title: Traditionally used Thai medicinal plants: in vitro anti-inflammatory, anticancer and antioxidant activities.
abstract: OBJECTIVE
  In order to assess traditional Thai claims about the therapeutic potential of medicinal plants and to select plants for future phytochemical research, nine plant species with anti-inflammatory uses were selected from Thai textbooks and assessed for their in vitro anti-inflammatory, antiproliferative and antioxidant activities.
  
  
  METHODS
  Nuclear factor-kappaB (NF-kappaB) inhibitory effects in stably transfected HeLa cells were determined by luciferase assay, and effects on LPS-induced pro-inflammatory mediators prostaglandin E2 (PGE2), interleukin (IL)-6, IL-1beta, and tumour necrosis factor (TNF)alpha in primary monocytes were assessed by ELISA. Cytotoxic activities were examined against HeLa cells, human leukaemia CCRF-CEM cells and the multidrug-resistant CEM/ADR5000 subline using the MTT and XTT tests. However, a redox status has been linked with both inflammation and cancer, antioxidant effects were also assessed using the DPPH, lipid-peroxidation, and Folin-Ciocalteau methods.
  
  
  RESULTS
  Among all the nine species, Gynura pseudochina var. hispida and Oroxylum indicum showed the most promising NF-kappaB inhibitory effects with the lowest IC(50) values (41.96 and 47.45 microg/ml, respectively). Muehlenbeckia platyclada did not inhibit the NF-kappaB activation but effectively inhibited the release of IL-6, IL-1beta and TNF-alpha with IC(50) values ranging between 0.28 and 8.67 microg/ml. Pouzolzia indica was the most cytotoxic against CCRF-CEM cells and the multidrug-resistant CEM/ADR5000 cells (9.75% and 10.48% viability, at 10 microg/ml, respectively). Rhinacanthus nasutus was the most potent cytotoxicity against HeLa cells (IC(50) 3.63 microg/ml) and showed specific cytotoxicity against the multidrug-resistant CEM/ADR5000 cells (18.72% viability at 10 microg/ml, p<0.0001 when compared to its cytotoxicity against CCRF-CEM cells). Moreover, Oroxylum indicum showed a high level of antioxidant activity by inhibiting lipid-peroxidation (IC(50) 0.08 microg/ml).
  
  
  CONCLUSIONS
  This study provides in vitro evidence for the use of the Thai plants, most importantly Gynura pseudochina var. hispida, Oroxylum indicum and Muehlenbeckia platyclada as Thai anti-inflammatory remedies and these plants are now a priority for further phytochemical research.
authors.affiliation: Centre for Pharmacognosy and Phytotherapy, The School of Pharmacy, University of London, London, United Kingdom.
authors.forename: Nisarat
authors.initials: N
authors.lastname: Siriwatanametanon
authors.forename: Bernd L
authors.initials: BL
authors.lastname: Fiebich
authors.forename: Thomas
authors.initials: T
authors.lastname: Efferth
authors.forename: Jose M
authors.initials: JM
authors.lastname: Prieto
authors.forename: Michael
authors.initials: M
authors.lastname: Heinrich
mesh_terms: D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D019659:Asteraceae; D029402:Bignoniaceae; D002470:Cell Survival / Q000187:drug effects; D015232:Dinoprostone / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D019008:Drug Resistance, Neoplasm; D006367:HeLa Cells; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D020128:Inhibitory Concentration 50; D053583:Interleukin-1beta / Q000378:metabolism; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D019684:Magnoliopsida; D008519:Medicine, Traditional; D009000:Monocytes / Q000187:drug effects / Q000276:immunology; D016328:NF-kappa B / Q000037:antagonists & inhibitors; D010636:Phenols / Q000032:analysis; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D010946:Plants, Medicinal; D019664:Polygonaceae; D013785:Thailand; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D000972:Antineoplastic Agents, Phytogenic; D000975:Antioxidants; C508600:IL6 protein, human; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D015850:Interleukin-6; D016328:NF-kappa B; D010636:Phenols; D010936:Plant Extracts; D014409:Tumor Necrosis Factor-alpha; D015232:Dinoprostone