Chrysin inhibits propagation of HeLa cells by attenuating cell survival and inducing apoptotic pathways

Chrysin, one of the main active constituents of flavonoids, is known for demonstrating protective effects against various types of cancer including cervical cancer. The aim of this study was to determine apoptosis induction and antiproliferative action of chrysin on human cervical cancer cells.

In this study, attempts have been made to establish anticancer role of chrysin on HeLa cells. MTT, mitochondrial potential, DNA fragmentation, annexin V/propidium iodide assays, qPCR and protein profiling were performed.

Chrysin treated HeLa cells showed time and dose dependent decrease in cell viability and demonstrated profound effects on nuclear morphology and DNA fragmentation. Chrysin treatment increased the expression of proapoptotic genes BAD, BAX, BID, BOK and APAF1, TNF, FASL, FAS, FADD and caspases (like caspase 3, caspase 7, caspase 8 and caspase 9), whereas it decreased the expression level of antiapoptotic genes MCL-1, NAIP, XIAP and Bcl-2 and cell cycle regulatory genes CCNB1, CCNB2, CCND1, CCND2, CCND3, CCNE2, CDK4 and CDK2 at transcript level. Furthermore, chrysin significantly upregulated pro-apoptotic proteins, like TRAILR2/DR5, TRAILR1/DR4, Fas/TNFRSF6/CD95, phosphoP53(S15), BAD, BAX, cleaved caspase 3, procaspase 3, HTRA2/Omi and SMAC/Diablo, while downregulated anti-apoptotic proteins like BCL-X, BCL2, XIAP and CIAPs that support chrysin mediated apoptosis in HeLa cells. Remarkably, chrysin downregulated the phosphorylated AKT pathway proteins, (p-473) AKT, (p-Ser 2448) mTOR, (p-Ser241) PDK1, (p-Ser112) BAD, and upregulated (p-Ser21) GSK3b, (p-Thr172) AMPKa, P27 (p-Thr198) and (p-Ser15) P53, which endorses chrysin mediated apoptosis.

Chrysin significantly inhibited proliferation and induced apoptosis by modulation of various apoptotic genes and AKT/MAPK pathway genes.