title: Danhong Huayu Koufuye combined with metformin attenuated diabetic retinopathy in Zucker diabetic fatty rats.
abstract: OBJECTIVE
  To evaluate effects of Danhong Huayu Koufuye (DHK, a Chinese medicinal formulae) alone or combined with metformin on diabetic retinopathy (DR) in Zucker diabetic fatty (ZDF) rats, an animal model of obese type-2 diabetes, and then to investigate the mechanisms.
  
  
  METHODS
  ZDF (fa/fa) rats were administered with vehicle (distilled water), metformin, DHK, and DHK plus metformin. Electrophysiological and histological analysis were applied to evaluated effects of DHK alone or combined with metformin on DR. The levels of fasting blood glucose (FBG) and glycosylated hemoglobin (HbA1c) in blood were measured to evaluate the antihyperglycemic activity of DHK. Furthermore, levels of nitric oxide (NO), malondialdehyde (MDA) and activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) in serum were measured to study effects of DHK on oxidative stress in ZDF rats. In addition, body weight, lipidic indexes and insulin level were also assessed.
  
  
  RESULTS
  DHK combined with metformin significantly reversed the prolongation of latency times of flash electroretinogram (FERG) and oscillatory potentials (OPs) in diabetic rats. Furthermore, DHK alone or combined with metformin showed a remarkable suppression of retinal neovascularization and amelioration of retinal internal limiting membrane morphology. Moreover, DHK alone or plus metformin reduced FBG (P<0.05), HbA1c (P<0.01) and MDA (P<0.01) levels in diabetic rats. In addition, reductions in levels of triglycerides (TG) (P<0.01) and low density lipoprotein cholesterol (LDL-c) (P<0.01 and P<0.05, respectively) were also observed in diabetic rats treated with DHK alone or plus metformin.
  
  
  CONCLUSIONS
  DHK in combination with metformin had a preventive and therapeutic effect on DR in type-2 diabetic rats, and the possible mechanisms may be alleviating hyperglycemia, reducing oxidative stress and improving lipid metabolism.
authors.affiliation: School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006, Guangdong Province, China.
authors.forename: Wen-Pei
authors.initials: WP
authors.lastname: Chen
authors.affiliation: Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou 510060, Guangdong Province, China.
authors.forename: Yan-Dong
authors.initials: YD
authors.lastname: Wang
authors.affiliation: School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006, Guangdong Province, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Ma
authors.affiliation: School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006, Guangdong Province, China.
authors.forename: Zi-Yang
authors.initials: ZY
authors.lastname: Zhang
authors.affiliation: School of Chinese Materia Medica, China Pharmaceutical University, Nanjing 210000, Jiangsu Province, China.
authors.forename: Lu-Yun
authors.initials: LY
authors.lastname: Hu
authors.affiliation: School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006, Guangdong Province, China.
authors.forename: Jun-Li
authors.initials: JL
authors.lastname: Lin
authors.affiliation: School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006, Guangdong Province, China.
authors.forename: Bao-Qin
authors.initials: BQ
authors.lastname: Lin
keywords: Danhong Huayu Koufuye; Zucker diabetic fatty rat; antihyperglycemic activity; diabetic retinopathy; metformin; oxidative stress