A LARGE SCALE METHOD FOR PREPARATION OF PLANT THYLAKOIDS FOR USE IN BODY WEIGHT REGULATION

Abstract

A method for preparation of thylakoids from plant leaves on a large scale is described. The method involves: 1) disruption of the cells with a blender followed by filtration to remove large cell debris and non disrupted cells. 2) precipitation of the thylakoids by adjusting the pH to the isoelectric point, pH 4.7. 3) a washing step by dilution of the precipitate in water followed by precipitation at the same pH. 4) concentration of the precipitate by freeze- thawing or freeze -drying to get the final product. The product is characterized, with respect to protein composition, by SDS-PAGE and mass-spectroscopy, the content of carotenoids, particularly the xanthophylls violaxanthin, antheraxanthin, and zeaxanthin.

The thylakoid preparation has about the same capacity to inhibit pancreatic lipase/colipase activity as thylakoids prepared by standard laboratory methods using sucrose in the medium and centrifugation.

In a study with mice, it was found that, when the thylakoids were added to the food over 32 days, they significantly reduced the body weight gain and the percentage body fat. The large scale method described here allows studies on the effect of thylakoids in appetite regulation on experimental animals in a longer lasting time and also on humans.

Keywords:

• adipose tissue
• chloroplast
• colipase
• food intake
• lipase
• xanthophylls

ACKNOWLEDGMENTS

This work was supported by grants from Swedish Research Council, the Carl Trygger foundation, the Sven and Lilly Lawski Foundation and The Royal Physiographic Society in Lund. We thank Rita Wallén, Department of Zoology, Lund University, for taking the electron microscopy pictures and Tommy Olsson, Department of Ecology, Lund University for the analysis of the metals.