Molecular mechanism of anti-prostate cancer activity of Scutellaria baicalensis extract.

Abstract

Scutellaria baicalensis is a widely used Chinese herbal medicine historically used in antiinflammatory and anticancer therapy. The goals of the study were to 1) determine its in vitro and in vivo anti-prostate cancer activity, 2) investigate its molecular mechanism directed at cell proliferation control including cyclooxygenase-2(COX-2) prostaglandin E2 (PGE2) and cyclins/cdks pathways, and 3) compare it with those of PC-SPES (PC stands for prostate cancer and spes is Latin for hope), a former herbal mixture for prostate cancer treatment of which S. baicalensis is a major constituent. Two human prostate cancer cell lines (LNCaP, androgen dependent, and PC-3, androgen independent) were assessed for growth inhibition. S. baicalensis exerted dose- and time-dependent increased growth inhibition in both cell lines. However, the PC-3 cells IC50 (50% growth inhibition concentration) were slightly more sensitive than LNCaP cells (IC50=0.15 mg/ml), although the former is androgen independent. S. baicalensis was more effective in inhibition of cell growth compared with PC-SPES (IC50=0.38 mg/ml for PC-3 cells). Significant reduction of PGE2 synthesis in both cells after treatment with S. baicalensis resulted from direct inhibition of COX-2 activity rather than COX-2 protein suppression. S. baicalensis also inhibited prostate-specific antigen production in LNCaP cells. Finally, S. baicalensis suppressed expression of cyclin D1 in LNCaP cells, resulting in a G1 phase arrest, while inhibiting cdk1 expression and kinase activity in PC-3 cells, ultimately leading to a G2/M cell cycle arrest. Animal studies showed a 50% reduction in tumor volume after a 7-wk treatment period. This study demonstrated that S. baicalensis may be a novel anticancer agent for the treatment of prostate cancer.

• Authors: Fei Ye, Shiquan Jiang, Helen Volshonok, Josephine Wu, David Y Zhang
• Journal: Nutrition and cancer (Nutr Cancer) Vol. 57 Issue 1 Pg. 100-10 ( 2007) ISSN: 0163-5581 [Print] United States
• PMID: 17516867 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Androgens
• Antineoplastic Agents, Phytogenic
• Cyclooxygenase 2 Inhibitors
• Plant Extracts
• Scutellaria baicalensis extract
• Cyclooxygenase 2
• Dinoprostone

Topics

• Androgens (metabolism)
• Animals
• Antineoplastic Agents, Phytogenic (therapeutic use)
• Cyclooxygenase 2 (metabolism)
• Cyclooxygenase 2 Inhibitors
• Dinoprostone (metabolism)
• Dose-Response Relationship, Drug
• Humans
• Inhibitory Concentration 50
• Male
• Mice
• Mice, Nude
• Phytotherapy
• Plant Extracts (therapeutic use)
• Prostatic Neoplasms (drug therapy)
• Scutellaria baicalensis
• Time Factors
• Tumor Cells, Cultured