Coompo Research Chemicals

The iridoid glycoside, monotropein, was tested for its anti-inflammatory antinociceptive effects using hot plate- and writhing antinociceptive assays and by using carrageenan-induced anti-inflammatory assays in mice and rats. Pretreatment with monotropein (at 20, 30 mg/kg/d, p.o.) significantly reduced stretching episodes and prolonged action time in mice. It also significantly reduced acute paw edema by carrageenan in rats. These results indicate that monotropein contributes to the antinociceptive and anti-inflammatory action of Morinda officinalis root.

Monotropein was found to inhibit the expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) mRNA in LPS-induced RAW 264.7 macrophages. Treatment with monotropein decreased the DNA binding activity of nuclear factor-κB (NF-κB). Consistent with these findings, monotropein also suppressed phosphorylation and degradation of inhibitory κB-α (IκB-α), and consequently the translocations of NF-κB. In the DSS-induced colitis model, monotropein reduced disease activity index (DAI), myeloperoxidase (MPO) activity, and inflammation-related protein expressions by suppressing NF-κB activation in colon mucosa. Taken together, these findings suggest that the anti-inflammatory effects of monotropein are mainly related to the inhibition of the expressions of inflammatory mediators via NF-κB inactivation, and support its possible therapeutic role in colitis.