Modulation of Reoviral Cytolysis (I): Combination Therapeutics.

Patients with stage IV gastric cancer suffer from dismal outcomes, a challenge especially in many Asian populations and for which new therapeutic options are needed. To explore this issue, we used oncolytic reovirus in combination with currently used chemotherapeutic drugs (irinotecan, paclitaxel, and docetaxel) for the treatment of gastric and other gastrointestinal cancer cells in vitro and in a mouse model. Cell viability in vitro was quantified by WST-1 assays in human cancer cell lines treated with reovirus and/or chemotherapeutic agents. The expression of reovirus protein and caspase activity was determined by flow cytometry. For in vivo studies, athymic mice received intratumoral injections of reovirus in combination with irinotecan or paclitaxel, after which tumor size was monitored. In contrast to expectations, we found that reoviral oncolysis was only poorly correlated with Ras pathway activation. Even so, the combination of reovirus with chemotherapeutic agents showed synergistic cytopathic effects in vitro, plus enhanced reovirus replication and apoptosis. In vivo experiments showed that reovirus alone can reduce tumor size and that the combination of reovirus with chemotherapeutic agents enhances this effect. Thus, we find that oncolytic reovirus therapy is effective against gastric cancer. Moreover, the combination of reovirus and chemotherapeutic agents synergistically enhanced cytotoxicity in human gastric cancer cell lines in vitro and in vivo. Our data support the use of reovirus in combination with chemotherapy in further clinical trials, and highlight the need for better biomarkers for reoviral oncolytic responsiveness.

Therapeutic effects of biobran, modified arabinoxylan rice bran, in improving symptoms of diarrhea predominant or mixed type irritable bowel syndrome: a pilot, randomized controlled study.

Background. Recently, it was revealed that low grade mucosal inflammation and/or immune imbalance of the lower digestive tract is one of the mechanisms involved in symptom generation in patients with irritable bowel syndrome (IBS). Biobran, arabinoxylan compound derived from rice bran, has been reported to have several biological actions such as anti-inflammatory and immune modulatory effects. So we investigated the therapeutic effects of Biobran in patients with IBS. Method. Forty patients with diarrhea predominant or mixed type IBS were randomly assigned to either a Biobran group for treatment with Biobran or a placebo group. Therapeutic efficacy and IBS symptoms were assessed subjectively by the patients after 4 weeks of administration. Results. The global assessment was effective in 63.2% of the Biobran group and in 30% of the placebo group (P < 0.05, Biobran group versus placebo group). Biobran group showed a significant decrease in the score of diarrhea and constipation and in CRP value. However, no significant changes were observed in the placebo group. Conclusion. The administration of Biobran improved IBS symptoms. It is likely that anti-inflammatory and/or immune modulatory effects of Biobran might be useful in IBS patients.

Effect of plaunotol in combination with clarithromycin against clarithromycin-resistant Helicobacter pylori in vitro and in vivo.

OBJECTIVES: Recently, there has been a decrease in the eradication rate of Helicobacter pylori due to the increase in antibiotic resistance of this bacterium. Plaunotol, a cytoprotective anti-ulcer agent, exhibits antibacterial activity against H. pylori. The purpose of the present study was to investigate the effect of plaunotol in combination with clarithromycin against clarithromycin-resistant H. pylori clinical isolates. METHODS AND RESULTS: In the chequerboard titration method, the combination of plaunotol and clarithromycin showed a synergistic effect against 67% (10/15) clarithromycin-resistant strains and an additive effect against the other strains. No indifferent and antagonistic effects were observed against any of the strains tested. In a gastritis model of Mongolian gerbils infected with clarithromycin-resistant H. pylori, the plaunotol (40 mg/kg) and clarithromycin (66.6 mg/kg) combination exhibited synergistic effects; however, neither plaunotol nor clarithromycin alone showed bactericidal effects. CONCLUSIONS: These results suggest that plaunotol may play a useful role in combination with anti-H. pylori drugs in the treatment of diseases associated with clarithromycin-resistant H. pylori.