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.
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...
The effect of ethanol extract obtained from Bulgaria inquinans on the scratching behavior and vascular permeability changes induced by compound 48/80, histamine and serotonin in ICR mice was studied. The extract dose-dependently inhibited scratching behavior induced by compound 48/80 and serotonin. A significant inhibition was observed at doses of 300 and 600 mg/kg when Bulgaria inquinans extract was administered orally. However, no inhibitory effect was observed on the histamine-induced scratching behavior by the extract, even at a dose of 600 mg/kg. In addition, it also inhibited the increase in the vascular permeability induced by compound 48/80 and serotonin at doses of 300 and 600 mg/kg; however, it failed to inhibit the increased vascular permeability induced by histamine, even at a dose of 600 mg/kg. Bulgaria inquinans extract showed a potent inhibitory effect on histamine release induced by compound 48/80. These results suggest that Bulgaria inquinans extract is effective in cutaneous pruritus and erythema, which were probably mediated by inhibiting the release of histamine from mast cells and antagonizing the effect on serotonin.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.