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Mesoporous silica particles (MSPs) can be used as food additives, clinically for therapeutic applications, or as oral delivery vehicles. It has also been discussed to be used for a number of novel applications including treatment for diabetes and obesity. However, a major question for their possible usage has been if these particles persist structurally and retain their effect when passing through the gastrointestinal tract (GIT). A substantial breaking down of the particles could reduce function and be clinically problematic for safety issues. Hence, we investigated the biostability of MSPs of the SBA-15 kind prepared at large scales (100 and 1000 L). The MSPs were orally administered in a murine model and clinically in humans. A joint extraction and calcination method was developed to recover the MSPs from fecal mass, and the MSPs were characterized physically, structurally, morphologically, and functionally before and after GIT passage. Analyses with N2 adsorption, X-ray diffraction, electron microscopy, and as a proxy for general function, adsorption of the enzyme α-amylase, were conducted. The adsorption capacity of α-amylase on extracted MSPs was not reduced as compared to the pristine and control MSPs, and adsorption of up to 17% (w/w) was measured. It was demonstrated that the particles did not break down to any substantial degree and retained their function after passing through the GITs of the murine model and in humans. The fact the particles were not absorbed into the body was ascribed to that they were micron-sized and ingested as agglomerates and too big to pass the intestinal barrier. The results strongly suggest that orally ingested MSPs can be used for a number of clinical applications. Validerad;2023;Nivå 2;2023-03-08 (joosat);Licens fulltext: CC BY License

Phenolic acids are widely found in fruits and vegetables. The inhibitory effect of phenolic acids on α-amylase, a key enzyme for starch digestion, has attracted the attention of researchers. To further investigate the effects of different substituents on the benzene ring of phenolic acid on the inhibition of α-amylase activity, in vitro experiments and molecular docking were used. The structure-activity relationships of 17 phenolic acids with benzoic acid as the parent nucleus were analyzed by determining their half inhibitory concentration (IC50) toward α-amylase. The results showed that 2,3,4-trihydroxybenzoic acid had the strongest inhibitory effect on α-amylase with an IC50 value of 17.30 ± 0.73 mM. According to the structure-activity analysis, the hydroxyl group at the 2-position on the benzene ring had a strong positive effect on the inhibitory activity of α-amylase, while methoxylation at the 2-position and hydroxylation at the 5-position had a negative effect. Molecular docking revealed that hydrogen bonding and hydrophobic interactions were involved in the inhibition, with hydrogen bonding being the primary force. These findings provide a more comprehensive understanding of phenolic acids as inhibitors of α-amylase and provide new ideas for the design of dietary formulations for diabetic patients.