Natural product as a lead for impairing mitochondrial respiration in cancer cells

Area of Science:

• Biochemistry
• Cell Biology
• Pharmacology

Background:

• Usnic acid derivatives are explored for therapeutic potential.
• Cancer cells exhibit altered metabolic pathways.
• Mitochondrial function is a key target in cancer therapy.

Purpose of the Study:

• To investigate the metabolic effects of ISOXUS on cancer and normal cells.
• To determine the molecular mechanism of ISOXUS action.
• To evaluate ISOXUS's impact on cell viability and ROS production.

Main Methods:

• Cell culture (MCF-7 breast cancer, HB2 normal epithelial cells).
• Metabolic assays measuring substrate utilization, oxygen consumption rate (OCR).
• Molecular docking and experimental validation of mitochondrial respiratory chain complex II inhibition.
• Reactive oxygen species (ROS) detection and assessment of antioxidant effects.

Main Results:

• ISOXUS significantly reduced metabolic substrate utilization, mitochondrial electron flow, and OCR in MCF-7 cells, but not HB2 cells.
• Molecular docking and experiments confirmed ISOXUS inhibits mitochondrial respiratory chain complex II.
• Inhibition led to increased ROS production in cancer cells, causing vacuolization and reduced cell survival.
• Antioxidant α-tocopherol protected against ISOXUS-induced cell damage.

Conclusions:

• ISOXUS acts as a metabolic inhibitor targeting mitochondrial complex II in breast cancer cells.
• This inhibition results in decreased ATP production and elevated ROS levels.
• The observed effects translate to reduced cancer cell viability, suggesting therapeutic potential.