NOS2 and major depressive disorder: Dihydromyricetin (DMY) is an important flavonoid extracted from Daphyllostachys, and Wei et al. (131) found that DMY could inhibit neuroinflammation and improve LPS-induced depression-like behavior in mice by decreasing the secretion of pro-inflammatory factors TNFα, IL-6, IL-1β, COX-2, and iNOS in vivo.