Possible attenuation of nitric oxide expression in anti-inflammatory effect of Ziziphus jujuba in rat.

The hydroalcoholic extract of fruits of Ziziphus jujuba (ZJ) was investigated for its anti-inflammatory effect using acute and chronic models of inflammation in rat. Wistar albino rats of either sex were employed in the present study (n = 6). Acute inflammation was induced by subplantar administration of carrageenan (1%) in rat hind paw. Chronic inflammation was induced by interscapular implantation of a sterile cotton pellet (50 mg). ZJ extract as test drug and indomethacin (10 mg/kg) as standard were used. Serum nitrite/nitrate was also estimated to determine the expression of nitric oxide. In the acute study, carrageenan (1%) administration caused marked paw edema. Pretreatment with ZJ extract exhibited marked dose-dependent attenuation in edema compared to control. In the chronic study, interscapular implantation of sterile cotton pellets caused significant granuloma formation after 7 days, serving as control. ZJ extract significantly decreased granuloma tissue formation compared to control. The serum nitrite/nitrate level was significantly increased after 7 days in the control group due to chronic inflammation, but was decreased by ZJ extract. Moreover, phytochemical studies indicated the presence of jujubosides, flavonoids and terpenes, which may produce the marked anti-inflammatory effect of ZJ fruit in acute and chronic inflammation, possibly by inhibiting nitric oxide expression. The study provides a scientific and ethnopharmacological rationale for the therapeutic use of ZJ fruit as an anti-inflammatory agent.