Evaluation of Anticancer Activity of Satureja montana Supercritical and Spray-Dried Extracts on Ehrlich's Ascites Carcinoma Bearing Mice
PLANTS-BASEL
Authors: Vladic, Jelena; Cebovic, Tatjana; Vidovic, Senka; Jokic, Stela
Abstract
Satureja montana herbal species belongs to aromatic medicinal plants with a significant place in traditional medicine. However, products produced with conventional procedures do not meet the requirements of the modern market which include environmentally-safe processes that provide quality, safe, and standardized products. In this study, the antiproliferative activity of S. montana extracts obtained by supercritical carbon dioxide and solid-liquid extraction followed by spray drying was investigated using the in vivo model of Ehrlich ascites carcinoma (EAC) in mice. The impact of two concentrations of extracts on the growth of tumor and the redox status of malignant cells was monitored. It was determined that the extracts induced oxidative stress in the malignant cells which was confirmed by the changes in activity of biochemical indicators of oxidative stress. The posttreatment was not an efficient approach, while the extracts applied as pretreatment and treatment resulted in an increase in the xanthine oxidase (XOD) activity, a decrease in catalase (CAT) activity, and an increase in the intensity of lipid peroxidation (LPx). Furthermore, a decrease in the values of reduced glutathione (GSH) and an increase in glutathione reductase (GR) and glutathione peroxidase (GSHPx) in EAC cells were recorded.
Transparent Cobalt Selenide/Graphene Counter Electrode for Efficient Dye-Sensitized Solar Cells with Co2+/(3+)-Based Redox Couple
ACS APPLIED MATERIALS & INTERFACES
Authors: Peng, Jia-De; Wu, Yu-Ting; Yeh, Min-Hsin; Kuo, Fang-Yu; Vittal, R.; Ho, Kuo-Chuan
Abstract
In this study, we demonstrate a facile, one-pot, and low-temperature (similar to 85 degrees C) chemical bath method for the preparation of a composite of cobalt selenide/graphene (Co0.85Se/Gr) as the electrocatalyst for the counter electrode (CE) of dye-sensitized solar cells (DSSCs) with a cobalt-based electrolyte. The Co0.85Se/Gr composite film was envisaged to have the advantages of both components, that is, the high electrochemical surface area of Co0.85Se and the straight paths for electron transfer from Gr. The DSSCs with Co0.85Se/Gr exhibited a power conversion efficiency (eta) of 11.26%. According to the results of the rotating disk electrode, the film of Co0.85Se/Gr showed a high electrocatalytic surface area (A(e)) and an extremely large intrinsic heterogeneous rate constant (k(0)). Furthermore, the composite film of Co0.85Se/Gr exhibits a high transparency in the wavelength region of 400800 nm (>82%), which implied that the corresponding electrode shall be a potential CE in rear-side illuminated DSSCs. The photovoltaic parameters of the DSSCs with Pt, Co0.85Se, Gr, and Co0.85Se/Gr were obtained for rear-side illumination and additionally for front- and rear-side illuminations (AM 1.5, 100 mW/cm(2)) using different electrolytes. As the cobalt-based electrolyte of [Co(bpy)(3)](2+/3+) exhibited a low light absorption and low overpotential for dye regeneration, a rear-side illuminated DSSC with a cobalt-based electrolyte showed the highest efficiency of 9.43 +/- 0.02%, which is greater than that of the DSSC with an I-/I-3(-) based electrolyte (eta = 7.63 +/- 0.04%).