The anti-inflammatory components from the effective fraction of Syringae Folium (ESF) and its mechanism investigation based on network pharmacology.

The Syringae Folium (SF), noted in Chinese Pharmacopeia, has been used in herbal medicines to treat inflammatory diseases and its water extract of SF, Yanlixiao (YLX) which is commercial preparation traditional Chinese medicine has been widely used clinically against intestinal inflammations. To explore its therapeutic material basis of SF, an effective fraction from SF (ESF) was found out by bio-guided isolation and enrichment of active components. In this research, ESF was identified as the anti-inflammatory fraction by comparing the survival rate of LPS-induced inflammation mouse model. The in vivo anti-inflammation efficacy of ESF was further tested by mouse ear edema model. Fifteen main components of ESF were separated from ESF after identification by UPLC-TOF-MS, and their inhibition on lipopolysaccharide (LPS)-induced nitric oxide (NO) production was tested along with ESF in RAW 264.7 macrophages cell line. Aiming to search its anti-inflammation mechanisms, the network pharmacology study was performed based on the main active components. As results, ESF was found with better efficacy in inhibiting ear swelling (82.2 mg/kg, 43.7%) compared with YLX (293.3 mg/kg, 37.9%). Meanwhile, the main ESF components, luteolin and quercetin were found with significant efficacy in reducing NO production compared with aminoguanidine (positive control) (81.3%, 78.7% and 76.3%, respectively, 50 μg/ml). Analysis of network pharmacology also suggested that luteolin and quercetin could be the key components for the anti-inflammation activity of ESF, and NFKB1, RELA, AKT1, TNF and PIK3CG were identified as key targets and MAPK, NF-κB, TCR and TLRs signaling pathways could be involved in the anti-inflammation action of ESF. The results attained in this study indicated that ESF had the potential to be developed as an anti-inflammation agent applied in clinic.