Suchart Kothan. Induction de l' appoptose et la reversion de la resistance multiple aux drogues engendrees par les flavonoides et mise en evidence de la cible intracellulaire de ces molecules dans les cellules cancereuses. Doctoral Degree(Biological Science). Burapha University. Library. : Burapha University, 2004.
Induction de l' appoptose et la reversion de la resistance multiple aux drogues engendrees par les flavonoides et mise en evidence de la cible intracellulaire de ces molecules dans les cellules cancereuses
Abstract:
Bioflavonoids are demonstrated to be effective in protection of various normal cell types from oxidative injury. Bioflavonoid as the strong antioxidants renews an interst for cancer treatment since they indce apoptosis of various cancer cell types, but not in normal cells,via induction of the mitochondrial dysfunction in both in vitro and in vivo. In this work.we show that four bioflavonoid molecules such as quercetin, apigenin, kaempferol and eriodictyol mekiated cytotoxicity with Ic50 of K562 and Glc varies 10 to 25 M,and about 2 time more efficient in K562/adr and GLC4/adr eclls. thesc compounds do not inhibit Pgp and MRP1-mediated efflux of Tc-MIBL. They affect the mitochndrial energetic stste by inducing an increase follwed by a decrease in values depending on thir concentrations. Decrasing in values is associated with asignificant increase in the percentage of eary apoptotic cells.An addition of exogenous antioxidant flavonoids into the cells prpvokes an immediate decrease in ROS in a dose-dependent menner which stimulates an increase in mitochondrial polarization reflection relecting an increase in cellular ATP production due to cellular biochemical maintenance.Although quercetin quercetin apigenin,kae,pfeol and eriodictylo show similar antioxidant activities but they interact on the adenine nucleotide translicator (ANT)int the inner mitochondrial membrane in different efficacy.As a consequence, it undergoes a conformation change and provides a cellular apoptotic signal to K562,K562/adr,GLC4/adr cells. A pyrone ring (ring C) with C2-C3 double bond presenting in all molecules used except eriodictyol seems to be necessary for such an interaction but not far their antioxidant activity.Overall results indicate that the flavonoids used in this study react at the mitochondrial level.Therefore mintochondria could be genrally considered as an intracellular drug targer target to overcomme MDR phenomena.