Chemical composition of Prunus padus L. flower extract and its anti-inflammatory activities in primary bone marrow-derived macrophages

Abstract

Ethnopharmacological relevancePrunus padus L. has been traditionally used in European ethnomedicine as a treatment for internal and external purposes and is mainly used to reduce inflammation, pain and fever. The activities of P. padus flower extracts are not well characterized, and additional experimental studies at the molecular level are needed to confirm the ethnobotanical findings. Aim of the studyTo assess the potential of P. padus flower extract (PPFE) as a source of bioactive compounds through the characterization of its chemical composition and antioxidant, anti-collagenase, and anti-inflammatory activities. Materials and methodsThe ethanolic extract (1:10 w/v in ethanol solution) from P. padus flowers was subjected to phytochemical analysis and evaluation of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Anti-collagenase activity was determined using a spectrophotometric method in vitro. The effect of PPFE on inflammation was evaluated by measuring specific markers using flow cytometry and assessing pro-inflammatory cytokine (IL-6) release by bone marrow-derived macrophages (BMDMs) ex vivo. ResultsThe major components of the ethanolic extract of P. padus flowers were quercetin diglycosides, chlorogenic acid and N′,N″-dicaffeoyl,N‴-coumaroyl spermidine. The total phenolic content of PPFE was 85.19 mg GAE/g extract, and the EC50 value in the DPPH assay was 0.55 mg/ml. PPFE exhibited the ability to inhibit collagenase activity in a dose-dependent manner. Preincubation of BMDMs with PPFE reduced the population of M1 (pro-inflammatory) and increased the population of M2 (anti-inflammatory) macrophages. Furthermore, PPFE decreased pro-inflammatory cytokine IL-6 release from BMDMs. ConclusionsPPFE is a rich source of bioactive compounds and possesses considerable anti-inflammatory properties, supporting its use in ethnomedicine for the reduction of inflammatory processes.