Using plant extract, heat to kill cancer cellsDate: 24 December 2019 Tags: Nanotechnology
Researchers from IIT-Hyderabad have found that lipid-based nanoparticles encapsulating chlorophyll-rich extract of a medicinal plant Anthocephalus cadamba and a near-infrared dye can selectively kill cancer cells when exposed to near-infrared light.
Unlike the conventional photothermal therapy that relies on heat to kill cancerous cells, the researchers used heat generated by the dye when exposed to light to destroy the encapsulation and release the extract.
The plant extract generated excess amount of reactive oxygen species, which caused cell death through autophagy (body’s way of removing damaged cells).
The extract showed selectivity in killing only cancer cells but its usage in normal cells caused insignificant cell death. The reason is that the extract did not increase the amount of reactive oxygen species generated inside normal cells thus not causing them through autophagy.
The researchers optimised the amount of dye used and the duration of illumination so that the thermal effect is mainly for triggering the release of the extract.
When photothermal therapy alone was used, nearly 50% cancer cells died in about 24 hours. But 45% cancer cells grew back in about a day. But there was no significant growth (about 7.5%) of cancer cells even 48 hours when photothermal therapy was used along with the extract.
Autophagy-mediated cell death was confirmed by using a particular protein that serves as an autophagy marker. The protein marker produced varied depending on the amount of extract used.
The tumour volume reduced significantly when treated with the extract along with photothermal therapy compared with controls and cells treated with the extract alone.
The nanoparticles from extract had no ill effects on body weight of the individual, indicating biocompatibility.