ABSTRACT
On the basis of reports that ginger [Zingiber officinale, Z. officinale] extract has antiinfalammatory activity, the present study was undertaken to investigate whether the aqueous extract of Z. officinale has any significant beneficial effect on chronic inflammation in diabetic mice. Control mice received normal saline [0.1 ml, i.p.], and in the test group, diabetes was induced by injection of streptozotocin [STZ, 180mg/kg, i.p.] which was confirmed by the measurement of blood glucose, 7 days after STZ injection. One week after saline or STZ injection, chronic inflammation was induced by implantation of cotton pellets [30 mg] on each side of the groin region subcutaneously. Then at the day of 3, the aqueous extract of Z.officinale was added to drinking water [100, 200 and 400 mg/100 ml] for 4 days. In another sets of experiments, L-NAME, a nitric oxide synthase inhibitor, [0.1 mg/kg, i.p.] and indomethacin, an inhibitor of the prostaglandin biosynthesis, [2 mg/kg, i.p.] were injected at the day of 5 of implantation. On the 8th day, the mice were killed and the pellets were removed, freed from extraneous tissue and dried at 60 °C for 24h. The increase in the weight of cotton pellets was higher in diabetic mice [control: 160 +/- 13.6 mg,diabetic: 271 +/- 11.8 mg, P<0.001]. Pretreatment with the aqueous extract of Z. officinale caused a significant but not dose-dependent reduction in cotton pellet weight in diabetic animals [diabetic + Z.officinale's extract: 181.4 +/- 21 mg, P<0.05 vs diabetic]. The anti-inflammatory effect of extract was almost the same as L-NAME, but less than indomethacin. Results suggest that the anti-inflammatory effects of aqueous extract of Z. officinale are comparable to L-NAME