Scutellaria baicalensis targets the hypoxia-inducible factor-1α and enhances cisplatin efficacy in ovarian cancer.

Hypoxia-inducible factor-1alpha (HIF-1α) is aberrantly upregulated in tumors and implicated in angiogenesis, metastasis, and drug resistance. Therefore, developing treatments that target HIF-1α may be a viable therapeutic approach. In Traditional Chinese Medicine (TCM), Scutellaria baicalensis (SB) is used for the treatment of cancer but the anti-cancer mechanisms are not known. We examined the effects of SB on HIF-1α expression in ovarian cancer (OC) cell lines grown under normoxic and hypoxic conditions. SB treatment attenuated HIF-1α expression in cancer cell lines. Treatment of cells with cycloheximide (CHX) reduced HIF-1α levels similar to cells treated with SB. Furthermore, SB-induced HIF-1α inhibition was abrogated by the proteasomal inhibitor MG132 and a lysosome inhibitor, chloroquine. Activation of PI3K/AKT and MAPK/ERK seen in OC cells was reduced with SB. Pretreatment of cells with LY294002 (phosphoinositide 3-kinase inhibitor) and PD98059 (mitogen-activated protein kinase inhibitor) reduced HIF-1α expression comparable to SB-treated cells. SB potentiated the anti-growth effects of cisplatin on OC cells by attenuating the expression of HIF-1α, ABCG1, and ABCG2. Taken together, the findings suggest that targeting HIF-1α with SB could be an effective treatment strategy for cancer and SB can improve the sensitivity of cancer cells to cisplatin, which is a major challenge in therapy for ovarian tumors.

The Chinese herbs Scutellaria baicalensis and Fritillaria cirrhosa target NFκB to inhibit proliferation of ovarian and endometrial cancer cells.

The herbs Scutellaria baicalensis (SB) and Fritillaria cirrhosa (FC) are widely used in Chinese medicine to treat several aliments and as an adjuvant to chemotherapy of lung cancer. No information is available regarding the two herbs' influence on ovarian and endometrial cancer. To fill this data gap we compared cell growth responses to SB and FC in ovarian and endometrial cancer cell lines. Dose-dependent cell growth inhibition was observed following higher doses in all cell lines while lower doses stimulated growth in only endometrial cell lines. Higher doses of SB and FC significantly decreased cell growth on soft agar and decreased the invasive potential of cancer cells. Treatment of cells with both herbs resulted in activation of caspase-3, G0 /G1 phase cell cycle arrest, downregulation of cyclins D1 and D3 and induction of p27. Both herbs decreased NFκB DNA binding, reduced expression of phosphorylated IκBα, abrogated NFκB activation, and downregulated NFκB-regulated metastasis-promoting proteins in cancer cells. Furthermore, knockdown of NFκB attenuated SB- and FC-induced cell growth inhibition. These results suggest that inhibition of NFκB activation may be an important mechanism for growth suppression by SB and FC. Data indicate that these herbs may represent a new source of agents for NFκB inhibition in cancer therapy.