A green chemistry approach for the synthesis of gold nanoconjugates that induce the inhibition of cancer cell proliferation through induction of oxidative stress and their in vivo toxicity study.

In this paper, we report the synthesis of gold nanoconjugates (b-Au-LM) using the aqueous leaf extract of Lantana montevidensis (LM), a naturally available medicinal plant. The biosynthesized b-Au-LM was biocompatible in both in vitro and in vivo systems. However, the LM extract as well as b-Au-LM exhibited significant inhibition of the proliferation of cancer cells. Interestingly, b-Au-LM showed enhanced anti-cancer activity compared to the pristine LM extract. Generation of reactive oxygen species (ROS) and oxidative stress, which triggered the upregulation of caspase-3, might be the plausible reason for anti-cancer activity. Cell cycle analysis demonstrated G₂/M (in A549 cells) or Sub-G₁ (in MCF-7) cell cycle arrest, which might lead to apoptosis. Together, the results support the future therapeutic application of an in situ biosynthesized gold nanoconjugates based drug delivery system (b-Au-LM) towards cancer therapy and other biomedical applications.