Efficacy identification and active compounds screening of topically administration of Scutellaria Radix in oral ulcer

Scutellaria Radix (SR) is often added to various preparations for the treatment of oral ulcer, but its own efficacy and active compounds are still unknown while topically administration for oral ulcer, bring obstacles in further research. We expected to demonstrate the anti-oral ulcer effect of SR and find out its hallmark compounds, so as to provide reference for its material basis research. In this study, in vivo and in vitro models were used to prove the efficacy of SR, and spectrum-effect analysis was used to figure out the active compounds. In oral ulcer rats, SR significantly reduced TNF-α and IL-8 level, raised IL-2 level in both serum and mucosa, enhanced SOD activity and decreased MDA level of serum, reduced inflammatory reaction and showed good therapeutic effect. As for in vitro models, SR increased the survival rates of H2O2 damaged HOK, inhibited the release of IL-1β and NO of LPS induced HOK and LPS induced RAW 264.7, demonstrating good efficacy on oral ulcer. Subsequently, fingerprints and cellular pharmacodynamic data for 18 batches of SR were acquired, and spectrum-effect analysis were carried out by grey correlation analysis (GRA), partial least squares regression (PLSR) and "spider-web" mode. Five potential compounds were screened out and validated by comparing with SR activity, and baicalin, baicalein, and wogonoside were finally identified as active compounds of SR. These results explained the material basis of SR in treating oral ulcer and provided a scientific evidence for the clinical application of SR in oral administration.