Author(s)

Ana Carla Broetto Biazon¹, Mariana Marques Nogueira Wendt², Júlia Rosa Moreira², Cristiane Vizioli Castro Ghizoni², Andreia Assunção Soares², Sandra da Silva Silveira², Anacharis Babeto de Sá-Nakanishi², Ciomar Aparecida Bersani Amado³, Rosane Marina Peralta², Adelar Bracht^2*, Jurandir Fernando Comar²

¹Pharmacy Department, Faculdades Integrado, Campo Mourao, Brazil.
²Biochemistry Department, University of Maringá, Maringá, Brazil.
³Pharmacology and Therapeutics Department, University of Maringá, Maringá, Brazil.

Leaf and root extracts of Smallanthus sonchifolius (yacon), have antihyper-glycemic activity and antioxidant properties. The present study aims to compare the in vivo hepatic antioxidant activity of hydroalcoholic extracts of yacon leaves and roots in rats with streptozotocin-induced diabetes in terms of their in vitro antioxidant capacity. Rats were treated during 14 days with 1060 mg·Kg^-1 root extract or 400 mg·Kg^-1 leaf extract. The latter was richer in phenolics and possessed a much higher in vitro antioxidant activity. Both extracts prevented hyperglycemia in diabetic rats. The liver of diabetic rats presented increased levels of protein carbonyls and ROS and decreased activities of antioxidant enzymes. Treatment with both root and leaf extracts restored the protein carbonyl levels to normality. The root extract also restored the ROS levels to normality, but the leaf extract was not effective. The root extract was also more effective in restoring the activity of at least two important antioxidant enzymes (glucose 6-phosphate dehydrogenase and glutathione peroxidase). In terms of the antioxidant load (which was 17 times lower in the root extract treatment), the in vivo action of the root extract was more effective than the leaf extract in reducing the hepatic oxidative stress that accompanies diabetes.

Smallanthus sonchifolius, Yacon, Streptozotocin-Induced Diabetes, Liver Oxidative Status

Biazon, A. , Wendt, M. , Moreira, J. , Ghizoni, C. , Soares, A. , da Silva Silveira, S. , de Sá-Nakanishi, A. , Amado, C. , Peralta, R. , Bracht, A. and Comar, J. (2016) The in Vitro Antioxidant Capacities of Hydroalcoholic Extracts from Roots and Leaves of Smallanthus sonchifolius (Yacon) Do Not Correlate with Their in Vivo Antioxidant Action in Diabetic Rats. Journal of Biosciences and Medicines, 4, 15-27. doi: 10.4236/jbm.2016.42003.