An antioxidant resveratrol significantly enhanced replication of hepatitis C virus

AIM:To elucidate the effect of antioxidants,resveratrol (RVT)and astaxanthin(AXN),on hepatitis C virus(HCV) replication. METHODS:We investigated the effect of recent popular antioxidant supplements on replication of the HCV replicon system OR6.RVT is a strong antioxidant and a kind of polyphenol that inhibits replication of various viruses.AXN is also a strong antioxidant.The replication of HCV RNA was assessed by the luciferase reporter assay.An additive effect of antioxidants on antiviral effects of interferon(IFN)and ribavirin(RBV) was investigated.RESULTS:This is the first report to investigate the effect of RVT and AXN on HCV replication.In contrast to other reported viruses,RVT significantly enhanced HCV RNA replication.Vitamin E also enhanced HCV RNA replication as reported previously,although AXN didnot affect replication.IFN and RBV significantly reduced HCV RNA replication,but these effects were dose-dependently hampered and attenuated by the addition of RVT.AXN didnot affect antiviral effects of IFN or RBV. CONCLUSION:These results suggested that RVT is not suitable as an antioxidant therapy for chronic hepatitis C.

Erythropoietin -induced proliferation of gastric mucosal cells

AIM： To analyze the localization of erythropoietin receptor on gastric specimens and characterize the effects of erythropoietin on the normal gastric epithelial proliferation using a porcine gastric epithelial cell culture model. METHODS： Erythropoietin receptor was detected by RT-PCR, Western blotting and immunohistochermistry. Growth stimulation effects of erythropoietin on cultured gastric mucosal cells were determined by ELISA using bromodeoxyuridine （BrdU）. RESULTS： Erythropoietin receptor was detected on cultured porcine gastric mucosal epithelial cells. Erythropoietin receptor was also detected histochemically at the base of gastric mucosal epithelium. BrdU assay demonstrated a dose-dependent increase in growth potential of cultured porcine gastric mucosal epithelial cells by administration of erythropoietin, as well as these effects were inhibited by administration of antierythropoietin antibody （P〈 0.01）. CONCLUSION： These findings indicate that erythropoietin has a potential to proliferate gastric mucosal epithelium via erythropoietin receptor.

Jumbo biopsy is useful for the diagnosis of colonic prolapsing mucosal polyps with diverticulosis

We report here a case of multiple prolapsing mucosal polyps with diverticulosis in the sigmoid colon. A 52-year- old man was admitted to our hospital because of bloody diarrhea. Colonoscopy and barium enema showed multiple diverticula, markedly thickened mucosal folds and polypoid lesions with mucus on the top of them in the sigmoid colon. Endoscopic ultrasonography showed thickening of the mucosal and submucosal layers. Several endoscopic biopsy specimens were taken from the polypoid lesions. Histological examination revealed only chronic inflammatory cell infiltration. In order to obtain a definite diagnosis, we performed endoscopic jumbo biopsy for the polypoid lesions after obtaining informed consent. Histological examination revealed marked lymphocyte infiltration, hemosiderin deposits and fibromuscular obliteration in the lamina propria, features similar to those of mucosal prolapsing syndrome. After anti-diarrhetic treatment, clinical findings were improved. Thus, jumbo biopsy is useful for diagnosis and treatment of prolapsing mucosal polyps.

Beneficial effect of an omega-6 PUFA-rich diet in non-steroidal anti-inflammatory drug-induced mucosal damage in the murine small intestine

AIM: To investigate the effect of a fat rich diet onnon-steroidal anti-inflammatory drug(NSAID)-induced mucosal damage in the murine small intestine.METHODS: C57BL6 mice were fed 4 types of diets with or without indomethacin.One group was fed standard laboratory chow.The other groups were fed a fat diet consisting of 8% w/w fat,beef tallow(rich in SFA),fish oil,(rich in omega-3 PUFA),or safflower oil(rich in omega-6 PUFA).Indomethacin(3 mg/kg) was injected intraperitoneally from day 8 to day 10.On day 11,intestines and adhesions to submucosal microvessels were examined.RESULTS: In the indomethacin-treated groups,mucosal damage was exacerbated by diets containing beef tallow and fish oil,and was accompanied by leukocyte infiltration(P < 0.05).The mucosal damage induced by indomethacin was significantly lower in mice fed the safflower oil diet than in mice fed the beef tallow or fish oil diet(P < 0.05).Indomethacin increased monocyte and platelet migration to the intestinal mucosa,whereas safflower oil significantly decreased monocyte and platelet recruitment(P < 0.05).CONCLUSION: A diet rich in SFA and omega-3 PUFA exacerbated NSAID-induced small intestinal damage via increased leukocyte infiltration.Importantly,a diet rich in omega-6-PUFA did not aggravate inflammation as monocyte migration was blocked.