Anti-neuroinflammatory triterpenoids from the seeds of Quercus serrata Thunb.

The seeds of Quercus serrata Thunb. (acorns) have been served as a healthy food in Asia. In this study, five previously undescribed triterpenoids, along with nineteen known triterpenoids were isolated from acorns. Their structures were identified on account of spectroscopic analysis and GC-MS analysis after acid hydrolysis. Meanwhile, the inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in microglia cells (BV-2) of the identified triterpenoids were evaluated. All these compounds revealed overt anti-neuroinflammatory activity expect for 7. Compounds 1, 16 and 17 had potent inhibitory effects on protein and mRNA expression of iNOS and COX-2 in LPS-induced BV-2 cells. Bioactive triterpenoids 1, 2, 16 and 17 could block LPS-induced NF-κB nuclear translocation. This study suggested that acorns could be served as natural healthy product against neuroinflammatory-associated diseases, such as Alzheimer's disease.