Renal protective effects of vicenin-2 and scolymoside in a mouse model of sepsis

This study was initiated to determine whether 2 structurally related flavonoids found in Cyclopia subternata-vicenin-2 (VCN) and scolymoside (SCL)-could modulate renal functional damage in a mouse model of sepsis, and to elucidate the relevant underlying mechanisms. The potential of VCN and SCL treatment to reduce renal damage induced by cecal ligation and puncture (CLP) surgery in mice was measured via assessment of serum creatinine, blood urea nitrogen (BUN), lipid peroxidation, total glutathione, glutathione peroxidase activity, catalase activity, and superoxide dismutase activity. Treatment with either VCN or SCL resulted in elevated plasma levels of BUN and creatinine, and of protein in the urine of mice with CLP-induced renal damage. Moreover, both VCN and SCL inhibited nuclear factor κB activation and reduced the induction of nitric oxide synthase and excessive production of nitric acid. VCN and SCL treatment also reduced the plasma levels of interleukin-6, and tumor necrosis factor-α, reduced lethality due to CLP-induced sepsis, increased lipid peroxidation, and markedly enhanced the antioxidant defense system by restoring the levels of superoxide dismutase, glutathione peroxidase, and catalase in kidney tissues. The present results suggest that VCN and SCL protect mice from sepsis-triggered renal injury

Efeito da talidomida sobre o processo inflamatório e desmielinização na encefalomielite auto-imune experimental: estudo histopatológico e expressão de TNF-α e iNOS / Effect of thalidomide on the inflammatory process and demyelination in experimental autoimmune encephalomyelitis: histopathologic study and expression of TNF-α e iN

A encefalomielite autoimune experimental (EAE) é uma doença inflamatória e desmielinizante do sistema nervoso central (SNC) caracterizada por incapacidades temporárias ou permanentes. A patogênese envolve a reação auto-imune associada com a produção de citocinas pró inflamatórias, tais como o fator de necrose tumoral alfa (TNF-α). Esta citocina está associada com o aumento de radicais livres de oxigênio, como o óxido nítrico, liberados pelas células imunes ativadas. Além de aumentar a inflamação, tanto o fator de necrose tumoral, como o óxido nítrico causam lesão tecidual direta. Este estudo avaliou o efeito da talidomida na progressão clínica da doença, desenvolvimento da reação inflamatória e desmielinização. A expressão tecidual "in situ" do TNF-α e iNOS, uma enzima associada com a produção de óxido nítrico, foi investigada em amostras do SNC obtidos durante o desenvolvimento do modelo de EAE em ratos Lewis. Métodos: Ratos Lewis(n = 30) foram divididos em grupo de controle saudável (I), grupo experimental de encefalomielite autoimune (II) e o grupo tratado com talidomida (III). Os ratos foram monitorizados durante 15 dias para determinação da condição clínica, após este período, os animais foram eutanasiados e as amostras do sistema nervoso central foram obtidas para a realização de estudo histopatológico e imuno-histoquímico Resultados: Todos os animais do grupo II tiveram sintomas relacionados a EAE, enquanto apenas um do grupo tratado talidomida apresentaram alterações clínicas. O estudo histopatológico revelou que as amostras de SNC do grupo II apresentaram áreas de intenso infiltrado inflamatório mononuclear difuso e presença de áreas de desmielinização. No entanto, os animais tratados com talidomida apresentaram ocasionalmente um leve infiltrado inflamatório e bainhas de mielina bem organizadas. Além disso, a expressão de TNF-α e iNOS foram significativamente maiores no grupo II, quando comparado com o grupo tratado com a talidomida. Conclusões: Os resultados considerados em conjunto sustentam a hipótese de que a talidomida inibe a intensidade do processo inflamatório e desmielinização, assim como reduz a produção de mediadores inflamatórios modulando o desenvolvimento da encefalomielite auto-imune experimental em ratos Lewis.

Experimental autoimmune encephalomyelitis is a inflammatory and demyelinating disease of central nervous system (CNS) characterized by permanents or temporary disabilities. Its pathogenesis involves autoimmune reaction associated with the production of pro inflammatory cytokines such as tumor necrosis factor alpha (TNF-α). This cytokine is associated with increase of reactive oxygen free radicals, such as nitric oxide, released by activated immune cells. Besides enhancing inflammation, both tumor necrosis factor as nitric oxide cause pathologically direct destruction of proteins and enzyme oxidation. This study focuses on clinical disease progression, development of the inflammatory reaction and evaluation axonal myelination . The " in situ" tissue expression of the TNF-α and inducible nitric oxide synthase iNOS ,an enzyme associated with the production of nitric oxide , were also investigated in CNS samples obtained during the development of experimental autoimmune encephalomyelitis model in Lewis rats. Methods: Lewis rats were used to perform the classical model of EAE. The rats ( n=30) were divided into the healthy control group (I), experimental autoimmune encephalomyelitis group (II) and thalidomide treated group (III). The rats were monitored for 15 days for determination of clinical score , after this period , the animals were euthanized and samples were obtained from the central nervous system in which histopatological study and immunohistochemistry for SNC in situ detection of TNF-α and inducible nitric oxide synthase (iNOS) were performed. Results: All animals of group II had symptoms related to experimental encephalomyelitis , while only one of the thalidomide treated group showed clinical changes. The histopatological study revealead that SNC samples of group II presented areas of intense focal and diffuse mononuclear inflammation and the myelin sheaths were scarce and poorly stained. However, thalidomide treated rats presented occasionally a mild perivascular inflammatory infiltrate and myelin sheaths were organized and well evidenced. In addition, the expression of TNF-α and iNOS were significantly higher in the group II when compared with thalidomide treated group. Conclusions: The results taken together support the hypothesis that thalidomide inhibits the intensity of the inflammation and demyelination process and as well as reduces the production of inflammatory mediators influencing the development of experimental autoimmune encephalomyelitis in Lewis rats

Contrasting effects of nitric oxide and corticotropin- releasing factor within the dorsal periaqueductal gray on defensive behavior and nociception in mice

The anxiogenic and antinociceptive effects produced by glutamate N-methyl-D-aspartate receptor activation within the dorsal periaqueductal gray (dPAG) matter have been related to nitric oxide (NO) production, since injection of NO synthase (NOS) inhibitors reverses these effects. dPAG corticotropin-releasing factor receptor (CRFr) activation also induces anxiety-like behavior and antinociception, which, in turn, are selectively blocked by local infusion of the CRF type 1 receptor (CRFr1) antagonist, NBI 27914 [5-chloro-4-(N-(cyclopropyl)methyl-N-propylamino)-2-methyl-6-(2,4,6-trichlorophenyl)aminopyridine]. Here, we determined whether i) the blockade of the dPAG by CRFr1 attenuates the anxiogenic/antinociceptive effects induced by local infusion of the NO donor, NOC-9 [6-(2-hydroxy-1-methyl-2-nitrosohydrazino)-N-methyl-1-hexanamine], and ii) the anxiogenic/antinociceptive effects induced by intra-dPAG CRF are prevented by local infusion of Nω-propyl-L-arginine (NPLA), a neuronal NOS inhibitor, in mice. Male Swiss mice (12 weeks old, 25-35 g, N = 8-14/group) were stereotaxically implanted with a 7-mm cannula aimed at the dPAG. Intra-dPAG NOC-9 (75 nmol) produced defensive-like behavior (jumping and running) and antinociception (assessed by the formalin test). Both effects were reversed by prior local infusion of NBI 27914 (2 nmol). Conversely, intra-dPAG NPLA (0.4 nmol) did not modify the anxiogenic/antinociceptive effects of CRF (150 pmol). These results suggest that CRFr1 plays an important role in the defensive behavior and antinociception produced by NO within the dPAG. In contrast, the anxiogenic and antinociceptive effects produced by intra-dPAG CRF are not related to NO synthesis in this limbic midbrain structure.

Participation of nitric oxide synthase and cyclooxygenase-2 in the salivary secretion of hypothyroid endotoxemic rats / Participação da sintase do óxido nítrico e da ciclooxigenase-2 na secreção salivar de ratos hipotireoidianos endotoxêmicos

Purpose: In the present study the participation of nitric oxide synthase (NOS) and cyclooxygenase-2 (COX-2) on salivary secretion in endotoxemic hypothyroid rats was investigated. Methods: Male Wistar rats with an initial weight of 180 g were distributed into two groups, normal (N) or treated with propylthiouracil, 0.05 g/100 mL, administered orally for 5 weeks to induce hypothyroidism. Both groups were treated with lypopolysaccharide (LPS) (2.5 mg/kg; i.p.) to induce endotoxemia, or saline solution (SL), 90 min before salivary stimulation with pilocarpine (5 mg/kg; i.p.). Normal and PTU rats were divided into two groups each (n=07/09), receiving either L-NAME (10 mg/kg; i.p.), NOS inhibitor, or meloxicam (MLX) (0.5 mg/kg; i.p.), preferential COX-2 inhibitor, 30 min before endotoxemia challenge. Saliva was collected over a 15 min period (µL/min/100 g body wt.) from the time of the first drop of saliva. Results: Hypothyroidism decreased salivary flow rate in both groups of rats (LPS and SL). Endotoxemia and NOS inhibition by L-NAME reduced salivary flow in N rats. Meloxicam stimulated salivary secretion in the physiological state and systemic inflammation, induced by LPS, in N and PTU rats (Mann-Whitney Test; P < 0.05). Conclusion: In hypothyroid endotoxemic rats, it is COX-2 that modulates salivary secretion, not NOS.

Objetivo: Investigou-se a participação da sintase do óxido nítrico (NOS) e da ciclooxigenase-2 (COX-2) na secreção salivar de ratos hipotireoidianos endotoxêmicos. Metodologia: Ratos Wistar com peso inicial de 180 g foram distribuídos em dois grupos, normais (N) ou tratados com propiltiouracil (PTU) 0,05 g/100 mL, via oral, durante 5 semanas, para induzir hipotireoidismo. Ambos os grupos foram tratados com lipopolissacarídeo (LPS), 2,5 mg/kg i.p., para indução de endotoxemia ou salina (SL), 90 min antes da estimulação salivar com pilocarpina (5 mg/kg; i.p.). Os ratos N e PTU foram divididos em dois grupos cada (n = 07/09) e receberam injeções de L-NAME (10 mg/kg; i.p.), inibidor da NOS, ou meloxicam (MLX) (0,5 mg/kg;i.p.), inibidor preferencial da COX-2, 30 min antes da indução da endotoxemia. O fluxo salivar (µl/min/100 g de p.c.) foi avaliado durante um período de 15 min a partir da primeira gota de saliva. Resultados: O hipotireoidismo diminuiu o fluxo salivar em ratos tratados ou não com LPS. A endotoxemia e a inibição da NOS, através do L-NAME reduziu o fluxo salivar em ratos N. O MLX estimulou a salivação em situações fisiológicas e inflamatórias nos ratos N e PTU (Mann-Whitney; P < 0,05). Conclusão: A COX-2, mas não a NOS, modula a secreção salivar em ratos hipotireoidianos endotoxêmicos.

Participation of nitric oxide synthase and cyclooxygenase-2 in the salivary secretion of hypothyroid endotoxemic rats / Participação da sintase do óxido nítrico e da ciclooxigenase-2 na secreção salivar de ratos hipotireoidianos endotoxêmicos

Purpose: In the present study the participation of nitric oxide synthase (NOS) and cyclooxygenase-2 (COX-2) on salivary secretion in endotoxemic hypothyroid rats was investigated. Methods: Male Wistar rats with an initial weight of 180 g were distributed into two groups, normal (N) or treated with propylthiouracil, 0.05 g/100 mL, administered orally for 5 weeks to induce hypothyroidism. Both groups were treated with lypopolysaccharide (LPS) (2.5 mg/kg; i.p.) to induce endotoxemia, or saline solution (SL), 90 min before salivary stimulation with pilocarpine (5 mg/kg; i.p.). Normal and PTU rats were divided into two groups each (n=07/09), receiving either L-NAME (10 mg/kg; i.p.), NOS inhibitor, or meloxicam (MLX) (0.5 mg/kg; i.p.), preferential COX-2 inhibitor, 30 min before endotoxemia challenge. Saliva was collected over a 15 min period (µL/min/100 g body wt.) from the time of the first drop of saliva. Results: Hypothyroidism decreased salivary flow rate in both groups of rats (LPS and SL). Endotoxemia and NOS inhibition by L-NAME reduced salivary flow in N rats. Meloxicam stimulated salivary secretion in the physiological state and systemic inflammation, induced by LPS, in N and PTU rats (Mann-Whitney Test; P < 0.05). Conclusion: In hypothyroid endotoxemic rats, it is COX-2 that modulates salivary secretion, not NOS.

Objetivo: Investigou-se a participação da sintase do óxido nítrico (NOS) e da ciclooxigenase-2 (COX-2) na secreção salivar de ratos hipotireoidianos endotoxêmicos. Metodologia: Ratos Wistar com peso inicial de 180 g foram distribuídos em dois grupos, normais (N) ou tratados com propiltiouracil (PTU) 0,05 g/100 mL, via oral, durante 5 semanas, para induzir hipotireoidismo. Ambos os grupos foram tratados com lipopolissacarídeo (LPS), 2,5 mg/kg i.p., para indução de endotoxemia ou salina (SL), 90 min antes da estimulação salivar com pilocarpina (5 mg/kg; i.p.). Os ratos N e PTU foram divididos em dois grupos cada (n = 07/09) e receberam injeções de L-NAME (10 mg/kg; i.p.), inibidor da NOS, ou meloxicam (MLX) (0,5 mg/kg;i.p.), inibidor preferencial da COX-2, 30 min antes da indução da endotoxemia. O fluxo salivar (µl/min/100 g de p.c.) foi avaliado durante um período de 15 min a partir da primeira gota de saliva. Resultados: O hipotireoidismo diminuiu o fluxo salivar em ratos tratados ou não com LPS. A endotoxemia e a inibição da NOS, através do L-NAME reduziu o fluxo salivar em ratos N. O MLX estimulou a salivação em situações fisiológicas e inflamatórias nos ratos N e PTU (Mann-Whitney; P < 0,05). Conclusão: A COX-2, mas não a NOS, modula a secreção salivar em ratos hipotireoidianos endotoxêmicos.