PTGS2 and lung cancer: 2003). The anti-cancer activities of S. baicalensis could be related with its inhibitory effects on PGE2 (prostaglandin E2) production via suppression of COX-2 (cyclooxygenase-2) expression and arachidonic acid release from cell membranes. The total free flavonoid extract (100 mg/kg for 30 d, p.o.)could also significantly reduce tumor size by 25.5% in A549 human lung cancer xenografted mice, via induction of growth arrest in S phase and inhibition of DNA synthesis (Wang Y et al. 2016).