Friday, June 8, 2012

Curry Spice Can Kill Cancer Cells?


In an article by the BBC, researchers discovered the chemical curcumin (found in the curry spice, turmeric) could help kill oesophageal cancer (cancer of the esophagus) cells. The rate of oesophageal cancer has gone up by more than a half since the 1970s as a result of rising rates of obesity, alcohol intake and reflux disease, according to the researchers at the Cancer Research facility in the UK, and curcumin might be a viable treatment. A team at the Cork Cancer Research Centre in the UK found that curcumin induced "apoptosis-independent death" in oesophageal cancer cells.

Several studies have shown that curcumin can induce death in cells that are resistant to apoptosis (i.e. malignant cancer cells). Curcumin seems to induce a type of cell death known as "mitotic catastrophe," which is a result of the disruption of the mitotic spindle and defects in cytokinesis and micronucleation. Curcumin has also been associated with autophagic cell death. In general, curcumin has been found to have the ability to affect multiple targets giving it a wide range of antioxidant, anti-inflammatory, anti-angiogenic, and anti-proliferative properties (a curious ability that scientists do not quite understand). The researchers at the Cork Cancer Research Centre focused on the cytotoxic activity of curcumin against oesophageal cancer cells.

 In this particular graph, researchers determined the sensitivity of a panel of oesophageal cancer cell lines (two squamous cell carcinoma cell lines, OE21 and KYSE450, and two adenocarcinoma cell lines, OE33 and OE19) to curcumin. In graph set A, the viability of cells (their ability to grow and divide) was tested after treatment with 5, 15, 25 and 50μM of curcumin for a period of 24 hours. In graph set B, the same cells were allowed to recover for 48 hours (the curcumin was removed) and then the treatment was applied again for another 24-hour period. The viability was measured using an MTT assay, which is a colorimetric assay for measuring the activity of enzymes that reduce MTT dyes (the presence of these enzymes reduces the dyes which indicates the presence of living, viable cells). The higher the absorbance on the graph, the more cells there are producing enzymes.

If you look at the graphs, in both cell lines increasing curcumin concentration decreased the number of viable cells. Furthermore, after the 48-hour recovery period, it seems that the cancer cells did not recover from the curcumin treatment (most, in fact, showed an even lower absorbance value). In analyzing the graphs, it also looks like the two squamous cell carcinoma lines were more affected by the curcumin. 

Why does curcumin seem to affect the squamous cell carcinoma cell lines more? In a different study conducted by researchers at the Louisiana State University Health Sciences Center, they found that curcumin reduced the average tumor size in mice affected with squamous cell carcinoma. They concluded that curcumin inhibited squamous cell carcinoma growth and blocked tumor progression by inhibiting pS6.

Based on the multitude of studies, it would seem that curcumin certainly has the potential to be an anti-cancer agent. Although, more research needs to be done in terms of the mechanism involved. pS6 might be the mechanism to investigate for the future.