Fig. 8: Biotransformed citrus extracts improve intestinal barrier integrity and reduce oxidative stress in female w¹¹¹⁸ D. melanogaster under challenge conditions.

a Schematic overview of in vivo challenges: (1) dextran sulphate sodium (DSS) challenge to reduce intestinal barrier integrity; (2) ferrous iron induced oxidative stress in female w¹¹¹⁸ D. melanogaster. AQE stands for aqueous citrus extract, FermCAE stands for fermented citric acid hydrolyzed citrus extract, DCF(DA) stands for 2’,7’-dichlorodihydrofluorescein (diacetate). b D. melanogaster fed with blue dye (1) with DSS-challenged intestinal barrier (Smurf phenotype) and (2) in control group. Scale bar: 500 µm. c, d Mortality and Smurf phenotype observed in D. melanogaster challenged by DSS and treated with citrus extracts for 7 d. Data are mean ± SD of n = 300 flies/treatment. e, f Reactive oxygen species (ROS) level and metabolic activity of D. melanogaster stressed with ferrous iron and treated with citrus extracts for 70 h, normalized to protein content. RFU stands for relative fluorescence units. Data are mean ± SD of n = 12 samples (25 flies each)/treatment. g, h Mortality and climbing performance of D. melanogaster stressed with ferrous iron and treated with citrus extracts for 7 d. Data are mean ± SD of n = 225 flies/treatment. Differences are analyzed by ordinary one-way ANOVAs with Šídák’s multiple comparison test.