title: The anti-arthritic, anti-inflammatory, antioxidant activity and relationships with total phenolics and total flavonoids of nine South African plants used traditionally to treat arthritis.
abstract: BACKGROUND
  Oxidative stress predisposes the human and animal body to diseases like cancer, diabetes, arthritis, rheumatoid arthritis, atherosclerosis and chronic inflammatory disorders. Hence, this study seeks to determine the antioxidant, anti-inflammatory and anti-arthritic activities of acetone leaf extracts of nine South African medicinal plants that have been used traditionally to treat arthritis and inflammation.
  
  
  METHODS
  The anti-inflammatory activity of the extracts was determined by investigating inhibition of nitric oxide production in lipopolysaccharide activated RAW 264.7 macrophages as well as 15-lipoxygenase enzyme inhibition. An anti-protein denaturation assay was used to determine the anti-arthritic properties of the extracts. The antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethyl-benzthiazoline-6-sulfonic acid) (ABTS) radical scavenging assays and ferric reducing antioxidant power (FRAP). The total phenolic and total flavonoid concentration of extracts were determined by using standard methods.
  
  
  RESULTS
  All extracts inhibited nitric oxide production in a dose-dependent manner in the LPS-stimulated RAW 264.7 macrophages. Extracts of Maesa lanceolata and Heteromorpha arborescens inhibited NO production by 99.16 % and 89.48 % at a concentration of 30 μg/ml respectively. Elaeodendron croceum and Calpurnia aurea extracts had strong activity against 15-lipoxygenase activity with IC50 values of 26.23 and 34.70 μg/ml respectively. Morus mesozygia and Heteromorpha arborescens extracts had good in vitro anti-arthritic activity with IC50 values of 11.89 and 53.78 μg/ml, the positive control diclofenac sodium had IC50 value of 32.37 μg/ml. The free radical scavenging activity of the extracts in DPPH assays ranged between 7.72 and 154.77 μg/ml. Trolox equivalent antioxidant capacity (TEAC) and FRAP values ranged from 0.06 to 1.32 and 0.06 to 0.99 respectively.
  
  
  CONCLUSIONS
  Results from this study support the traditional use of the selected medicinal plants in the management of arthritis and other inflammatory conditions. The free radical scavenging capacity of the extracts may be related to an immune boosting potential.
authors.affiliation: Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, Pretoria, South Africa.|Permanent address: Drug Development Section, Biochemistry Division, National Veterinary Research Institute, P.M.B 01, Vom-Plateau State, Nigeria.
authors.forename: Ishaku Leo
authors.initials: IL
authors.lastname: Elisha
authors.affiliation: Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, Pretoria, South Africa.|Permanent address: Department of Biochemistry, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Dzoyem
authors.affiliation: Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, Pretoria, South Africa.
authors.forename: Lyndy Joy
authors.initials: LJ
authors.lastname: McGaw
authors.affiliation: Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, Pretoria, South Africa.
authors.forename: Francien S
authors.initials: FS
authors.lastname: Botha
authors.affiliation: Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, Pretoria, South Africa. kobus.eloff@up.ac.za.
authors.forename: Jacobus Nicolaas
authors.initials: JN
authors.lastname: Eloff
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D001093:Arachidonate 15-Lipoxygenase / Q000187:drug effects; D001168:Arthritis; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D005419:Flavonoids / Q000032:analysis / Q000737:chemistry*; D051379:Mice; D010636:Phenols / Q000032:analysis / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*
chemical_list: D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D001093:Arachidonate 15-Lipoxygenase
keywords: Anti-arthritic activity; Anti-lipoxygenase; Antioxidant activity; Inhibition of nitric oxide production; Medicinal plants; Phytochemicals