Role of serotonin and prostaglandins in brain edema induced by heat stress. An experimental study in the young rat

Syringol isolated from Eleusine coracana (L.) Gaertn bran suppresses inflammatory response through the down-regulation of cPLA2, COX-2, IκBα, p38 and MPO signaling in sPLA2 induced mice paw oedema

Eleusine coracana (L.) Gaertn (E. coracana) is one of the highest consuming food crops in Asia and Africa. E. coracana is a plant with several medicinal values including anti-ulcerative, anti-diabetic, anti-viral and anti-cancer properties. However, the anti-inflammatory property of E. coracana remains to be elucidated. Therefore, the objective of present study was to investigate the potential in isolated molecule from E. coracana via a combination of in vitro, in vivo and in silico methods. In this study, we have isolated, purified and characterized an anti-inflammatory molecule from E. coracana bran extract known as syringol. Purification of syringol was accomplished by combination of GC-MS and RP-HPLC techniques. Syringol significantly inhibited the enzymes activity of sPLA₂ (IC₅₀ = 3.00 µg) and 5-LOX (IC₅₀ = 0.325 µg) in vitro. The inhibition is independent of substrate concentration, calcium ion concentration and was irreversible. Syringol interacts with purified sPLA₂ enzymes as evidenced by fluorescence and molecular docking studies. Further, the syringol molecule dose dependently inhibited the development of sPLA₂ and λ-carrageenan induced edema. Furthermore, syringol decreases the expression of cPLA₂, COX-2, IκBα, p38 and MPO in edematous tissues as demonstrated by western blots. These studies revealed that syringol isolated from E. coracana bran may develop as a potent anti-inflammatory molecule.