Safety evaluation and modulatory effects on innate immune system of pyrazoline-derived compounds

Pyrazolines are compounds that have been studied for their strong biological potential and structure diversity. Several studies demonstrated their biological effectiveness, highlighting their anti-inflammatory potential. This study aimed to evaluate the physicochemical profile, the safety, and the anti-inflammatory effects of four pyrazolines (PH0, PH3, PH4, and PH7). Initially, in silico analysis were performed on SwissADME and QSAR Toolbox platforms. The anti-inflammatory activity was assessed by in vitro and in vivo methodologies. Neutrophils collected from mice peritoneum and macrophages immortalized cell line (Raw 264.7) were stimulated with lipopolysaccharide (LPS), and subsequent measurement of nitric oxide (NO) and IL-1β, TNF, and IL-6 cytokines were performed by ELISA method. The effect on cell migration was evaluated by chemotaxis assay. The effect on efferocytosis was investigated using senescent neutrophils and macrophages from mice's bone marrow. The in silico results suggest suitable properties for a pharmacological prototype for oral administration, with no significant toxic effects. All compounds significantly reduced NO levels, as well as levels of IL-1β, TNF, and IL-6 cytokines. Also, they were able to reduce cell migration and increase efferocytosis. The in vivo air pouch model confirmed the effects of pyrazolines on cell kinetics and on the levels of cytokines (IL-1β and TNF) on the air pouch lavage. All of the pyrazolines evaluated showed to have positive effects on mechanisms that modulate the inflammatory response. Furthermore, the in silico analysis suggests that chemical changes in the structure can lead to improvement of the biological and pharmacokinetics proprieties.