In vivo COX-2 modulation and metabolite profiling of Pandanus tectoriusleaves extracts

The Pandanus tectoriusmethanolic (PTM) and P. tectoriusaqueous (PTA) extracts were investigated for their potential in vivo anti-inflammatory activity using carrageenan-induced rat paw edema. Parameters including paw thickness measurement, histopathological, and immunohistochemical cyclooxygenase (COX)-2 expression analyses were measured and analyzed. PTA at 500 mg/kg significantly reduced inflammation after induction of carrageenan (Carr), with mean paw thickness change of 0.110 ± 0.024 mm at sixth hour post-induction and histopathological mean inflammatory grade of 1.80 ± 0.20. The reduced immunohistochemical COX-2 expression using PTA at 500 mg/kg was determined with mean final 3,3′-diaminobenzidine (DAB) intensity of 63.70 ± 2.08. The profiling of metabolites by liquid chromatography–mass spectrometry (LC–MS) revealed presence of ethyl caffeate and dihydroconiferyl alcohol as putative secondary metabolites of PTA which were the major peaks and have been reported to possess anti-inflammatory activities. This research has provided scientific insights of utilizing P. tectoriusas a potential anti-inflammatory agent containing secondary metabolites which may be pharmacologically relevant.