Cultivar diversity in Malus domestica Borkh. determines bioactive potential of apple pulp extracts: evidence from C. elegans metabolic dysfunction model

The overconsumption of high-caloric diets is a primary driver of obesity and type 2 diabetes, conditions associated with oxidative stress, dyslipidaemia, and systemic metabolic dysfunction. Apples (Malus domestica Borkh.) are among the most widely consumed fruits globally and represent a significant dietary source of (poly)phenolic compounds with recognised health-promoting properties. However, commercial cultivar selection has substantially reduced the phytochemical richness of apple varieties available in food chains, potentially limiting their functional food value. In this study, we compared the bioactive potential of pulp extracts from an autochthonous Spanish cultivar, ‘Amarilla de Octubre’, and a commercially selected, ‘Pinova’, using a Caenorhabditis elegans model of glucose-induced metabolic dysfunction. Lipid accumulation, reactive oxygen species (ROS) production, bacterial intake, and health span-related markers were evaluated. ‘Amarilla de Octubre’ extract significantly reduced lipid accumulation by up to 23.24%, attenuated ROS production to levels comparable to non-stressed controls, decreased glucose-induced hyperphagia, and preserved locomotor function. In contrast, ‘Pinova’ extract showed limited and largely concentration-dependent effects across all parameters. These findings suggest that autochthonous apple cultivars with higher (poly)phenolic content like ‘Amarilla de Octubre’ may represent valuable functional food sources for the dietary management of metabolic dysfunction and highlight the nutritional relevance of preserving agrobiodiversity.