Methods: RAW264.7 macrophages were pretreated with ethanolic extracts of Zingiber cassumunar and its constituents (DMPBD, compound B, compound B' and compound D) at the concentration of 100 µg/ml for 4 h prior to stimulating with LPS (100 ng/ml) for 24 h. Then, the mRNA levels of iNOSwere detected by Real-time PCR method. Pretreated of Raw 264.7 cells with crude phlai extracts and its constituents (0-100 µg/ml) for 4 h and then with LPS (100 ng/ml) for 30 min to determine pI-κBα phosphorylation and pp65NF-κB nuclear translocation using western blotting.
Results: Crude phlai extracts and compound D at the concentration of 100 µg/ml inhibited iNOS expression by phosphorylated inhibitor of pp65NF-κB and pI-κBα from LPS-stimulated macrophages. In contrast, DMPBD, compound B, and compound B' at 100 µg/ml could not inhibited the pp65NF-κB and pI-κBα activation induced by LPS.
Conclusions: These results demonstrate that crude phlai extracts and compound D has anti-inflammatory effects through the inhibition of iNOS expression by suppressing the phosphorylation of pI-κBα and pp65NF-κB nuclear translocation.