title: Antioxidant and antimicrobial activities of ethanol and aqueous extracts from Urtica urens.
abstract: BACKGROUND
  Urtica urens L. (Urticaceae) is an important and commonly used plant for its medicinal and pharmacological properties.
  
  
  OBJECTIVE
  We analyzed the antioxidant and antimicrobial activities of the leaves of Urtica urens in ethanol (EtOH) and water (WA) solvents, employing standard analytical methods.
  
  
  METHODS
  Polyphenol, flavonoid and tannin content of Urtica urens leaves were determined, after their extraction, using EtOH (70%) and WA extracts as well as the antioxidant (DPPH, ABTS, β-carotene and FRAP) and the antibacterial (via the method of dilution tests) activities of EtOH and WA extracts.
  
  
  RESULTS
  The 70% EtOH of Urtica urens showed the highest values of total phenolic (31.41 mg GAE/g DW), flavonoids (6.81 mg quercetin/g DW), tannin (8.29 mg GAE/g DW) and TEAC (560 mmol Trolox/g DW), compared to the WA. The results of DPPH for EtOH (95.56%) were higher than that of WA (64.56%) at a concentration of 40 mg/L. The extracts displayed a FRAP 106.23 for EtOH and 30.55 μmol Fe(II)/g DW for WA. The results clearly indicated that EtOH was the strongest radical scavenger (IC50=245.65 ± 10.2 μg/mL). Ethanol was the most effective with minimum inhibitory concentration (MIC) < 250 μg/mL. WA has no antibacterial activity.
  
  
  CONCLUSIONS
  The results indicate that leaves of Urtica urens could be used as natural antioxidant and antimicrobial agents.
authors.affiliation: a Laboratory of Histology Embryology and Reproductive Biology, Faculty of Medicine of Sfax , University of Sfax , Sfax , Tunisia.
authors.forename: Massara
authors.initials: M
authors.lastname: Mzid
authors.affiliation: a Laboratory of Histology Embryology and Reproductive Biology, Faculty of Medicine of Sfax , University of Sfax , Sfax , Tunisia.
authors.forename: Sameh
authors.initials: S
authors.lastname: Ben Khedir
authors.affiliation: b Laboratory of Pharmacology, Faculty of Medicine of Sfax , University of Sfax , Sfax , Tunisia.
authors.forename: Maryem
authors.initials: M
authors.lastname: Ben Salem
authors.affiliation: b Laboratory of Pharmacology, Faculty of Medicine of Sfax , University of Sfax , Sfax , Tunisia.
authors.forename: Wafa
authors.initials: W
authors.lastname: Regaieg
authors.affiliation: a Laboratory of Histology Embryology and Reproductive Biology, Faculty of Medicine of Sfax , University of Sfax , Sfax , Tunisia.
authors.forename: Tarek
authors.initials: T
authors.lastname: Rebai
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D005419:Flavonoids / Q000032:analysis; D010936:Plant Extracts / Q000494:pharmacology*; D059808:Polyphenols / Q000032:analysis; D013634:Tannins / Q000032:analysis; D027003:Urticaceae / Q000737:chemistry
chemical_list: D000890:Anti-Infective Agents; D000975:Antioxidants; D005419:Flavonoids; D010936:Plant Extracts; D059808:Polyphenols; D013634:Tannins
keywords: Flavonoids; MIC; Polyphenols