Rhein alleviates advanced glycation end products (AGEs)-induced inflammatory injury of diabetic cardiomyopathy in vitro and in vivo models.

In diabetic patients, diabetic cardiomyopathy (DCM) is one of the most common causes of death. The inflammatory response is essential in the pathogenesis of DCM. Rhein, an anthraquinone compound, is extracted from the herb rhubarb, demonstrating various biological activities. However, it is unclear whether rhein has an anti-inflammatory effect in treating DCM. In our research, we investigated the anti-inflammatory properties as well as its possible mechanism. According to the findings in vitro, rhein could to exert an anti-inflammatory effect by reducing the production of NO, TNF-α, PGE2, iNOS, and COX-2 in RAW264.7 cells that had been stimulated with advanced glycosylation end products (AGEs). In addition, rhein alleviated H9C2 cells inflammation injury stimulated by AGEs/macrophage conditioned medium (CM). In vivo have depicted that continuous gavage of rhein could improve cardiac function and pathological changes. Moreover, it could inhibit the accumulation of AGEs and infiltration of inflammatory factors inside the heart of rats having DCM. Mechanism study showed rhein could suppress IKKß and IκB phosphorylation via down-regulating TRAF6 expression to inhibit NF-κB pathway in AGEs/CM-induced H9C2 cells. Moreover, the anti-inflammation effect of rhein was realized through down-regulation phosphorylation of JNK MAPK. Furthermore, we found JNK MAPK could crosstalk with NF-κB pathway by regulating IκB phosphorylation without affecting IKKß activity. And hence, the protective mechanism of rhein may involve the inhibiting of the TRAF6-NF/κB pathway, the JNK MAPK pathway, and the crosstalk between the two pathways. These results suggested that rhein may be a promising drug candidate in anti-inflammation and inflammation-related DCM therapy.

Protective Mechanisms of Suxiao Jiuxin Pills () on Myocardial Ischemia-Reperfusion Injury in vivo and in vitro.

OBJECTIVE: To study the protective mechanism of Chinese medicine Suxiao Jiuxin Pills (, SXJ) on myocardial ischemia and reperfusion (I/R) injury. METHODS: Mouse myocardial I/R injury model was created by 30-min coronary artery occlusion followed by 24-h reperfusion, the mice were then divided into the sham group (n=7), the I/R group (n=13), the tirofiban group (TIR, positive drug treatment, n=9), and the SXJ group (n=11). Infarct size (IS), risk region (RR), and left ventricle (LV) were analyzed with double staining methods. In addition, H9C2 rat cardiomyocytes were cultured with Na2S2O4 to simulate I/R in vitro. The phosphorylation of extracellular regulated protein kinases1/2 (ERK1/2), protein kinase B (AKT), glycogen synthase kinase-3ß (GSK3ß), and protein expression of GATA4 in nucleus were detected with Western blot assay. RESULTS: The ratio of IS/RR in SXJ and TIR groups were lower than that in I/R group (SXJ, 22.4% ±6.6%; TIR, 20.8%±3.3%; vs. I/R, 35.4%±3.7%, P<0.05, respectively). In vitro experiments showed that SXJ increased the Na2S2O4-enhanced phosphorylation of AKT/GSK3ß and nuclear expression of GATA4. CONCLUSION: SXJ prevents myocardial I/R injury in mice by activating AKT/GSK3ß and GATA4 signaling pathways.