Novel antioxidant peptides in fermented pork sausage: Purification, characterization, and cytoprotective functions on Caco-2 cells

Effect of Digested Selected Food Items on Markers of Oxidative Stress and Inflammation in a Caco-2-Based Human Gut Epithelial Model

The human gut epithelium presents a crucial interface between ingested food items and the host. Understanding how different food items influence oxidative stress and inflammation in the gut is of great importance. This study assessed the impact of various digested food items on oxidative stress, inflammation, and DNA/RNA damage in human gut epithelial cells. Differentiated Caco-2 cells were exposed to food items and their combinations (n = 22) selected from a previous study, including sausage, white chocolate, soda, coffee, orange juice, and curcumin. Following stimulation with TNF-α/IFN-1β/LPS and H2O2 for 4 h, the cells were exposed to digested food items or appropriate controls (empty digesta and medium) for a further 16 h. Cell viability, antioxidant capacity (ABTS, FRAP), IL-6, IL-8, F2-isoprostanes, lipid peroxidation (MDA), and DNA/RNA oxidative damage were assessed (3 independent triplicates). The ABTS assay revealed that cells treated with "white chocolate" and "sausage + coffee" exhibited significantly reduced antioxidant capacity compared to stimulated control cells (ABTS = 52.3%, 54.8%, respectively, p < 0.05). Similar results were observed for FRAP (sausage = 34.9%; white chocolate + sausage = 35.1%). IL-6 levels increased in cells treated with "white chocolate + sausage" digesta (by 101%, p < 0.05). Moreover, MDA levels were significantly elevated in cells treated with digested "sausage" or sausage in combination with other food items. DNA/RNA oxidative damage was found to be higher in digesta containing sausage or white chocolate (up to 550%, p < 0.05) compared to stimulated control cells. This investigation provides insights into how different food items may affect gut health and underscores the complex interplay between food components and the epithelium at this critical interface of absorption.

From microbes to molecules: a review of microbial-driven antioxidant peptide generation

Oxidative stress, arising from excess reactive oxygen species (ROS) or insufficient antioxidant defenses, can damage cellular components, such as lipids, proteins, and nucleic acids, resulting in cellular dysfunction. The relationship between oxidative stress and various health disorders has prompted investigations into potent antioxidants that counteract ROS's detrimental impacts. In this context, antioxidant peptides, composed of two to twenty amino acids, have emerged as a unique group of antioxidants and have found applications in food, nutraceuticals, and pharmaceuticals. Antioxidant peptides are sourced from natural ingredients, mainly proteins derived from foods like milk, eggs, meat, fish, and plants. These peptides can be freed from their precursor proteins through enzymatic hydrolysis, fermentation, or gastrointestinal digestion. Previously published studies focused on the origin and production methods of antioxidant peptides, describing their structure-activity relationship and the mechanisms of food-derived antioxidant peptides. Yet, the role of microorganisms hasn't been sufficiently explored, even though the production of antioxidant peptides frequently employs a variety of microorganisms, such as bacteria, fungi, and yeasts, which are recognized for producing specific proteases. This review aims to provide a comprehensive overview of microorganisms and their proteases participating in enzymatic hydrolysis and microbial fermentation to produce antioxidant peptides. This review also covers endogenous peptides originating from microorganisms. The information obtained from this review might guide the discovery of novel organisms adept at generating antioxidant peptides.