Enhancement of paclitaxel transport and cytotoxicity by 7,3',4'-trimethoxyflavone, a P-glycoprotein inhibitor.

Purpose: Paclitaxel has problems with respect to bioavailability and resistance. The aim of this study was to select a P-glycoprotein (Pgp)- inhibitory flavonoid to enhance paclitaxel bioavailability in the Caco-2 cell monolayer.

Methods: Cytotoxicity and chemosensitization were determined using MTT assay.

Antioxidant and chemosensitizing effects of flavonoids with hydroxy and/or methoxy groups and structure-activity relationship.

Purpose: Flavonoids have been used as antioxidant, chemopreventive and chemosensitizing agents. In this study, eleven flavonoids containing a variety of hydroxy (OH) and/or methoxy (OMe) groups were evaluated for their antioxidant, cytotoxic and chemosensitizing effects to create a structure-activity relationship (SAR).

Methods: 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical solution-based chemical assay and and 2',7'-dichlorofluorescin diacetate (DCFH-DA) cellular-based assay were used to compare the free radical scavenging activity on the same molar concentration basis using the AML-2/DX100 cells which are characterized by the down-regulated expression of catalase and resulting supersensitiviy to hydrogen peroxide.