TLR4 and atherosclerosis: Emodin was extracted from the dried rhizome and root of P. cuspidatum and was shown to inhibit the levels of inflammatory factors and reactive oxygen species (ROS) by inhibiting the TLR4/NF-κB signalling pathway, thereby acting as an anti-inflammatory and antioxidant agent, protecting the vascular endothelium and preventing atherosclerosis [19].