טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentAdi Jonas Levi
SubjectEffect of 6-O- Palmitoyl Ascorbate on Collagen Synthesis
DepartmentDepartment of Biotechnology and Food Engineering
Supervisor Mr. Neeman Ishak (Deceased)


Abstract

Collagen is the most common extra cellular protein in mammalians. Collagen biomass is regulated through many stages and by several factors, in which ascorbic acid (AA) possesses a major role. The mechanism of AA's on collagen metabolism is not understood yet. Consumption of AA was shown as useful against few cancer types. Ascorbyl palmitate (AP) has shown the best results in the protection against cancer in mice, with a comparison to other derivatives of AA.

This study represents the influence and mechanism of AA versus AP on collagen synthesis. Experiments were performed using tissue culture and mouse skin. Results show that AP at a concentration of 10mM increases collagen synthesis as 100mM AA does. The AA or AP-induced increase in collagen was detected through protein and mRNA levels, but not through the promoteror through the action of matrix metaloproteinases. Furthermore, in mouse skin collagen bundles structure and orientation were changed.

By investigating the mechanism of action we show that: (1) In vitro, AA was a stronger antioxidant than AP. In vivo, AA induces more membrane lipid-peroxidation than AP dose. In the citosol, AP inhibits the NADPH oxidase, and the transcription factor NF kappa B. (2) AP shows higher stability than AA. (3) AP interacts with cell membranes and increases phospholipase A2 activity.

Considering the extensive use of AP by the cosmetic and food industries together with its wide and powerful influences, further studies are necessary to advance our knowledge of the physiological aspects of AP and to establish guidelines for the safe usage of this material.