Pharmacological and Genotoxic Properties of Polyphenolic Extracts of Cedrela odorata L. and Juglans regia L. Barks in Rodents.

Dulce Carolina Almonte-Flores,Gerardo Escalona-Cardoso,Martha Rosales-Castro,Norma Paniagua-Castro

doi:10.1155/2015/187346

Abstract

Evaluation of the phenolic compounds and antioxidant activity of Cedrela odorata L. and Juglans regia L. bark extracts was performed in vitro. Juglans regia showed greater extract concentration and higher antioxidant activity. Hypoglycemic activity in rats was assessed by generating a glucose tolerance curve and determining the area under the curve (AUC). Diabetes was later induced by an injection with streptozotocin (65 mg/kg of b.w.) and confirmed after 24 hours. The extract was administered (200 mg/kg b.w.) over 10 days, and blood glucose was monitored and compared with a control group. The glucose AUC showed a hypoglycemic effect of J. regia and C. odorata in normal rats. Both extracts reduced hepatic lipid peroxidation in diabetic rats. Polyphenolic extracts reduced cholesterol levels in a hypercholesterolemic mouse model and decreased hepatic lipid peroxidation. Polyphenolic extract doses of 100 and 200 mg/kg b.w. were administered alone or with cyclophosphamide (CPA) 50 mg/kg ip, which was used as a positive control. Analyses were performed using leukocytes in a comet assay after 4 and 24 h of treatment. Genotoxic effects were evaluated by the comet assay, which showed that while J. regia extract had no effect, C. odorata extract induced slight damage at 200 mg/kg, with the formation of type 0 and 1 comets.

Highlights

Juglans regia L. (Juglandaceae) comprises several species and is widely distributed throughout the world
The hypoglycemic effect of the extracts was tested in female Wistar rats (5 animals/dose of extract) with previously induced type I diabetes by intraperitoneal streptozotocin injection (STZ, 65 mg/kg of body weight, in citrate buffer, pH 4.4) in which the hyperglycemia was confirmed by measuring the glucose levels in the blood 24 hours after injection
This work showed that J. regia extracts have a high concentration of phenolic compounds and have antioxidant activity

Summary

Introduction

Juglans regia L. (Juglandaceae) comprises several species and is widely distributed throughout the world. The walnut tree is a well-known deciduous species that is found primarily in temperate areas and is cultivated commercially throughout southern Europe, northern Africa, eastern Asia, the United States, and western South America. There are reports that extracts of J. regia and C. odorata have phenolic compounds in their composition, but insufficient toxicological and genotoxicological studies have been performed on these compounds. The genotoxicity of plants can be measured with a group of techniques that include the micronucleus (MN), Ames test, AO/EB tint double, and the comet assay [10]. Despite the studies on phenolic compounds in Juglans regia, there is little information about the hypoglycemic and hypocholesterolemic properties of their barks and the relationship between the pharmacological effects of the phenolic compounds and their genotoxic effects. A recent study on C. odorata reports hypoglycemic activity from a hydro alcoholic extract without toxic effects. Phenolic compounds were not tested, underlining the importance of the present research [14]

Materials and Methods

Results

Discussion