title: 4,5,4'-Trihydroxychalcone, 8,8'-(ethene-1,2-diyl)-dinaphtalene-1,4,5-triol and rutin from Gynura segetum inhibit phagocytosis, lymphocyte proliferation, cytokine release and nitric oxide production from phagocytic cells.
abstract: BACKGROUND
  Gynura segetum is used traditionally to treat various ailments related to the immune system, which include cancer, inflammation, rheumatism, diabetes, hypertension, and viral infections but little studies have been carried out to validate their ethnopharmacological aspects. In this study the immunosuppressive effects of G. segetum and its constituents were investigated.
  
  
  METHODS
  Isolation of compounds from G. segetum leaves was conducted using vacuum liquid chromatography (VLC) and column chromatography (CC). Two new compounds, namely 4,5,4'-trihydroxychalcone and 8,8'-(ethene-1,2-diyl)-dinaphtalene-1,4,5-triol, together with stigmasterol and β-sitosterol were isolated from G. segetum methanol extract and their structures were determined spectroscopically. The presence of gallic acid and rutin in the extract was determined quantitatively by a validated HPLC method. G. segetum methanol extract and its constituents were investigated for their effects on chemotaxis, phagocytosis, β2 integrin (CD18) expression, and reactive oxygen species (ROS) of polymorphonuclear leukocytes (PMNs), lymphocytes proliferation, cytokine release and nitric oxide (NO) production of phagocytes.
  
  
  RESULTS
  All the samples significantly inhibited all the innate immune responses tested except CD 18 expression on surface of leukocytes. Among the samples, 8,8'-(ethene-1,2-diyl)-dinaphtalene-1,4,5-triol exhibited the strongest inhibitory on chemotaxis, phagocytosis, ROS and NO production. The compound exhibited exceptionally strong inhibitions on ROS and chemotaxis activities with IC50values lower than the positive controls, aspirin and ibuprofen, respectively. 4,5,4'-Trihydroxychalcone revealed the strongest immunosuppressive activity on proliferation of lymphocytes (IC50value of 1.52 μM) and on release of IL-1β (IC50value of 6.69 μM). Meanwhile rutin was the most potent sample against release of TNF-α from monocytes (IC50,16.96 μM).
  
  
  CONCLUSIONS
  The extract showed strong immunosuppressive effects on various components of the immune system and these activities were possibly contributed mainly by 4,5,4'-trihydroxychalcone, 8,8'-(ethene-1,2-diyl)-dinaphtalene-1,4,5-triol and rutin.
authors.affiliation: Fakultas Farmasi, Universitas Sumatera Utara, 5 Jalan Almamater, USU-Kampus, Medan, 20155, Indonesia.
authors.lastname: Yuandani
authors.affiliation: Drug and Herbal Research Center, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300, Kuala Lumpur, Malaysia. profibj@gmail.com.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Jantan
authors.affiliation: Drug and Herbal Research Center, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300, Kuala Lumpur, Malaysia.
authors.forename: Khairana
authors.initials: K
authors.lastname: Husain
mesh_terms: D000818:Animals; D019659:Asteraceae / Q000737:chemistry*; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D002599:Chalcone / Q000494:pharmacology*; D016207:Cytokines / Q000378:metabolism*; D006801:Humans; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism*; D010586:Phagocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010587:Phagocytosis / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*; D000067996:RAW 264.7 Cells; D012431:Rutin / Q000494:pharmacology*
chemical_list: D016207:Cytokines; D010936:Plant Extracts; D009569:Nitric Oxide; D012431:Rutin; D002599:Chalcone
keywords: 4,5,4'-Trihydroxychalcone; 8,8'-(Ethene-1,2-diyl)-dinaphtalene-1,4,5-triol; Gynura Segetum; HPLC analysis; Immunosuppressive effects; Rutin