Baicalin Inhibits Coxsackievirus B3 Replication by Reducing Cellular Lipid Synthesis.

Baicalin is a flavonoid extracted from Scutellariae Radix and shows a variety of biological activities as reducing lipids, diminishing inflammation, and inhibiting bacterial infection. However, there is no report of baicalin against CVB3 infection. In this study, we found that baicalin can reduce viral titer in a dose-dependent manner in vitro at a dose with no direct virucidal effect. Moreover, we revealed that baicalin can also improve survival rate, reduce heart weight/body weight ratio, prevent virus replication, and relieve myocardial inflammation in the acute viral myocarditis mouse model induced by CVB3. Then, in order to explore the mechanism of baicalin inhibiting CVB3 replication, we respectively examined the expression of autophagosome marker LC3-II by Western blot, tested the concentration of free fatty acid (FFA) and cholesterol (CHO) by commercial kits, detected the mRNA levels of fatty acid synthase (Fasn) and acetyl coenzyme a carboxylase (ACC) by RT-PCR, and observed the lipid content of cells by fluorescence staining. The results showed that CVB3 infection increased autophagosome formation and lipid content in HeLa cells, but these changes were significantly blocked by baicalin. Finally, in order to confirm that baicalin inhibits viral replication and reduces autophagosome formation by reducing cellular lipids, we added exogenous palmitate to cell culture supernatants to promote intracellular lipid synthesis and found that palmitate did not alter LC3-II and CVB3/VP1 expression in HeLa cells with or without CVB3 infection. Interestingly, palmitate can reverse the inhibitory effect of baicalin on autophagosome formation and viral replication. In conclusion, our results indicated that lipids play an important role in CVB3 replication, and the effect of baicalin against CVB3 was associated with its ability to reduce cellular lipid synthesis to limit autophagosome formation.

MicroRNA-141 ameliorates alcoholic hepatitis­induced intestinal injury and intestinal endotoxemia partially via a TLR4-dependent mechanism.

Alcoholic hepatitis (AH) is a fatal inflammatory syndrome with no effective treatments. Intestinal injury and intestinal endotoxemia (IETM) contribute greatly in the development of AH. MicroRNAs (miRNAs/miRs) have been reported to affect intestinal injury. The present study aims to investigate the role of miR­141 in intestinal injury and IETM of AH. An AH model was successfully established in mice and they were the injected with a series of miR­141 mimic, miR­141 inhibitor or toll like receptor 4 monoclonal antibody (TLR4mAb; an inhibitor of the Toll­like receptor TLR pathway). After that, the intestinal tissues and intestinal epithelial cells were isolated from differently treated AH mice. The expression of miR­141 and TLR pathway­associated genes and the levels of inflammatory factors were determined. Furthermore, a target prediction program and a luciferase reporter assay were employed to examine whether miR­141 targets TLR4. Finally, MTT and transwell assays were carried out to detect cell viability and cell permeability. Intestinal tissues from AH mice treated with miR­141 mimic or TLR4mAb exhibited lower levels of inflammatory factors and reduced expression of the TLR pathway­associated genes, suggesting a decreased inflammatory response as well as inactivation of the TLR pathway by miR­141. The luciferase reporter assay suggested that miR­141 negatively regulated TLR4. Intestinal epithelial cells treated with miR­141 mimic or TLR4mAb demonstrated enhanced viability and reduced permeability. Opposite results were observed in AH mice treated with a miR­141 inhibitor. Collectively, the results of the present study demonstrated that miR­141 could ameliorate intestinal injury and repress the progression of IETM through targeting TLR4 and inhibiting the TLR pathway.