The bile salt/phospholipid ratio determines the extent of in vitro intestinal lipolysis of triglycerides: Interfacial and emulsion studies.

This study focused on the protein-stabilised triglyceride (TG)/water interfaces and oil-in-water emulsions, and explored the influence of varying molar ratios of bile salts (BSs) and phospholipids (PLs) on the intestinal lipolysis of TGs. The presence of these two major groups of biosurfactants delivered with human bile to the physiological environment of intestinal digestion was replicated in our experiments by using mixtures of individual BSs and PLs under in vitro small intestinal lipolysis conditions. Conducted initially, retrospective analysis of available scientific literature revealed that an average molar ratio of 9:4 for BSs to PLs (BS/PL) can be considered physiological in the postprandial adult human small intestine. Our experimental data showed that combining BSs and PLs synergistically enhanced interfacial activity, substantially reducing oil-water interfacial tension (IFT) during interfacial lipolysis experiments with pancreatic lipase, especially at the BS/PL-9:4 ratio. Other BS/PL molar proportions (BS/PL-6.5:6.5 and BS/PL-4:9) and an equimolar amount of BSs (BS-13) followed in IFT reduction efficiency, while using PLs alone as biosurfactants was the least efficient. In the following emulsion lipolysis experiments, BS/PL-9:4 outperformed other BS/PL mixtures in terms of enhancing the TG digestion extent. The degree of TG conversion and the desorption efficiency of interfacial material post-lipolysis correlated directly with the BS/PL ratio, decreasing as the PL proportion increased. In conclusion, this study highlights the crucial role of biliary PLs, alongside BSs, in replicating the physiological function of bile in intestinal lipolysis of emulsified TGs. Our results showed different contributions of PLs and BSs to lipolysis, strongly suggesting that any future in vitro studies aiming to simulate the human digestion conditions should take into account the impact of biliary PLs - not just BSs - to accurately mimic the physiological role of bile in intestinal lipolysis. This is particularly crucial given the fact that existing in vitro digestion protocols typically focus solely on applying specific concentrations and/or compositions of BSs to simulate the action of human bile during intestinal digestion, while overlooking the presence and concentration of biliary PLs under physiological gut conditions.

Effect of Vita Glucan on some antioxidant parameters of the human blood. In vitro study.

Recently, beta-glucan has been postulated to modulate antioxidant enzyme activity (superoxide dismutase-SOD) as well as to inhibit lipid peroxidation in studies concerning rats or rabbits. There are very few reports on antioxidant effect of beta-glucan in the human blood. The study was aimed to estimate influence of Vita Glucan (VG) on SOD and catalase (CAT) activities as well as on total antioxidant power measured as ferric reducing activity and ascorbate concentration (FRASC) in the human blood in vitro. SOD activities were measured according to Fridovich's method, CAT activity by Aebi's and FRASC value by Benzi's one. Results of this study have shown that Vita Glucan at concentrations 42.5, 85, 170, and 340 mg x 100 mL(-1) increased markedly activities of antioxidant enzymes and FRASC values in human red blood cells hemolysates.