Green therapy for cancer
doi:10.1038/nindia.2010.91 Published online 13 July 2010
A new study has shown that nanoparticles loaded with grape seed extract (GSE) can cause the death of cancer cells. The GSE-loaded nanoparticles were tagged with folic acid, a vitamin that selectively targets cancer cells while sparing normal cells.
This research has future applications in the field of anti-cancer phytonanomedicine, where it may provide efficient green chemotherapy agents.
GSE is rich in proanthocyanidins, dietary polyphenols with anti-cancer properties. Unfortunately, owing to their large size, GSE polyphenols are not readily absorbed through the human gut, making them unavailable for targeting cancer cells.
To overcome this, the researchers chose to ferry GSE to cancer cells using poly(lactic-co-glycolic acid), a polymer nanoparticle that had already demonstrated the delivery of phytodrugs such as curcumin and quercetin. They prepared three types of phytodrugs — bare GSE, nanoparticle-loaded GSE (NanoGSE) and folic-acid-tagged NanoGSE (FA-NanoGSE).
Around 40% of cancer cells express folate receptors, a cell membrane protein that has an affinity for folic acid and its derivatives. This is why NanoGSE was tagged with folic acid to facilitate entry of the phytodrug into cancer cells.
The researchers exposed cultured cancer cells such as nasopharyngeal, lung and breast cancer cells and normal fibroblast cells to varying concentrations of the three types at similar doses. FA-NanoGSE proved more effective than both NanoGSE and bare GSE.
"Targeted delivery using folic acid aids the tumour-specific uptake of anti-cancer drugs," says lead researcher Deepthy Menon.