Many of us drink green tea for its wonderful health benefits, including proven antioxidant, antimicrobial, anti-aging and anti-cancer properties. Now, researchers in Singapore have taken its cancer-fighting properties to the next level, developing a green tea-based nanocarrier that encapsulates cancer-killing drugs. It is the first time green tea has been used to deliver drugs to cancer cells, with promising results. Animal studies show far more effective tumor reduction than use of the drug alone while significantly reducing the accumulation of drugs in other organs.
The new drug delivery system, developed at the Institute of Bioengineering and Nanotechnology (IBN) of A*STAR, uses epigallocatechin gallate (EGCG), a powerful antioxidant and catechin found in green tea and used therapeutically to treat cancer and other disorders.
"We have developed a green tea-based carrier in which the carrier itself displayed anti-cancer effect and can boost cancer treatment when used together with the protein drug," says Dr Motoichi Kurisawa, IBN Principal Research Scientist and Team Leader.
One of the main drawbacks of chemotherapy is that it also kills healthy cells in surrounding tissues and organs. Carriers allow more accurate treatment, acting like homing missiles that target diseased cells and release cancer-destroying drugs. However, the amount of the drug they can deliver is limited so more carriers need to be administered for treatment to be effective. Current carriers are made of materials that at best offer no therapeutic value and at worst may have adverse effects when used in large quantities, so the green tea-based carrier is an exciting development.
The carrier uses a core made of an oligomer of EGCG to enclose cancer-destroying drugs. The shell of the carrier is made of PEG, a molecule which camouflages the carrier and prevents the immune system from destroying it before it reaches its target.
Animal studies using the green tea-based nanocarrier loaded with Herceptin, a drug used to treat breast cancer, delivered promising results. Twice as much Herceptin accumulated in cancer cells than if the drug had been used alone, enabling more effective tumor targeting and reduced tumor growth. On the other hand, the level of Herceptin in surrounding organs was significantly lower, with a 70 percent reduction in the liver and kidneys and a 40 percent reduction in the lungs.
The IBN team is developing the technology for clinical applications.
The research has been published in nature nanotechnology.
Source: IBN (PDF)
