White Tea Inhibits Proliferation of Colon Cancer Cells

I was searching for journals about new research within cosmetic chemistry when I came across this journal about white tea. This is the first time I have heard about white tea. Black, green and herbal teas are the most renowned teas that everybody hears of and green tea has been getting a lot of good media coverage for its anti-oxidant properties.

White tea (biological name: Camellia Sinensis) is grown in China and is light yellow in colour.  The leaves are left to dry in natural sunlight with little processing (only steamed) to prevent the oxidation of the tea, by deactivating the enzyme: polyphenol oxidase, maintaining its biological properties.

The way white tea is prepared means that white tea keeps its anti-oxidant properties as the silky tea has a high concentration of polyphenols. Polyphenols are potent anti-oxidants that fight and kill carcinogenic (cancer-inducing) cells, stronger than any other tea.  Increased activity of enzymes that function to detoxify carcinogens.  Inhibit cell signalling pathways that induct the transformation of healthy cells to cancerous cells.

A study conducted by Hajighaalipour et al, studies the proliferation of colorectal cancer cell line HT-29 Extract inhibited HT-29 cells with an IC50 of 87 μg/ml.  The study was conducted by preparing a tea infusion of white tea (Silver needle, KWF Food Industries, China) by placing tea leaves in 100ml of boiling distilled water (100°C degrees Celsius) and brewed for 5 minutes. The brew was then filtered through filter paper and the extract was freeze-dried and then diluted with distilled water to achieve the desired concentrations for each specific assay and stored at 20°C until further analysis.

The brewed, white tea extract was then tested against five different in vitro assays: Ferric Reducing Ability of Plasma (FRAP), DPPH (2,2-diphenyl-1-picrylhydrazyl), Nitric Oxide, super oxide anion, and hydroxyl radical scavenging assays. They found that white tea had strong antioxidant activity, which correlated to the content of phenolic compounds, without being toxic to normal fibroblasts.

The extract inhibited HT-29 colon cancer cells by the death receptor and mitochondrial apoptotic pathways shown by an increase in caspases (cysteine-aspartic proteases): -3/7, -8, -9 enzyme expression. Caspases are the enzymes that regulate apoptosis, the programmed cell death. Failure of apoptosis can lead to tumour development- the onset of cancer; therefore and increased expression of caspases indicated that the white tea extract encourages programmed cell death preventing the multiplication of cancerous cells in the colon.

White tea has been proven to be a promising chemotherapeutic agent and regular consumption of white tea could protect your health and guard the body against harmful diseases. I am very glad that I came across this novel journal and will be making white tea a part of my daily diet from now on.

[1] White tea (Camellia sinensis) inhibits proliferation of the colon cancer cell line, HT-29, activates caspases and protects DNA of normal cells against oxidative damage - http://www.sciencedirect.com/science/article/pii/S0308814614010280