Selective Inos and COX-2 inhibition of Morinda Citrifolia (Noni) fruit extract in rat gastric ulcerated mucosa

Gastric nitric oxide synthase (nNOS, iNOS) and cyclooxygenase (COX-1 and COX-2) inhibitory activity of Morinda citrifolia (noni) aqueous fruit extract (AFE) and ethanolic fruit extract (EFE), two common forms of noni fruit extract used in traditional medicine, was studied in rats treated with topical application of acetic acid. The gastric ulcerated area was excised and the mRNA expression of NOS and COX was analyzed using one-step RT-PCR analysis. Treatment with AFE and EFE at the dose that contain 0.5–1mg/kg of active ingredient: scopoletin for 10d after ulcer induction markedly accelerated ulcer healing that related to their inhibitory activity on an increased mRNA expression level of both pro-inflammatory enzymes (iNOS and COX-2) at the transcription level and at only the excess expression level, but had no markedly inhibitory effect on the mRNA expression level of constitutive nNOS and COX-1 which produce gastric mucosal protective NO and PGs respectively. This indicated that both the fruit extracts at the dose use exerted an optimal oral dose for further clinical study on treatment of human chronic gastric ulcer.