effect of artichoke (Cynara scolymus L.) extract on respiratory chain system activity in rat liver mitochondria

• Published in: Phytotherapy research Vol. 24; no. S2; pp. S123 - S128
• Main Authors: Juzyszyn, Z, Czerny, B, Myśliwiec, Z, Pawlik, A, Droździk, M
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.06.2010
• Subjects: Animals; antioxidants; artichoke; Cynara scolymus - chemistry; Electron Transport - drug effects; Electron Transport Complex IV - antagonists & inhibitors; Male; Mitochondria, Liver - drug effects; MRC activity; Oxidoreductases - antagonists & inhibitors; Plant Extracts - pharmacology; Rats; Rats, Wistar
• ISSN: 0951-418X; 1099-1573
• DOI: 10.1002/ptr.2995

The effect of artichoke extract on mitochondrial respiratory chain (MRC) activity in isolated rat liver mitochondria (including reaction kinetics) was studied. The effect of the extract on the activity of isolated cytochrome oxidase was also studied. Extract in the range of 0.68-2.72 μg/ml demonstrated potent and concentration-dependent inhibitory activity. Concentrations ≥5.4 μg/ml entirely inhibited MRC activity. The succinate oxidase system (MRC complexes II-IV) was the most potently inhibited, its activity at an extract concentration of 1.36 μg/ml being reduced by 63.3% compared with the control (p < 0.05). The results suggest a complex inhibitory mechanism of the extract. Inhibition of the succinate oxidase system was competitive (Ki = 0.23 μg/ml), whereas isolated cytochrome oxidase was inhibited noncompetitively (Ki = 126 μg/ml). The results of this study suggest that the salubrious effects of artichoke extracts may rely in part on the effects of their active compounds on the activity of the mitochondrial respiratory chain system. Copyright © 2010 John Wiley & Sons, Ltd.