title: A mechanistic review on medicinal plants used for rheumatoid arthritis in traditional Persian medicine.
abstract: OBJECTIVE
  Rheumatoid arthritis (RA) is a chronic, inflammatory, autoimmune disease, which affects synovial tissue in multiple joints. Although conventional treatments of RA commonly alleviate the symptoms, high incidence of adverse reactions leads to research tendency towards complementary and alternative medicine. As various medicinal plants are traditionally used for the management of symptomatologies associated with RA in Persian medicine, we reviewed medicinal literature to confirm their efficacy in the management of RA.
  
  
  RESULTS
  Scientific evidence revealed that traditional medicaments exert beneficial effects on RA through several cellular mechanisms including downregulation of pro-inflammatory cytokines such as TNF-α, IL-6 and NF-κB, suppression of oxidative stress, inhibition of cartilage degradation with destructive metalloproteinases and enhancement of antioxidant performance. Various active constituents from different chemical categories including flavonols, lignans, coumarins, terpenes, glycosylflavons, dihydroflavonols, phytoestrogens, sesquiterpene lactones, anthraquinones, alkaloids and thymoquinones have been isolated from the medicinal plants.
  
  
  CONCLUSIONS
  The pharmacological mechanisms of the medicinal plants traditionally used for RA in Persian medicine are discussed in the current review. Further investigations are mandatory to focus on bioefficacy of these phytochemicals for finding novel natural drugs.
authors.affiliation: Pharmaceutical Sciences Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran.|Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran.|Phytopharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran.
authors.forename: Mohammad Hosein
authors.initials: MH
authors.lastname: Farzaei
authors.affiliation: Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Farzaei
authors.affiliation: Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Abdollahi
authors.affiliation: Pharmaceutical Sciences Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Abbasabadi
authors.affiliation: Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Karaj, Iran. amirhosein172@hotmail.com.|Department of Pharmacology & Toxicology, Faculty of Pharmacy, Alborz University of Medical Sciences, Karaj, Iran. amirhosein172@hotmail.com.|Gastrointestinal Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran. amirhosein172@hotmail.com.
authors.forename: Amir Hossein
authors.initials: AH
authors.lastname: Abdolghaffari
authors.affiliation: Kermanshah University of Medical Sciences, Kermanshah, Iran.
authors.forename: Bahman
authors.initials: B
authors.lastname: Mehraban
mesh_terms: D000818:Animals; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000378:metabolism; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D008519:Medicine, Traditional / Q000379:methods; D016328:NF-kappa B / Q000378:metabolism; D028321:Plant Preparations / Q000494:pharmacology* / Q000627:therapeutic use*; D010946:Plants, Medicinal / Q000737:chemistry; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D015850:Interleukin-6; D016328:NF-kappa B; D028321:Plant Preparations; D014409:Tumor Necrosis Factor-alpha
keywords: biological mechanisms; complementary and alternative medicine; inflammatory cytokines; metalloproteinases; mitogen-activated protein kinases; natural drugs; nuclear factors; phytochemicals; phytotherapy; transduction signalling pathways