Bioavailable Human Metabolites from TOTUM- 448 (Plant-Based, Polyphenol-Rich Ingredient) Maintain Liver Cell Functionality in a Lipotoxic Context that Drives MASLD Onset

Abstract Lipotoxic and inflammatory environment drives metabolic dysfunction-associated steatotic liver disease (MASLD) onset. Since most related treatments evidence side effects, alternatives have emerged, including preventive nutritional strategies, however they require further clinical validation. In this study, we conducted an innovative ex vivo clinical study considering the circulating metabolites produced by the digestive tract following the oral intake of TOTUM-448 (a plant-based, polyphenol-rich ingredient) in humans, to provide insights on whether and how these metabolites may influence hepatocytes behavior. The bioavailability of circulating polyphenol metabolites was confirmed and characterized by UHPLC-MS/MS. Then, human serum enriched with polyphenol metabolites was further incubated with human hepatocytes (HepG2), pretreated or not with palmitate (250µM). Hepatocyte responses were monitored to determine the effects of TOTUM-448’s metabolites on cell viability, lipid metabolism, inflammation, oxidative stress and endoplasmic reticulum (ER) stress which are all key features of MASLD.Treated hepatocytes showed resistance to the induced lipotoxic stress with reduced palmitate-induced intracellular lipid storage. TOTUM-448’s metabolites also inhibited palmitate-induced inflammatory gene expression. Additionally, while palmitate potently induced both CHOP and XBP1 mRNA expression, ATF-6 and Caspase-3 activities, the presence of TOTUM-448’s metabolites normalized these ER stress markers.