title: Phenolic content and anti-hyperglycemic activity of pecan cultivars from Egypt.
abstract: BACKGROUND
  Pecans are commonly used nuts with important health benefits such as anti-hyperglycemic and anti-hyperlipidemic effects.
  
  
  OBJECTIVE
  A comparative investigation of the antihyperglycemic and total phenolic content of the leaves and shells of four pecan cultivars growing in Egypt was carried out. The selected cultivars (cv.) were Carya illinoinensis Wangneh. K. Koch. cv. Wichita, cv. WesternSchely, cv. Cherokee, and cv. Sioux family Juglandaceae.
  
  
  METHODS
  Total phenolic and flavonoid contents of the leaves and shells of pecan cultivars were carried out using Folin-Ciocalteu's and aluminum chloride assays, respectively. Moreover, HPLC profiling of phenolic and flavonoid contents was carried out using RP-HPLC-UV. In addition, in vivo anti-hyperglycemic activity of the ethanolic extracts (125 mg/kg bw, p.o.) of C. illinoinensis cultivars was carried out using streptozotocin (STZ)-induced diabetes in Sprague-Dawley rats for 4 weeks.
  
  
  CONCLUSIONS
  Phenolic contents were higher in shells than leaves in all studied cultivars, while flavonoids were higher in leaves. Leaves and shells of cv. Sioux showed the highest phenolics (251.7 µg gallic acid equivalent (GAE)/g), and flavonoid contents (103.27 µg rutin equivalent (RE)/g and 210.67 µg quercetin equivalent (QE)/g), respectively. The HPLC profiling of C. illinoinensis cultivars resulted in the identification of eight flavonoids (five of these compounds are identified for the first time from pecan), and 15 phenolic acids (six are identified for the first time from pecan). Leaves of cv. Sioux revealed the most potent decrease in blood glucose and glycated hemoglobin (HbA1c%) (194.9 mg/dl and 6.52%, respectively), among other tested cultivars. Moreover, leaves of cv. Sioux significantly elevated serum total antioxidant capacity (TAC) and reduced glutathione (GSH) (0.33 mMol/l and 30.68 mg/dl, respectively), and significantly suppressed the markers of both lipid peroxidation (malondialdehyde, MDA) and protein oxidation (protein carbonyl, PC) (14.25 µmol/ml and 3.18 nmol/mg protein, respectively).
  
  
  CONCLUSIONS
  Different pecan cultivars showed significant variation in its phenolic and flavonoid contents and consequently their antioxidant and anti-hyperglycemic effects.
authors.affiliation: a Department of Pharmacognosy , Faculty of Pharmacy, Cairo University , Cairo , Egypt .
authors.forename: Seham S
authors.initials: SS
authors.lastname: El Hawary
authors.affiliation: b Department of Pharmacognosy , Faculty of Pharmacy, MSA University , Giza , Egypt .
authors.forename: Soumaya
authors.initials: S
authors.lastname: Saad
authors.affiliation: a Department of Pharmacognosy , Faculty of Pharmacy, Cairo University , Cairo , Egypt .|c Faculty of Pharmacy , King Abdulaziz University , Jeddah , Saudi Arabia , and.
authors.forename: Ali Mahmoud
authors.initials: AM
authors.lastname: El Halawany
authors.affiliation: d Department of Biochemistry , National Organization for Drug Control and Research (NODCAR) , Giza , Egypt.
authors.forename: Zeinab Y
authors.initials: ZY
authors.lastname: Ali
authors.affiliation: b Department of Pharmacognosy , Faculty of Pharmacy, MSA University , Giza , Egypt .
authors.forename: Mahitab
authors.initials: M
authors.lastname: El Bishbishy
mesh_terms: D000818:Animals; D031325:Carya; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy* / Q000378:metabolism; D004534:Egypt; D016166:Free Radical Scavengers / Q000302:isolation & purification / Q000627:therapeutic use; D007004:Hypoglycemic Agents / Q000302:isolation & purification / Q000627:therapeutic use*; D008297:Male; D010636:Phenols / Q000302:isolation & purification / Q000627:therapeutic use*; D010936:Plant Extracts / Q000302:isolation & purification / Q000627:therapeutic use*; D018515:Plant Leaves; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D016166:Free Radical Scavengers; D007004:Hypoglycemic Agents; D010636:Phenols; D010936:Plant Extracts
keywords: Antidiabetes; Carya illinoinensis; HPLC; glycated hemoglobin; phenolics; protein carbonyl