The EU approved antimalarial pyronaridine shows antitubercular activity and synergy with rifampicin, targeting RNA polymerase.

The search for compounds with biological activity for many diseases is turning increasingly to drug repurposing. In this study, we have focused on the European Union-approved antimalarial pyronaridine which was found to have in vitro activity against Mycobacterium tuberculosis (MIC 5 µg/mL). In macromolecular synthesis assays, pyronaridine resulted in a severe decrease in incorporation of 14C-uracil and 14C-leucine similar to the effect of rifampicin, a known inhibitor of M. tuberculosis RNA polymerase. Surprisingly, the co-administration of pyronaridine (2.5 µg/ml) and rifampicin resulted in in vitro synergy with an MIC 0.0019-0.0009 µg/mL. This was mirrored in a THP-1 macrophage infection model, with a 16-fold MIC reduction for rifampicin when the two compounds were co-administered versus rifampicin alone. Docking pyronaridine in M. tuberculosis RNA polymerase suggested the potential for it to bind outside of the RNA polymerase rifampicin binding pocket. Pyronaridine was also found to have activity against a M. tuberculosis clinical isolate resistant to rifampicin, and when combined with rifampicin (10% MIC) was able to inhibit M. tuberculosis RNA polymerase in vitro. All these findings, and in particular the synergistic behavior with the antitubercular rifampicin, inhibition of RNA polymerase in combination in vitro and its current use as a treatment for malaria, may suggest that pyronaridine could also be used as an adjunct for treatment against M. tuberculosis infection. Future studies will test potential for in vivo synergy, clinical utility and attempt to develop pyronaridine analogs with improved potency against M. tuberculosis RNA polymerase when combined with rifampicin.

Changes in portal hemodynamics after TIPS in liver cirrhosis and portal hypertension.

OBJECTIVE: The objective of this study is to analyze the changes in portal hemodynamics that occurs in portal hypertension before and after transjugular intrahepatic portosystemic shunt (TIPS), to investigate the relationship between these changes and portal pressure (PP) and to determine the significance of sonographic parameters in measuring PP. METHODS: Ultrasonography of the portal and splenic veins and direct measurement of the PP were performed in 92 patients before and after TIPS. The differences observed in the portal and splenic vein diameters, the blood flow velocity in the portal and splenic veins and the PP were measured, and the correlations between PP and the other parameters were assessed using the SPSS 13 (SPSS Inc., Chicago, IL, USA). P < 0.05 was considered statistically significant. RESULTS: We observed a significant decrease in the PP and the diameters of the portal and splenic veins compared to preoperative conditions (p < 0.001). The velocity of blood flow in the portal and splenic veins was significantly increased after TIPS (p < 0.001). The PP correlated with the diameter and velocity of blood flow in portal (r = 0.46, p = 0.020; r = 0.47, p = 0.017) and splenic vein (r = 0.57, p = 0.003; r = 0.33, p = 0.003) only in Child's A and was absent in Child's B cirrhosis patients. CONCLUSION: The PP is influenced by the complex interaction between intrahepatic vascular resistance, collaterals and the amount of portal blood flow, which varies considerably between individuals. Once a certain pressure threshold is reached, collaterals form, and the correlation between the ultrasonographic parameters and PP becomes limited.

Resveratrol ameliorates the deleterious effect of severe acute pancreatitis.

Resveratrol (RES) is a traditional Chinese herbal medicine having anti-inflammatory properties. We sought to explore the role of RES in intestinal injury during severe acute pancreatitis (SAP) in a rat model study. For this purpose, RES-treated and sham-operated (SO) SAP rat models were established, and SAP was induced in rats by injecting 4% sodium taurocholate into the biliary-pancreatic duct. In the RES group, RES was infused intravenously immediately after the SAP induction in rats; SO group served as controls. Histopathological analysis, determination of tissue levels of superoxide dismutase (SOD) and malondialdehyde (MDA) and serum levels of TNF-α as well as ICAM-1 and VCAM-1 expression were carried out at 3, 6, and 12 h following SAP induction. The data show that following SAP induction, SOD levels decreased and MDA levels increased along with ICAM-1 and VCAM-1 expression in the intestine. Serum TNF-α levels increased in the SAP group. Importantly, RES treatment significantly reversed all the pathological changes. In conclusion, this study confirmed the anti-inflammatory properties of RES and demonstrated the prevention of injury to the intestinal barrier in the rat SAP model.

Acute pancreatitis: a literature review.

Acute pancreatitis (AP) is an inflammatory disease characterized by steady, acute abdominal pain of varying severity, often radiating from the epigastrium to the back. Its presentation ranges from a self-limiting mild disorder to a more severe and fulminant disease. Severe acute pancreatitis accounts for 30% of all deaths related to pancreatitis. The incidence of AP is increasing progressively with a corresponding increase in the incidence of its risk factors. Alcohol abuse and gallstone migration are the established risk factors for development of AP. In recent years, genetic factors and obesity have also been identified as risk factors responsible for the development of AP. The pathophysiology of AP involves acute inflammation of the acinar cells. Excessive acinar cell injury leads to a condition called systemic inflammatory response syndrome (SIRS). Protracted SIRS is responsible for most of the life-threatening complications associated with AP. Most common AP-related complications include pulmonary, renal, cardiovascular, and central nervous system dysfunction. Thus prompt and accurate diagnosis of AP is of paramount importance. The medical management of AP includes controlling pain, providing adequate nutritional support, and monitoring complications. Endoscopic retrograde cholangiopancreatography and surgery have also shown to reduce the mortality and morbidity associated with AP. Drugs such as resveratrol and rosiglitazone are being investigated as potential candidates for the treatment of AP.

Relationship of fibronectin and CD44v6 expression with invasive growth and metastasis of liver cancer.

Fibronectin and CD44v6 are involved in tumor invasion and metastasis. We examined fibronectin and CD44v6 expression in normal liver and liver cancer by immunohistochemistry. Fibronectin expression was identified in 37.5% of liver cancer specimens. Well-differentiated tumors and expansive growth were associated with continuous periacinar, or cytoplasmic and periacinar fibronectin expression; poorly differentiated and invasive tumors showed interrupted periacinar or vascular mesenchymal fibronectin expression. CD44v6 expression was absent in controls but was observed in 67.5% of liver cancers. Increased CD44v6 expression was more common with poor clinical tumor characteristics. FN and CD44v6 are potential markers for determining liver cancer invasion and metastasis.