Mechanisms of action of plant sterols on inhibition of cholesterol absorption
- Cite this article as:
- Heinemann, T., Kullak-Ublick, G.-., Pietruck, B. et al. Eur J Clin Pharmacol (1991) 40: S59. doi:10.1007/BF01409411
The effects of two different plant sterols on intestinal cholesterol absorption were compared in normal volunteers by an intestinal perfusion study during a control period followed by high dose infusion of sitosterol or sitostanol (3.6 μmol/min), to which subjects were allocated in a randomized manner. Cholesterol absorption during the control period was similar in the two groups, averaging 0.88 ± 0.48 μmol/min (32 ± 11%) for group I (sitosterol) and 0.68 ± 0.33 μmol/min (29 ± 9%) for group II (sitostanol). The infusion of a high dose of sitosterol resulted in a significant reduction of cholesterol absorption to 0.47 μmol/min (16%). Following the same dose of sitostanol, cholesterol absorption diminished significantly to 0.15 ± 0.11 μmol/min (5.1 ± 2.9%). Overall cholesterol absorption declined during sitosterol infusion by almost 50%, whereas sitostanol infusion caused a reduction of cholesterol absorption by almost 85%. These findings of a more effective inhibition of cholesterol absorption by sitostanol might confirm the observation recorded by others that an increase in hydrophobicity of a plant sterol results in a higher affinity but lower capacity to mixed micells. This may cause an effective displacement of cholesterol from micellar binding and therefore diminished cholesterol absorption.