Effects of Chromium VI stress on green alga Ulva lactuca (L.) [Yeşil Alg Ulva lactuca (L.) üzerinde krom (VI) Stresinin Etkileri]

In order to contribute to the understanding of its response to metal stress, Ulva lactuca (L.) was treated with different concentration of chromium (VI) (0.2, 0.5, 1, and 5 mM K2CrO4), and alterations in Fv/Fm ratio (maximal photochemical efficiency of PSII) and cell viability were investigated. Significant alterations of the maximal photochemical efficiency of PSII (Fv/Fm) ratio were observed in response to the increase in chromium concentration. The Fv/Fm ratio decreased in Ulva lactuca following 2 h treatment with 1 and 5 mM Cr(VI) solution. The cell viability was decreased in cells exposed to higher Cr(VI) concentrations. Thallus cell morphology was altered in thalli exposed to chromium. A cytotoxic effect of chromium was demonstrated for the first time using acridine orange/ethidium bromide staining in macroalgae. In 1 and 5 mM of Cr(VI) treated samples, the rate of necrotic cells increased about 76.93% and 84.23%, respectively. © TÜBİTAK

Green synthesis of Ag-ZnO nanocomposites by using Usnea florida and Pseudevernia furfuracea lichen extracts and evaluation of their neurotoxic effects

© 2022 Taylor & Francis Group, LLC.First time in this study, neuroprotective or neurotoxic effects of Pseudevernia furfuracea and Usnea florida lichen extracts based silver decorated zinc oxide nanocomposites (Ag-ZnO NCs) were evaluated. The characteristic light absorption point of P. furfuracea and U. florida based Ag-ZnO NCs were observed at 339 nm and 361 nm; effective diameter was detected at 342 nm and 495 nm. According to SEM analysis, the diameter of P. furfuracea and U. florida extract based NCs were approximately 35 nm and 85 nm, respectively. When we examined the toxicity of SH-SY5Y against human neuroblastoma cells, it was observed that NCs have neurotoxic effects on a concentration of 100 μg/ml. In this study, it was predicted that P. furfuracea and U. florida extract based Ag-ZnO NCs could be used in cytotoxic studies by synthesizing them in a cheap, short time and with eco-friendly method