title: Anti-Allergic Activities of Smilax glabra Rhizome Extracts and Its Isolated Compounds.
abstract: BACKGROUND
  The rhizomes of Smilax glabra (SG) has long been used in Traditional Chinese and Thai herbal medicine to treat a variety of infectious diseases and immunological disorders.
  
  
  OBJECTIVE
  To investigate the in vitro anti-allergic activities of crude extracts andpure isolated flavonoid compounds from SG by determination of inhibitory effect on antigen-induced release of β-hexosaminidasefrom RBL-2H3 cells.
  
  
  METHODS
  The in vitro inhibitory effects ofcrude aqueous and organic extracts on β-hexosaminidase release in RBL-2H3 cells were evaluated as an in vitro indication ofpossible anti-allergic activity. Bioassay-guided fractionation of extracts was used to isolate flavonoid compounds from the ethanolic extracts.
  
  
  RESULTS
  The 95% and 50% ethanolic extracts of SG showed remarkably high anti-allergic activity, with IC50 values of 5.74 ± 2.44 and 23.54 ± 4.75 µg/ml, much higher activity than that for Ketotifen (IC50 58.90 µM). The water extract had negligible activity (IC50 > 100 µg/ml). The two isolated flavonols, Engeletin and Astilbin, showed weak anti-allergic activity, IC50 values 97.46 ± 2.04 and >100 µg/ml, respectively.
  
  
  CONCLUSIONS
  The 95% and 50% ethanolic extracts of SG showed strong anti-allergic activity, but two flavonol constituents did not show any significant anti-allergic activity. These findings suggest that a combination of effects of various phytochemicals in crude extracts used in traditional medicine, are responsible for the purported anti-allergic activity of SG herbal preparations. The plethora of constituents in crude extracts, as yet unidentified, are likely to be acting synergistically to account for the strong observed anti-allergic in vitro activity.
authors.forename: Arunporn
authors.initials: A
authors.lastname: Itharat
authors.forename: Kamonmas
authors.initials: K
authors.lastname: Srikwan
authors.forename: Srisopa
authors.initials: S
authors.lastname: Ruangnoo
authors.forename: Pakakrong
authors.initials: P
authors.lastname: Thongdeeying
mesh_terms: D000818:Animals; D018926:Anti-Allergic Agents / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology*; D002478:Cells, Cultured; D005419:Flavonoids / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology; D044948:Flavonols / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology; D006027:Glycosides / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology; D008519:Medicine, Traditional; D010936:Plant Extracts / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry / Q000276:immunology*; D051381:Rats; D027343:Rhizome / Q000737:chemistry / Q000276:immunology*; D032281:Smilax / Q000737:chemistry / Q000276:immunology*; D001619:beta-N-Acetylhexosaminidases / Q000187:drug effects / Q000276:immunology
chemical_list: D018926:Anti-Allergic Agents; D005419:Flavonoids; D044948:Flavonols; D006027:Glycosides; D010936:Plant Extracts; C522936:engeletin; C099069:astilbin; D001619:beta-N-Acetylhexosaminidases