title: Antioxidant capacity of hesperidin from citrus peel using electron spin resonance and cytotoxic activity against human carcinoma cell lines.
abstract: BACKGROUND
  Hesperidin is a flavonoid that has various pharmacological activities including anti-inflammatory, antimicrobial and antiviral activities.
  
  
  OBJECTIVE
  The aim of the study is the isolation of hesperidin from the peel of Citrus sinensis L. (Rutaceae), and the evaluation of its antioxidant capacity and cytotoxicity against different human carcinoma cell lines.
  
  
  METHODS
  In the present work, hesperidin is identified and confirmed using chromatographic and spectral analysis. To correlate between hesperidin concentration and antioxidant capacity of peel extracts, extraction was carried out using 1% HCl-MeOH, MeOH, alkaline solution, the concentration of hesperidin determined qualitatively and quantitatively using high performance thin layer chromatography (HPTLC), high performance liquid chromatography (HPLC) analysis, in vitro antioxidant capacity of hesperidin and the extracts against free radical diphenylpicrylhydrazyl (DPPH•) performed using an electron spin resonance spectrophotometer (ESR). Cytotoxic assay against larynx, cervix, breast and liver carcinoma cell lines was performed.
  
  
  RESULTS
  Hesperidin was found to be moderately active as an antioxidant agent; its capacity reached 36%. In addition, the results revealed that hesperidin exhibited pronounced anticancer activity against the selected cell lines. IC₅₀ were 1.67, 3.33, 4.17, 4.58 µg/mL, respectively.
  
  
  CONCLUSIONS
  Orange peels are considered to be a cheap source for hesperidin which may be used in the pharmaceutical industry as a natural chemopreventive agent. Hesperidin and orange peel extract could possess antioxidant properties with a wide range of therapeutic applications.
authors.affiliation: Research of Drugs and Pharmaceutical Industries Division, National Research Center, Dokki, Giza, Egypt. hanan_alashaal@yahoo.com
authors.forename: Hanan A
authors.initials: HA
authors.lastname: Al-Ashaal
authors.forename: Shakinaz T
authors.initials: ST
authors.lastname: El-Sheltawy
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification* / Q000494:pharmacology; D000975:Antioxidants / Q000302:isolation & purification* / Q000494:pharmacology; D045744:Cell Line, Tumor; D032084:Citrus sinensis; D003603:Cytotoxins / Q000302:isolation & purification* / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D006367:HeLa Cells; D006569:Hesperidin / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D010936:Plant Extracts / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D000975:Antioxidants; D003603:Cytotoxins; D010936:Plant Extracts; D006569:Hesperidin