Effets de l’extrait hydroéthanolique de la pulpe du fruit de Baillonella toxisperma sur l’hyperglycémie et quelques désordres associés

Abstract

One way to limit the uncontrolled slaughter of Baillonella toxisperma is to enhance the value of its fruit, which is a source of potential ingredients for the pharmaceutical, nutraceutical and agri-food industries. The purpose of this study was to evaluate the effects of the hydroethanolic extract from the pulp of B. toxisperma fruit on selected markers of glucose metabolism and cardiometabolic health. An acute and subacute toxicity study was also conducted. The effects of the extract on hyperglycemia were evaluated in an animal model of streptozotocin-induced hyperglycemia followed by its effects on endogenous glucose production. In addition, some antihyperglycemic mechanisms were evaluated: inhibition of carbohydrate digestion and/or absorption, regulation of the regulatory capacity of residual beta cells, glucose adsorption and cellular glucose capture. Finally, the effects of the extract on hemoglobin glycation, oxidative stress and cardiovascular risk were evaluated. The toxicity study revealed a DL50˃2000 mg/kg body weight, but the subacute toxicity showed toxic effects at the hepatic level at 400 mg/Kg of body weight. In hyperglycemic rats, the extract caused a 54.23% drop in initial blood glucose levels just after 1 week of treatment; as well as a decrease (p˂0,05) in endogenous glucose production through inhibition of gluconeogenesis and glycogenolysis. The extract did indeed (p˂0,05) limit glycemic peaks (by more than 10 mg/mL compared to the control group) after administration of starch and sucrose in normoglycemic rats. The extract also showed in vitro glucophagic capacity (glucose uptake percentages up to 60%), and stimulated glucose uptake by insulin-dependent cells (muscle glucose uptake rate up to 43.64% versus 21.64% for insulin alone) and insulin-independent cells (glucose uptake rate by yeast cells up to 56.62%). In hyperglycemic rats, the extract resulted (p˂0,05) in decreased hemoglobin glycation, increased markers of antioxidant status (superoxide dismutase and total antioxidant capacity) and decreased markers of prooxidant status (malondialdehyde and hydroperoxides). In vitro, the extract resulted in the scavenging of DPPH, ABTS+ and NO radicals (SC50 of 3.49, 3.24 and 4.28 mg/mL respectively); a reduction of MoO42-and Fe3+; and the chelation of Cu2+. The extract decreased (p˂0,05) creatinine levels and showed (p˂0,05) hypocholesterolemic and hypotriglyceridemic properties, with a decrease in cardiovascular risk. In conclusion, the hydroethanolic extract of the pulp of the fruit of Baillonella toxisperma is slightly hepatotoxic, and has beneficial effects on hyperglycemia, oxidative stress and cardiovascular health.