Administration of the aqueous extract of the stem bark of Hancornia speciosa Gomes (Apocynaceae) does not alter obesity induced by high-fat diet in mice

Abstract

Ethnobotanical surveys have shown that the stem bark of Hancornia speciosa Gomes (Apocynaceae) is popularly used to treat obesity and diabetes. However, there is no experimental evidence that confirms such use. The present study investigated the effects of the aqueous extract of the stem bark of H. speciosa (AEHS) on the glycemic and adipogenic profiles of obese mice. Mice were divided into four groups that received standard diet (SD), standard diet plus AEHS (SDE), high-fat diet (HD) and high-fat diet plus AEHS (HDE). The administration of AEHS (in a concentration of 0.3 mg.mL-1. ad libitum in the drinking water) was performed for the last 8 weeks totaling a period of 18 weeks, in which the animals received the diets. Whole body weight, liquid intake and food consumption were measured during the entire experiment. Blood glucose levels, insulin sensitivity, glucose tolerance and adipose pads weight were evaluated. Animals from the HD group presented higher body weight in comparison to animals from the SD group. That was associated with insulin resistance and glucose intolerance, as well as increased blood glucose levels (p < 0.05) and weight of adipose tissue pad (p < 0.05), when compared to the SD group. The treatment with AEHS did not alter obesity induced by high-fat diet, because no significant difference was observed between the HD and the HDE groups in all of the parameters evaluated. These findings allowed the conclusion that AEHS does not reverse the alterations caused by high-fat diet in mice, what goes against the popular use.