Neuroprotective effects of phenolic compounds isolated from spiraea prunifolia var. Simpliciflora

The leaves of Spiraea prunifolia were extracted with 80% aqueous MeOH and the concentrates were partitioned into EtOAc, n-BuOH, and H₂O fractions. The repeated SiO₂ or ODS column, and medium pressure liquid chromatographies for the n-BuOH fraction led to isolation of two phenolic glucosides. The chemical structures of these compounds were determined as isosalicin (1) and crenatin (2) based on spectroscopic analyses including Nuclear magnetic resonance and MS. Extracts were analyzed using UPLC-MS/MS providing a short analysis time within 5 min using MRM technique. The concentration of crenatin was higher as 9.53 mg/g and isosalicin was lower as 0.65 mg/g. Neuroprotective effects of these compounds against hydrogen peroxide (H₂O₂₎-induced neurotoxicity were evaluated. The results showed that exposure to H₂O₂ induced morphological changes, cell death and neurotoxicity in SK-N-MC cells. However, pretreatment with crenatin resulted in inhibition of morphological change, reduction of loss of cell viability and attenuation of neuronal damage. These results suggested that neuroprotective effect of crenatin isolated from S. prunifolia can be a good candidate for the development of health beneficial foods which can ameliorate the degenerative neuronal disease caused by oxidative stress.