Intestinal oxidative state can alter nutrient and drug bioavailability

Area of Science:

• Biochemistry
• Cell Biology
• Pharmacology

Background:

• Organic cations (OCs) are essential molecules that require specific transporters for cellular uptake.
• Organic cation transporters (OCTs) play a crucial role in regulating OCs, and their activity can be modulated by cellular conditions.
• Oxidative stress is implicated in altering protein function, potentially affecting OCT-mediated transport.

Purpose of the Study:

• To investigate the influence of oxidative stressors, particularly glutathione, on intestinal organic cation absorption.
• To assess the impact of redox potential on the uptake of 1-methyl-4-phenylpyridinium iodide (MPP+) in Caco-2 cells.

Main Methods:

• Utilized Caco-2 enterocyte cell line cultured under physiological (5 mM glucose) and high-glucose (25 mM glucose) conditions.
• Assessed the uptake of MPP+ in response to compounds with varying redox potentials, including glutathione and procyanidins.
• Evaluated the effect of cellular oxidative state on MPP+ transport.

Main Results:

• High-glucose conditions significantly reduced MPP+ uptake compared to physiological conditions.
• Redox-modifying interventions altered MPP+ uptake in both control and high-glucose Caco-2 cells.
• Cellular glutathione levels were found to significantly impact membrane transporter activity.

Conclusions:

• Modifications in the cellular oxidative state directly influence MPP+ uptake by Caco-2 cells.
• Glutathione and other antioxidants play a role in regulating organic cation absorption.
• Changes in intestinal organic cation absorption due to oxidative stress may affect nutrient and drug bioavailability.