The Use of Seahorse Extracellular Flux Analyzer in Mechanistic Studies of Naturally Occurring Cancer Chemopreventive Agents

Metabolic pathways and bioenergetics were described in great detail over half a century ago, and during the past decade a resurgence in integrating these cellular processes with other biological properties of the cell, including growth control, protein kinase cascade signaling, cell cycle division, and autophagy, has occurred. Because many chronic pathological conditions, including cancer, are associated with altered metabolism and production of energy, developing new approaches to measure these cellular parameters is important. Recent studies also indicate that many naturally occurring cancer chemopreventive agents, such as watercress constituent phenethyl isothiocyanate and Withania somnifera component withaferin A, alter mitochondrial bioenergetics to elicit death of cancer cells. This chapter summarizes a relatively new and exciting approach based on the Seahorse Extracellular Flux Analyzer, which takes real-time measurements of oxidative phosphorylation and glycolysis in living cells. These bioenergetic profiles are then compared with steady-state levels of cellular adenosine triphosphate as measured by a luciferase assay.