Cytotoxic and genotoxic properties of silver nanoparticles synthesized by ethanolic extract of Salacia chinensis

In this study, in vitro and in vivo methods were used to evaluate the cytotoxicity and genotoxicity properties of silver nanoparticles (Ag-NPs) made from a crude ethanolic extract of Salacia chinensis. The test Ag-NPs had no cytotoxicity on the fibroblast cell line at a concentration of 100 μg/mL, according to the MTT assay results. The Chinese hamster ovary (CHO) cell line treated with varied concentrations of test Ag-NPs, with a maximum concentration of 200 μg/mL, did not exhibit any appreciable genotoxic activity, either by comparing the results with positive controls of genotoxicity caused by Methyl methane sulfonate and Benzo (a) pyrene at the concentration of 20 μg/mL, the lack of genotoxicity was established. An in vivo study in Swiss albino mice using various concentrations (250, 500, and 1000 mg/kg) of test Ag-NPs, which were compared with positive controls, further confirmed this in vitro result pattern. Contrary to the genotoxicity caused by the positive control, mouse bone marrow micronucleus testing findings revealed the absence of genotoxicity. These findings imply that at the measured doses, the Ag-NPs produced from the crude ethanolic extract of Salacia chinensis do not exhibit any cytotoxicity or genotoxicity.

Establishment and characterization of a fibroblast cell line from postmortem skin of an adult Chinese muntjac (Muntiacus reevesi)

Isolation and culture of somatic cells from animals especially endangered species have raised great concerns as it is being an effective and convenient way to preserve genetic materials for future studies. As a species native to China, Chinese muntjac (Muntiacus reevesi) is listed as a beneficial species with economic and scientific research values. To our knowledge, however, there have been no published reports on somatic cell preservation of this species to date. To conserve biological resources for sustainability of Chinese muntjacs' genetic diversity, we established a fibroblast cell line from the postmortem ear skin of an adult male Chinese muntjac. The cultured cells were adherent to the plastic and showed an elongated, thin, and spindle-like shape. Moreover, they were FSP1- and VIM-positive characterizing them to be fibroblastic. No microorganisms (bacteria, fungi, or mycoplasmas) were detected throughout the whole study. Cell viability was high although it declined somehow after passaging. The population doubling time was 21.28 h according to the growth curve. Chromosome analysis revealed that the established fibroblast cell line contained 23 pairs of chromosomes, one pair of which was sex chromosomes (XY). Mitochondrial cytochrome C oxidase I gene of cultured cells shared 98.32% identity with those of Muntiacus reevesi registered in GenBank, which verified the cell line was derived from Muntiacus reevesi. In conclusion, we propagated and characterized fibroblast cells from a Chinese muntjac. We believe that this somatic cell line could facilitate animal cloning and breeding studies and become a useful in vitro model to address genetic questions.

Establishment and characterization of Caspian horse fibroblast cell bank in Iran

Caspian horse, a rare horse breed found in 1965 by Louise Firouz in northern Iran, is a small horse which is reported to be in danger of extinction in its original homeland. There seems to be a great need to prevent extinction of this valuable horse. In this study, 51 fibroblast cell lines from Caspian horse ear marginal tissue were successfully established by sampling 60 horses using primary explant technique. Cells were authenticated and growth curve was plotted. According to results obtained, population doubling time (PDT) was calculated 23 ± 0.5 h for all cell lines. Multiplex polymerase chain reaction (multiplex PCR) revealed that cell lines had no cross-contamination with other species. Bacteria, fungi, and mycoplasma contamination were checked using standard methods such as PCR, direct culture, and Hoechst staining. In addition to providing a valuable source for genomic, postgenomic, and somatic cloning researches, the established cell lines would preserve Caspian horse genetic resources. It will also create an accessible database for researchers.

Establishment and genetic characteristics analysis of in vitro culture a fibroblast cell line derived from Wuzhishan miniature pig

Establishment of fibroblast cell lines of endangered pig breeds and research on the gene functions based on the cells made a significant contribution to the conservation and utilization of genetic resources. The Wuzhishan miniature pig ear marginal tissue fibroblast cell line (WPF22) from 22 samples, stocking 87 cryogenically-preserved vials, was successfully established by using primary explants technique and cell cryopreservation techniques. WPF22 cells were adherent, with a population doubling time of 30.2h. Chromosome karyotyping and G-banding analysis showed that >90.2% of cells were diploid (2n=38) prior to the 4th generation. Neither microbial contamination nor cross-contamination was detected by isoenzyme analyses. Cell viability was 97.8% before cryopreservation and 94.9% after recovery. To determine cell permeability, intracellular path and stability of exogenous proteins during the transduction, six fluorescent protein genes were transferred into fibroblasts by lipofectamine-mediated method. The transfection efficiency of six fluorescent protein genes fluctuated between 8.1% and 42.6%. ECFP and DsRed were mostly shown in cytoplasmic in dots around the nucleus, and EYFP and EGFP had a slightly stronger expression in the nucleus than in the cytoplasm, but without expression in some vacuoles. Every index of the WPF22 cell line meets all the standard quality controls of American type Culture Collection (ATCC). This research thus does not only preserve important genetic resources of Wuzhishan miniature pig at the cell level, but also serve as a valuable resource for genome, postgenome and somacloning research.

Construction of cDNA library and preliminary analysis of expressed sequence tags from Siberian tiger

In this study we successfully constructed a full-length cDNA library from Siberian tiger, Panthera tigris altaica, the most well-known wild Animal. Total RNA was extracted from cultured Siberian tiger fibroblasts in vitro. The titers of primary and amplified libraries were 1.30×10⁶ pfu/ml and 1.62×10⁹ pfu/ml respectively. The proportion of recombinants from unamplified library was 90.5% and average length of exogenous inserts was 1.13 kb. A total of 282 individual ESTs with sizes ranging from 328 to 1,142bps were then analyzed the BLASTX score revealed that 53.9% of the sequences were classified as strong match, 38.6% as nominal and 7.4% as weak match. 28.0% of them were found to be related to enzyme/catalytic protein, 20.9% ESTs to metabolism, 13.1% ESTs to transport, 12.1% ESTs to signal transducer/cell communication, 9.9% ESTs to structure protein, 3.9% ESTs to immunity protein/defense metabolism, 3.2% ESTs to cell cycle, and 8.9 ESTs classified as novel genes. These results demonstrated that the reliability and representativeness of the cDNA library attained to the requirements of a standard cDNA library. This library provided a useful platform for the functional genomic research of Siberian tigers.