Antiproliferative Activity of the Isofuranonaphthoquinone Isolated from Bulbine frutescens against Jurkat T Cells

Figure 10

Schematic diagram of GSH-based detoxification pathway. MCB is used as a model substrate for conjugation to GSH by GST in the cytosol and there is subsequent sequestration by a GSX pump. MCB is not fluorescent until conjugated to GSH giving the MCB-GSH conjugate. If another xenobiotic substrate for conjugation is present such as isofuranonaphthoquinone (Iso), competition will occur (Iso-GSH), resulting in the decrease in fluorescence signal from MCB-GSH conjugate formation.