Calotropis gigantea stem bark extracts inhibit liver cancer induced by diethylnitrosamine.

Several fractions of Calotropis gigantea extracts have been proposed to have potential anticancer activity in many cancer models. The present study evaluated the anticancer activity of C. gigantea stem bark extracts in liver cancer HepG2 cells and diethylnitrosamine (DEN)-induced primary liver cancer in rats. The carcinogenesis model induced by DEN administration has been widely used to study pathophysiological features and responses in rats that are comparable to those seen in cancer patients. The dichloromethane (CGDCM), ethyl acetate, and water fractions obtained from partitioning crude ethanolic extract were quantitatively analyzed for several groups of secondary metabolites and calactin contents. A combination of C. gigantea stem bark extracts with doxorubicin (DOX) was assessed in this study to demonstrate the enhanced cytotoxic effect to cancer compared to the single administration. The combination of DOX and CGDCM, which had the most potential cytotoxic effect in HepG2 cells when compared to the other three fractions, significantly increased cytotoxicity through the apoptotic effect with increased caspase-3 expression. This combination treatment also reduced ATP levels, implying a correlation between ATP and apoptosis induction. In a rat model of DEN-induced liver cancer, treatment with DOX, C. gigantea at low (CGDCM-L) and high (CGDCM-H) doses, and DOX + CGDCM-H for 4 weeks decreased the progression of liver cancer by lowering the liver weight/body weight ratio and the occurrence of liver hyperplastic nodules, fibrosis, and proliferative cells. The therapeutic applications lowered TNF-α, IL-6, TGF-ß, and α-SMA inflammatory cytokines in a similar way, implying that CGDCM had a curative effect against the inflammation-induced liver carcinogenesis produced by DEN exposure. Furthermore, CGDCM and DOX therapy decreased ATP and fatty acid synthesis in rat liver cancer, which was correlated with apoptosis inhibition. CGDCM reduced cleaved caspase-3 expression in liver cancer rats when used alone or in combination with DOX, implying that apoptosis-inducing hepatic carcinogenesis was suppressed. Our results also verified the low toxicity of CGDCM injection on the internal organs of rats. Thus, this research clearly demonstrated a promising, novel anticancer approach that could be applied in future clinical studies of CGDCM and combination therapy.

Analysis of Prevalence and Clinical Features of Ameloblastoma and its Histopathological Subtypes in Southeast Myanmar and Lower Northern Thailand Populations: A 13-Year Retrospective Study.

INTRODUCTION: Prevalence of ameloblastomas has been established worldwide but collective data of ameloblastoma in Southeast Asian countries has not been well analyzed. AIM: Aim of this study was to report analysis and comparison of the prevalence and demographic data of clinical features of ameloblastoma and its histopathological variants in Southeast Myanmar and lower Northern Thailand populations. MATERIALS AND METHODS: A retrospective study on ameloblastoma was performed based on the availability of oral biopsy specimens in Faculty of Dentistry, Naresuan University, Phitsanulok, Thailand, between January 2002 and August 2015. The collected data were subjected to descriptive statistical analyses with the SPSS version 17.0 statistical software package (SPSS Inc., Chicago, USA). Pearson's chi square (χ2) test and t-test were employed. The critical level of significance was set at p<0.05. RESULTS: Total of 616 cases were reviewed, 30 cases (5%) were diagnosed as ameloblastoma with male:female ratio of 1.14:1. The mean age of the patients was 31.3±15.6 years. The predominance anatomical distribution was observed in the mandible (86.7%). Posterior body-ramus-angle region was the most common site. Almost all cases were asyptomatic and most common clinical manifestation was swelling of affected region. Multilocular radiolucency was observed in 70% of cases, whereas 30% were unilocular. Three subtypes of ameloblastomas were diagnosed: unicystic ameloblastoma (20%), conventional solid/multicystic ameloblastoma (70%), and desmoplastic ameloblastoma (10%). The most common histologic pattern was the plexiform type (57.2%) followed by follicular type (23.8%). CONCLUSION: Prevalence of ameloblastoma in Southeast Myanmar and lower Northern Thailand populations correspond with data from other geographic areas of Thailand and other Asian countries. However, some demographic and histopathological profiles are different, with plexiform ameloblastoma being the most common subtype in this study.

Expression of midkine in ameloblastomas and its correlation with clinicopathologic parameters.

OBJECTIVE: Midkine (MK) is a heparin-binding growth factor that is overexpressed in various human cancers. The aim of this study was to investigate the expression of MK in ameloblastomas and correlate the results with clinicopathologic parameters. STUDY DESIGN: Cases of ameloblastoma seen between 1999 and 2010 were identified. Clinical information was collected regarding age, gender, race, and location of tumor. Cases were classified as solid/multicystic, unicystic, and peripheral. The expression of midkine was assessed using immunohistochemistry. A significant difference was considered present at P < 0.05. RESULTS: A total of 34 cases of ameloblastoma and 4 cases of ameloblastic carcinomas were identified. MK was expressed in 67% of lesions (23.5% weak expression; 14.7% moderate expression; 29.4% strong expression). A significant difference was seen between solid/multicystic and unicystic lesions. CONCLUSIONS: MK is expressed in the majority of ameloblastomas, suggesting a role of the protein in the tumor's development, progression, and behavior.

Farnesol-induced apoptosis in Candida albicans is mediated by Cdr1-p extrusion and depletion of intracellular glutathione.

Farnesol is a key derivative in the sterol biosynthesis pathway in eukaryotic cells previously identified as a quorum sensing molecule in the human fungal pathogen Candida albicans. Recently, we demonstrated that above threshold concentrations, farnesol is capable of triggering apoptosis in C. albicans. However, the exact mechanism of farnesol cytotoxicity is not fully elucidated. Lipophilic compounds such as farnesol are known to conjugate with glutathione, an antioxidant crucial for cellular detoxification against damaging compounds. Glutathione conjugates act as substrates for ATP-dependent ABC transporters and are extruded from the cell. To that end, this current study was undertaken to validate the hypothesis that farnesol conjugation with intracellular glutathione coupled with Cdr1p-mediated extrusion of glutathione conjugates, results in total glutathione depletion, oxidative stress and ultimately fungal cell death. The combined findings demonstrated a significant decrease in intracellular glutathione levels concomitant with up-regulation of CDR1 and decreased cell viability. However, addition of exogenous reduced glutathione maintained intracellular glutathione levels and enhanced viability. In contrast, farnesol toxicity was decreased in a mutant lacking CDR1, whereas it was increased in a CDR1-overexpressing strain. Further, gene expression studies demonstrated significant up-regulation of the SOD genes, primary enzymes responsible for defense against oxidative stress, with no changes in expression in CDR1. This is the first study describing the involvement of Cdr1p-mediated glutathione efflux as a mechanism preceding the farnesol-induced apoptotic process in C. albicans. Understanding of the mechanisms underlying farnesol-cytotoxicity in C. albicans may lead to the development of this redox-cycling agent as an alternative antifungal agent.