Pharmacological Activity of 6-Gingerol in Dextran Sulphate Sodium-induced Ulcerative Colitis in BALB/c Mice

Role of serotonin and nuclear factor-kappa B in the ameliorative effect of ginger on acetic acid-induced colitis

The current study was designed to investigate the role of serotonin (5-HT) and nuclear factor-kappa beta (NF-κB) in the ameliorative effect of ginger on acetic acid (AA)-induced colitis rat model. Colitis was induced by intra-colonic instillation of 3% AA, preceded or followed by daily administration of ginger (400mg/kg) by gavage for 5 days. Colons were assessed macroscopically and microscopically and the expression of NF-κB was evaluated by immunohistochemistry. Colonic tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10), total peroxide (TP), and serum 5-HT levels were assessed. Administration of ginger ameliorated the effects of AA-induced colitis by plummeting colon weight-to-length ratio, macroscopic and microscopic scores. These effects were further supported by down-regulation of NF-κB and reduction of colonic TNF-α, IL-10, TP and serum 5-HT levels. Moreover, there were significant positive correlations between serum 5-HT and macroscopic, microscopic, immunoreactivity scores and colonic TNF-α level. In conclusion, ginger ameliorated AA-induced colitis not only through its anti-inflammatory and anti-oxidant properties, but also through the reduction of 5-HT which may contribute to the down-regulation of NF-κB-dependent TNF-α expression and the reduction of lipid peroxidation and tissue damage. In addition, the therapeutic effect of ginger was more pronounced than its preventive effect.

Gingerol protects against experimental liver fibrosis in rats via suppression of pro-inflammatory and profibrogenic mediators

6-Gingerol (Gin) is known to possess hepatoprotective effects. Liver fibrosis is a major health concern that results in significant morbidity and mortality. There is no FDA-approved medication for liver fibrosis. The present work aimed at exploring the beneficial effects of Gin against liver fibrosis in rats. Experimental fibrosis was induced by challenging animals with CCl4 for 6 weeks. Gin significantly ameliorated the increase in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, albumin, total cholesterol (TC) and triglyceride (TG) concentrations, and liver index. These effects were confirmed by light and electron microscopic examinations. The antifibrotic effects were confirmed by examining Masson trichrome-stained liver sections which indicated reduced collagen deposition in Gin-treated animals. Further, Gin administration hampered alpha-smooth muscle actin (α-SMA) expression and significantly reduced hepatic content of transforming growth factor-beta (TGF-β). Also, Gin elicited profound antioxidant actions as indicated by preventing reduced glutathione (GSH) depletion and lipid peroxide accumulation. The observed antifibrotic activities involved decreased production of nuclear factor κB (NF-κB), tumor necrosis factor alpha (TNF-α), expression of toll-like receptor 4 (TLR4), intercellular adhesion molecule (ICAM), and vascular cell adhesion molecule (VCAM). Involvement of Gin anti-inflammatory activity was verified by the decreased expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in livers of animals treated with Gin. Thus, it can be concluded that Gin protects against CCl4-induced liver fibrosis in rats. This can be ascribed, at least partly, to its antioxidant, anti-inflammatory effects as well as the inhibition of NF-κB/TLR-4 expression.

6-Gingerol modulates proinflammatory responses in dextran sodium sulfate (DSS)-treated Caco-2 cells and experimental colitis in mice through adenosine monophosphate-activated protein kinase (AMPK) activation

BACKGROUND

6-gingerol has been reported to have anti-inflammatory effects in different experimental settings. The present study aimed at evaluating the effect of 6-gingerol on dextran sodium sulfate (DSS)-induced barrier impairment and inflammation in vitro and in vivo.

METHODS

a differentiated Caco-2 monolayer was exposed to DSS and treated with different concentrations of 6-gingerol (0, 1, 5, 10, 50, and 100 μM). Changes in intestinal barrier function were determined using transepithelial electrical resistance (TEER). The anti-inflammatory activity of 6-gingerol was examined as changes in the expression of proinflammatory cytokine using quantitative real-time PCR. Western blotting was employed to determine the activation of adenosine monophosphate-activated protein kinase (AMPK). Mice with DSS-induced colitis were given different oral dosages of 6-gingerol daily for 14 days. Body weight and colon inflammation were evaluated, and level of proinflammatory cytokines in colon tissues was measured.

RESULTS

6-gingerol treatment was shown to restore impaired intestinal barrier function and to suppress proinflammatory responses in DSS-treated Caco-2 monolayers. We found that AMPK was activated on 6-gingerol treatment in vitro. In animal studies, 6-gingerol significantly ameliorated DSS-induced colitis by restoration of body weight loss, reduction in intestinal bleeding, and prevention of colon length shortening. In addition, 6-gingerol suppressed DSS-elevated production of proinflammatory cytokines (IL-1β, TNFα, and IL-12).

CONCLUSION

our findings highlight the protective effects of 6-gingerol against DSS-induced colitis. We concluded that 6-gingerol exerts anti-inflammatory effects through AMPK activation. It is suggested that 6-gingerol has a promising role in treatment of IBD.

The Sasa quelpaertensis Leaf Extract Inhibits the Dextran Sulfate Sodium-induced Mouse Colitis Through Modulation of Antioxidant Enzyme Expression

Background:

Oxidative stress plays an important role in the pathogenesis of inflammatory bowel disease. The objective of this study is to investigate the protective effect of Sasa quelpaertensis leaf extract (SQE) against oxidative stress in mice with dextran sulfate sodium (DSS)-induced colitis.

Methods:

Mice were treated with SQE (100 mg/kg or 300 mg/kg body weight) by gavage in advance two weeks before inflammation was induced. Then, the mice were administered with 2.5% DSS in drinking water for 7 days and normal drinking water for 7 days between two DSS treatment. Disease activity index values, gut motility, and severity of the resulting oxidative DNA damage were analyzed. The antioxidant effect of SQE was evaluated by measuring malondialdehyde (MDA) and superoxide dismutase (SOD) activity in plasma samples. Catalase activity and expressions levels of glutathione peroxidase 1 (Gpx1), SOD1, and SOD2 were also detected in colon tissues.

Results:

Administration of SQE significantly reduced the severity of DSS-induced colitis compared to the control (Ctrl) group. Levels of 8-oxo-dG, an oxidative DNA damage marker, were significantly lower in the SQE group compared to the untreated DSS Ctrl group. In the SQE (300 mg/kg) group, MDA levels were significantly lower, while SOD and catalase activity levels in the plasma samples were significantly higher compared with the DSS Ctrl group. The expression levels of the antioxidant enzymes, SOD2 and Gpx1, were significantly higher, while the levels of SOD 1 expression were lower, in the colon tissues of the DSS Ctrl group compared with those of the Ctrl group. In contrast, administration of SQE significantly down-regulated SOD2 and Gpx1 expressions and up-regulated SOD1 expression.

Conclusions:

These results indicate that SQE efficiently suppresses oxidative stress in DSS-induced colitis in mice, and its action is associated with the regulation of antioxidant enzymes.