Abstract

Turmeric (Curcuma longa L.) is the only edible plant recognized as a dietary source of curcuminoids, among which curcumin, demethoxycurcumin (DMC) and bis-demethoxycurcumin (Bis-DMC) are the most representative ones. Curcumin shows a very low systemic bioavailability and for this reason, several technologies have been adopted to improve it. These technologies generally improve curcuminoid absorption in the small intestine, however, no data are available about the effect of curcuminoid formulation on colonic biotransformation. The present study aims at investigating the human colonic metabolism of curcuminoids, prepared with two different technologies, using an in vitro model. Unformulated curcuminoid and lecithin-curcuminoid botanical extracts were fermented using an in vitro fecal model and colonic catabolites were identified and quantified by uHPLC-MSn. Native compounds, mainly curcumin, DMC and bis-DMC, were metabolized by colonic microbiota within the 24-h incubation. The degradation of curcuminoids led to the formation of specific curcuminoid metabolites, among which higher concentrations of bis(demethyl)-tetrahydrocurcumin and bis(demethyl)-hexahydrocurcumin were found after lecithin-extract fermentation compared to the concentration detected after unformulated extract. In conclusion, both curcumin-based botanical extracts can be considered important sources of curcuminoids, although the lecithin-formulated extract led to a higher production of curcuminoid catabolites. Moreover, a new curcuminoid catabolite, namely bis(demethyl)-hexahydrocurcumin, has been putatively identified, opening new perspectives in the investigation of curcuminoid bioavailability and their potential metabolite bioactivity.

Highlights

  • Turmeric (Curcuma longa L.) is the only edible plant recognized as a dietary source of curcuminoids, among which curcumin is the most abundant compound, followed by demethoxycurcumin (DMC)and bis-demethoxycurcumin (Bis-DMC)

  • Hydroxycurcumin identification was based on MS3 experiments, obtained by fragmentation of MS2 ion peak at m/z 217, which resulted in the same MS3 fragmentation pattern of curcumin, having a product ion at m/z 173 (Table 2)

  • This common limitation does not condition the comparison between the two curcumin-derived botanical extracts

Read more

Summary

Introduction

These compounds are yellow-orange non-polar polyphenols, made of two aromatic rings joined by a seven-carbon alkyl chain that contains two ketone groups. Curcumin shows low oral absorption, little biodistribution, and a very low systemic bioavailability For these reasons, several technologies and different formulations have been investigated to improve the bioavailability of this diarylheptanoid. Other technologies, including phytosomes, liposomes, and micelles, besides the curcumin co-formulation with adjuvants, like piperine, have been adopted to enhance the bioavailability of curcumin [6] These technologies and formulations improve the curcuminoid absorption in the small intestine, a large fraction of curcuminoids generally reaches the colon and is excreted via feces, as a favorite elimination route [7]. Several studies have reported an important role of curcumin on gut microbiota modulation [1,8,9,10] and, as a consequence, the investigation of the interaction between curcuminoids and gut microbiota has gained more relevance

Objectives
Methods
Results
Discussion
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call