Recent research finding

No.25 Influence of the Glycolytic Enzyme against Fat-soluble Substances - γCyclodextrin Complexes



We previously reported the plausible mechanism for the bioavailability enhancement of Coenzyme Q10 (CoQ10) which includes the enzymatic degradation of γ-Cyclodextrin (γ-CD) out of CoQ10 - γCD complex with the aid of sodium taurocholate (NaTC) in small intestine 1),2),3).
In this study, the influence of NaTC on the enzymatic degradation of non-complexed γCD and γCD out of Curcumin - γCD (Cur - γCD) complex were investigated to demonstrate the previous presumption.

1) K. Terao, et al., Nutrition Research, 2006, 26 503-508.
2) Ikeda, et al., Japan Society for Bioscience, Biotechnology, and Agrochemistry, (2009.3.27-29, Fukuoka)
3) K. Terao, et al., The Society of Cyclodextrins, Japan 26th (2009.9.8-9, Utsunomiya) 2P-1.


In vivo study on bioavailability in rats from 0 to 4 h after oral gavage with three curcumin products:

Curcumin Complex,
Curcumin Extract,
Brand Name Curcumin

Single dose study @ 500 mg/kg in Sprague Dawley rats
Plasma was analysed for free curcumin, curcumin sulphate and curcumin glucuronide by HPLC


Cavamax Curcumin demonstrated the greatest bioavailability of all products tested in the 4 h bioavailability study followed by Brand Name Curcumin and Curcumin Extract

*) single dose study @ 500 mg/kg in rats Citation:Wacker Chemical Corporation

Degradation of γCD

Enzymatic degradation of γ-CD with the aid of NaTC as component of the bile acids

γCD was decomposed by amylase.
But the results showed that γCD was decomposed slowly by adding NaTC.

Enzymatic degradation of γ-CD in Cur - γCD complex with the aid of NaTC

Cur of Cur - γCD complex can be replaced by NaTC.
Cur - γCD complex is insoluble in water, so amylase can’t work.
But amylase can work efficiently to NaTC - γCD because of its high water solubility.

Solubilization of Curcumin in water out of Cur-γCD complex with the aid of NaTC

Non-complexed Curcumin could dissolve in water to some extent with NaTC, but Curcumin of Cur - γCD complex dissolved more.


Enzymatic degradation of γCD of Cur - γCD complex with the aid of NaTC was facilitated.
→ Curcumin released from Cur - γCD complex with the aid of NaTC.
Solubility of Curcumin in water was stimulated by use of Cur-γCD complex with NaTC better than Curcumin itself.

These results support the mechanism for the bioavailability enhancement of Cur - γCD complex and CoQ10 - γCD complex .