Increased bioavailability of ubiquinol compared to that of ubiquinone is due to more efficient micellarization during digestion and greater GSH-dependent uptake and basolateral secretion by Caco-2 cells.
Level 5 - mechanism / opinion, no new human data
In vitro digestion and cell culture model (no human or animal subjects)
PubMed 24979483 · doi:10.1021/jf5017829
What was done
The authors compared the bioaccessibility and intestinal cell absorption of solubilized ubiquinol versus ubiquinone added to yogurt using a simulated gastrointestinal digestion system coupled with a Caco-2 cell monolayer model. They evaluated coenzyme Q (CoQ) partitioning into mixed micelles during small intestinal digestion, apical uptake by Caco-2 cells, and basolateral secretion across the cell monolayer, both at baseline and after cellular glutathione (GSH) depletion.
What was found
The abstract reports no numerical values or statistical effect sizes. CoQ partitioning into mixed micelles during simulated small intestinal digestion was significantly greater for yogurt enriched with ubiquinol than with ubiquinone. Apical uptake from mixed micelles and transepithelial transport across Caco-2 cells were also significantly greater for ubiquinol. Depletion of cellular GSH significantly reduced cellular uptake and basolateral secretion of both forms, but the adverse impact was substantially greater for ubiquinol.
Why it matters
This study provides a mechanistic basis for the greater oral bioavailability of ubiquinol observed in humans, demonstrating more efficient micellar incorporation during digestion and GSH-dependent enterocyte transport.
Limits
This is purely an in vitro study using simulated digestion and a Caco-2 cell line, which cannot fully replicate human gastrointestinal physiology, mucus barriers, or in vivo metabolism. The abstract provides no quantitative data, replicate counts, or variance estimates. Results were tested only in a yogurt matrix and may not generalize to other food matrices or delivery formulations.
Cited by
- supports Ubiquinol possesses higher bioavailability compared to ubiquinone, the oxidized form of coenzyme Q10.