Anti-inflammatory and analgesic activities of indigo through regulating the IKKß/IκB/NF-κB pathway in mice.

This study investigated the anti-inflammatory and analgesic activities of indigo in mice and explored the possible related mechanisms. Xylene-induced ear edema, carrageenan-induced paw edema, and acetic acid-induced vascular permeability tests were used in investigating the anti-inflammatory activities. The anti-nociceptive effects of indigo were assessed through acetic acid-induced writhing, hot plate test, and formalin test, and spontaneous locomotor activity and motor performance were evaluated. The mechanisms of activities of indigo were explored by evaluating the expression levels of IκB kinase (IKK)ß, p-IKKß, inhibitor κB (IκB)α, p-IκBα, p65 nuclear factor (NF)-kB, p-p65 NF-κB, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) through western blotting and the expression levels of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and prostaglandin E2 (PGE2) through enzyme-linked immunosorbent assay. The results showed that indigo significantly reduced xylene-induced ear edema, carrageenan-induced paw edema, and acetic acid-induced vascular permeation. In addition, indigo significantly inhibited nociception induced by acetic acid and formalin. However, the level of nociception was not decreased by indigo in the hot plate test, and indigo did not affect spontaneous locomotor activity and motor performance. The expression levels of p-IKKß, p-IκBα, p65 NF-kB, p-p65 NF-κB, COX-2, iNOS, TNF-α, IL-1ß, IL-6, and PGE2 decreased, whereas the expression level of IκBα increased obviously after indigo treatment. In conclusion, indigo exerts significant anti-inflammatory and analgesic activities in mice by inhibiting IKKß phosphorylation and reducing the production of important pain mediators, such as PGE2 and COX-2, via the IKKß/IκB/NF-κB pathway.

N-Methylcytisine Ameliorates Dextran-Sulfate-Sodium-Induced Colitis in Mice by Inhibiting the Inflammatory Response.

This study aimed to investigate the anti-inflammatory effects of N-methylcytisine (NMC) in a dextran sulfate sodium (DSS)-induced colitis model and explore its possible mechanisms. Experimental colitis was induced by administering the mice with 5% DSS for 7 days. Different doses of NMC (1, 4 and 16 mg/kg) and 5-aminosalicylic acid (100 mg/kg) were given orally once every day for 7 days. The protective effect of NMC was evaluated using the disease activity index, colon length and results of histopathological examination. The possible mechanisms of NMC were explored by evaluating the expression levels of tumour necrosis factor-α, interleukin-1ß and interleukin-6 (IL-6) using ELISA and analysing the protein expression levels of nuclear factor (NF)-κB p65, p-NF-κB p65, p-IκB, IκB, IκB kinase (IKK) and p-IKK using western blots. Results demonstrated that the oral administration of NMC attenuated the DSS-induced clinical symptoms and pathological damage. In addition, NMC treatment significantly reduced myeloperoxidase activity and level of pro-inflammatory cytokines. Further studies revealed that NMC blocked the activation of NF-κB by inhibiting IκB and IKK phosphorylation. These findings suggested that NMC exerts anti-inflammatory effects on DSS-induced colitis, and its mechanism may be related to the suppression of NF-κB activation. Thus, NMC may have potential therapeutic value in the treatment of colitis.

Protective effect of gentiopicroside against dextran sodium sulfate induced colitis in mice.

This study was designed to investigate the anti-inflammatory activity of the pure compound gentiopicroside (Gent) on dextran sulfate sodium (DSS)-induced colitis in a mouse model and to explore the possible related mechanisms. Experimental colitis was induced in ICR mice by dissolving 5% DSS in their drinking water for 7days. Gent (200, 100, and 50mg/kg) and 5-aminosalicylic acid (5-ASA, 100mg/kg) were oral administrated once a day for 7days. Anti-inflammatory effects were evaluated by comparing extend of colonic mucosal injury assessed by disease activity index (DAI), colon length, histopathological examination, and biochemical test. The possible mechanisms of Gent activities were explored by evaluating expression levels of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), IL-6 using real-time fluorogenic PCR and expression levels of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) using Western blotting. The results showed that oral administration of Gent significantly attenuated DSS-induced loss of body weight, diarrhea, shortening of colon length and histological changes, associated with the decrease in the activity of myeloperoxidase (MPO) in the colon. In addition, the mRNA expression of TNF-α, IL-1ß, IL-6 and the overexpression of COX-2 and iNOS proteins in the colon were down-regulated by Gent treatment. To our knowledge, this is the first study to demonstrate that Gent treatment can exert anti-inflammatory effects on experimental acute colitis through attenuating the expression levels of TNF-α, IL-1ß, IL-6, iNOS and COX-2, and it may present the therapeutic potential in the treatment of colitis.