Flavonoid composition of orange peel and its association with antioxidant and anti-inflammatory activities

Food Chem. 2017 Mar 1;218:15-21. doi: 10.1016/j.foodchem.2016.09.016. Epub 2016 Sep 6.

Abstract

Dried citrus peel derived from Citrus reticulata, also called "chenpi", possesses a complex mixture of flavonoids and has a history of traditional use to treat a variety of digestive disorders. We compared three sources of conventional chenpi from California (USA), Guangxi, Zhejiang, and two sources of "nchenpi", which contain greater nobiletin content, from Sichuan and Xinhui (China). Xinhui orange peel extract (OPE) had highest content of polymethoxylated flavones, along with greatest capacity to scavenge 2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), 2,2-diphenyl-1-pcrylhydrazyl (DPPH), and 2,2'-azobis-2-methyl-propanimidamide, dihydrochloride (AAPH) radicals and nitric oxide (NO). OPE also had higher NO, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) inhibitory activity than an equivalent mixture of flavonoids (P<0.05). In conclusion, nobiletin is a good chemical marker for assessing the anti-inflammatory potential of OPE from different sources. Obtaining "nchenpi" from either Sichuan or Xinhui provided potentially superior health benefits compared to conventional chenpi sources.

Keywords: 2,2-Azino-bis(3-ethylbenzthiazoline-6-sulphonic acid; 2,2-Diphenyl-1-picrylhydrazyl; 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; Anti-inflammation; Antioxidant; Flavonoid; Hesperidin; Inducible nitric oxide synthase; Narirutin; Nitric oxide; Nobiletin; Orange peel extract; Tangeritin; “Nchenpi”.

MeSH terms

  • Amidines / analysis
  • Animals
  • Anti-Inflammatory Agents / analysis
  • Anti-Inflammatory Agents / pharmacology*
  • Antioxidants / analysis
  • Antioxidants / pharmacology*
  • Benzothiazoles / analysis
  • Biphenyl Compounds / analysis
  • California
  • Cell Survival / drug effects
  • China
  • Chromatography, High Pressure Liquid
  • Citrus / chemistry*
  • Cyclooxygenase 2 / metabolism
  • Cyclooxygenase 2 Inhibitors / analysis
  • Cyclooxygenase 2 Inhibitors / pharmacology
  • Drugs, Chinese Herbal / pharmacology
  • Flavones / analysis
  • Flavones / pharmacology
  • Flavonoids / analysis
  • Flavonoids / pharmacology*
  • Fruit / chemistry*
  • Mice
  • Nitric Oxide / analysis
  • Nitric Oxide / antagonists & inhibitors
  • Nitric Oxide Synthase Type II / antagonists & inhibitors
  • Nitric Oxide Synthase Type II / metabolism
  • Phenols / analysis
  • Phenols / pharmacology
  • Picrates / analysis
  • Plant Extracts / analysis
  • RAW 264.7 Cells
  • Sulfonic Acids / analysis

Substances

  • Amidines
  • Anti-Inflammatory Agents
  • Antioxidants
  • Benzothiazoles
  • Biphenyl Compounds
  • Cyclooxygenase 2 Inhibitors
  • Drugs, Chinese Herbal
  • Flavones
  • Flavonoids
  • Phenols
  • Picrates
  • Plant Extracts
  • Sulfonic Acids
  • 2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid
  • Nitric Oxide
  • 2,2'-azobis(2-amidinopropane)
  • nobiletin
  • 1,1-diphenyl-2-picrylhydrazyl
  • Nitric Oxide Synthase Type II
  • Nos2 protein, mouse
  • Ptgs2 protein, mouse
  • Cyclooxygenase 2
  • chenpi