Comparative evaluation of antiplaque and antigingivitis effects of an herbal and chlorine dioxide mouthwashes: A clinicomicrobiological study.

AIM: The aim of the present study was to compare the efficacy of herbal mouthwash and chlorine dioxide mouthwash in reduction of plaque and gingivitis. SETTINGS AND DESIGN: In a randomized clinical trial, forty patients were randomly selected and divided equally into two groups. MATERIALS AND METHODS: After professional oral prophylaxis, the clinical parameters plaque index, gingival index, and modified sulcular bleeding index were recorded at baseline, 7th day, 14th day, and 21st day. The plaque samples were collected from gingival sulcus with an absorbent sterile paper point and were stored in a thioglycollate broth, then sent for microbiological examination. The microbial colony-forming units were assessed at baseline, 7th day, 14th day, and 21st day for Streptococcus mutans, Tannerella forsythia, and Fusobacterium nucleatum. RESULTS: There was a statistical significant reduction in both clinical and microbiological parameters were observed with use of both the mouthwashes. However, herbal mouthwash was more effective in reducing the plaque and gingivitis than chlorine dioxide mouthwash. CONCLUSION: Herbal mouthwash was statistically efficacious in controlling plaque and gingivitis with potent antimicrobial activity.

Isolation and characterization of human gastric cell lines with stem cell phenotypes.

AIM: The aim of this study was to develop an in vitro human gastric stem and/or progenitor cell model that may be used to study the mechanism of gastric carcinogenesis induced by Helicobacter pylori infection. METHODS: Human gastric biopsy was minced and digested with collagenase and dispase and cultured in a low-calcium medium (serum-free keratinocyte medium; keratinocyte-SFM) supplemented with N-acetyl-L-cysteine and L-ascorbic acid 2-phosphate. Actively proliferating epithelial colonies with sustained growth were isolated and characterized for karyotype and phenotypes related to stem cell characteristics including proliferation and differentiation potential, ability of anchorage-independent growth (AIG), gap junctional intercellular communication (GJIC) and the expression of Oct-4, a transcription factor previously shown to be expressed in embryonic stem cells, adult stem cells and undifferentiated tumor cells. To study the carcinogenic effect of H. pylori infection, gastric stem and/or progenitor cells were incubated with H. pylori culture products and/or N-methyl-N-nitro-N-nitrosoguanidine (MNNG), a chemical carcinogen, to see the telomerase activation. RESULTS: Multiple cell lines with stem cell features were isolated by this new cell culture method. The results based on detailed characterization of one cell clone, KMU-GI2, revealed stem cell features of these cells. The initial clone contained mostly undifferentiated epithelial-like cells, which, upon subculture and propagation, gave rise to a heterogeneous cell population. Single cell-derived subclones, similar to the parental population, retained high differentiation potential and were capable of giving rise to many morphologically different cell types (i.e. epithelial-like, glial or neuron-like, round and various peculiar-shaped cells). Although these cells were normal in karyotype and competent in GJIC, they had the ability to grow in soft agar. Cells expressing epithelial membrane antigen (EMA), mucin 5AC, glial fibrillary acidic protein (GFAP), cytokeratin-18 (CK-18), trefoil factor 1 (TFF-1) and Oct-4 were found in the cell culture, but not E-cadherin-, gastrin- or telomerase-expressing cells. Furthermore, spontaneously immortalized non-tumorigenic clones could be derived from the cell population. After treating these cell cultures with the chemical carcinogen, MNNG and H. pylori culture products for 5 days, telomerase activity and telomerase mRNA expression were significantly elevated, while treatment with either of them showed no effect. CONCLUSION: The new cell culture method can be used to develop gastric epithelial cell clones with sustained growth from endoscopic biopsy. The gastric cell clone showed several stem and/or progenitor cell phenotypes (i.e. the ability of AIG, high differentiation capacity, high susceptibility to spontaneous immortalization and the expression of Oct-4). The telomerase expression in these gastric stem and/or progenitor cells can be upregulated by exposure to H. pylori culture products and MNNG, an important step in neoplastic transformation. These results show that putative human gastric stem and/or progenitor cell clones can be developed by our method and these cells could be useful for studying the mechanisms of human gastric carcinogenesis including the mechanism of action of H. pylori, as well as the regulation of the proliferation and differentiation of human gastric mucosa.

Petiveria alliacea L. extract protects mice against Listeria monocytogenes infection--effects on bone marrow progenitor cells.

In this study we have investigated the effects of Petiveria alliacea on the hematopoietic response of mice infected with Listeria monocytogenes. Our results demonstrate a protective effect of the crude extract of P. alliacea since the survival of the treated/infected was higher than that in the infected group. Moreover, the number of granulocyte/macrophage colonies (CFU-GM) and the serum colony stimulating activity levels were increased in the treated/infected mice in relation to the infected group. These results suggest an immunomodulation of Petiveria alliacea extract on hematopoiesis, which may be responsible, at least in part, for the increased resistance of mice to Listeria monocytogenes infection.