Cancer, rightly called as ‘The Emperor of all Maladies’ in Siddhartha Mukherjee’s Pulitzer awarded book, is one of the leading causes of deaths worldwide.
Cancer is abnormal cell growth wherein the cancer cells fail to undergo the mechanism of apoptosis i.e. pre-programmed cell death- a mechanism by which normal cells commit suicide when required.
The need of natural anti-cancer agents
Cancer is usually treated with the help of chemotherapeutic agents which are classified under three categories namely:
- Carcinogen blocking agents.
These agents are not only toxic to cancer cells but also to normal cells, hence, producing a large number of side effects like nausea, vomiting and hair loss.
A 2012 research entitled “New perspectives of curcumin in cancer prevention” reported that curcumin, the primary polyphenol of turmeric, the ‘Indian saffron’, has multiple mechanisms of action and fits into all three categories.
Mechanism of Action
A 2009 research published in the AAPS Journal gives an account of the mechanisms by which curcumin causes cell death.
Apoptosis is brought about by curcumin by both activation of cell death pathways and inhibition of growth/proliferation pathways.
One of the pathways is up-regulation of death receptors like FAS by curcumin in cancer cells for example in kidney, skin, and nose and throat cancer .
FAS death receptor induces apoptosis by activating the FAS-associated death domain, death receptor 5 and death receptor 4. FAS-associated death domain protein (FADD) further activates caspase-8 protease .
Caspase proteases destroy the cancer cells from within , also known as death by a thousand cuts .
Curcumin can also induce cell death directly in a dose-independent and time-independent manner by activation of Caspase-3 and production of Ca2+ ions and reactive oxygen species (ROS) as it did to cause cell death of Human colon cancer Colo 205 cells in a recent research.
Various other pathways followed by Curcumin to induce cell death have also been discussed and reported in the study entitled ‘Curcumin and cancer cells: how many ways can curry kill Tumor cells selectively?’.
Some of them are the induction of p53/p21 pathway, the release of an apoptosis-Inducing factor, inhibition of COX-2 and 5-LOX etc.
Another positive outcome of the research was that it was found that cellular uptake of curcumin was higher in cancer cells than normal cells.
Therefore, no adverse effects are produced by curcumin on the normal cells. The actual reason behind this result is still not known.
Unlike conventional chemotherapeutic agents, which are expensive and produce numerous side effects, curcumin is an affordable, less toxic and easily available chemopreventive agent.
It does not produce any side effect and resistance against curcumin cannot be easily developed by cancer cells owing to the large number of diverse mechanisms it follows to induce cell death.
Hence, curcumin is a highly promising natural compound for prevention as well as treatment of cancer.