Antioxidant and anti-inflammatory activities of cytocompatible Salvia officinalis extracts: A comparison between traditional and soxhlet extraction

Abstract

Chronic inflammation is characterized by an overproduction of several inflammatory mediators (e.g., reactive species and interleukins -IL) that play a central role in numerous diseases. The available therapies are often associated with serious side effects and, consequently, the need for safer drugs is of utmost importance. A plant traditionally used in the treatment of inflammatory conditions is Salvia officinalis. Therefore, conventional maceration and infusion of its leaves were performed to obtain hydroethanolic (HE-T) and aqueous extracts (AE-T), respectively. Their efficacy was compared to soxhlet extracts, namely aqueous (AE-S), hydroethanolic (HE-S), and ethanolic extracts (EE-S). Thin-layer chromatography demonstrated the presence of rosmarinic acid, carnosol, and/or carnosic acid in the different extracts. Generally, soxhlet provided extracts with higher antioxidant activities than traditional extraction. Moreover, under an inflammatory scenario, EE-S were the most effective, followed by HE-S, HE-T, AE-T, and AE-S, in the reduction of IL-6 and TNF-α production. Interestingly, the extracts presented higher or similar anti-inflammatory activity than diclofenac, salicylic acid, and celecoxib. In conclusion, the extraction method and the solvents of extraction influenced the antioxidant activity, but mainly the anti-inflammatory activity of the extracts. Therefore, this natural resource can enable the development of effective treatments for oxidative stress and inflammatory diseases.