Using liposomes, little microcapsules made from phospholipids, can encapsulate curcumin and lead to a quadrupling in the compound’s absorption, according to findings published in the Journal of Agricultural and Food Chemistry.
“These liposomal formulations can enable enhanced curcumin food functionalization,” wrote the researchers, led by Dr Koji Wada from the University of the Ryukyus.
Curcumin is a natural pigment that gives the spice turmeric its yellow colour. Recent studies have investigated its potential to lower cholesterol levels, improve cardiovascular health, reduce the risk of Alzheimer's and diabetes as well as cancer-fighting properties.
Despite the potential health benefits of curcumin, Wada and co-workers say that digestive juice in the gastrointestinal tract quickly destroys most curcumin, leading to only a little actually getting into the blood.
The new study used commercially available lecithins to prepare liposomes for the encapsulation of curcumin. Using 2.5 per cent curcumin, the researchers obtained an encapsulation efficiency of 68 per cent, with average particle sizes of abour 263 nanometres.
The formulations were then fed to Sprague-Dawley rats at a curcumin dose of 100 milligrams for every kilogram of rat body weight.
Results showed that the nano-encapsulated curcumin led to blood levels up to 320 micrograms per litre, compared to 65 micrograms per litre for non-encapsulated curcumin.
“These results indicated that curcumin enhanced the gastrointestinal absorption by liposomes encapsulation,” said the researchers.
This enhancement could be due to the particle size, they said, with other studies showing that liposomes of around 200 nanometres are efficienty taken up in the intestine, and therefore avoid metabolism in the liver.
Incorporation in liposomes may also lead to the curcumin being included in phospholipid membranes in the body
“Encapsulation also allows for prolonged contact with the intestinal wall due to the adhesive property that liposomes exhibit toward the epithelial mucosal surface of the small intestine,” wrote Wada and his co-workers. “Accordingly, it seems that encapsulation of curcumin is highly advantageous for optimizing food functionality,” they added.
An increase in plasma antioxidant activity was also observed following ingestion of the curcumin liposomes, with activity three-fold that of the non-encapsulated curcumin-fed animals.
“The available information strongly suggests that liposome encapsulation of ingredients such as curcumin may be used as a novel nutrient delivery system,” concluded the researchers.
Source: Journal of Agricultural and Food Chemistry
Volume 57, Pages 9141–9146, doi:10.1021/jf9013923
"Evaluation of an Oral Carrier System in Rats: Bioavailability and Antioxidant Properties of Liposome-Encapsulated Curcumin"
Authors: M. Takahashi, S. Uechi, K. Takara, Y. Asikin, K. Wada