Effect of Lemongrass Essential Oil based Mouthwash against Microflora Associated with Dental Plaque

Mouthwash is one of the most convenient and effective method employed for dental plaque management. The aim of the undertaken study was to establish the antimicrobial and anti-biofilm properties of lemongrass essential oil (LGEO) based mouthwash on microbial flora from dental plaque and also check cytotoxicity of mouthwash formulation. Five main colonizers of dental plaque representing dental microflora and three different bacterial species mainly responsible for the formation of biofilm were selected in this study. LGEO based mouthwash was developed and its stability was also determined. The antimicrobial and anti-biofilm activity of LGEO based mouthwash has been evaluated against the representative dental microflora as per CLSI guidelines. Cytotoxicity of mouthwash was checked by globally used MTT assay employing NIH 3T3 mouse fibroblast cell line. The mouthwash has been found to exhibit the stability in its major component, citral and also found exhibit antimicrobial and anti-biofilm activity against dental microflora. No cytotoxic effect was observed on mouse fibroblast cell line. LGEO in formulated mouthwash being a natural, herbal material isolated from traditional medicinal plants appears as a good and effective substitute to control the microflora linked with dental plaque.

Synthesis of the Macrolactone Cores of Maltepolides via a Diene–Ene Ring-Closing Metathesis Strategy

Synthesis of the C19-truncated maltepolide E has been accomplished via a diene–ene RCM strategy without damage to the C11–C14 alkenyl epoxy unit. Upon release of the C17-OH group, it attacked at the C14 position with double bond migration and epoxide ring-opening to furnish the C19-truncated maltepolide A and B as proposed for the biosynthesis of maltepolides. Preliminary cytotoxicity data of the synthesized C19-truncated maltepolides against L929 mouse fibroblast cell line suggest irrelevance of the vinyl epoxide and importance of the conjugated dienyl keto unit for the observed anticancer activity.

Cytotoxicity and Morphological Effects of Aqueous Areca Nut Crude Extract on L929 Fibroblast Cell Line

Betel quid chewing is a detrimental recreational habit amongst Asians and a risk factor for oral cancer. Arecoline, a component of areca nut (a major constituent of betel quid) is a known carcinogen. However, the effect of areca nut crude extract is not much studied. To evaluate the cytotoxicity and morphologic effects of areca nut aqueous extract on mouse fibroblast cell line (L929). Dried raw areca nut obtained from a local market in Kota Bharu, Kelantan was prepared and suspended in DMEM (Dulbecco’s Modified Eagle’s medium), prior to serial dilution of 1.56, 0.781, 0.39, 0.195, 0.0976, 0.0488, and 0.0244 mg/ml. The L929 was then exposed to each of the aqueous areca nut extract dilutions and incubated at 37 °C for 24, 48 and 72 hours. Following incubation, the cytotoxicity level of treated L929 was measured using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium] assay. Five highest concentrations of areca nut extract showed significantly decreased L929 cell viability (1.56, 0.781, 0.39, 0.195, 0.0976 mg/ml) for all incubation periods compared to untreated cells (p<0.05). The IC50 values of aqueous areca nut extract on L929 were 0.1516, 0.1040, and 0.09136 mg/ml at 24, 48 and 72 hours, respectively. The L929 cell showed altered morphology when cultured in the extract for 24 hours. Higher concentrations of the areca nut aqueous extract is cytotoxic to L929. Prolonged exposure to the extract reduced the IC50 value. Investigation on the role of areca nut in cell proliferation could be further undertaken to assess its association with oral cancer. Keywords: areca nut, L929, mouse fibroblast cell line, cytotoxicity, MTT assay

Development of Bionanocomposites Based on PLA, Collagen and AgNPs and Characterization of Their Stability and In Vitro Biocompatibility

Bionanocomposites including poly(lactic acid) (PLA), collagen, and silver nanoparticles (AgNPs) were prepared as biocompatible and stable films. Thermal properties of the PLA-based bionanocomposites indicated an increase in the crystallinity of PLA plasticized due to a small quantity of AgNPs. The results on the stability study indicate the promising contribution of the AgNPs on the durability of PLA-based bionanocomposites. In vitro biocompatibility conducted on the mouse fibroblast cell line NCTC, clone 929, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed high values of cell viability (>80%) after cell cultivation in the presence of bionanocomposite formulations for 48 h, while the percentages of lactate dehydrogenase (LDH) released in the culture medium were reduced (<15%), indicating no damages of the cell membranes. In addition, cell cycle analysis assessed by flow cytometry indicated that all tested bionanocomposites did not affect cell proliferation and maintained the normal growth rate of cells. The obtained results recommend the potential use of PLA-based bionanocomposites for biomedical coatings.

Primary Human Hepatocytes, But not HepG2 or Balb/c 3T3 Cells, Efficiently Metabolize Salinomycin and Are Resistant to Its Cytotoxicity

Salinomycin is a polyether antibiotic showing anticancer activity. There are many reports of its toxicity to animals but little is known about the potential adverse effects in humans. The action of the drug may be connected to its metabolism. That is why we investigated the cytotoxicity of salinomycin and pathways of its biotransformation using human primary hepatocytes, human hepatoma cells (HepG2), and the mouse fibroblast cell line (Balb/c 3T3). The cytotoxicity of salinomycin was time-dependent, concentration-dependent, and cell-dependent with primary hepatocytes being the most resistant. Among the studied models, primary hepatocytes were the only ones to efficiently metabolize salinomycin but even they were saturated at higher concentrations. The main route of biotransformation was monooxygenation leading to the formation of monohydroxysalinomycin, dihydroxysalinomycin, and trihydroxysalinomycin. Tiamulin, which is a known inhibitor of CYP450 izoenzymes, synergistically induced cytotoxicity of salinomycin in all cell types, including non-metabolising fibroblasts. Therefore, the pharmacokinetic interaction cannot fully explain tiamulin impact on salinomycin toxicity.

Synthesis, Spectroscopic Analysis and Assessment of the Biological Activity of New Hydrazine and Hydrazide Derivatives of 3-Formylchromone

The hydrazine and hydrazide derivatives of benzo-γ-pyrones with fluorine substituents remain an unexplored group of chemical compounds. This preliminary study reports the synthesis, structural assessment, initial microbiological screening and biological testing of the synthesized compounds on cell lines using the XTT-assay. A series of 10 novel hydrazine and hydrazide derivatives of 3-formylchromone were synthesized and their structures determined. Structural assessment consisted of elemental analysis, IR, 1H-NMR, 13C-NMR, MS and crystallographic studies. Antimicrobial activity was tested on standard strains representing different groups of microorganisms. The tested compounds were found to inhibit microbial growth. Concentrations of 0.01–1250 µmol/L were found to influence cell proliferation, demonstrating antiproliferative and stimulation of proliferation against two cell lines: the L929 cell line (mouse fibroblast cell line) and the EA.hy926 cell line (the human umbilical vein, somatic cell hybrid).