title: In-vitro antioxidant and antibacterial activities of Xanthium strumarium L. extracts on methicillin-susceptible and methicillin-resistant Staphylococcus aureus.
abstract: OBJECTIVE
  The excessive and repeated use of antibiotics in medicine has led to the development of antibiotic-resistant microbial strains, including Staphylococcus aureus whose emergence of antibiotic-resistant strains has reduced the number of antibiotics available to treat clinical infections caused by this bacterium. In this study, antioxidant and antimicrobial activities of methanolic extract of Xanthium strumarium L. leaves were evaluated on methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MRSA) spp.
  
  
  METHODS
  Antiradical and antioxidant activities X. strumarium L. leaf extract were evaluated based on its ability to scavenge the synthetic 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical and by the paired diene method, respectively, whereas the antimicrobial activity was assayed by the disc diffusion method.
  
  
  METHODS
  Data were subjected to analysis of variance following an entirely random design to determine the least significant difference at P < 0.05 using SPSS v. 11.5.
  
  
  CONCLUSIONS
  The IC50 values of the extract were 0.02 mg/mL and 0.09 mg/mL for the antioxidant and DPPH-scavenging capacity, respectively. X. strumarium extract affected both methicillin-sensitive Staphylococcus aureus and MRSA, though antibacterial activity was more effective on methicillin-susceptible S. aureus spp. The antibacterial and antioxidant activities exhibited by the methanol extract may justify the traditional use of this plant as a folk remedy worldwide.
authors.affiliation: Zabol Medicinal Plants Research Center, Zabol University of Medical Sciences, Zabol, Iran ; Department of Pharmacognosy, Faculty of Pharmacy, Zabol University of Medical Sciences, Zabol, Iran.
authors.forename: Javad Sharifi
authors.initials: JS
authors.lastname: Rad
authors.affiliation: Department of Bacteriology and Virology, Shiraz Medical School, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Seyedeh Mahsan Hoseini
authors.initials: SM
authors.lastname: Alfatemi
authors.affiliation: Department of Range and Watershed Management, Faculty of Natural Resources, University of Zabol, Zabol, Iran.
authors.forename: Majid Sharifi
authors.initials: MS
authors.lastname: Rad
authors.affiliation: Department of Agricultural and Environmental Sciences, Milan State University, via G. Celoria 2, 20133, Milan, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Iriti
keywords: 1,1-diphenyl-2-picrylhydrazyl; Staphylococcus aureus; Xanthium strumarium L; antioxidant activity; methicillin-resistant Staphylococcus aureus; methicillin-sensitive Staphylococcus aureus