Introduction: Scutellaria baicalensis is commonly used in Asia as an herbal medicine to treat a variety of ailments, including cancer. Wogonoside, one major constituent of S. baicalensis, can be primarily converted to wogonin through deglycosylation via enteric microbiome metabolism.
Materials and methods: The antiproliferative effects of the glycoside (wogonoside) and its deglycosylated compound (wogonin) on a panel of human cancer cell lines from the most common solid tumors were evaluated using the MTS colorimetric assay. Cell cycle and apoptosis were determined using flow cytometry. Enzymatic activities of caspases were measured, and the interactions of wogonin and caspases were explored by a docking analysis.
Results: Wogonoside did not have obvious antiproliferative effects on the cancer cells. In contrast, wogonin showed significant antiproliferative activities on all the tested cancer cells. Wogonin arrested the cells in the G1 phase and significantly induced cell apoptosis. The compound also activated the expression of caspases 3 and 9. The docking results suggest that the compound forms hydrogen bonds with Phe250 and Ser251, and π-π interactions with Phe256 in caspase 3, and with Asp228 in caspase 9.
Conclusions: After wogonoside deglycosylation, wogonin significantly enhanced its anticancer potential as a potent anticancer compound derived from S. baicalensis.
Keywords: Apoptosis; deglycosylation; receptor-ligand docking; wogonin; wogonoside.