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The effects of hop extracts (Humulus lupulus L.) on histamine release from rat peritoneal mast cells and human basophilic KU812 cells were studied. Hop water extract (HWE) and XAD-4 50% methanol fraction of HWE (MFH) inhibited histamine release from rat mast cells induced by compound 48/80 at concentrations of 100 and 10 m mg/ml, respectively. Almost the same findings were observed with A23187-induced histamine release from KU812 cells. Next, we studied the effects of hop extracts on antigen-induced nasal rubbing and sneezing in sensitized BALB/c mice. HWE caused a significant inhibition of nasal rubbing and sneezing at a dose of 500 mg/kg. MFH also inhibited nasal rubbing and sneezing dose-dependently. A significant difference was observed from 100 mg/kg in nasal rubbing and 200 mg/kg in sneezing. The effects of both extracts became clear after repeated administration. HWE and MFH significantly inhibited both nasal rubbing and sneezing, respectively, after consecutive treatment for 15 d at smaller doses compared with single administration. This finding indicates that the active component of hop is included in MFH, which was absorbed to Amberlite XAD-4 and eluted with 50% methanol. These results clearly demonstrated that hop extracts may be effective in the relief of symptoms of allergic rhinitis.

Atopic dermatitis, allergic rhinitis, food allergy and asthma are classified as type I allergy. Atopic dermatitis is a common disorder in the population, and recent studies have shown that the disease is increasing, its prevalence increasing by 2-to 3-fold during the past three decades in industrialized countries, 1) and the reported prevalence among children up to the age of 16 ranges between 15% and 30% in Europe. 2)Atopic dermatitis is a condition manifesting eczema, serous papules, scaling and crust and in severe cases, erosion of the affected skin. Itching, a sensation causing the urge to scratch, is the most significant outcome of atopic dermatitis. This unpleasant sensation stimulates scratching of the lesioned skin, thus worsening the lesions.3) In the treatment of atopic dermatitis, anti-histamine and anti-allergy drugs are generally used, but they do not allay a severe itching sensation in atopic dermatitis. 4,5) Corticosteroid is also used as external medicine to relieve cutaneous pruritics, but it has many adverse effects including skin atrophy, rosacea, acne, purpura and so on 6) ; therefore, it is worth developing new treatment drugs besides the generally used medicines.Traditional Chinese medicines have a long history dating back several thousands of years. There are many herb medicines which have been applied to cutaneous disease and some traditional Chinese herbal medicines are prescribed for dermatitis.7) Among these, Moutan Cortex, the root bark of Paeonia suffruticosa ANDREWS, is a widely used drug for cutaneous disease in traditional Chinese medicine. 8,9) In association with this, Moutan Cortex is effective in cardiovascular and female genital disease. 10,11) In addition, Moutan Cortex has been described to show analgesic, sedative, antiinflammatory and antimicrobial properties 12) ; however, we have as yet very little information as to whether Moutan Cortex is effective in experimental allergy models.In the present study, therefore, we demonstrated the inhibitory effects of ethanol extract from Moutan Cortex on experimental immediate allergic reactions both in vitro and in vivo. MATERIALS AND METHODS AnimalsFemale ICR mice (6-10 weeks old) and male Wistar rats (7 weeks old) were obtained from Japan SLC, Inc., Shizuoka, Japan. The animals were housed in an airconditioned room maintained at 24Ϯ2°C with a relative humidity of 55Ϯ15%. They were given standard laboratory rodent food chow (Oriental Yeast, Tokyo) and water ad libitum. All procedures involving animals were conducted in accordance with the Guidelines for Animal Experiments at Okayama University Advanced Science Research Center. Chemicals and ReagentsThe following reagents were used in this study and their sources are shown in parentheses: histamine dihydrochloride (Sigma, St. Louis, MO, U.S.A.), compound 48/80 (Sigma) and Evans blue (Wako, Tokyo, Japan). Compound 48/80 and histamine were dissolved in physiological saline and administered intradermally. The drugs used were azelastine hydrochloride (Sigma), ketotifen fumarate (Sigma)...

Lo Han Kuo (Siraitia grosvenori Swingle) is the fruit of the Siraitia grosvenori plant.1) This plant has been cultivated in a restricted area of the southern part of China, Guangxi Province, and only the heated and dried fruit or extract were traded to other countries such as southeast Asia, Japan and the United States of America.2) Lo Han Kuo has been used as a sweet beverage, it contains sweet components called mogrosides, which are triterpene glycosides 400 times sweeter than sucrose.3) In addition, the extract of the dried fruit has been employed as a folk medicine for pharyngitis, cough and stomach or intestinal catarrh. 4) Konoshima and Takasaki 2) found that the mogroside V contained in Lo Han Kuo might be valuable as a chemopreventive agent against chemical carcinogenesis. It has been recognized that the overproduction of nitric oxide, or NO radicals, induce mutation of genes and strongly initiate multistage carcinogenesis. 5,6) When Siratia grosvenori extract was tested on lowdensity lipoprotein (LDL) oxidation, it was found that its sweet elements reduced the atherogenic potential of LDL by inhibiting not only copper-mediated, but also human umbilical vein endothelial cell-mediated LDL oxidation in a dosedependent manner. 7) Similarly, Shi et al. demonstrated that Lo Han Kuo extract has antioxidant activity against free radicals generated by a hypoxanthine and xanthine oxidase system and Fe(II)-induced lipid peroxidation.8) It is well established that drugs having an antioxidant effect have anti-allergic effects as well, and that superoxide generation plays an important role in mast cell activation.9-11) The release of chemical mediators from tissue mast cells has been centrally implicated in a diversity of allergic and inflammatory disorders. Therefore, in the present study, the effect of Lo Han Kuo on allergic symptoms such as nasal rubbing and skin scratching behavior induced by histamine and compound 48/80, respectively, were studied in ICR mice. MATERIALS AND METHODS AnimalsFemale ICR mice (6-10 week-old) were obtained from Japan SLC, Inc., Shizuoka. The animals were housed in an air-conditioned room maintained at 24Ϯ2°C with a relative humidity of 55Ϯ15%. They were given standard laboratory rodent chow (Oriental Yeast, Tokyo) and water ad libitum. All procedures involving animals were conducted in accordance with the guidelines of the Animal Care and Use Committee, Faculty of Pharmaceutical Sciences, Okayama University.Lo Han Kuo Samples To obtain Lo Han Kuo extract, fresh Lo Han Kuo fruits was washed and crushed; then, an extraction was done using hot water at a temperature range of 80 to 90°C. After filtration, the obtained extract was evaporated under reduced pressure. The moisture content of the extract was about 40 w/w%. To prepare the Lo Han Kuo glycoside, Lo Han Kuo extract in paste form was diluted and the sweet components were selectively adsorbed onto a reversal phase column. Using an ethanolic solution, the sweet components that had been adsorbed onto the columns were eluted. Ethano...

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