Capsiate attenuates atherosclerosis by activating Nrf2/GPX4 pathway and reshaping the intestinal microbiota in ApoE-/- mice.

Abstract

Atherosclerosis (AS) is the basis of cardiovascular diseases (CVDs) and remains the major contributor to death worldwide. Capsiate is derived from sweet pepper fruit and exhibits numerous pharmacological activities. The objective of this study was to elucidate the protective role of capsiate in atherosclerosis by examining its effect and the underlying regulatory pathways. Here, we showed that capsiate treatment alleviates atherosclerosis in atherosclerosis-prone apolipoprotein E-deficient (ApoE^-/-) mice. We found that capsiate effectively reduced the plaque area and body weight compared to the Model group. Capsiate inhibited inflammatory response by downregulating phosphoinositide 3-kinase/protein kinase B/nuclear factor-κB pathway. Additionally, further investigation indicated that capsiate could regulate lipid levels in mice via reducing the expressions of 3-hydroxy-3-methylglutaryl coenzyme A reductase and low-density lipoprotein receptor, and increasing the expression of recombinant cytochrome P450 7A1. Furthermore, capsiate effectively activated transient receptor potential vanilloid subfamily member 1 in ApoE^-/- mice fed a high-fat diet. The microbial sequencing demonstrated capsiate administration significantly regulated the gut microbiota disturbance and increased some beneficial bacterial (Lachnospiraceae NK4A136 group) levels in ApoE^-/- mice. Human umbilical vein endothelial cells (HUVECs) were exposed to oxidized low-density lipoprotein (ox-LDL) to stimulate atherosclerotic endothelial damage in vitro. Our study revealed that capsiate inhibited ox-LDL-induced HUVECs injury and inflammation. We further investigated the effects of capsiate on ferroptosis in vivo and in vitro; it was found that capsiate exhibited anti-ferroptosis through regulating nuclear factor erythroid 2-related factor 2/glutathione peroxidase 4 pathway. Interestingly, ML385 reversed the anti-ferroptosis effect of capsiate in HUVECs. Taken together, our findings suggest a promising use of small-molecule drug capsiate for the treatment of AS and related CVDs.

Importance: Capsiate has been found to inhibit fat accumulation, promote energy metabolism, and exhibit anti-inflammatory and antioxidative properties. However, there has still been no study on the ferroptosis and gut microbiota of capsiate in atherosclerosis (AS) mouse models. Our study is the first to report on the reshaping of the structure of the gut microbiota by capsiate in AS, and to explore the potential mechanism underlying the improvement of AS. In this study, we demonstrated that capsiate could effectively alleviate high-fat diet-induced AS in apolipoprotein E-deficient mice by inhibiting inflammatory response, improving serum lipid profiles, activating transient receptor potential vanilloid subfamily member 1 pathway, and suppressing ferroptosis. Moreover, the study reported the potential of gut microbiota as mediators of capsiate therapy for AS in animal models. Therefore, these findings may provide robust experimental support for the clinical use of capsiate for AS treatment.