Regulation of the nitric oxide synthesis pathway and cytokine balance contributes to the healing action of Myristica malabarica against indomethacin-induced gastric ulceration in mice.

The role of the ariginine-metabolism in the healing action of the methanol extract of Myristica malabarica (rampatri) (RM) and omeprazole (Omez) against indomethacin-induced stomach ulceration in mouse was investigated. Indomethacin (18 mg/kg) was found to induce maximum stomach ulceration in Swiss albino mice on the 3rd day of its administration, which was associated with reduced arginase activity (38.5%, p < 0.05), eNOS expression, along with increased iNOS expression, total NOS activity (5.37 fold, p < 0.001), NO generation (55.1%, p < 0.01), and ratio of pro-/anti-inflammatory cytokines. Besides providing comparable healing as Omez (3 mg/kg × 3 d), RM (40 mg/kg × 3 d, p.o.) shifted the iNOS/NO axis to the arginase/polyamine axis as revealed from the increased arginase activity (59.5%, p < 0.01), eNOS expression, and reduced iNOS expression, total NOS activity (73%, p < 0.001), and NO level (49.8%, p < 0.01). These could be attributed to a favourable anti/pro inflammatory cytokines ratio, generated by RM. The healing by Omez was however, not significantly associated with those parameters.