ALKALOIDS FROM JUÁ-AÇU (Solanum oocarpum Sendt.) AS AN EFFECTIVE ALTERNATIVE TO CONTROLING ROS PRODUCTION IN INSULIN PRODUCING CELLS

Juá-açu (Solanum oocarpum Sendt) is a native Brazilian fruit with high antioxidant capacity associated with phenolic compounds derived from hydroxycinnamic acids. Also, our group previously identified the alkaloids solasonine and kukoamines A and B in the juá-açu pulp. Kukoamines, especially kukoamine A, exhibited potent antioxidant activities and was able to attenuate insulin resistance using in vitro models. The aim of this study was to obtain a kukoamine enriched extract and evaluate its effects on the reactive oxygen species generation (ROS) and insulin secretion in INS-1E cells exposed to high-glucose conditions. Kukoamines were isolated by solid-phase extraction using a polyamide as an adsorbent. The characterization of kukoamine rich extract was performed by UHPLC-Q-ToF. INS-1E cells were treated with 11 mM glucose (Normal Glucose group - NGG); 11 mM glucose plus Kukoamine extract 100 uM (Kukoamine group - NKG); high glucose 30 mM (High Glucose group – HGG); and 30 mM glucose plus Kukoamine extract 100 uM (Kukoamine High Glucose group – HKG) during 48h. Superoxide anion radical (SO2●-) production was measured by Red Mitochondrial Superoxide Indicator (MitoSOX) and dihydroethidium (DHE). Insulin secreted was measured by ELISA. The enriched extract obtained had 5.1 % of kukoamine A and B. High glucose exposure increased the superoxide anion production and kukoamine extract was able to keep SO2●- at the levels of normal glucose exposure (p < 0.05). Kukoamine extract also improved insulin secretion in high-glucose conditions. These data showed the beneficial effects of kukoamine extracts against oxidative damage evoked by glucotoxicity in β-cells. These results are promising and kukoamine extracts rises as a natural compound with the potential to be used for prevention and/or coadjutant therapy for diabetes.