ApigeninS2262

Apigenin inhibits PKC by competing with adenosine triphosphate (ATP). Apigenin also reduces the level of TPA-stimulated phosphorylation of cellular proteins and inhibits TPA-induced c-jun and c-fos expression. Apigenin exhibits the reverting effect on the transformed morphology of v-H-ras transformed NIH3T3 cells. ^[1] Apigenin has been shown to possess anti-mutagenic properties in a setting of nitropyrene-induced genotoxicity in Chinese hamster ovary cells. Apigenin suppresses of LPS-induced cyclooxygenase-2 and nitric oxide synthase-2 activity and expression in mouse macrophages. Apigenin has been reported to inhibit protein kinase C activity, mitogen-activated protein kinase (MAPK), transformation of C3HI mouse embryonic fibroblasts and downstream oncogenes in v-Ha-ras-transformed NIH3T3 cells. Apigenin blocks peroxisome proliferation-regulated kinase (ERK), a MAPK in isolated hepatocytes. Apigenin has further been shown to down-regulate the expression of the Na⁺/Ca²⁺-exchanger, a protein important for calcium extrusion in neonatal rat cardiac myocytes. Apigenin induces a reversible G2/M and G0/G1 arrest by inhibiting p34 (cdc2) kinase activity, accompanied by increased p53 protein stability in epidermal cells and fibroblasts. Apigenin is also effective in inhibiting TNFα-induced intracellular adhesion molecule-1 upregulation in cultured human endothelial cells. Apigenin inhibits the expression of HIF-1α and VEGF via the PI3K/Akt/p70S6K1 and HDM2/p53 pathways in human ovarian cancer cells. ^[2] Apigenin inhibits differentiation by suppressing MAPK signal transduction and reducing API transcription factor level in human keratinocytes. Apigenin also inhibits proliferating of human keratinocytes. ^[3]