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Contribution of non-ionic interactions on bile salt sequestration by chitooligosaccharides: Potential
Filipe Coreta-Gomes1, Inês M V Silva1, Cláudia Nunes2
1LAQV-REQUIMTE, Chemistry Department, University of Aveiro, 3810-193 Aveiro, Portugal; Coimbra Chemistry Center - Institute of Molecular Sciences (CQC-IMS), Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal.
Journal of Colloid and Interface Science
|May 25, 2023
Summary
Chitooligosaccharides effectively bind bile salts, reducing cholesterol accessibility. Non-ionic interactions, not just charge, are key to their cholesterol-lowering effects in the gut.
Area of Science:
- Biochemistry
- Nutritional Science
- Polymer Chemistry
Background:
- Chitooligosaccharides (COS) are explored for cholesterol reduction, primarily through bile salt sequestration.
- Ionic interactions are typically assumed for COS-bile salt binding.
- At physiological pH, COS may be largely uncharged, suggesting other binding mechanisms.
Purpose of the Study:
- To investigate the bile salt sequestration and cholesterol accessibility effects of specific COS.
- To elucidate the nature of interactions between COS and bile salts under varying conditions.
Main Methods:
- Characterization of COS (DP 10, 90% deacetylated) in aqueous solutions.
- Measurement of bile salt sequestration and cholesterol accessibility using Nuclear Magnetic Resonance (NMR).
- Assessment of binding capacity under varying ionic strength and pH, including electrophoretic mobility analysis.
Main Results:
- COS demonstrated significant bile salt binding, comparable to colestipol, reducing cholesterol accessibility at pH 7.4.
- Increased binding capacity with decreased ionic strength confirmed ionic interaction involvement.
- No significant increase in bile salt sequestration at pH 6.4, despite increased COS charge, indicated non-ionic interactions.
Conclusions:
- Non-ionic interactions play a crucial role in COS-bile salt binding and cholesterol sequestration.
- COS's non-ionic character is a significant feature for developing hypocholesterolemic ingredients.
- Further research into COS interactions can optimize their use in functional foods.
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