Effects of alcoholic extract of Zingiber officinalis rhizome on acute and chronic inflammation and pain in rats

Patients with chronic, painful diseases often seek alternative therapy. The rhizome of Zingiber (Z) officinalis is a common constituent of diets around the world and its extracts have been reported to exhibit several pharmacological activities. We investigated the effects of alcoholic Zingiber oficinalis rhizome extract on two different models of acute and chronic inflammation and pain. Formalin, xylen and acetic acid were used to induce acute inflammation in paw, ear and peritoneum, respectively. The amount of Evan's blue dye leakage into these tissues was used as an index of acute inflammation. For chronic inflammation, a piece of sterile cotton (30 mg) was impalnated into the groin region for a period of seven days. Following, t he weight of the cotton piece before implantation is subtracted from the weight of the dried piece and used as an index of chronic inflammation. Finally, acute and chronic pain assessment was carried out via the formalin test protocol. In acute inflammation model, the formalin-induced inflammation in paw and peritoneum was significantly (P <0.05) reduced by the extract of Z. oficinalis rhizome at doses of 200 and 400 mg/kg. Also, the extract at the dose of 400mg/kg significantly (P<0.05) reduced the paw diameter. In chronic inflammation model, the extract at the dose of 200 mg/kg significantly (P< 0.01) dimished inflammation. Finally, both acute and chronic pain significantly (P< 0.05) suppressed by the extract at the dose of 200 mg/kg. Findings of this study indicate that alcoholic extract of Z. oficinalis has anti-inflammatory and antinociceptive effects. Thus, using the extract of Z. oficinalis could be a potential alternative therapy in ameliorating inflammation and pain in patients suffering from chronic diseases.