According to new research led Swansea University, UK, nanoparticles derived from leaves of the tea plant (Camellia sinensis) inhibit the growth of lung cancer cells, destroying up to 80% of them.
Swansea University researcher Sudhagar Pitchaimuthu and colleagues from Bharathiar University and the K. S. Rangasamy College of Technology, both in India, made the discovery while they were testing out a new method of producing quantum dots, nanoparticles which measure less than 10 nm.
“Quantum dots can be made chemically, but this is complicated and expensive and has toxic side effects,” the scientists said.
“We were exploring a non-toxic plant-based alternative method of producing the dots, using tea leaf extract.”
“Tea leaves contain a wide variety of compounds, including polyphenols, amino acids, vitamins and antioxidants.”
The study author mixed tea leaf extract with cadmium sulfate (CdSO4) and sodium sulfide (Na2S) and allowed the solution to incubate, a process which causes quantum dots to form. They then applied the dots to lung cancer cells.
They found that tea leaves are a simpler, cheaper and less toxic method of producing quantum dots, compared with using chemicals, confirming the results of other research in the field.
“Quantum dots produced from tea leaves inhibit the growth of lung cancer cells,” the researchers said.
“The nanoparticles penetrated into the nanopores of the cancer cells and destroyed up to 80% of them.”
“Our research confirmed previous evidence that tea leaf extract can be a non-toxic alternative to making quantum dots using chemicals,” Dr. Pitchaimuthu said.
“The real surprise, however, was that the dots actively inhibited the growth of the lung cancer cells. We hadn’t been expecting this.”
“The CdS quantum dots derived from tea leaf extract showed exceptional fluorescence emission in cancer cell bioimaging compared to conventional CdS nanoparticles.”
“Building on this exciting discovery, the next step is to scale up our operation, hopefully with the help of other collaborators,” Dr. Pitchaimuthu noted.
“We want to investigate the role of tea leaf extract in cancer cell imaging, and the interface between quantum dots and the cancer cell.”
“We would like to set up a ‘quantum dot factory’ which will allow us to explore more fully the ways in which they can be used.”
The results were published recently in the journal Applied Nano Materials.
Kavitha Shivaji et al. 2018. Green-Synthesis-Derived CdS Quantum Dots Using Tea Leaf Extract: Antimicrobial, Bioimaging, and Therapeutic Applications in Lung Cancer Cells. Appl. Nano Mater 1 (4): 1683-1693; doi: 10.1021/acsanm.8b00147