RESUMO
OBJECTIVES: Juglans regia L. is largely used by diabetic population, but its bark is scarcely investigated. The major aim of this study was to investigate the effect of the hydro-methanolic extract and fractions of J. regia L. barks on normoglycemic and diabetic rats through the evaluation of some biochemical parameters. METHODS: Phenolic enriched extracts were investigated for their effect on normoglycemic and diabetic rats through the determination of fasting blood glucose levels in short- and long-term. As well as plasma total cholesterol, triglycerides, insulin, urea, creatinine, alanine amino transferase (ALT) and aspartate amino transferase (AST) levels were measured after 28 days of treatment. Furthermore, the phytochemical composition was assessed by standard methods. RESULTS: Among the different extracts tested, the n-Butanol fraction presented the highest amounts of total phenolic, total flavonoids and flavonol contents (745 ± 0.6 mg GAE g-1, 162 ± 0.78 mg CE g-1 and 56.02 ± 0.92 mg QE g-1, respectively) and it found to be the most effective to decrease plasma total cholesterol, triglycerides and FGLs in treated diabetic rats in both short- and long-term treatment, mainly the dose 200 mg/kg after 28 days of treatment which found to be more effective than glibenclamide. This fraction also revealed pronounced improvement in liver and renal profiles. CONCLUSIONS: J. regia L. barks had an important antidiabetic role similar to the reference glibenclamide. This may be related to the high contents of phenolic compounds.
