Oxidative stress parameters in tobacco seedlings (Nicotiana tabacum) exposed to silver nanoparticles in combination with cysteine

Prethodna istraživanja pokazala su da nanočestično srebro (AgNP) može biti toksično za različite sudionike ekosistema, što posljedično može utjecati i na čovjeka. Cilj ovoga istraživanja bio je ispitati uzrokuju li AgNP stabilizirane polivinilpirolidonskom ovojnicom (AgNP-PVP) promjene u koncentraciji proteina i parametrima oksidacijskog stresa, malondialdehidu i proteinskim karbonilima u klijancima duhana (Nicotiana tabacum). Tražio se i odgovor na pitanje može li se potencijalno toksični učinak AgNP-PVP spriječiti dodatkom cisteina, dobrog kelatora otpuštenih iona srebra koji također mogu doprinjeti, ako dođe do njihovog oslobađanja, toksičnosti AgNP-PVP. Klijanci duhana bili su tjedan dana izloženi AgNP-PVP u koncentracijama 25, 50 i 100 μM. Dio klijanaca bio je izložen AgNP-PVP u kombinaciji s cisteinom (AgNP-PVP + cistein: 25 + 125 μM, 50 + 250 μM, 100 + 500 μM) te samom cisteinu u koncentracijama od 125, 250 i 500 μM. Jedan dio klijanaca bio je netretiran te je služio kao kontrola. Rezultati su pokazali kako parametri oksidacijskog stresa nisu značajno porasli nakon tretmana s AgNP-PVP-om. Također, značajnije razlike nakon tretmana s AgNP-PVP i AgNP-PVP u kombinaciji s cisteinom nije bilo. Iz dobivenih rezultata može se zaključiti kako u navedenim eksperimentalnim uvjetima (modelni organizam, koncentracija i dužina tretmana) AgNP-PVP nije uzrokovao oksidacijski stres. S obzirom da nije uočena razlika u tretmanu s AgNP-PVP i AgNP-PVP u kombinaciji s cisteinom, može se zaključiti da je PVP omotač taj koji doprinosi stabilnosti AgNP te da ne dolazi do otpuštanja iona srebra.Previous research has shown that silver nanoparticles (AgNP) can be toxic to various ecosystem participants, which can consequently affect humans as well. The aim of this study was to investigate whether polyvinylpyrrolidone coated AgNPs (AgNP-PVP) cause changes in the protein concentration and concentration of the oxidative stress parameters, malondialdehyde and protein carbonyls in tobacco seedlings (Nicotiana tabacum). The question whether the potentially toxic effect of AgNP-PVP could be prevented by the addition of cysteine, a good chelator of silver ions that, if released, also contribute to toxicity of AgNPPVP, was also posed. Tobacco seedlings were exposed to AgNP-PVP for one week at concentrations of 25, 50 and 100 μM. A part of the seedlings was exposed to AgNP-PVP in combination with cysteine (AgNP-PVP + cysteine: 25 + 125 μM, 50 + 250 μM, 100 + 500 μM) and cysteine alone at concentrations of 125, 250 and 500 μM. One part of the plants remained untreated, as a control group. The results showed that the parameters of oxidative stress did not significantly increase with AgNP-PVP treatment. Also, there were no significant differences after treatments with AgNP-PVP and AgNP-PVP in combination with cysteine. From the obtained results it can be concluded that under the mentioned experimental conditions (model organism, concentration and length of treatment) AgNP-PVP did not cause oxidative stress. Given that no difference was observed in the treatment with AgNP-PVP and AgNP-PVP in combination with cysteine, it can be concluded that PVP is a coating that contributes to the stability of AgNP and it prevents release of silver ions