Gold nanoparticles from Celastrus hindsii and HAuCl4: Green synthesis, characteristics, and their cytotoxic effects on HeLa cells

The extract from Celastrus hindsii (C. hindsii), a plant that naturally grows in the forests of several provinces of Vietnam, has been traditionally used as an alternative medicine for the treatment of inflammation because of its anticancer and antitumor properties. This study reported the green synthesis of stable gold nanoparticles (Au-NPs) derived from HAuCl4 using the extract of C. hindsii as reducing and capping agents. Their particle size could be controlled by adjusting the ratio of the extract to HAuCl4 solution used (1.25%, 2.5%, 3.75%, 5.0%, and 6.25%). The optimal ratio of the extract was 3.75% (Au-NPs-3.75%). The X-ray powder diffraction analysis demonstrated that the Au-NPs was successfully synthesized. Fourier-transform infrared spectroscopy result indicated the possible presence of phenolic acids and flavonoids (acting as reducing agents and potential natural antioxidants). Transmission electron microscopy images showed that the particle diameter of Au-NPs-3.75% varied between 13 and 53 nm (average: similar to 30 nm) in its spherical shape. The biosynthesized Au-NPs-3.75% exhibited dose-dependent cytotoxicity against HeLa cells, and the inhibitory concentration (IC50) was 12.5 mu g/mL at 48 h. Therefore, Au-NPs that were synthesized from environmentally friendly method without the presence of potentially toxic chemicals were highly possible in biomedical applications.

Automated summary

The study successfully synthesized gold nanoparticles from C. hindsii extract without the presence of potentially toxic chemicals, showing promising biomedical applications.