Immunomodulatory Effects of Plant Extracts from Salvia deserta Schang. and Salvia sclarea L.

Abstract

Medicines, their safety, effectiveness and quality are indispensable factors of national security, important on a global scale. The COVID-19 pandemic has once again emphasized the importance of improving the immune response of the body in the face of severe viral infections. Plants from the Salvia L. genus have long been used in traditional medicine for treatment of inflammatory processes, parasitic diseases, bacterial and viral infections. The aim of the current study was to evaluate the immunomodulatory effects of plant extracts LS-1, LS-2 from Salvia deserta Schang. and LS-3, LS-4 from Salvia sclarea L. plants growing in southern Kazakhstan by conventional and ultrasonic-assisted extraction, respectively. The cytotoxic effects of the named sage extracts on neonatal human dermal fibroblasts (HDFn) were evaluated using the MTT assay. Immunomodulatory effects of the studied extracts were compared by examining their influence on pro-inflammatory cytokine secretion and phagocytic activity of murine immune cells. Depending on the physiological state of the innate immune cells, sage extracts LS-2 and LS-3 had either a stimulating effect on inactivated macrophages or suppressed cytokine-producing activity in LPS-activated macrophages. The greatest increase in TNF-α secretion was found after treatment of spleen T lymphocytes with sage extract LS-2, obtained by ultrasonic-assisted extraction.

Natural Compounds of Salvia L. Genus and Molecular Mechanism of Their Biological Activity

“…On the contrary, when LPS-stimulated macrophages were treated with the same sage extracts, the level of IL-1β secretion in macrophages was remarkably inhibited [119]. The data obtained by us comply with those of other scientists, who demonstrated that several groups of plant secondary metabolites (phenolic compounds, terpenes, polysaccharides) impact the functional activity of macrophages [120]. For instance, S. miltiorrhiza extract is reported to inhibit the production of NO, PGE2, IL-6, IL-1β, and TNF-α, and chemokines expression, RANTES, CX3CL1, and CX3CR1, as well as inflammatory mediators like TLR-4 and 11β-HSD1 in LPS-stimulated RAW 264.7 macrophages [121].…”

“…In our experiments, extracts of S. deserta and S. sclarea obtained by conventional and ultrasonic-assisted extraction significantly reduced the production of pro-inflammatory cytokine TNF-α in both unstimulated and LPS-stimulated peritoneal macrophages. At the same time, it had a strong stimulatory effect on the release of IL-1β in previously unstimulated macrophages remarkably in comparison to control [120]. On the contrary, when LPS-stimulated macrophages were treated with the same sage extracts, the level of IL-1β secretion in macrophages was remarkably inhibited [119].…”

“…In addition to antioxidant properties, the administration of S. officinalis decoction to gastric and small bowel injured rats abolished acute ethanolic-induced oxidative stress in the gastric and duodenal mucosa, which is an effect possibly related to a high content of flavonoids and phenolic acids [120]. S. elegans decoction has shown antioxidant effects, scavenging free radicals DPPH, NO and O 2 , reducing Fe 3+ , being the most effective inhibitor of α-glucosidase.…”