Phellopterin is a natural product isolated from P. trifoliata. Phellopterin reduce TNF-alpha-induced VCAM-1 expression through regulation of the Akt and PKC pathway, which contributes to inhibit the adhesion of monocytes to endothelium[1].
[1]. Nizamutdinova IT, et al. Hesperidin, hesperidin methyl chalone and phellopterin from Poncirus trifoliata (Rutaceae) differentially regulate the expression of adhesion molecules in tumor necrosis factor-alpha-stimulated human umbilical vein endothelial cells. Int Immunopharmacol. 2008 May;8(5):670-8.