In vitro fungistatic activity of 36 traditional oriental medicines and their synergistic effect against Trichophyton rubrume

Objective:To investigate the fungistatic activity and synergistic effects of natural products and their constituents, including traditional oriental medicines (TOMs).Methods:Fungistatic activities of TOMs prepared by hot-water (115 °C) or ethanol (70%; 40 °C) extraction were determined by their minimum inhibitory concentration. To assess possible synergistic effects, minimum inhibitory concentrations of various combinations were evaluated.Results:By evaluating antifungal susceptibility of Trichophyton rubrum, which is a major causative fungus for several types of dermatophytosis, we confirmed that ethanol extracts were more active than hot-water extracts in 25 of the 36 TOMs, suggesting that the constituents with high hydrophobicity tend to contribute significantly to fungistatic activity. We selected four TOMs with high fungistatic activity, including Aucklandiae radix, Gentianae macrophyllae radix, Scutellariae radix, and Galla rhois, and their synergistic effects were investigated through the combination studies between TOMs or TOM-conventional drug terbinafine. In combinations between four TOMs, partial synergistic effects were observed in Aucklandiae radix–Galla rhois and Gentianae macrophyllae radix–Galla rhois combinations, as supported by the lowest fractional inhibitory concentration index value of 0.66 for both combinations. Furthermore, Galla rhois showed the strongest synergistic effect on growth inhibition of Trichophyton rubrum with a fractional inhibitory concentration index value of 0.50 in combination with terbinafine.Conclusions:Our findings indicate that the combination of TOMs and TOM-terbinafine may be effective on treatment for chronic and recurrent dermatophytosis by improving fungistatic activity and led to decrease systemic toxicity in clinical practice.

Epigenetic Changes (Aberrant DNA Methylation) in Colorectal Neoplasia

Both genetic and epigenetic events have been implicated in the stepwise histological progression involving adenoma-carcinoma and hyperplastic polyp/serrated adenoma-carcinoma sequences in the development of colorectal cancer. Genetic changes have been observed at each step in the initiation and progression of polyps to adenocarcinomas. Epigenetic changes also occur at each step in the pathogenesis of colorectal cancers and include CpG island DNA hypermethylation in the promoter region of genes resulting in transcriptional silencing through associated changes in chromatin structure and effects on binding of transcription factors, and DNA global hypomethylation which leads to chromosomal instability. Recent studies on MLH1 and APC genes indicate that epigenetic and genetic changes cooperate to facilitate tumor initiation and progression. Since aberrant CGI DNA promoter hypermethylation can be detected not only in colorectal polyps and cancers, but also in sera and stool, hypermethylated genes may serve as molecular markers for early detection, risk assessment and diagnosis. In addition, silenced genes caused by CGI DNA promoter hypermethylation can be reactivated by demethylating agents and also by both the inhibitors of DNA methyltransferases and histone deacetylases. Therefore, these epigenetically acting drugs should be evaluated for their chemopreventive and therapeutic potential for colorectal cancers.

Usefulness of expression of protease as biologic marker in 5-FU resistant human colon cancer cell line HT29 / 대한내과학회지

There have been many reports that colon cancer responds poorly to chemotherapy. Several classes of matrix metalloproteinases(MMPs) have been implicated in the process of invasion of epithelial and endothelial basement membranes in several steps of tumor invasion and metastasis. This study was performed to determine the biologic behavior and the histopathological characteristics of a 5-FU resistant colon cancer cell line. METHODS: We performed several biologic assays including liver colonization assay, cell adhesion assay, invasion assay and zymogram for protease activity using parental HT29 cell and 5-FU resistant HT29 cell (HT29-FU cell). RESULTS: In liver colonization assay, HT29-FU cell revealed a 2.5-fold increase in the liver weight and tumor burden compared with HT29 cell. HT29-FU cell showed moderate increase in adhesion and invasion assays in comparison to HT29 cell. HT29-FU cell revealed increased activity of MMPs and serine protease. Xenograft tumors of HT29-FU cell formed moderately differentiated adenocarcinoma with more glandular formations of mucin. CONCLUSION: The increased expression of MMPs in 5-FU resistant colon cancer cell can explain poor prognosis. These are potentially poor prognostic indicators in 5-FU resistant colon cancer. Consequently, it can be suggested that modulation of MMPs is needed to prevent invasion and metastasis in colon cancer by using inhibitors of these enzymes.

Differential Mucin Gene Expression Associated with Methotrexate Resistance of Human Colonic Adenocarcinoma Cell Line, HT29 / 대한암학회지

PURPOSE: In normal tissue, MUC2 mucin gene is expressed predominantly in goblet cells, while MUC3 is expressed in both goblet cells and columnar absorptive cells of small intestine and colon. MUC5 mucin genes are expressed predominantly in the surface epithelial cells, while MUC6 is expressed mainly in the mucus neck cells of gastric glands and pyloric glands of stomach. In this paper, we determined any changes of mucin in drug-resistant cell lines from those parental cells, and we evaluated the altered regulation of mucin production in drug-resistant cells. MATERIALS AND METHODS: In the study of 17 day postconfluent parental HT29 (HT29) and methotrexate-resistant HT29 (HT29-MTX) colon cancer cell lines were examined for the expression of MUC2, 3, 5 and 6 mucin polypeptide (apomucin) by Northern blot and slot blot analysis, and also by immunoblot analysis. RESULTS: The level of MUC2 expression was unchanged, while there was increase in MUC3 expression in HT29-MTX compared to HT29. Interestingly there was a marked increase in the expression of MUC5 mRNA in HT29-MTX. The densitometric readings expressed as HT29-MTX/HT29 at 17th day after the cells were confluent are MUC2 (1.1), MUC3 (1.3), MUC5 (>70), MUC6 (1.0) with RNA slot blot. Immunoblot analysis was consistent with these data. CONCLUSION: Marked induction in MUC5 but not MUC6 gastric mucin gene was found in MTX resistance in HT29 colon cancer cells. The possible biological consequences of altered regulation of mucin genes in drug resistant colon cancer cells require further investigation.