title: Terpenoids from Zingiber officinale (Ginger) induce apoptosis in endometrial cancer cells through the activation of p53.
abstract: Novel strategies are necessary to improve chemotherapy response in advanced and recurrent endometrial cancer. Here, we demonstrate that terpenoids present in the Steam Distilled Extract of Ginger (SDGE) are potent inhibitors of proliferation of endometrial cancer cells. SDGE, isolated from six different batches of ginger rhizomes, consistently inhibited proliferation of the endometrial cancer cell lines Ishikawa and ECC-1 at IC(50) of 1.25 µg/ml. SDGE also enhanced the anti-proliferative effect of radiation and cisplatin. Decreased proliferation of Ishikawa and ECC-1 cells was a direct result of SDGE-induced apoptosis as demonstrated by FITC-Annexin V staining and expression of cleaved caspase 3. GC/MS analysis identified a total of 22 different terpenoid compounds in SDGE, with the isomers neral and geranial constituting 30-40%. Citral, a mixture of neral and geranial inhibited the proliferation of Ishikawa and ECC-1 cells at an IC(50) 10 µM (2.3 µg/ml). Phenolic compounds such as gingerol and shogaol were not detected in SDGE and 6-gingerol was a weaker inhibitor of the proliferation of the endometrial cancer cells. SDGE was more effective in inducing cancer cell death than citral, suggesting that other terpenes present in SDGE were also contributing to endometrial cancer cell death. SDGE treatment resulted in a rapid and strong increase in intracellular calcium and a 20-40% decrease in the mitochondrial membrane potential. Ser-15 of p53 was phosphorylated after 15 min treatment of the cancer cells with SDGE. This increase in p53 was associated with 90% decrease in Bcl2 whereas no effect was observed on Bax. Inhibitor of p53, pifithrin-α, attenuated the anti-cancer effects of SDGE and apoptosis was also not observed in the p53(neg) SKOV-3 cells. Our studies demonstrate that terpenoids from SDGE mediate apoptosis by activating p53 and should be therefore be investigated as agents for the treatment of endometrial cancer.
authors.affiliation: Department of Obstetrics and Gynecology, Shandong University, Qi Lu Hospital, Ji Nan, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Whelan
authors.forename: Bikash R
authors.initials: BR
authors.lastname: Pattnaik
authors.forename: Kai
authors.initials: K
authors.lastname: Ludwig
authors.forename: Enkateswar
authors.initials: E
authors.lastname: Subudhi
authors.forename: Helen
authors.initials: H
authors.lastname: Rowland
authors.forename: Nick
authors.initials: N
authors.lastname: Claussen
authors.forename: Noah
authors.initials: N
authors.lastname: Zucker
authors.forename: Shitanshu
authors.initials: S
authors.lastname: Uppal
authors.forename: David M
authors.initials: DM
authors.lastname: Kushner
authors.forename: Mildred
authors.initials: M
authors.lastname: Felder
authors.forename: Manish S
authors.initials: MS
authors.lastname: Patankar
authors.forename: Arvinder
authors.initials: A
authors.lastname: Kapur
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D016889:Endometrial Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D005260:Female; D020939:Zingiber officinale; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D013729:Terpenes / Q000494:pharmacology* / Q000627:therapeutic use; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D010936:Plant Extracts; D013729:Terpenes; D016159:Tumor Suppressor Protein p53