In the mountains of Nagaland, a weed is becoming an ally of medicine. The invasive Mikania micrantha, known here as "mile-a-minute" for its rapid growth, has long threatened local ecosystems. But scientists at Nagaland University, in collaboration with Fazl Ali College, have found an unexpected way to turn the pest into an ally: using the plant's leaves to synthesize silver nanoparticles with pronounced anticancer and antibacterial properties.
The key lies in the principles of green chemistry. An aqueous extract of the leaves reduces silver ions, forming stable nanoparticles 12–47 nanometers in size without a single toxic reagent of the kind usual in industrial synthesis. The resulting particles retain their activity even when heated and withstand up to six cycles of reuse, demonstrating remarkable catalytic stability.
The practical value shows itself in the speed of synthesis. The nanoparticles serve as an effective catalyst for the synthesis of imidazoles — key building blocks of many medicinal molecules. A reaction that usually requires hours and aggressive solvents is completed in just 30–180 seconds. This means not only speed but also purity: less waste, less pollution, lower costs.
The medical potential was tested on microorganisms. The nanoparticles inhibited the growth of Staphylococcus aureus, Yersinia pestis and other pathogenic bacteria. The effect works through synergy: silver ions destroy the cells, while the plant compounds remaining on the surface of the particles enhance the action.
The most promising results were on colon cancer cells (Caco-2). The half-maximal inhibitory concentration of the nanoparticles was 36,17 micrograms per milliliter — almost two times lower than that of the original plant extract (72,15 µg/ml). This indicates that the nanoparticles enhance the cytotoxic effect, causing the death of cancer cells. The results open a new direction in oncological research.
The work was published in a reputable journal and received support from India's national science foundations. The authors emphasize the practical scalability of the method. In countries where M. micrantha covers arable land and plantations, the grass that is currently expensive to destroy can now be directed to a more useful purpose — the development of new medicines and antimicrobial agents.
