title: In vitro antioxidant and anti-inflammatory activities of Radix Isatidis extract and bioaccessibility of six bioactive compounds after simulated gastro-intestinal digestion.
abstract: BACKGROUND
  Radix Isatidis called "Ban-Lan-Gen" is one of the most commonly-used traditional Chinese medicines for antiviral, anti-inflammatory, antioxidant and antipyretic purposes. Investigate the bioaccessibility of uridine, epigoitrin, adenosine, clemastanin B, indigoticoside A and isolariciresinol as well as the antioxidant and anti-inflammatory activities during an in vitro gastro-intestinal digestion of the Radix Isatidis extract (RIE).
  
  
  METHODS
  High performance liquid chromatography (HPLC) technique was adopted to determine the bioaccessibility of six bioactive compounds in RIE. Antioxidant activities of RIE in different digestive stages were determined by 1,1-Diphenyl-2-picrylhydrazyl (DPPH), superoxide anion and hydroxyl radical scavenging abilities. Anti-inflammatory activity was assayed by the inhibitions of inflammatory cytokines such as nitrous oxide (NO), prostaglandin E2 (PGE2) and tumor necrosis factor α(TNF-α) producted by lipopolysaccharide (LPS) stimulated RAW264.7 cells.
  
  
  RESULTS
  The bioaccessibility of uridine, epigoitrin, adenosine, clemastanin B, indigoticoside A and isolariciresinol were 15.38%, 18.28%, 24.01%, 6.50%, 8.65% and 17.78%, respectively. Also, the digestion products still possessed certain antioxidant activities. The antioxidant activity was highly correlated with lignans (clemastanin B, indigoticoside A and isolariciresino). The anti-inflammation activity of the three samples decreased in the order: IN sample (the solution that had diffused into the dialysis tubing)>Nondigested sample (RIE solution)>Gastric sample (post-gastric digestion)>OUT sample (material that remained in the gastro-intestinal tract).
  
  
  CONCLUSIONS
  Results obtained in this research reveal the amount of bioactive compounds from RIE that could be available for absorption in vivo. The antioxidant activity decreased significantly but the anti-inflammatory activity was enhanced in serum-available fraction after gastro-intestinal digestion in vitro. This study could provide a scientific basis for a deeper pharmacological activity study of Radix Isatidis and a simple method for pharmacodynamic material basis research.
authors.affiliation: College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, PR China.
authors.forename: Ping
authors.initials: P
authors.lastname: Xiao
authors.affiliation: College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, PR China.
authors.forename: Hongzhi
authors.initials: H
authors.lastname: Huang
authors.affiliation: College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, PR China.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Chen
authors.affiliation: College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, PR China. Electronic address: lixiang_8182@163.com.
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000302:isolation & purification / Q000494:pharmacology*; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D016166:Free Radical Scavengers / Q000302:isolation & purification / Q000494:pharmacology; D007249:Inflammation / Q000188:drug therapy / Q000473:pathology; D031219:Isatis / Q000737:chemistry*; D051379:Mice; D010936:Plant Extracts / Q000494:pharmacology*; D018517:Plant Roots
chemical_list: D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D016166:Free Radical Scavengers; D010936:Plant Extracts
keywords: Adenosine (Pubchem CID: 60961); Anti-inflammatory; Antioxidant; Bioaccessibility; DPPH (Pubchem CID: 2735032); Epigoitrin (Pubchem CID: 3032313); Hydrochloric acid (Pubchem CID: 313); Isolariciresinol (Pubchem CID: 160521); Lipopolysaccharide (Pubchem CID: 11970143); Nicotinamide-adenine dinucleotid (Pubchem CID: 5893); Nitro blue tetrazolium (Pubchem CID: 9281); PGE(2) (Pubchem CID: 5280360); Radix Isatidis; Simulated gastro-intestinal digestion; Uridine (Pubchem CID: 6029); Vitamin C (Pubchem CID: 54678501)