Hydrogen influences HDL-associated enzymes and reduces oxidized phospholipids levels in rats fed with a high-fat diet.

AIMS

Oxidized phospholipids (OxPLs) are formed as a result of oxidative stress, which potentially mediate multiple pathological effects. We aimed to evaluate the effects of hydrogen (H) on OxPLs in vivo and the underlying mechanism.

MAIN METHODS

Rats were randomly assigned to three groups: control group fed with a chow diet, model group fed with a high-fat diet, and H-treated group fed with a high-fat diet and treated by 4% H inhalation for ten weeks. OxPLs in liver and plasma were analyzed by liquid chromatography-mass spectrometry. High-density lipoprotein (HDL) was separated by ultracentrifugation. A proteomic analysis was performed to reveal the alternation of HDL protein composition and he antioxidant capacity of HDL was tested by low-density lipoprotein oxidation experiment. Furthermore, the activity or expression of HDL-associated enzymes were evaluated.

KEY FINDINGS

Inhalation of 4% H decreased the accumulation of OxPLs in rats. In vitro tests revealed that the different concentrations of H did not inhibit the formation of OxPLs mediated by non-enzymatic oxidation. H inhalation altered the components and enhanced the anti-oxidative capacity of HDL in rats fed with a high-fat diet. Further experiments showed that H significantly regulated the activity of lipoprotein-associated phospholipase A, paraoxonase-1, and the expression of lecithin:cholesterol acyltransferase.

SIGNIFICANCE

Our findings revealed that H may reduce the OxPLs levels through its influence on HDL-associated enzymes that can act on OxPLs, suggesting that H can be used in alleviating diseases related to lipid peroxidation due to oxidative stress.