Anti-inflammatory active fraction screening and mechanism of unripe Forsythiae Fructus based on ¹H-NMR metabolomics

Abstract

To screen the anti-inflammatory active fraction of unripe Forsythiae Fructus, and elucidate the action mechanism, water decoction, ethyl acetate portion, n-butanol portion and residue water extracts of unripe Forsythiae Fructus were administered into rats for continuously 15 days. The acute lung injury inflammatory model was established to observe the section structure of lung tissues. Levels of IL-6, TNF-α, IL-1β and IL-10 in bronchoalveolar lavage fluid were determined by ELISA kits, and changes in endogenous metabolites in serum were analyzed based on 1H-NMR metabolomics. The results showed that ethyl acetate portion of unripe Forsythiae Fructus had a better anti-inflammatory activity against acute lung injury, and could suppress the release of inflammatory factors of IL-6, TNF-α, IL-1β, significantly reduce contents of creatine, β-OH-butyrate, succinate, lysine, valine, isoleucine and glutamine, and elevate the content of GPC in serum. Ethyl acetate portion was proved to be the main fraction of anti-inflammatory activity from the perspective of endogenous metabolites in serum, and played an anti-inflammatory role by regulating creatine metabolism, choline metabolism, branched-chain amino acid metabolism and TCA cycles. This study could lay a foundation for studying pharmacodynamic material basis of unripe Forsythiae Fructus.