Dietary crystalline common-, micro-, nanoscale and emulsified nanoscale sitosterol reduce equally the cholesterol pool in guinea pigs, but varying nanosystems result in different sterol concentrations in serosal jejunum

Due to hypocholesterolemic effects, sitosterol is used in functional foods and nanoscale dispersions. To investigate the influence of dietary sitosterol on sterol concentrations in Dunkin Hartley guinea pigs, seven groups consisting of eight animals each were fed either a basal diet (BD), a high-cholesterol diet (HC) or a high-cholesterol diet supplemented with crystalline commonscale (CCS), microscale (CMS, low-dosed: CMLS), nanoscale (CNS) or emulsified nanoscale (ENS) sitosterol. When compared to HC group, all sitosterol formulations decreased liver cholesterol concentrations. No differences in cholesterol or sitosterol concentration were found in plasma and liver between CCS, CMS, CNS, and ENS groups. Apparent cholesterol digestibility decreased by increasing crystalline microscale sitosterol doses. Despite a lower sitosterol intake, ENS group had higher serosal sitosterol concentrations in jejunum than CNS group. To elucidate an impact of the sitosterol nanosystem on gut tissues further studies are necessary.From the Clinical EditorIn this study, the use of sitosterols in a rat model led to contradicting conclusions regarding their ability to reduce cholesterol levels efficiently in guinea pigs, suggesting that more preclinical data is needed before this method could become applicable to human studies.

Graphical AbstractCrystalline micro- or nanoscale as well as emulsified nanoscale sitosterol in a high-cholesterol diet were fed to guinea pigs analyzing their impact on cholesterol and sitosterol concentrations in different gut tissues and body parts of the animals. The crystalline nanoscale sitosterol was visualized by scanning electron microscopy on the left picture; applicated emulsified nanoscale sitosterol is shown on the right picture.Figure optionsDownload high-quality image (137 K)Download as PowerPoint slide