Tracey Kajer, a third-year PhD student in the Free Radical Research Group at The Heart Research Institute, has been exploring the ability to reduce heart disease with various naturally occurring compounds found in green tea.

Myeloperoxidase is an enzyme that is essential to the body’s immune response but contrarily, it leads to the production of a variety of small damaging molecules such as hypochlorite (household bleach) and hypothiocyanous acid - both of which are thought to be involved in the development of inflammatory diseases such as atherosclerosis, rheumatoid arthritis, and cystic fibrosis. There is therefore, widespread interest in finding natural materials that can reduce the activity of myeloperoxidase in order to minimise damage.

A number of studies have shown that a family of small, polyphenolic compounds in green tea (known collectively as flavanols), are effective antioxidants. Ms Kajer is trying to understand the specifics surrounding this effect. Interestingly, these compounds are particular to green tea as the further processing required to make other types of tea (black, oolong, etc.) reduces the levels of these compounds.

Ms Kajer has studied the effect of these flavonoids, both individually and in combination, in an isolated (test-tube) enzyme system and also with human white blood cells. In both cases, the green tea compounds significantly reduced the activity of myeloperoxidase and the damage it causes. Importantly, this effect occurs with levels of flavanols that are present in green tea.

This work was most recently presented at the 16th Biennial Meeting of the Society for Free Radical Research International, London at which Ms Kajer was awarded a ‘Young Investigator Award’ for her presentation.