Studies on HDL associated enzymes under experimental hypercholesterolemia: possible modulation on selenium...

Area of Science:

• Biochemistry
• Nutritional Science
• Cardiovascular Research

Background:

• Atherosclerosis is a chronic arterial disease characterized by plaque formation.
• High-density lipoproteins (HDL) possess antioxidant properties, partly via paraoxonase1 (PON1) and platelet-activating factor acetylhydrolase (PAF-AH).
• Experimental hypercholesterolemia in rats was induced using a high-fat diet (HFD).

Purpose of the Study:

• To investigate HDL-associated enzymes PON1 and PAF-AH in experimental hypercholesterolemia.
• To evaluate the modulatory effects of selenium (Se) supplementation on these enzymes.

Main Methods:

• Male Sprague Dawley rats were divided into three groups: control, HFD, and HFD + Se.
• Dietary interventions lasted for 4 months.
• Lipid profiles, serum selenium, reactive oxygen species (ROS) levels, PON1 and PAF-AH activities/protein levels, and hepatic mRNA expression were assessed.

Main Results:

• HFD significantly increased cholesterol, triglycerides, HDL, and LDL. Se supplementation reduced triglycerides but did not alter other lipid values.
• HFD elevated hepatic ROS levels and reduced serum PON1 activity and protein. Se supplementation diminished ROS and improved PON1 activity and levels.
• Se did not significantly affect PAF-AH protein levels or the hepatic mRNA expression of PON1 and PAF-AH in HFD-fed rats.

Conclusions:

• Selenium supplementation demonstrates a protective effect in hypercholesterolemia, primarily by restoring the antioxidant function of HDL-associated PON1.
• The biological system appears to maintain PAF-AH levels despite selenium supplementation, suggesting complex roles in atherogenesis.
• Selenium supplementation may be a valuable strategy to mitigate hypercholesterolemia's adverse effects, warranting further investigation.