Curcumin nanoemulsion supplementation prevents metabolic damage in a Drosophila melanogaster model of insulin resistance fed a high-sugar diet.

Chronic noncommunicable diseases affect populations in all geographic regions and are one of the leading causes of morbidity and mortality, especially in low- and middle-income countries. Excessive sugar consumption has been linked to an increase in the incidence and prevalence of these diseases. In contrast, various bioactive compounds, such as curcumin—a polyphenol found in Curcuma longa—have demonstrated remarkable therapeutic potential due to their anti-inflammatory, antioxidant, lipid-lowering, and blood-sugar-lowering properties. However, curcumin’s low stability reduces its bioactivity, so technological strategies are needed to improve its nutraceutical effectiveness. The objective of this study was to evaluate the protective effect of a curcumin nanoemulsion in a model of insulin resistance (IR) induced in Drosophila melanogaster flies fed a high-sucrose, high-calorie diet (HSD) for 10 days. Using wild-type male flies, we established the following experimental groups: control diet (CD), HSD, HSD supplemented with 1% w/v vehicle nanoemulsion (HSD+V), and HSD supplemented with 1% w/v nanoemulsion containing curcumin (HSD+NC). After 10 days of exposure, we estimated food intake under the different conditions. We evaluated circulating glucose levels in hemolymph, total triglycerides, and malondialdehyde (MDA) production (as an indicator of lipid peroxidation). Additionally, we assessed the long-term effect using a survival assay. Our results show that, as expected, the high-sugar diet promotes metabolic damage, as evidenced by increased levels of inflammation markers, insulin resistance, hyperglycemia, triglyceride accumulation, and reduced lifespan. Interestingly, in flies fed the curcumin nanoemulsion (HSD+NC), circulating glucose levels were reduced by 45.5% and total triglycerides by 24% compared to those fed HSD (p<0.05). Additionally, MDA levels decreased by 31.5% compared to the control group (CD) (p<0.05). However, we observed no positive changes in life expectancy. Based on these data, we conclude that the curcumin nanoemulsion protects against metabolic damage induced by a sucrose-rich diet in a model of insulin resistance in Drosophila melanogaster, supporting its therapeutic potential in diabetes and diseases related to high-sugar diet consumption.