Comparison of Two Commercial Preparations of Curcumin using the Caco-2 in vitro Assay of Human Intestinal Permeability
Alex McLellan, ND




Objectives: The transport of curcuminoids in Caco-2 cell monolayers, which are widely used as an in vitro model of drug permeability in the human small intestine, was investigated. The formulations tested demonstrated two distinct methods for enhancing the intestinal absorption and bioavailability of curcumin: a curcumin– phospholipid complex and a turmerone/piperine-enhanced curcumin product.

Design and outcome measures: Two unique formulations representing distinct approaches to maximizing curcumin bioavailability were compared with each other and with standard control compounds. Outcomes evaluated included apparent permeability, which reflects the ability of drug molecules to penetrate the intestinal tract; percentage recovery of compound through the Caco-2 monolayer; and efflux ratio, which is generally considered to reflect the role of efflux proteins in expelling compounds from the intestinal lumen.

Results: In our widely used Caco-2 cell model experiments, the absorption of curcumin from each unique commercial formulation was equivalent at the single concentration tested. Furthermore, curcumin efflux was substantially reduced in the turmerone/piperine formula, though the difference between formulations was not significant. This reduction of curcumin efflux was expected on the basis of reports of piperine’s P-glycoprotein-inhibitory activity.

Conclusion: The results of the present experiment strongly suggest that the incorporation of turmerones and piperine into curcumin preparations may be a simple way to improve the poor bioavailability of curcumin, which has previously been shown to be improved by the formulation of curcumin into curcumin–phospholipid complexes.



1. Kidd PM. Bioavailability and activity of phytosome
complexes from botanical polyphenols: the silymarin,
curcumin, green tea, and grape seed extracts. Altern Med
Rev. 2009;14:226–46.
2. Nelson KM, Dahlin JL, Bisson J, et al. The essential
medicinal chemistry of curcumin. J Med Chem.
3. Lao CD, Ruffin MT 4th, Normolle D, et al. Dose escalation
of a curcuminoid formulation. BMC Complement
Altern Med. 2006;6:10.
4. Khan J, Alexander A, Ajazuddin A, Saraf S. Recent
advances and future prospects of phyto-phospholipid
complexation technique for improving pharmacokinetic
profile of plant actives. J Control Release.
5. Shoba G, Joy D, Joseph T, et al. Influence of piperine on
the pharmacokinetics of curcumin in animals and human
volunteers. Planta Med. 1998;64:353–6.
6. Yue GG, Cheng SW, Yu H, et al. The role of
turmerones on curcumin transportation and
P-glycoprotein activities in intestinal Caco-2 cells. J Med
Food. 2012;15:242–52.
7. Bhattacharya S. Phytosomes: the new technology for
enhancement of bioavailability of botanicals and nutraceuticals.
Int J Health Res. 2009;2:225–32.
8. More Minakshi S, Shende Mulchand A, Kolhe Deul
B, Jaiswal Nayna M. Herbosomes: herbo-phospholipid
complex: an approach for absorption enhancement. Int J
Biol Pharm Res. 2012;3:946–55.
9. Maiti K, Mukherjee K, Gantait A, et al. Curcuminphospholipid
complex: preparation, therapeutic
evaluation and pharmacokinetic study in rats. Int J
Pharm. 2007;330:155–63.
10. Marczylo TH, Verschoyle RD, Cooke DN, et al.
Comparison of systemic availability of curcumin with
that of curcumin formulated with phosphatidylcholine.
Cancer Chemother Pharmacol. 2007;60:171–7.
11. Toden S, Goel A. The Holy Grail of curcumin and its
efficacy in various diseases: is bioavailability truly a big
concern? J Restor Med. 2017;6:27–36.
12. Artursson P, Karlsson J. Correlation between oral drug
absorption in humans and apparent drug permeability
coefficients in human intestinal epithelial (Caco-2) cells.
Biochem Biophys Res Commun. 1991;175:880–5.
13. Belcaro G, Cesarone MR, Dugall M, et al. Efficacy
and safety of Meriva, a curcumin–phosphatidylcholine
complex, during extended administration in osteoarthritis
patients. Altern Med Rev. 2010;15:337–44.
14. Appendino G, Belcaro G, Cornelli U, et al. Potential
role of curcumin phytosome (Meriva) in controlling the
evolution of diabetic microangiopathy: a pilot study.
Panminerva Med. 2011;53(3 Suppl 1):43–9.
15. Xue M, Cheng Y, Xu L, Zhang L. Study of the intestinal
absorption characteristics of curcumin in vivo and in
vitro. J Appl Pharm. 2017;9:246.
16. Katiyar SS, Muntimadugu E, Rafeeqi TA, et al. Co-delivery
of rapamycin- and piperine-loaded polymeric nanoparticles
for breast cancer treatment. Drug Deliv. 2016;23:2608–16.
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