Oral Treatment with the Pectin Fibre Obtained from Yellow Passion Fruit Peels Worsens Sepsis Outcome in Mice by Affecting the Intestinal Barrier.

The biological activities of plant-derived soluble dietary fibres (SDFs) have been widely investigated. Pectin from yellow passion fruit (YPF-peSDF) peels was suggested as a protective macromolecule in ulcers and colitis due to its antioxidant and anti-inflammatory properties. Sepsis has high mortality and morbidity and is characterised by inflammatory and oxidative stress imbalances. Evidence suggests that pectins may aid sepsis treatment; however, the effects of YPF-peSDF on sepsis remain unclear. Herein, polymicrobial sepsis was induced by cecal-ligation and puncture in mice treated with YPF-peSDF (1 and 10 mg/kg; gavage). YPF-peSDF accelerated mortality, reaching 100% in 24 h. Inflammation was present in the colons and small intestines (SI) of both vehicle- and fibre-treated mice. Although crypt depth and width, and villus height were preserved in the SI of septic mice administered YPF-peSDF, they exhibited exacerbated muscle layer atrophy and mucosa and submucosa hypertrophy, along with shortened enterocytes. Larger crypts and shorter enterocytes were noted in their colons in comparison with vehicle-controls. YPF-peSDF also reduced inflammatory cell numbers and exacerbated IL-6 levels in peritoneal lavage fluid (PELF) samples. YPF-peSDF modulated SI but not colon cytokines. Lipoperoxidation and antioxidant capacity levels were attenuated in PELF samples. Overall, in contrast to previous evidence, YPF-peSDF worsened polymicrobial sepsis outcomes in mice.

Soluble dietary fibres decrease α-glucosidase inhibition of epigallocatechin gallate through affecting polyphenol-enzyme binding interactions.

The effects of soluble dietary fibres (SDFs) on α-glucosidase inhibition of EGCG were studied. Three arabinoxylans and polygalacturonic acid (PGA) significantly decreased inhibitory activity of EGCG against α-glucosidase, while two ß-glucans hardly affected the inhibition. Although arabinoxylans and PGA weakened the competitive inhibition character of EGCG, they maintained the fluorescence quenching effect of EGCG. Then, arabinoxylans and PGA significantly decreased the particle size and turbidity of EGCG-enzyme complex. These results suggest that there formed SDFs-EGCG-enzyme ternary complexes. The stronger decreasing-effects of arabinoxylans and PGA on α-glucosidase inhibition of EGCG than ß-glucans resulted from the stronger non-covalent interactions of arabinoxylans and PGA with EGCG. This is considered to arise from the short-branches of arabinoxylans that provided more opportunity for capturing EGCG, and from the strong polarity of PGA carboxyl that promoted hydrogen bondings with EGCG. Conclusively, SDFs should be considered as an impact factor when evaluating α-glucosidase inhibition of dietary polyphenols.