Još o toksičnosti kadmija - s posebnim osvrtom na nastanak oksidacijskoga stresa i na interakcije s cinkom i magnezijem

Discovered in late 1817, cadmium is currently one of the most important occupational and environmental pollutants. It is associated with renal, neurological, skeletal and other toxic effects, including reproductive toxicity, genotoxicity, and carcinogenicity. There is still much to find out about its mechanisms of action, biomarkers of critical effects, and ways to reduce health risks. At present, there is no clinically efficient agent to treat cadmium poisoning due to predominantly intracellular location of cadmium ions. This article gives a brief review of cadmium-induced oxidative stress and its interactions with essential elements zinc and magnesium as relevant mechanisms of cadmium toxicity. It draws on available literature data and our own results, which indicate that dietary supplementation of either essential element has beneficial effect under condition of cadmium exposure. We have also tackled the reasons why magnesium addition prevails over zinc and discussed the protective role of magnesium during cadmium exposure. These findings could help to solve the problem of prophylaxis and therapy of increased cadmium body burden.Iako je otkriven tek 1817. godine, kadmij je trenutačno jedan od najvažnijih onečišćivača životne i radne sredine. Štetno djeluje na bubrege, živčani sustav, kosti, reproduktivni sistem, a ima i genotoksične i karcinogene efekte. Nužna su dalja istraživanja vezana za mehanizme njegove toksičnosti, biomarkere efekata, kao i načine smanjenja rizika za zdravlje. Osim toga, do danas nije otkriven agens efikasan u terapiji trovanja kadmijem s obzirom na to da je kadmij intracelularni kation. U ovom radu dan je sažet pregled važnih mehanizama toksičnosti kadmija, kao što su nastanak oksidativnog stresa i interakcije s esencijalnim elementima, cinkom i magnezijem, na osnovi dostupnih literaturnih podataka, kao i naših ispitivanja koja upućuju na to da povećani unos navedenih esencijalnih elemenata pokazuje pozitivne efekte pri ekspoziciji kadmiju. Obrazložena je prednost suplementacije magnezijem pred suplementacijom cinkom i razmatrana preventivna uloga magnezija pri intoksikaciji kadmijem. Ovi su rezultati doprinos rješavanju problema profi lakse i terapije trovanja kadmijem

Physiological and cell ultrastructure disturbances in wheat seedlings generated by Chenopodium murale hairy root exudate.

Chenopodium murale L. is an invasive weed species significantly interfering with wheat crop. However, the complete nature of its allelopathic influence on crops is not yet fully understood. In the present study, the focus is made on establishing the relation between plant morphophysiological changes and oxidative stress, induced by allelopathic extract. Phytotoxic medium of C. murale hairy root clone R5 reduced the germination rate (24% less than control value) of wheat cv. Nataša seeds, as well as seedling growth, diminishing shoot and root length significantly, decreased total chlorophyll content, and induced abnormal root gravitropism. The R5 treatment caused cellular structural abnormalities, reflecting on the root and leaf cell shape and organization. These abnormalities mostly included the increased number of mitochondria and reorganization of the vacuolar compartment, changes in nucleus shape, and chloroplast organization and distribution. The most significant structural changes were observed in cell wall in the form of amoeboid protrusions and folds leading to its irregular shape. These structural alterations were accompanied by an oxidative stress in tissues of treated wheat seedlings, reflected as increased level of H2O2 and other ROS molecules, an increase of radical scavenging capacity and total phenolic content. Accordingly, the retardation of wheat seedling growth by C. murale allelochemicals may represent a consequence of complex activity involving both cell structure alteration and physiological processes.This is a post-peer-review, pre-copyedit version of an article published in Protoplasma. The final authenticated version is available online at: [http://dx.doi.org/10.1007/s00709-018-1250-0