Mechanism of Didangtang in Inhibiting Aortic NLRP3 Inflammasome Cascade of Mice with Diabetic Macrovascular Disease / 中国实验方剂学杂志

ABSTRACT

Objective:To explore the progression of diabetic macrovascular disease and the effects of Didangtang at different doses on it. Method:Four-week-old male apolipoprotein-E knockout （ApoE^-/-） mice with diabetic macrovascular disease induced by exposure to high-fat diet combined with streptozotocin （STZ） were randomly divided into the model， simvastatin， as well as high-， medium-， and low-dose Didangtang groups. The age-matched ApoE^-/- mice of the same batch only fed with a high-fat diet were classified into the ApoE^-/- （model control） group， and C57BL/6 mice with the same genetic background receiving a regular diet into the normal group. The sampling was conducted at the 8th and 20th weeks of the experiment for observing the pathological characteristics of the aorta and the proportion of plaque area in mice of each group at different time points， followed by the comparison of blood glucose， blood lipid， and oxidized low-density lipoprotein （ox-LDL） levels. The aortic NOD-like receptor protein 3 （NLRP3） and cysteinyl aspartate-specific proteinase-1 （Caspase-1） protein expression was detected by Western blot assay， and the serum interleukin-1<italic>β</italic> （IL-1<italic>β</italic>）， interleukin-18 （IL-18）， interleukin-1<italic>α</italic> （IL-1<italic>α</italic>）， and tumor necrosis factor-<italic>α</italic> （TNF-<italic>α</italic>） levels by enzyme-linked immunosorbent assay （ELISA）. Result:The comparison with the normal group revealed that the proportions of plaque area in the ApoE^-/- group and the model group were increased （<italic>P</italic><0.01）， while the proportion of plaque area in each administration group was significantly reduced in contrast to that of the model group （<italic>P</italic><0.05）. The aortic NLRP3 and Caspase-1 protein expression levels as well as the serum IL-1<italic>β</italic>， IL-18， IL-1<italic>α</italic>， and TNF-<italic>α </italic>levels in the ApoE^-/- group and the model group were significantly higher than those in the normal group （<italic>P</italic><0.01）. Compared with the model group， each administration group exhibited a significant reduction in aortic NLRP3 and Caspase-1 protein expression and serum IL-1<italic>β</italic>， IL-18， IL-1<italic>α</italic>， and TNF-<italic>α</italic> levels （<italic>P</italic><0.05）， with the strongest inhibitory effect detected in the medium-dose Didangtang group （<italic>P</italic><0.05）. Conclusion:Didangtang directly alleviates diabetic macrovascular disease possibly by down-regulating NLRP3 and Caspase-1 protein expression and easing the inflammatory cascade.