Biosynthesis of Silver Nanoparticles from Leaf Extract of Salvia coccinea and Its Effects of Anti-inflammatory Potential in Human Monocytic THP-1 Cells

Inflammation is one of the basic pathophysiologically important components in many life-threatening diseases. Metallic nanoparticles play a crucial role in biomedical applications. The present study was aimed at investigating the ameliorative effect of biosynthesized silver nanoparticles (ScAgNPs) using Salvia coccinea leaf extracts and characterizing them using physical and chemical methods, followed by evaluation of their cytotoxic, anti-oxidant, and anti-inflammatory potentials in monocytic THP-1 cells. Luciferase reporter assays and qRT-PCRs were used for gene expression studies. As oxidative stress and inflammation are mutually induced by each other, inhibiting oxidative stress could subsequently lead to inhibition of inflammation. Spherical-shaped ScAgNPs with 24 nm average size were successfully synthesized. The DCF staining technique, in addition to DPPH and reducing power activity assays, showed that 100-400 mu g/mL concentration of ScAgNPs decreased oxidative stress significantly, induced by high glucose, in THP-1 cells. Anti-inflammatory effects of ScAgNPs have corroborated inhibition of high-glucose-induced oxidative stress-sensitive transcription factor NF-kappa B-driven transcription of proinflammatory COX-2, MCP-1, IP-10, IL-17E, and IL-6 promoters significant in high-glucose-grown THP-1 cells, consistent with promoter inhibition, and the corresponding mRNA expression levels were also decreased, suggesting that ScAgNPs could be a potential anti-inflammatory agent, which could efficiently inhibit inflammation in THP-1 cells. Our initial in vitro studies suggested that ScAgNPs could serve as therapeutic candidates to alleviate inflammatory diseases by inhibiting oxidative stress and inflammation.