by Allanah Leahy – EM TV Online
A component found in green tea has been scientifically proven to kill mouth cancer cells.
Scientists from Pennsylvania State University revealed how the compound “epigallocatechin-3-gallate” (EGCG), found in green tea, kills oral cancer cells without harming normal cells.
Penn State’s findings revealed the previously unknown explanation as to how green tea is able to target the cancer cells. Research shows that EGCG activates a process in the mitochondria – the energy generating “powerhouse” cell – that leads to cell death.
“EGCG is doing something to damage the mitochondria and that mitochondrial damage sets up a cycle causing more damage and it spirals out, until the cell undergoes programmed cell death,” said Joshua Lambert, co-director of Penn State’s Centre for Plant and Mushroom Foods for Health.
“It looks like EGCG causes the formation of reactive oxygen species in cancer cells, which damages the mitochondria, and the mitochondria responds by making more reactive oxygen species.”
Reactive oxygen species (ROS) are chemically reactive molecules containing oxygen, with the chief roles of cell signalling and homeostasis. Cell signalling and homeostasis relate to the monitoring and control of internal conditions, including temperature.
As mitochondrial cells die, the cancer cell’s anti-oxidant genes are reduced, further lowering its defences and essentially ‘turning off its mechanism of protection at the same time that EGCG is causing this oxidative stress’.
The same reaction was not found in normal cells; rather, protective capabilities of the cell were increased.
Normal mouth cancer cells were grown and tested alongside oral cancer cells in petri dishes. The cells were then exposed to EGCG. Scientists routinely checked for signs of oxidative stress and antioxidant response.
Researchers say that a protein called sirtuin 3 (SIRT3) is critical to the process.
“It plays an important role in mitochondrial function and in anti-oxidant response in lots of tissues in the body, so the idea that EGCG might selectively affect the activity of SIRT3 in cancer cells – to turn it off – and in normal cells – to turn it on – is probably applicable in multiple kinds of cancers,” Lambert continued.
Penn State had previously published studies on the effects of green tea on oral cancer cells as well as other researchers who have looked at oral cancer and prevention of oral cancer.
The next step, Lambert says, will be to study the mechanism in animals; once proven successful, along with human trials, the researchers hope to develop anti-cancer treatments significantly less harmful than current cancer treatment and side effects.
“The problem with a lot of chemotherapy drugs – especially early chemotherapy drugs – is that they really just target rapidly diving cells, so cancer divides rapidly, but so do cells in your hair follicles and cells in your intestines, so you have a lot of side effects.
“But you don’t see these sorts of side effects with green tea consumption,” Lambert said.
Cervical cancer is the most common form of cancer in PNG, but at the National No Betel Nut Day, World Health Organisation Country Representative Dr William Adu-Krow announced that PNG tops the list globally in having the highest oral cancer rates.
This is primarily attributed to the high level of betel nut, tobacco and alcohol consumption in the country.
“The combination of tobacco, excessive alcohol consumption and betel nut chewing greatly increases the risk of oral cancer in PNG. Measures are now needed to discourage the use of betel nut with or without tobacco,” Adu-Krow said.
