MATERIALS AND METHODS: This study involves administration of 4NQO solution for 8 weeks alone (cancer induction) or with Dracaena cinnabari (DC) extract at 100, 500, and 1000 mg/kg. DC extract administration started 1 week before exposure until 1 week after the carcinogen exposure was stopped. All rats were sacrificed after 22 weeks, and histological analysis was performed to assess any incidence of pathological changes. Immunohistochemical expressions of selected tumor marker antibodies were analyzed using an image analyzer computer system, and the expression of selected genes involved in apoptosis and proliferative mechanism related to oral cancer were evaluated using RT2-PCR.
RESULTS: The incidence of OSCC decreased with the administration of DC extract at 100, 500, and 1000 mg/kg compared to the induced cancer group. The developed tumor was also observed to be smaller when compared to the induced cancer group. The DC 1000 mg/kg group inhibits the expression of Cyclin D1, Ki-67, Bcl-2, and p53 proteins. It was observed that DC 1000 mg/kg induced apoptosis by upregulation of Bax and Casp3 genes and downregulation of Tp53, Bcl-2, Cox-2, Cyclin D1, and EGFR genes when compared to the induced cancer group.
CONCLUSIONS: The data indicated that systemic administration of the DC resin methanol extract has anticarcinogenic potency on oral carcinogenesis.
CLINICAL RELEVANCE: Chemoprevention with DC resin methanol extract may significantly reduce morbidity and possibly mortality from OSCC.
OBJECTIVE: This article reviews the association between the development of oral squamous cell carcinoma in potentially malignant oral lesions with chronic candidal infection and describes mechanisms that may be involved in Candida-associated malignant transformation.
METHODS: One hundred and twenty dentine discs were divided into three groups. The discs from each group were brushed with toothpaste containing bioactive glass, arginine and control toothpaste. Each group was then divided into four subgroups and exposed to acidic soft drink over four different time durations.
RESULTS: The scoring and the percentage of occluded dentinal tubules by Novamin-containing toothpaste was significantly better compared with arginine or the control toothpaste. Acidic soft drink challenge reduced the extent of dentinal tubules occlusion along with time. Dentinal tubules occluded by Novamin-containing toothpaste withstand the acidic challenge comparatively for a longer period.
CONCLUSIONS: The findings demonstrated that occlusion of dentinal tubules is more efficient by the bioactive glass-containing toothpaste and thus may contribute to its better resistance to acidic soft drink challenge.
Methods: Male Sprague-Dawley (SD) rats were randomized into six groups (n = 7 per group): Group 1 (untreated group); Group 2 (control cancer group) received 4NQO only for 8 weeks in their drinking water; Groups 3 and 4 (chemopreventive) received 4NQO for 8 weeks and were simultaneously treated with FD extract at 250 and 500 mg/kg, respectively, by oral gavage; Groups 5 and 6 (chemotherapeutic) received 4NQO for 8 weeks followed by the administration of FD extract at 250 and 500 mg/kg, respectively, for another 10 weeks. The incidence of oral cancer was microscopically evaluated. Moreover, immunohistochemical expression was analysed in tongue specimens using an image analyser computer system, while the RT2 profiler PCR array method was employed for gene expression analysis.
Results: The results of the present study showed a beneficial regression effect of the FD extract on tumor progression. The FD extract significantly reduced the incidence of oral squamous cell carcinoma (OSCC) from 100% to 14.3% in the high-dose groups. The immunohistochemical analysis showed that the FD extract had significantly decreased the expression of the key tumor marker cyclin D1 and had significantly increased the expression of the β-catenin and e-cadherin antibodies that are associated with enhanced cellular adhesion. Based on the gene expression analysis, FD extract had reduced the expression of the TWIST1 and RAC1 genes associated with epithelial-mesenchymal transition (EMT) and had significantly downregulated the COX-2 and EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.β-catenin and e-cadherin antibodies that are associated with enhanced cellular adhesion. Based on the gene expression analysis, FD extract had reduced the expression of the TWIST1 and RAC1 genes associated with epithelial-mesenchymal transition (EMT) and had significantly downregulated the COX-2 and EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.TWIST1 and RAC1 genes associated with epithelial-mesenchymal transition (EMT) and had significantly downregulated the COX-2 and EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.RAC1 genes associated with epithelial-mesenchymal transition (EMT) and had significantly downregulated the COX-2 and EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.COX-2 and EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.