title: Liuwei Dihuang, a traditional Chinese herbal formula, suppresses chronic inflammation and oxidative stress in obese rats.
abstract: OBJECTIVE
  To investigate the anti-inflammatory, anti-oxidative stress, and adipokine-ameliorating effects of Liuwei Dihuang (LWDH), a traditional Chinese herbal formula, in obese rats.
  
  
  METHODS
  After 2 weeks of acclimation with free access to regular rodent chow and water, obese-prone-caesarean-derived (OP-CD) rats were fed a modified AIN-93G diet containing 60% energy from fat. Treatment was performed twice daily by gavage feeding with 500, 1 500, or 3 500 mg/kg body weight LWDH suspended in water (n=12 rats per group). Twelve obese-resistant-CD (OR-CD) rats were fed the atherogenic diet and gavaged with water, and served as the normal control. Blood biomarkers of inflammation, oxidative stress and adiponectin were measured post-sacrifice and used to determine the treatment effect of LWDH and assess the suitability of OR/OP-CD rats for studying these parameters.
  
  
  RESULTS
  After 9 weeks of treatment, LWDH lowered serum C-reactive protein (CRP) and tumour necrosis factor-α (TNF-α) levels. Serum interleukin-6 (IL-6) levels showed a tendency towards reduction, but were not significantly different from the OP-CD control. Liver superoxide dismutase (SOD) activity was increased in response to all three doses of LWDH, while the levels of reduced (GSH) and oxidized glutathione (GSSG) and thiobarbituric acid reactive substances (TBARS) were unchanged. Serum adiponectin levels were increased in response to oral administration of LWDH at the dose of either 500 or 1 500 mg/kg body weight. In addition, comparisons between OR-CD and OP-CD rats revealed differential, and for some biomarkers, conflicting characteristics of high-fat diet-fed OP-CD rats in reference to obese human subjects in terms of inflammatory and oxidative stress biomarkers and circulating adiponectin levels.
  
  
  CONCLUSIONS
  The results show, for the first time, the anti-inflammatory, anti-oxidative stress and adiponectin-ameliorating effects of LWDH in obese rats. The suitability of the OR/OP-CD rat model as a research tool to study inflammation, oxidative stress, and adipokine production requires further investigation.
authors.affiliation: Aquatic and Crop Resource Development, Life Sciences Branch, National Research Council Canada, Charlottetown, PE, Canada, C1A 4P3.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Perry
authors.affiliation: Aquatic and Crop Resource Development, Life Sciences Branch, National Research Council Canada, Charlottetown, PE, Canada, C1A 4P3.
authors.forename: Junzeng
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Biomedical Sciences, University of Prince Edward Island, Charlottetown, PE, Canada, C1A 4P3.
authors.forename: Tarek
authors.initials: T
authors.lastname: Saleh
authors.affiliation: Aquatic and Crop Resource Development, Life Sciences Branch, National Research Council Canada, Charlottetown, PE, Canada, C1A 4P3; E-mail: yanwen.wang@nrc.ca.
authors.forename: Yanwen
authors.initials: Y
authors.lastname: Wang
mesh_terms: D052242:Adiponectin / Q000097:blood; D000818:Animals; D002097:C-Reactive Protein / Q000032:analysis; D002908:Chronic Disease; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D005978:Glutathione / Q000378:metabolism; D007249:Inflammation / Q000188:drug therapy*; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D009765:Obesity / Q000150:complications*; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats
chemical_list: D052242:Adiponectin; D004365:Drugs, Chinese Herbal; D015850:Interleukin-6; C042579:Liuwei Dihuang Decoction; D002097:C-Reactive Protein; D005978:Glutathione