New Insights into the Antioxidant and Anti-Inflammatory Effects of Italian Salvia officinalis Leaf and Flower Extracts in Lipopolysaccharide and Tumor-Mediated Inflammation Models

This work aimed to investigate and compare the in vitro antioxidant and anti-inflammatory effects of Salvia officinalis L. (sage) from Italy, with the aim of raising its current knowledge in this field. Leaves and flowers (S1-S8), harvested in two areas of Southern Italy, were extracted with methanol as a solvent by maceration or ultrasound-assisted extraction. Sage extracts, analysed by high pressure liquid chromatography-diode-array detection-electrospray ionization-quadrupole-mass spectroscopy (HPLC-DAD-ESI-Q-MS), exerted a promising antioxidant activity investigated using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2 '-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and beta-carotene bleaching tests, and elicited a significant decrease in reactive oxygen species (ROS) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophages. The anti-inflammatory activity was analysed in the same in vitro model. All the extracts did not affect cell viability although they showed anti-inflammatory activity, as they induced a decrease in nitrite levels that was greater than 50%, when employed at 50 mu g/mL. Furthermore, they elicited a decrease in nitrite levels, as well as a decline in pro-inflammatory cytokine expression. The NF-kappa B transcription factor proved to be involved in the mechanisms that underlie such effects. Interestingly, sage extracts were able to interfere with the inflammatory activity induced by breast cancer cell-conditioned media (nitrite levels were significantly decreased, p < 0.05; p < 0.01), highlighting for the first time the important role of S. officinalis in controlling inflammation processes related to neoplastic progression.

Automated summary

This study investigated and compared the antioxidant and anti-inflammatory effects of Salvia officinalis L. (sage) from Italy in vitro, showing promising results in both aspects. The sage extracts exhibited significant antioxidant activity and decreased ROS production, as well as anti-inflammatory effects by reducing nitrite levels and pro-inflammatory cytokine expression in murine macrophages. The NF-kappa B transcription factor was found to be involved in the mechanisms underlying these effects, and the sage extracts also showed potential in controlling inflammation related to neoplastic progression.