Rice Endosperm Protein Improves the Anti-Inflammatory Effects of High-Density Lipoprotein and Produces Lower Atherosclerotic Lesion Accelerated by the Renal Mass Reduction than Casein in a Mouse Model.

Chronic kidney disease (CKD) impairs the anti-inflammatory effects of high-density lipoprotein (HDL) and increases cardiovascular mortality. Though the potential role of dietary interventions to manage HDL is well studied, the clinical trials aimed to increase HDL levels have failed to reduce cardiovascular risk, rendering HDL function to be explored as a more relevant clinical parameter. This study investigates the effects of rice endosperm protein (REP), a plant-based protein, on the anti-inflammatory properties of HDL and renal injury-driven atherosclerosis in comparison with casein, an animal protein.

Ten-week-old apolipoprotein E-deficient hyperlipidemic mice underwent uninephrectomy. The mice (n = 6 each) were pair-fed a normal casein-based diet or a REP-based diet (both with 20.0% protein content) for seven weeks. Atherosclerotic lesions were detected by en face Sudan IV staining of the aorta.

The number and sizes of the atherosclerotic lesions were significantly lower in the REP-based diet-fed group than the casein-based diet-fed group ( p  = 0.038). However, the REP-based diet neither elicited an ameliorative effect on kidney function or histology nor impacted the cholesterol profiles. Furthermore, HDL from the REP-based diet-fed mice significantly suppressed the inflammatory cytokine response of human umbilical vein endothelial cells than that from the casein-based diet-fed mice (MCP-1, p  = 0.010; IL-6, p  = 0.011; IL-1β, p  = 0.028).

The REP-based diet has a higher potential to lessen the atherosclerotic lesions accelerated by renal mass reduction than a casein-based diet, which could be associated with the anti-inflammatory effects of HDL.