Inhibition of Hepatitis C Virus Replication and Viral Helicase by Ethyl Acetate Extract of the Marine Feather Star Alloeocomatella polycladia

Hepatitis C virus (HCV) is a causative agent of acute and chronic hepatitis, leading to the development of hepatic cirrhosis and hepatocellular carcinoma. We prepared extracts from 61 marine organisms and screened them by an in vitro fluorescence assay targeting the viral helicase (NS3), which plays an important role in HCV replication, to identify effective candidates for anti-HCV agents. An ethyl acetate-soluble fraction of the feather star Alloeocomatella polycladia exhibited the strongest inhibition of NS3 helicase activity, with an IC50 of 11.7 µg/mL. The extract of A. polycladia inhibited interaction between NS3 and RNA but not ATPase of NS3. Furthermore, the replication of the replicons derived from three HCV strains of genotype 1b in cultured cells was suppressed by the extract with an EC50 value of 23 to 44 µg/mL, which is similar to the IC50 value of the NS3 helicase assay. The extract did not induce interferon or inhibit cell growth. These results suggest that the unknown compound(s) included in A. polycladia can inhibit HCV replication by suppressing the helicase activity of HCV NS3. This study may present a new approach toward the development of a novel therapy for chronic hepatitis C

Aprepitant plus granisetron and dexamethasone for prevention of chemotherapy-induced nausea and vomiting in patients with gastric cancer treated with S-1 plus cisplatin

Background: We aimed to evaluate the efficacy of a new combination antiemetic therapy comprising aprepitant, granisetron, and dexamethasone in gastric cancer patients undergoing chemotherapy with cisplatin and S-1. Methods: Gastric cancer patients scheduled to receive their first course of chemotherapy with cisplatin (60 mg/m2) and S-1 (80 mg/m2) were treated with a new combination antiemetic therapy aprepitant, granisetron, and dexamethasone on day 1; aprepitant and dexamethasone on days 2 and 3; and dexamethasone on day 4. The patients reported vomiting, nausea, use of rescue therapy, and change in the amount of diet intake, and completed the Functional Living Index-Emesis (FLIE) questionnaire. The primary endpoint was complete response (CR; no emesis and use of no rescue antiemetics) during the overall study phase (0-120 h after cisplatin administration). The secondary endpoints included complete protection (CP; CR plus no significant nausea); change in the amount of diet intake; and the impact of chemotherapy-induced nausea and vomiting (CINV) on daily life during the overall, acute (0-24 h), and delayed (24-120 h) phases. Results: Fifty-three patients were included. CR was achieved in 88.7, 98.1, and 88.7 % of patients in the overall, acute, and delayed phases, respectively. The corresponding rates of CP were 67.9, 96.2, and 67.9 %. Approximately half of the patients had some degree of anorexia. FLIE results indicated that 79.5 % of patients reported "minimal or no impact of CINV on daily life". Conclusions: Addition of aprepitant to standard antiemetic therapy was effective in gastric cancer patients undergoing treatment with cisplatin and S-1. © 2013 Springer Japan

PBDE: Structure-Activity Studies for the Inhibition of Hepatitis C Virus NS3 Helicase

The helicase portion of the hepatitis C virus nonstructural protein 3 (NS3) is considered one of the most validated targets for developing direct acting antiviral agents. We isolated polybrominated diphenyl ether (PBDE) 1 from a marine sponge as an NS3 helicase inhibitor. In this study, we evaluated the inhibitory effects of PBDE (1) on the essential activities of NS3 protein such as RNA helicase, ATPase, and RNA binding activities. The structure-activity relationship analysis of PBDE (1) against the HCV ATPase revealed that the biphenyl ring, bromine, and phenolic hydroxyl group on the benzene backbone might be a basic scaffold for the inhibitory potency

Identification of Hydroxyanthraquinones as Novel Inhibitors of Hepatitis C Virus NS3 Helicase

Hepatitis C virus (HCV) is an important etiological agent of severe liver diseases, including cirrhosis and hepatocellular carcinoma. The HCV genome encodes nonstructural protein 3 (NS3) helicase, which is a potential anti-HCV drug target because its enzymatic activity is essential for viral replication. Some anthracyclines are known to be NS3 helicase inhibitors and have a hydroxyanthraquinone moiety in their structures; mitoxantrone, a hydroxyanthraquinone analogue, is also known to inhibit NS3 helicase. Therefore, we hypothesized that the hydroxyanthraquinone moiety alone could also inhibit NS3 helicase. Here, we performed a structure–activity relationship study on a series of hydroxyanthraquinones by using a fluorescence-based helicase assay. Hydroxyanthraquinones inhibited NS3 helicase with IC50 values in the micromolar range. The inhibitory activity varied depending on the number and position of the phenolic hydroxyl groups, and among different hydroxyanthraquinones examined, 1,4,5,8-tetrahydroxyanthraquinone strongly inhibited NS3 helicase with an IC50 value of 6 µM. Furthermore, hypericin and sennidin A, which both have two hydroxyanthraquinone-like moieties, were found to exert even stronger inhibition with IC50 values of 3 and 0.8 µM, respectively. These results indicate that the hydroxyanthraquinone moiety can inhibit NS3 helicase and suggest that several key chemical structures are important for the inhibition

Identification and Biochemical Characterization of Halisulfate 3 and Suvanine as Novel Inhibitors of Hepatitis C Virus NS3 Helicase from a Marine Sponge

Hepatitis C virus (HCV) is an important etiological agent that is responsible for the development of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. HCV nonstructural protein 3 (NS3) helicase is a possible target for novel drug development due to its essential role in viral replication. In this study, we identified halisulfate 3 (hal3) and suvanine as novel NS3 helicase inhibitors, with IC50 values of 4 and 3 µM, respectively, from a marine sponge by screening extracts of marine organisms. Both hal3 and suvanine inhibited the ATPase, RNA binding, and serine protease activities of NS3 helicase with IC50 values of 8, 8, and 14 µM, and 7, 3, and 34 µM, respectively. However, the dengue virus (DENV) NS3 helicase, which shares a catalytic core (consisting mainly of ATPase and RNA binding sites) with HCV NS3 helicase, was not inhibited by hal3 and suvanine, even at concentrations of 100 µM. Therefore, we conclude that hal3 and suvanine specifically inhibit HCV NS3 helicase via an interaction with an allosteric site in NS3 rather than binding to the catalytic core. This led to the inhibition of all NS3 activities, presumably by inducing conformational changes

内視鏡を用いたomental patch method にて胃管を温存し救命しえた胸腔鏡下食道切除後胃管穿孔の1例

金沢大学附属病院肝胆膵・移植外科患者は70 歳，男性．腹部食道癌に対して胸腔鏡下食道亜全摘，胸骨後胃管再建，頸部吻合を施行した．第2 病日に右胸腔ドレーンより腸液色の排液を認め，CT，上部消化管透視にて胃管穿孔と診断し，再手術を行った．頸部吻合より肛門側約10 cm に胃管穿孔を認めた．胃管切除は手術侵襲が大きいと判断し，消化管内視鏡の先端を穿孔部へ通し，把持鉗子を腹腔内に進め，大網を把持して胃管内まで吊上げ，クリップにて胃壁に固定した．再手術後，ドレーン排液量は漸減し，穿孔部は再生組織に覆われた．食道癌術後胃管穿孔に対して胃管切除が選択できない場合，穿孔部の大網被覆と穿孔部周囲のドレナージは有効な場合もあると考えられたため，若干の考察を加えて報告する．A 70 -year-old man underwent retrosternal gastric tube reconstruction following subtotal esophagectomyfor advanced abdominal esophageal cancer. On the second post-operative day, drained fluid changed to intestinaljuice. Computed tomography and gastrointestinal fluoroscopy showed perforation of the gastric tube. Wethen performed emergency surgery, and laparotomy was redone. During surgery, gastrointestinal endoscopydemonstrated gastric tube perforation at 10 cm from the anastomosis of stomach to cervical esophagus. Itwas too invasive to perform the resection of gastric tube, so we pulled the greater omentum into the stomachthrough the perforation site and fastened with clips（ omental patch method）. The drainage then graduallydecreased, and the perforation healed with regenerating epithelium. The omental patch method and drainageproved useful to treat gastric tube perforation following esophagectomy, and should be considered if resectionof the gastric tube is difficult