing gliosis, which in turn contributes to the neuronal dysfunction and or death. Flavonoids are secondary metabolites of plant origin widely investigated at present and represent one of the most important and diversified among natural products phenolic groups. Several biological activities are attributed to this class of polyphenols, such as antitumor activity, antioxidant, antiviral, and anti-inflammatory, among others, which give significant pharmacological importance. Our group have observed that flavonoids derived from Brazilian plants Dimorphandra mollis Bent., Croton betulaster Müll. Arg., e Poincianella pyramidalis Tul., botanical synonymous Caesalpinia pyramidalis Tul. also elicit a broad spectrum of responses in astrocytes and neurons in culture as activation of astrocytes and microglia, astrocyte associated protection of neuronal progenitor cells, neuronal differentiation and neuritogenesis. It was observed the flavonoids also induced neuronal differentiation of mouse embryonic stem cells and human pluripotent stem cells. Moreover, with the objective of seeking preclinical pharmacological evidence of these molecules, in order to assess its future use in the treatment of neurodegenerative disorders, we have evaluated the effects of flavonoids in preclinical in vitro models of neuroinflammation associated with Parkinson's disease and glutamate toxicity associated with ischemia. In particular, our efforts have been directed to identify mechanisms involved in the changes in viability, morphology, and glial cell function induced by flavonoids in cultures of glial cells and neuronal cells alone or in interactions and clarify the relation with their neuroprotective and morphogetic effects.