Hexavalent chromium induces expression of mesenchymal and stem cell markers in renal epithelial cells.

Cr(VI) causes severe kidney damage. The patient's renal function could gradually recover by spontaneous kidney regeneration. The molecular effect of Cr(VI) on recovery of kidney cells, however, has not been clearly elucidated. Here we show that Cr(VI) induces expression of mesenchymal and stem cell markers, cell markers, such as paxillin, vimentin, α-SMA, nanog, and CD133 of HK-2 cells. Moreover, Cr(VI) activates epithelial-to-mesenchymal transition (EMT). By revealing that levels of dihydrodiol dehydrogenase were promptly reduced following Cr(VI) challenge, our data suggested that DDH could be involved in a Cr(VI)-related oxidation to generate massive reactive oxygen species and H2 O2 , and to create intracellular hypoxia, which then increased levels of SUMO-1 activating enzyme subunit 2, and sumoylation of eukaryotic elongation factor-2, to mediate the subsequent molecular and cellular responses, e.g., expression of mesenchymal and stem cell markers. Pretreatment with vitamin C reduced Cr(VI)-related cellular effects. However, no evident effect was observed when vitamin C was added following Cr(VI) challenge.

Antioxidant and anticancer aporphine alkaloids from the leaves of Nelumbo nucifera Gaertn. cv. Rosa-plena.

Fifteen compounds were extracted and purified from the leaves of Nelumbo nucifera Gaertn. cv. Rosa-plena. These compounds include liriodenine (1), lysicamine (2), (-)-anonaine (3), (-)-asimilobine (4), (-)-caaverine (5), (-)-N-methylasimilobine (6), (-)-nuciferine (7), (-)-nornuciferine (8), (-)-roemerine (9), 7-hydroxydehydronuciferine (10) cepharadione B (11), ß-sitostenone (12), stigmasta-4,22-dien-3-one (13) and two chlorophylls: pheophytin-a (14) and aristophyll-C (15). The anti-oxidation activity of the compounds was examined by antiradical scavenging, metal chelating and ferric reducing power assays. The results have shown that these compounds have antioxidative activity. The study has also examined the antiproliferation activity of the isolated compounds against human melanoma, prostate and gastric cancer cells. The results shown that 7-hydroxydehydronuciferine (10) significantly inhibited the proliferation of melanoma, prostate and gastric cancer cells. Together, these findings suggest that leaves of Nelumbo nucifera Gaertn. cv. Rosa-plena are a good resource for obtaining the biologically active substances with antioxidant properties.

Biofunctional constituents from Liriodendron tulipifera with antioxidants and anti-melanogenic properties.

From the stems of Liriodendron tulipifera, seventeen known compounds have been extracted, isolated and purified. By using spectroscopic analysis, the structures of these pure constituents were determined as three lignans, four steroids and ten benzenoids. Identified compounds were screened for antioxidant abilities using: 1,1-diphenyl-2-picrylhydrazul (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging free radical activity assays; metal chelating power test; and ferric reducing/antioxidant power (FRAP) examination. The result revealed that seventeen compounds had potential anti-oxidative capabilities. In addition, the anti-tyrosinase effect was determined by calculating the hydroxylation of L-tyrosine to L-dopa and the oxidization of L-dopa to dopaquinone, according to in vitro mushroom tyrosinase evaluation platform. Furthermore, based on assays on B16F10 cell line, our data suggest that five compounds isolated from L. tulipifera would be able to inhibit tyrosinase activity and reduce the melanin content in animal cells. Therefore, some of the examined compounds could be potentially used in the cosmetic skin whitening business, therapeutic applications or the food industry.

Cancer cell identification by bi-color ZnO and TiO2 nanowires.

Semiconductor nanocomposites provide advantages beyond the capability of typical fluorescent materials for cancer detection. In this work, nanowire-based probes with dual color channels are employed to demonstrate the capacity of cancer cell detection. Purple emitting ZnO/antibody probes are applied to detect cancer cells and meanwhile TiO2 /antibody probes with green light emission are applied to identify normal fibroblast cells. A series of quantitative analyses are conducted to verify the correlation between the concentrations of ZnO and TiO2 probes, cell numbers, and peak intensities of the PL spectra. The results provide a quantitative reference for developing nanowire-based cancel cell probes.

Alkaloids from Cinnamomum philippinense.

A new pyridine, 2-(4'-hydroxypyridin-3'-yl)-acetic acid (1), along with five known alkaloids, cinnaretamine (2), crykonisine (3), corydaldine (4), glaziovine (5) and zenkerine (6), were isolated from the roots of Cinnamomum philippinense (Lauraceae). Their structures were characterized and identified by spectral analysis.