# Effect of Propolis Extracts on OxLDL and LOX-1 Levels in ApoE Knockout Mice Fed a High Fat Diet

## TL;DR

This study shows that propolis extracts can reduce markers of atherosclerosis in mice fed a high-fat diet.

## Contribution

The novel finding is that both water and ethanolic propolis extracts significantly lower OxLDL and LOX-1 levels in a mouse model of atherosclerosis.

## Key findings

- Propolis extracts reduced serum total cholesterol, triglycerides, OxLDL, and LOX-1 levels in mice.
- Aortic tissue OxLDL levels and plaque burden were also significantly decreased by propolis extracts.
- These results suggest propolis may be a potential treatment for atherosclerosis.

## Abstract

Atherosclerosis, which has important effects on the development of cardiovascular diseases, is a widespread health problem with the highest mortality rate globally. In this study, we aimed to assess the impact of water and ethanolic extracts of propolis on oxidized low-density lipoprotein (OxLDL) and lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) in the progression of the atherosclerotic process, which is characterized by oxidative stress, inflammation, and dyslipidemia. In our study, apolipoprotein E knockout (ApoE−/−) and C57BL/6J mice were used as study groups. Water (WEP) and ethanolic extracts (EEP) of propolis were administered intraperitoneally to ApoE−/− and C57BL/6J mice modeled with a high-fat diet. Under anesthesia, the animals were euthanized by decapitation, and serum, along with aortic tissues, was collected. Serum total cholesterol (TC), triglyceride (TG), OxLDL and LOX-1 levels, OxLDL levels in aortic tissue homogenate, and subendothelial lipid accumulation levels by histological staining were determined in mice and statistical analyses were performed. WEP and EEP supplementation significantly decreased serum TC, TG, OxLDL, LOX-1, and tissue OxLDL levels and reduced plaque burden in the aortic root, with statistically significant differences observed. Those results suggest that propolis extracts have a potential treatment option for atherosclerosis, as a food supplement or a complementary medical/functional food. However, further research is needed to elucidate their molecular mechanisms, evaluate clinical efficacy and safety, and explore possible synergistic effects with existing atherosclerosis treatments.