Related Experiment Video
Updated: May 18, 2026

Cell-free Biochemical Fluorometric Enzymatic Assay for High-throughput Measurement of Lipid Peroxidation in High Density Lipoprotein
Published on: October 12, 2017
Human plasma paraoxonase 1 (PON1) arylesterase activity during aging: correlation with susceptibility of LDL
Mohammad Murtaza Mehdi1, Syed Ibrahim Rizvi
1Department of Biochemistry, University of Allahabad, Allahabad, Uttar Pradesh 211002, India.
Background And Aims:
The role of free radicals has long been proposed as a cause for the aging process. Oxidative stress is considered a major factor for altering many physiological processes and enzymatic activities during aging and is also known to play a major role in the development of several age-dependent diseases. Paraoxonase 1 (PON1) is an anti-atherosclerotic enzyme that mainly prevents accumulation of lipoperoxides and inhibits the lipid oxidation in low-density lipoproteins (LDL). This study was undertaken to investigate the antioxidant behavior of PON1 by measuring its arylesterase activity. The susceptibility of LDL for oxidation and the radical scavenging activity of plasma were also measured during aging in humans.
Methods:
Arylesterase activity of PON1 was measured in plasma of human subjects between 20 and 81 years of age of both genders. The susceptibility of LDL for oxidation and radical scavenging activity were measured in plasma.
Results:
Decrease in plasma arylesterase activity of PON1, increase in susceptibility of LDL for oxidation and decrease in plasma radical scavenging activity were observed as a function of human age.
Conclusions:
The study provides evidence of a relationship between PON1 activity, LDL oxidation and free radical scavenging activity of plasma. The present results emphasize the dependency of PON1 activity to prevailing oxidative stress during human aging. Our findings assume significance in view of the possible categorization of PON1 as a longevity gene.
Related Concept Videos
Peroxisomes
Pharmacokinetics in Geriatric Patients: Effect of Age on Drug Metabolism
Pharmacokinetics in Geriatric Patients: Effect of Age on Drug Distribution
Oxidation of Phenols to Quinones
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...

