International scientists use plant extracts to create silver nanoparticles with potential applications in cancer treatment

Russian researchers, in collaboration with experts from other countries, have found a way to use the leaves of the melaleuca plant, or Australian tea tree, to combat bacteria, fungi and even cancer cells.

One of the researchers was Aleksander Vetcher, an associate professor in the Insitute of Pharmacy and Biotechnology at the Russian University of Peoples’ Friendship (RUDN), according to a publication on the RUDN website, a partner of TV BRICS.

Silver has been known for its antimicrobial properties for centuries, but at the nanoscale (particles approximately a thousand times thinner than a human hair), it becomes even more active. This is because the smaller the particles, the greater the surface area in contact with the surrounding environment.

During the study, melaleuca leaves (from which melaleuca oil is extracted) were treated with hot water to prepare an infusion, to which a silver salt solution was then added. In just a few minutes, the previously colourless solution turned brown, which was a sign that nanoparticles had formed.

A key finding of the study was the anti-cancer potential of the nanoparticles produced. The scientists tested various doses on cells from the aggressive MCF-7 breast cancer line. Healthy cells survived, whilst the cancerous cells died.

The IC50 value (the concentration at which half the cancer cells die) was just 8.16 micrograms per millilitre (µg/ml). By way of comparison, this value is approximately five times lower than the dose at which an antioxidant effect is observed (41.17 µg/ml). In other words, the nanoparticles act as a targeted drug: cancer cells "recognise" them and destroy them by changing their shape (contracting and detaching from the surface).

Furthermore, the nanoparticles demonstrated positive antioxidant activity, neutralising up to 69 per cent of free radicals, which is beneficial in cases of inflammation and tissue ageing.

Research is still ongoing at the testing stage, but, according to the source, there is great potential for these green nanoparticles to serve as the basis for the development of ointments to treat hard-to-cure fungal infections, coatings for catheters and even new anti-cancer drugs with reduced side effects.