Mechanism of Didangtang Against Inflammatory Cascade Triggered by Foam Cell Pyroptosis in High-glucose Environment / 中国实验方剂学杂志

ObjectiveTo explore the mechanism of Didangtang （DDT） against the inflammatory cascade triggered by foam cell pyroptosis in high-glucose environment. MethodOxidized low density lipoprotein （ox-LDL， 100 mg·L-1） was used to induce pyroptosis of foam cells. The control group （5.5 mmol·L-1 glucose）， foam cell group （100 mg·L-1 ox-LDL）， high-glucose group （33.3 mmol·L-1 glucose）， DDT group （10% DDT-containing serum）， and NOD-like receptor family pyrin domain-containing 3 （NLRP3） inhibitor group （MCC950， 10 nmmol·L-1） were designed. The cell membrane damage was observed by lactate dehydrogenase （LDH） release assay. The expression of cysteinyl aspartate-specific proteinase-1 （Caspase-1） was detected by immunofluorescence method， and expression of key proteins NLRP3， Caspase-1， gastermin D （GSDMD）， interleukin-1β （IL-1β）， and interleukin-18 （IL-18） in the pyroptosis pathway was determined by Western blot. The release of IL-18 and IL-1β， monocyte chemoattractant protein-1 （MCP-1）， and tumor necrosis factor α （TNF-α） in cell supernatant was measured by enzyme-linked immunosorbent assay （ELISA）. ResultThe expression of NLRP3， Caspase-1， and GSDMD was up-regulated （P<0.01） and the release of IL-1β， IL-18， MCP-1， IL-1α， and TNF-α was increased （P<0.01） in foam cell group compared with those in the control group. The expression of NLRP3， Caspase-1， and GSDMD was higher （P<0.01） and the release of inflammatory factors was more （P<0.01） in the high-glucose group than in the foam cell group. DDT and MCC950 can inhibit expression of NLRP3， Caspase-1， GSDMD and reduce the release of IL-1β， IL-18， MCP-1， IL-1α， and TNF-α. ConclusionDDT can suppress the pyroptosis of foam cells induced by NLRP3/Caspase-1 pathway in high-glucose environment and thereby alleviate the inflammatory cascade.

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

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.

Early intervention with Di-Dang Decoction prevents macrovascular fibrosis in diabetic rats by regulating the TGF-β1/Smad signalling pathway / 中国天然药物

Macroangiopathy is a complication of Type II Diabetes Mellitus (T2DM), which is mainly caused by fibrosis of blood vessels. Using T2DM rat models, we investigated whether the traditional Chinese medicine, Di-Dang Decoction (DDD), exhibited anti-fibrotic actions on great vessels. T2DM rats were randomly divided into non-intervention group, early-, middle-, late-stage DDD intervention groups and control groups, including pioglitazone group and aminoguanidine group. After administration of DDD to T2DM rats at different times, we detected the amount of extracellular matrix (ECM) deposition in the thoracic aorta. The results showed that early-stage intervention with DDD could effectively protect great vessels from ECM deposition. Considering that TGF-β1 is the master regulator of fibrosis, we further validated at the molecular level that, compared to middle- and late-stage intervention with DDD, early-stage intervention with DDD could significantly decrease the expression levels of factors related to the activated TGF-β1/Smad signalling pathway, as well as the expression levels of downstream effectors including CTGF, MMP and TIMP family proteins, which were directly involved in ECM remodelling. Therefore, early-stage intervention with DDD can reduce macrovascular fibrosis and prevent diabetic macroangiopathy.