shogaol and Carcinoma--Squamous-Cell

Ginger (Zingiber officinale Roscoe) is used for a wide array of conditions in traditional medicine in Asia, but little is known about the effect on head and neck cancer. In this study, the effect of two major pharmacologically active compounds of ginger, 6-gingerol and 6-shogaol, were studied on head and neck cancer cell lines. Furthermore, experiments in combination with established treatment methods for head and neck cancer were performed. Proliferation assays showed a dose-dependent reduction of cell viability. Flow cytometry analysis revealed the induction of apoptosis. Western blot analysis indicated that the antiapoptotic protein survivin was suppressed after treatment. Although a combination of 6-shogaol with cisplatin exhibited no synergistic effect, the combination with irradiation showed a synergistic reduction of clonogenic survival. In conclusion, ginger compounds have many noteworthy effects on head and neck cancer cell lines. In particular, the enhancement of radiosensitivity is remarkable.

Topics: Aged; Apoptosis; Carcinoma, Squamous Cell; Catechols; Cell Line, Tumor; Head and Neck Neoplasms; Humans; Male; Middle Aged; Plant Extracts; Zingiber officinale

Nuclear factor-kappaB (NF-κB) and activator protein 1 (AP-1) is a major transcription factor which regulates many biological and pathological processes such as inflammation and cell proliferation, which are major implicates in cancer progression. [6]-Shogaol ([6]-SHO) is a major constituent of ginger, exhibits various biological properties such as anti-oxidants, anti-inflammation and anti-tumor. Recently, we proven that [6]-SHO prevents oral squamous cell carcinoma by activating proapoptotic factors in in vitro and in vivo experimental model. However, the preventive efficacy of [6]-SHO in 7,12-dimethylbenz[a]anthracene (DMBA) induced hamster buccal pouch carcinogenesis (HBP) has not been fully elucidated, so far. Hence, we aimed to investigate the effect of [6]-SHO on inflammation and cell proliferation by inhibiting the translocation of NF-κB and AP-1 in DMBA induced HBP carcinogenesis. In this study, we observed upregulation of inflammatory markers (COX-2, iNOS, TNF-α, interleukin-1 and -6), cell proliferative markers (Cyclin D1, PCNA and Ki-67) and aberrant activation of NF-κB, AP-1, IKKβ, c-jun, c-fos and decreased IκB-α in DMBA induced hamsters. Conversely, oral administration of [6]-SHO strongly inhibited constitutive phosphorylation and degradation of IκB and inhibit phosphorylation of c-jun, c-fos, resulting in inhibition of nuclear translocation of NF-κBp65 and AP-1. Thus, inhibition of NF-κB and AP-1 activation by [6]-SHO attenuates inflammation and cell proliferative response in DMBA induced hamsters. Our finding suggested that [6]-SHO is a novel functional agent capable of preventing DMBA induced inflammation and cell proliferation associated tumorigenesis by modulating multiple signalling molecules.

Topics: Animals; Anthracenes; Biomarkers, Tumor; Carcinogenesis; Carcinoma, Squamous Cell; Catechols; Cell Proliferation; Inflammation; Male; Mesocricetus; Mouth Mucosa; Mouth Neoplasms; NF-kappa B; Oncogenes; Signal Transduction; Transcription Factor AP-1; Zingiber officinale

Oral cancer is a major cause of morbidity and mortality in developing countries. Despite advances in chemotherapy for the cancer management, the survival rate has not yet been improved. Dietary nutrient has been receiving a lot of attention and interest in the chemotherapeutic development. [6]-Shogaol is a major bioactive compound identified in ginger that possesses many pharmacological properties. The aim of the present study is to investigate the effect of [6]-shogaol on 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch (HBP) carcinogenesis. Oral squamous cell carcinoma induced in HBP by painting with 0.5% 7,12-dimethylbenz(a)anthracene (DMBA), thrice in a week for 16 weeks. We observed 100% tumour incidence, decreased levels of lipid peroxidation, antioxidant, and phase II detoxification enzymes (GST, GR and GSH) in DMBA-induced hamsters. Further, enhanced activity of phase I enzymes (cytochrome p450 and b5) and over-expression of mutant p53, Bcl-2 and decreased expression of wild type p53 and Bax were noticed in DMBA-induced hamsters. Our results indicated that [6]-shogaol (10, 20 and 40 mg/kg body weight) treated with DMBA-painted hamsters, considerably reversed tumour incidence, improved antioxidant status, phase II detoxification enzymes, and also inhibit lipid peroxidation and phase I enzymes. Moreover, [6]-shogaol inhibits mutant p53 and Bcl-2 expression and significantly restored normal p53, Bax levels. Thus, we concluded that [6]-shogaol prevents DMBA-induced HBP carcinogenesis through its antioxidant as well as modulating apoptotic signals.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Antioxidants; Apoptosis; bcl-2-Associated X Protein; Carcinogenesis; Carcinoma, Squamous Cell; Catechols; Cheek; Cricetinae; Cytochrome P-450 Enzyme System; Lipid Peroxidation; Male; Mesocricetus; Mouth Neoplasms; Oxidation-Reduction; Proto-Oncogene Proteins c-bcl-2; Thiobarbituric Acid Reactive Substances; Tumor Suppressor Protein p53; Zingiber officinale