Cisplatin is an antitumor drug widely used in the treatment of many malignant tumors. However, the most common adverse effect, nephrotoxicity, limits the use of this drug in many cancer patients. Resveratrol is a phytoalexin that presents highly efficient protection in experimental nephrotoxicity models. This study evaluated the effect of resveratrol on cisplatin-induced kidney damage. Male Wistar rats were treated with resveratrol (25 mg/kg b.w., i.p.) before the administration of cisplatin (5 mg/kg b.w., i.p.) and killed 2 or 5 days later. Blood and urine samples were collected and the kidneys were removed. Rats from the cisplatin group showed acute tubular cell necrosis and increased immunostaining for ED1 (macrophages/monocytes) and T-lymphocytes in the renal cortex and outer medulla when compared with the control group. These alterations were less intense in animals pre-treated with resveratrol. Moreover, indicators of renal injury such as increased serum creatinine levels, urinary volume and urinary protein caused by the administration of cisplatin, were also significantly reduced with resveratrol. Increased lipid peroxidation and glutathione depletion in tissue were attenuated by resveratrol. In conclusion, resveratrol attenuated the cisplatin-induced structural and functional renal changes by reducing free radicals and inhibiting inflammatory cell infiltrates.

Hydrogen sulfide (H(2)S) is a gaseous neuromodulator endogenously produced in the brain by the enzyme cystathionine β-synthase (CBS). We tested the hypothesis that H(2)S acts within the anteroventral preoptic region of the hypothalamus (AVPO) modulating the production of prostaglandin (PG) E(2) (the proximal mediator of fever) and cyclic AMP (cAMP). To this end, we recorded deep body temperature (Tb) of rats before and after pharmacological modulation of the CBS-H(2)S system combined or not with lipopolysaccharide (LPS) exposure, and measured the levels of H(2)S, cAMP, and PGE(2) in the AVPO during systemic inflammation. Intracerebroventricular (icv) microinjection of aminooxyacetate (AOA, a CBS inhibitor; 100 pmol) did not affect basal PGE(2) production and Tb, but enhanced LPS-induced PGE(2) production and fever, indicating that endogenous H(2)S plays an antipyretic role. In agreement, icv microinjection of a H(2)S donor (Na(2)S; 260 nmol) reduced the LPS-induced PGE(2) production and fever. Interestingly, we observed that the AVPO levels of H(2)S were decreased following the immunoinflammatory challenge. Furthermore, fever was associated with decreased levels of AVPO cAMP and increased levels of AVPO PGE(2). The LPS-induced decreased levels of cAMP were reduced to a lesser extent by the H(2)S donor. The LPS-induced PGE(2) production was potentiated by AOA (the CBS inhibitor) and inhibited by the H(2)S donor. Our data are consistent with the notion that the gaseous messenger H(2)S synthesis is downregulated during endotoxemia favoring PGE(2) synthesis and lowering cAMP levels in the preoptic hypothalamus.

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Background: The mechanism of cisplatin-induced nephrotoxicity is unknown, but has been associated with renal lipid peroxidation. The bioflavonoid quercetin may be a potential alternative to reduce cisplatin-induced nephrotoxicity. The aim of this study was to evaluate the effect of quercetin on the evolution of cisplatin-induced acute tubular necrosis. Methods: One hundred and three male Wistar rats were injected with cisplatin (5 mg/kg, i.p.), 43 of them received quercetin (50 mg/kg, by gavage) before cisplatin injection. Blood and urine were collected 5 and 20 days after the injection for the determination of plasma creatinine, urine volume and osmolality. The kidneys were removed for the determination of renal malondialdehyde (MDA) and for histological and immunohistochemical studies. The renal expression of fibronectin, α-smooth muscle actin, vimentin, Jun N-terminal kinase, nuclear factor-ĸB, and macrophages during the evolution of the acute tubular necrosis induced by cisplatin and the histological changes observed in the kidneys were analyzed. Results: Cisplatin-treated rats presented a transitory increase in plasma creatinine levels, tubular cell necrosis and increased immunostaining for vimentin, α-SM-actin, fibronectin, ED1, NF-ĸB, and p-JNK in the renal cortex and outer medulla. These alterations were less intense in animals treated with quercetin. Conclusion: Quercetin treatment attenuated the functional, histological and immunohistochemical alterations induced by cisplatin.

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