title: Liposomes as carriers of the lipid soluble antioxidant resveratrol: evaluation of amelioration of oxidative stress by additional antioxidant vitamin.
abstract: OBJECTIVE
  Resveratrol (RES) is a well-known antioxidant, yet in combination with other antioxidant vitamins, it was found to be more effective than any of these antioxidants alone. Present work aims to compare the antioxidant actions of resveratrol with and without vitamin C following delivery as liposomes tested using chemical and cellular antioxidative test systems.
  
  
  METHODS
  Liposomes were prepared by the thin film hydration method and characterised for percent drug entrapment (PDE), Z-average mean size (nm), polydispersity index (PDI) and zeta potential. Antioxidative capacity was determined by studying the inhibition of AAPH induced luminol enhanced chemiluminescence and inhibition of ROS production in isolated blood leukocytes. Intracellular oxygen-derived radicals were measured using flow cytometry with buffy coats (BC) and human umbilical vein endothelial cells using H2DCF-DA dye.
  
  
  RESULTS
  Particle size varied from 134.2 ± 0.265 nm to 103.3 ± 1.687 nm; PDI ≤ 0.3; zeta potential values were greater than -30 mV and PDE ≥ 80%. Radical scavenging effect was enhanced with liposomal systems; oxidative burst reaction in BC was inhibited by liposomal formulations, with the effect slightly enhanced in presence of vitamin C. Reduction in reactive oxygen species (ROS) production during spontaneous oxidative burst of BC and incubation of HUVECs with H2O2 further intensified the antioxidative effects of pure RES and liposomal formulations.
  
  
  CONCLUSIONS
  The present work clearly shows that the antioxidative effects of resveratrol loaded into liposomes are more pronounced when compared to pure resveratrol. Liposomal resveratrol is even active within the intracellular compartments as RES could effectively quench the intracellular accumulation of ROS.
authors.affiliation: Institute of Physiology, Eberhard Karls Universität Tübingen, Gmelinstr. 5, Tuebingen D-72076, Germany; Visveswarapura Institute of Pharmaceutical Sciences, Bangalore, India.
authors.forename: K
authors.initials: K
authors.lastname: Vanaja
authors.forename: M A
authors.initials: MA
authors.lastname: Wahl
authors.forename: L
authors.initials: L
authors.lastname: Bukarica
authors.forename: H
authors.initials: H
authors.lastname: Heinle
mesh_terms: D000578:Amidines / Q000037:antagonists & inhibitors; D000975:Antioxidants / Q000008:administration & dosage* / Q000494:pharmacology*; D019540:Area Under Curve; D001205:Ascorbic Acid / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D004396:Coloring Agents; D004337:Drug Carriers; D016166:Free Radical Scavengers / Q000494:pharmacology; D006801:Humans; D007202:Indicators and Reagents; D007962:Leukocytes / Q000187:drug effects / Q000378:metabolism; D008081:Liposomes; D049449:Luminescence; D008165:Luminol; D018384:Oxidative Stress / Q000187:drug effects*; D010316:Particle Size; D017382:Reactive Oxygen Species / Q000378:metabolism; D000077185:Resveratrol; D013267:Stilbenes / Q000008:administration & dosage* / Q000494:pharmacology*; D013778:Tetrazolium Salts; D013844:Thiazoles; D014815:Vitamins / Q000494:pharmacology*
chemical_list: D000578:Amidines; D000975:Antioxidants; D004396:Coloring Agents; D004337:Drug Carriers; D016166:Free Radical Scavengers; D007202:Indicators and Reagents; D008081:Liposomes; D017382:Reactive Oxygen Species; D013267:Stilbenes; D013778:Tetrazolium Salts; D013844:Thiazoles; D014815:Vitamins; D008165:Luminol; C046728:2,2'-azobis(2-amidinopropane); C022616:thiazolyl blue; D001205:Ascorbic Acid; D000077185:Resveratrol
keywords: Antioxidant activity; Chemiluminescence; Flow cytometry; Liposomes; Resveratrol; Vitamin C