Triagem de microalgas verdes, coletadas em Ontário-Canadá, com potencial anti-inflamatório sobre macrófagos Murinos J744A.1

Abstract

Inflammation is a protective physiological response triggered by harmful stimuli, characterized mainly by the production of pro- and anti-inflammatory mediators. Excessively or persistently activated inflammation can lead to tissue damage and can cause chronic inflammatory diseases. That said, controlling inflammation is vital for the prevention and treatment of inflammatory diseases. Lipopolysaccharide (LPS) stimulates macrophages via TLR4 receptors, activating inflammatory signaling pathways including MAPK, NF-κB and nitric oxide production, leading to gene activation and the production of pro-inflammatory mediators and cytokines. Thus, it is a well-established model for the selection of anti-inflammatory compounds. Algae are attracting increasing interest in the pharmaceutical field because they contain a wide range of bioactive compounds with biological potential. In this context, we evaluated the effect of aqueous, ethanolic and methanolic extracts of green microalgae (Chlamydomonas sp., Coccomyxa sp., Scenedesmus sp.), collected in Ontario-Canada, in a total of 15 samples, on cell viability, as well as their anti-inflammatory potential on nitrite production in J744A.1 cells stimulated by LPS. Cell viability was assessed for all the extracts, at concentrations of 25 and 50 μg/mL, using the MTT method (3-[4,5-dimethyl-thiazol-2-yl]-2,5-diphenyltetrazolium bromide). The extracts that showed no cytotoxicity were evaluated for their ability to reduce nitrite production in J744A.1 cells stimulated by LPS, using the Griess technique. All the aqueous extracts and the methanolic extract of Coccomyxa sp. showed a reduction in cell viability after exposure for 24 hours. The ethanolic extracts of Chlamydomonas sp. (sample LL2A), Scenedesmus sp. (samples CC, LLI and P918), reduced nitrite levels in the supernatant of J744A.1 cells stimulated by LPS. The ethanolic extracts of Scenedesmus sp. (CC) and Chlamydomonas sp. (sample LL2A) show potential anti-inflammatory action, at concentrations without cytotoxicity, but more studies are needed to better understand this effect.