Cancer has become a major health issue throughout the world. The Agency for Healthcare Research and Quality estimated that the direct medical cost of cancer was around $80.2 billion in the U.S. in 2015. In 2019, more than 1.7 million newly diagnosed cancer patients are expected in the U.S.1 With an increase in human lifespan, the prevalence of cancer will raise and subsequently incur huge costs.
The Definition of Cancer
The Mayo Clinic in Rochester, Minnesota, defines сancer as ‘One of a large number of diseases characterized by the development of abnormal cells that divide uncontrollably and have the ability to infiltrate and destroy normal body tissue. Cancer often has the ability to spread throughout your body.2
Let’s look into some alarming statistics provided by the World Health Organization:
Cancer treatment options
There are many types of cancer treatments available. The type of treatment depends on the severity of the disease and its type. Popular cancer treatment options are as follows:
These treatments are very expensive and come with major side effects. Moreover, these options are not suitable for cancer prevention. In contrast, traditional natural medicines are inexpensive and free from deleterious side effects.
Turmeric—a miraculous spice
Turmeric, scientifically known as Curcuma longa, is a traditional South Asian spice that is safe, affordable, and efficacious for killing cancer cells. Curcumin is the principal bioactive component present in Curcuma longa and it is able to target tumor cells and destroy them. It is a yellow-colored polyphenol, which is also known as diferuloylmethane. Apart from diferuloylmethane, turmeric spice also contains a minor amount of demethoxycurcumin, bisdemethoxycurcumin, and cyclocurcumin. The oxygen bonded hydrogen moieties, otherwise known as hydroxyl groups, are present in these derivatives. These hydroxyl groups are responsible for antioxidant activity, while the methoxy groups are responsible for its anti-inflammatory and antiproliferative (inhibiting cell growth) activity.5
In various animal models, curcumin treatment inhibits tumor initiation and tumor promotion. Scientific studies have shown that curcumin is able to:
A research team based at Washington State University has developed a curcumin-based drug delivery system and it successfully inhibits bone cancer cells and promotes the growth of healthy bones. This research work is published in the journal American Chemical Society Applied Materials and Interfaces.7
Curcumin controls tumor growth by regulating several cell signaling pathways which include cell proliferation, cell survival, caspase activation, tumor suppressor, death receptor, mitochondrial and protein kinase pathways.5
Mechanism of action of Curcumin
Various scientific evidence suggests that curcumin follows two types of the mechanism of action for killing tumor cells: a) activation of cell death pathways; and b) inhibition of growth proliferation pathways. Numerous mechanisms for cell death of cancer cells exhibited by curcumin make it a very suitable agent for the drug delivery system and there are fewer chances of developing resistance against curcumin-induced cell death. Moreover, curcumin selectively kills tumor cells and normal cells remain unhurt, which makes it a more suitable candidate for drug development.5
Phase one clinical trials were conducted with curcumin on patients with high-risk conditions and premalignant lesions of the bladder, skin, cervix, stomach, or oral mucosa. The dosage ranges from 500-8,000 mg/ day for three months were well tolerated. Even at higher doses, curcumin appears non-toxic to animals and humans8,9.
Bioavailability of curcumin
Although curcumin produces no major side effects and is well tolerated by humans, its in-vitro bioavailability is poor and it becomes a hurdle to use it as a therapeutic agent. A pharmacokinetics study of curcumin reveals that curcumin might get metabolized in the gut through extensive conjugation and reduction.10 Curcumin forms various chemical compounds like glucuronide, sulfates, tetrahydrocurcumins, and hexahydrocurcumins. All of these compounds of curcumin are less bioavailable due to the water-repelling nature of these molecules.11,12
How to improve the bioavailability of curcumin?
Several formulations have been suggested by scientists to improve the bioavailability of curcumin. These formulations include the addition of piperine to prevent glucuronidation of curcumin in the liver and the use of liposomal curcumin (with a special vehicle to deliver curcumin to a site of action), curcumin nanoparticles, phospholipid complex, and structural analogs. A scientific study reported that combined treatment of curcumin with piperine (20 mg/kg) produces a higher serum concentration of curcumin and increases the bioavailability of curcumin by 2,000%.13
Through various research studies, it is proven that curcumin can destroy a wide range of tumor cells through diverse mechanisms.5 Because of various cell death mechanisms, it is very unlikely to develop resistance to curcumin-induced cell death. Furthermore, being a natural curative agent, it does not have any side effects, it only targets cancer cells and does not harm normal cells.