Apigenin-d5 is an internal standard for the quantificaiton of apigenin by GC- or LC-MS. Apigenin is a flavonoid compound found in many fruits and vegetables that selectively inhibits casein kinase 2 (CK2). Apigenin inhibits CK2 activity in the renal cortex with an IC50 value of 30 μM to improve renal function in a rat model of glomerulonephritis. CK2 inhibition by 20 μM apigenin decreases the degradation of IκBα and down-regulates NF-κB levels in WEHI-231 cells. Apigenin, at 5 μM, is a potent inhibitor of the synthesis of the inflammatory mediators nitric oxide and prostaglandin E2, reducing inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression by 56% and 64%, respectively, in the macrophage cell line J774A.1.
