Graphene quantum dots protect SH-SY5Y neuronal cells from SNP-induced apoptotic death

Introduction: We examined the molecular mechanisms of graphene quantum dot (GQD)- mediated protection of SH-SY5Y human neuroblastoma cells from oxidative/nitrosative stress induced by iron-nitrosyl complex sodium nitroprusside (SNP). Methods: GQD was produced by electrochemical oxidation of graphite and characterized by AFM, UVVIS and FTIR spectroscopy. The antioxidant activity of GQD in cell-free conditions was assessed by DPPH, NBT and EPR analysis. The neuroprotective potential of GQD was determined by cell viability assays MTT, CV. Flow cytometry was used to assess markers of apoptosis and GQD scavenging of intracellular ROS/RNS as well. Cellular internalization of GQD was determined using TEM. Results: GQD prevented SNP-induced apoptosis, caspase activation and mitochondrial depolarization in neuroblastoma cells. Although GQD diminished the NO levels in SNP-treated cells, NO scavengers displayed only a slight protection. GQD significantly protected SH-SY5Y cells from neurotoxicity of lightexhausted SNP, incapable of producing NO, implying that protective mechanism is independent of NO-scavenging. GQD reduced SNP-triggered increase in intracellular levels of ROS, particularly •OH, O2•− in cells and cell-free condition. Nonselective antioxidants, •OH scavengers and iron chelators, mimicked GQD cytoprotection, indicating that GQD protect cells by neutralizing •OH generated in the Fenton reaction. Cellular GQD internalization was required for optimal protection since the removal of extracellular GQD by extensive washing partly diminished their protective effect, suggesting that GQD exerted neuroprotective effect intra- and extracellularly. Conclusion: By demonstrating that GQD protect neuroblastoma cells from SNP-induced apoptosis by •OH/NO scavenging, our results suggest that GQD could be valuable candidates for treatment of neurodegenerative diseases associated with oxidative/nitrosative stress

Uticaj načina združivanja useva na prinos nadzemne biomase i zrna kukuruza i soje

Kombinovanjem potencijala žita (kukuruza) i leguminoze (soje) uz primenu odgovarajućeg prostornog rasporeda dolazi do povećanja prinosa nadzemne biomase i zrna. Kukuruz ispoljava zavisnost od prostornog rasporeda i vrste hibrida, dajući veće prinose gajenjem u združenim usevima. Soja ispoljava zavisnost od prostornog rasporeda i dobre rezultate daje setvom u čistim usevima, pa je zato u združenim usevima pomoćni usev kukuruza. Na ovaj način se smanjuje količina utotrebljenog mineralnog đubriva i prisutnost korovskih vrsta na obradivim površinama. Ovakav način gazdovanja kombinuje elemente dobre poljoprivredne prakse sa visokim stepenom raznolikosti (biodiverziteta), uz očuvanje prirodnih resursa, i dobijanje poljoprivrednih proizvoda koji zadovoljavaju potreba kupaca

Profit from the rural tourism as a stimulus for the further development of agriculture

The aim of this paper is to raise awareness of agricultural producers to work with entrepreneurs who are engaged in tourism organization, with aim to achieve higher profts. Given that organic farming is based on application-specifc approach to organizing and producing agricultural products, tourism, as a suitable market for direct implementation products for consumption, as well as for presentation to the positive effects of nonpolluted environment can have on the health of the whole organism, through the introduction of various of sports and recreation, the combination of agriculture and tourism is essential. Various studies in this feld has shown that now we have a positive trend in the development of rural tourism in our country, which together with increased agricultural production and exports (which continues, a positive result), we can expect to increase the total gross income of Serbia

Graphene quantum dot antioxidant and proautophagic actions protect SH-SY5Y neuroblastoma cells from oxidative stress-mediated apoptotic death

We investigated the ability of graphene quantum dot (GQD) nanoparticles to protect SH-SY5Y human neuro blastoma cells from oxidative/nitrosative stress induced by iron-nitrosyl complex sodium nitroprusside (SNP). GQD reduced SNP cytotoxicity by preventing mitochondrial depolarization, caspase-2 activation, and subsequent apoptotic death. Although GQD diminished the levels of nitric oxide (NO) in SNP-exposed cells, NO scavengers displayed only a slight protective effect, suggesting that NO quenching was not the main protective mechanism of GQD. GQD also reduced SNP-triggered increase in the intracellular levels of hydroxyl radical ( • OH), superoxide anion (O2 •− ), and lipid peroxidation. Nonselective antioxidants, • OH scavenging, and iron chelators, but not superoxide dismutase, mimicked GQD cytoprotective activity, indicating that GQD protect cells by neutralizing • OH generated in the presence of SNP-released iron. Cellular internalization of GQD was required for optimal protection, since a removal of extracellular GQD by extensive washing only partly diminished their protective effect. Moreover, GQD cooperated with SNP to induce autophagy, as confirmed by the inhibition of autophagy limiting Akt/PRAS40/mTOR signaling and increase in autophagy gene transcription, protein levels of proauto phagic beclin-1 and LC3-II, formation of autophagic vesicles, and degradation of autophagic target p62. The antioxidant activity of GQD was not involved in autophagy induction, as antioxidants N-acetylcysteine and dimethyl sulfoxide failed to stimulate autophagy in SNP-exposed cells. Pharmacological inhibitors of early (wortmannin, 3-methyladenine) or late stages of autophagy (NH4Cl) efficiently reduced the protective effect of GQD. Therefore, the ability of GQD to prevent the in vitro neurotoxicity of SNP depends on both • OH/NO scavenging and induction of cytoprotective autophagy