doi:10.1038/nindia.2012.162 Published online 7 November 2012
Researchers have used extract of Bhringaraj (Eclipta alba) leaves to synthesize gold nanoparticles that could ferry doxorubicin, a widely used anticancer drug, and help kill breast cancer cells. This offers a new eco-friendly technique to make biocompatible cancer drug carriers to increase the efficacy of cancer drugs.
Gold nanoparticles have gained popularity for their non-toxic and biocompatible properties. However, chemical methods produce nanoparticles that are often laden with toxic chemicals and thus unsuitable for drug delivery and other biomedical applications. Although researchers have tried to devise eco-friendly ways to make biocompatible gold nanoparticles using plants, cost-effective and simple methods have proven elusive.
To develop a simple, fast and safe way to make gold nanoparticles, the researchers prepared water-based leaf extracts of Bhringaraj leaves. They added different volumes of leaf extract to a constant amount of chloroauric acid and stirred the mixtures on a magnetic stirrer between 10 minutes and 96 hours. This led to formation of gold nanoparticles in under 10 minutes with 1 ml of leaf extract.
They then carried out biocompatibility and toxicity studies using the leaf extract-based nanoparticles and two types of breast cancer cells and compared results with chemically synthesized gold nanoparticles. Leaf extract-based nanoparticles showed better biocompatibility and less toxicity than chemically synthesized nanoparticles.
The study found that inhibition of breast cancer cell proliferation increased when doxorubicin was attached to leaf extract-based nanoparticles compared with free doxorubicin. In addition, leaf extract-based gold nanoparticles were coated with various biomolecules including proteins present in leaf extract, giving extra stability to the nanoparticles.
"This green method will be a competitive alternative to the existing methods for large-scale production of biocompatible gold nanoparticles using an efficient bioresource such as Bhringaraj leaves," says lead researcher Chitta Ranjan Patra.
The authors of this work are from: Centre for Chemical Biology, and Inorganic and Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology, Hyderabad, Andhra Pradesh, India.