Abstract Asthma is thought to result from dysregulated Th2-like airway inflammatory responses to the environment. Although the etiology of asthma is not fully understood in humans, clinical and epidemiological evidence suggest a potential link between exposure to environmental fungi, such as Alternaria, and development and/or exacerbation of asthma. The goal of this project was to investigate the mechanisms of airway Th2 responses by using Alternaria as a clinically relevant model for environmental exposure. Airway exposure of naive animals to an experimental Ag, OVA, or a common allergen, short ragweed pollen, induced no or minimal immune responses to these Ags. In contrast, mice developed strong Th2-like immune responses when they were exposed to these Ags in the presence of Alternaria extract. Extracts of other fungi, such as Aspergillus and Candida, showed similar Th2 adjuvant effects, albeit not as potently. Alternaria stimulated bone marrow-derived dendritic cells (DCs) to express MHC class II and costimulatory molecules, including OX40 ligand, in vitro. Importantly, Alternaria inhibited IL-12 production by activated DCs, and DCs exposed to Alternaria enhanced Th2 polarization of CD4+ T cells. Furthermore, adoptive airway transfer of DCs, which had been pulsed with OVA in the presence of Alternaria, showed that the recipient mice had enhanced IgE Ab production and Th2-like airway responses to OVA. Thus, the asthma-related environmental fungus Alternaria produces potent Th2-like adjuvant effects in the airways. Such immunogenic properties of certain environmental fungi may explain their strong relationships with human asthma and allergic diseases.
Clinical and Pharmacological Studies on Liver Disease Treated with Kampo Herbal Medicine
Hepatitis C virus (HCV) infection frequently causes chronic hepatitis, which is linked to the development of liver cirrhosis and hepatocellular carcinoma. Most physicians who practice Kampo medicine in Japan have observed that Kampo medicine can be as effective as interferon therapy in the treatment of chronic hepatitis C. In the present study, to evaluate the effect of Kampo medicine on chronic hepatitis C, clinical treatment was assessed in short-term and long-term study, and it was shown that Ninjin-yoei-to (Formula ginseng compositae: TJ-108 was very effective. Therefore, to find the most active herbal component of TJ-108, in the treatment of HCV, Citrus Unshiu Peel, Schisandra Fruit, and Polygala Root, which are specific to TJ-108, were screened using an in vitro HCV infection model. Among the three herbs, Schisandra Fruit was found to be most active. In the next step, Gomisin A, an active component of Schisandra Fruit, was studied using an in vitro model with MOLT-4 cells and an animnal model of immunologically induced acute hepatic failures. It is concluded that the therapeutic effect of TJ-108 on chronic hepatitis C is from the inhibitory effect on HCV infection, and also from the protective effect on immunological hepatopathy of Schisandra Fruit and its lignan component, Gomisin A.
Effect of Kampo Herbal Medicines on Murine Water Metabolism in a Microgravity Environment
To determine the possibility of new applications of Oriental medicines, we examined the changes in water metabolism of mice that underwent microgravity and were treated with Kampo medicines. Male ICR mice were used in this experiment. Eight extracts of Kampo herbal medicines were dissolved in water and added to the drinking water administered to mice at 1 g/kg body weight for two days. The microgravity experiment was performed at the Japan Microgravity Center. We used a drop-shaft type microgravity experimental system with a free fall of 490 m. Before the drop, 7 ml of physiological saline was injected intraperitoneally. Under fasting and dehydration, body weights were measured and loss of body weight was calculated as urine. Blood samples were collected 24 hours after the microgravity experiment, and the antidiuretic hormone (ADH) in plasma related to water metabolism was measured by the radioimmunoassay (RIA) method. Heat shock protein in the spleen was measured by the enzyme-linked immunosolvent assay (ELISA) method. In the Hachimi-jio-gan and Hochu-ekki-to groups in microgravity, a decrease of urine was observed, which significantly suppressed the increase of ADH due to microgravity. Hachimi-jio-gan reduced the content of heat shock protein (HSP) 70 in the spleen. It is suggested that Hachimi-jio-gan and Hochu-ekki-to could be used as water metabolism adjustment reagents in a space environment. Furthermore, it is suggested that Hachimi-jio-gan could ease the stresses caused by microgravity. The physiological changes resulting from a microgravity environment are serious problems for space flight. Pre-treatment with Kampo medicines is expected to prevent, ease and treat these problems.