Inhibitory Effect of Phenolic Extract from Garlic on Angiotensin-1 Converting Enzyme and Cisplatin induced Lipid Peroxidation – In Vitro

Allium sativum have been an important food ingredient in the management or treatment of renal disease. Therefore, this study sought to determine the inhibitory effect of phenolic-rich extract from A. sativum on angiotensin 1 converting enzyme (ACE) activity (key enzyme linked to renal dysfunction) and cisplatin-induced lipid peroxidation in rat kidney in vitro. The free phenolics were extracted with 80% acetone, while the bound phenolics were extracted from the alkaline and acid hydrolyzed residue with ethyl acetate. Thereafter, their inhibitory effect on angiotensin 1 converting enzyme (ACE) activity and cisplatin-induced lipid peroxidation in rat kidney were determined-in vitro. The results revealed that the free phenolics had significantly higher (P<0.05) inhibitory effect on ACE activity than the bound phenolics. Furthermore, incubation of rat kidney in presence of 1 mM cisplatin caused a significant increase (P<0.05) in the malondialdehyde (MDA) content, however, both extracts inhibited MDA produced in a dose dependent manner. The additive and/or synergistic action of the free and bound phenolics could have contributed to the observed medicinal properties of the spice. Therefore, inhibition of ACE activity and prevention of oxidative stress in the kidney could be some of the possible mechanism by which they exert nephroprotective properties. However, the bound phenolic extracts showed stronger inhibition on ACE activity in vitro.