Ginger and Its Pungent Constituents Non-Competitively Inhibit Serotonin Currents on Visceral Afferent Neurons

Nausea and emesis are a major side effect and obstacle for chemotherapy in cancer patients. Employ of antiemetic drugs help to suppress chemotherapy-induced emesis in some patients but not all patients. Ginger, an herbal medicine, has been traditionally used to treat various kinds of diseases including gastrointestinal symptoms. Ginger is effective in alleviating nausea and emesis, particularly, for cytotoxic chemotherapy drug-induced emesis. Ginger-mediated antiemetic effect has been attributed to its pungent constituents-mediated inhibition of serotonin (5-HT) receptor activity but its cellular mechanism of action is still unclear. Emetogenic chemotherapy drugs increase 5-HT concentration and activate visceral vagal afferent nerve activity. Thus, 5-HT mediated vagal afferent activation is essential to provoke emesis during chemotherapy. In this experiment, water extract of ginger and its three major pungent constituent's effect on 5-HT-evoked responses were tested on acutely dispersed visceral afferent neurons with patch-clamp methods. The ginger extract has similar effects to antiemetic drug ondansetron by blocking 5-HT-evoked responses. Pungent constituents of the ginger, [6]-shogaol, [6]-gingerol, and zingerone inhibited 5-HT responses in a dose dependent manner. The order of inhibitory potency for these compounds were [6]-shogaol>[6]-gingerol>zingerone. Unlike well-known competitive 5-HT3 receptor antagonist ondansetron, all tested ginger constituents acted as non-competitive antagonist. Our results imply that ginger and its pungent constituents exert antiemetic effects by blocking 5-HT-induced emetic signal transmission in vagal afferent neurons.

IL-18Ralpha Mediated GATA-3 Induction by Th2 Cells: IL-12 Supports IL-18Ralpha Expression in Th2 Cells

BACKGROUND: IL-18 was originally cloned as a IFN-gamma inducing factor in primed T cells. In synergy with IL-12, IL-18 has been shown to induce strikingly high levels of IFN-gamma production by T cells and to enhance Th1 development. Also this cytokine exerts induction of Th2 development through IL-4 induction. METHODS: Resting CD4+ T cells were sorted by negative selection and activated by anti-CD3 plus anti-CD28 Ab. Expression of IL-12 binding sites, IL-18 binding sites, IL-18Ralpha, and GATA-3 mRNA were analysed by FACS and RT-PCR, respectively. RESULTS: Resting CD4+ T cells expressed IL-18Ralpha chain but not IL-18 binding sites, suggesting a lack of IL-18Rbeta expression. IL-18Ralpha was maintained on the Th1 and Th2 committed cells. IL-18 binding sites were induced on the Th1 but not Th2 cells. Exposure of these cells to IL-18 led to up-regulation of GATA-3 mRNA expression only in Th2 committed cells. To elucidate the relationship between IL-18Ralpha expression and GATA-3 induction by IL-18, Th1 and Th2 committed cells were further cultured in medium with or without IL-12 for 2 days. IL-12 binding sites were maintained on the Th1 and Th2 cells regardless of IL-12 treatment, but IL-18Ralpha expression was rapidly down-regulated on the IL- 12-untreated Th2 cells which did not induce GATA-3 mRNA expression followed by IL-18 stimulation. CONCLUSION: IL-12 supports expression of IL-18Ralpha and GATA-3 mRNA expression was induced by IL-18 through IL-18Ralpha without expression of IL-18 binding site in Th2 cells.

A monoclonal antibody to common acute lymphoblastic leukemia antigen (CALLA) and its expression on several human tumor cell lines

We describe a newly-made murine monoclonal antibody to the common acute lymphoblastic leukemia antigen (CALLA), named SHB-10. The antigen detected by SHB-10 has a molecular weight of about 105 kDa. This antibody is very similar to that of conventional anti-CD10 Ab on indirect flowcytometric analysis using lymphoid malignant cell lines and peripheral lymphocytes of acute lymphoblastic leukemia (ALL) patients. The binding of anti-CD10 to Daudi cell and peripheral lymphocytes of ALL patients is blocked by SHB-10. Thus this monoclonal antibody is thought to detect the CALLA. The distribution of antigen detected by SHB-10 on several cell lines of neuroectodermal tumor and lymphoid malignancy was analysed and a slight difference in their cell surface expression is observed when compared with that by conventional anti-CD10. Further biochemical analysis is now under way for a better characterization of this antigen.