H O can degrade haemoglobin to release Fe ions that

H2O2 can degrade haemoglobin, to release Fe2+ ions that can lead to erythrolysis. Azizova et al. [39] showed that erythrocyte membranes during atherosclerotic conditions are prone to lysis in the presence of oxidized LDL. We found that EOC could efficiently inhibit lipid peroxidation, which supports its potential to stabilize erythrocyte membranes thereby acts as an anti-inflammatory agent. The erythrocyte membrane resembles the lysosomal membrane and, as such, the effect of drugs on the stabilization of erythrocyte membrane could be extrapolated to the stabilization of lysosomal membrane [44]. Thus, EOC exerts its protective effect on the lysosomal membrane which could otherwise lead to oxidative stress induced cell death. OxLDL and H2O2 LDL induction lead to macrophage conversion and glycation of collagen which enhances the entrapment of LDL and its subsequent oxidative modification. Thus, there is a release of reactive oxygen intermediates associated with the formation. The increased LDH leakage induced by OxLDL and H2O2 LDL cytotoxicity increased the permeability of the cell. Arterial smooth muscle diazoxide modify LDL so that macrophages will take it up faster. The mechanism of LDL modification by cells involves lipid peroxidation. Lipid peroxidation was found to be increased upon OxLDL and H2O2 LDL induction. On treatment with C. citratus the levels were significantly reduced. This proves that C. citratus possesses strong anti-lipid peroxidation property [45]. Peroxidation of lipid is probably one of the important intermediary events in oxidative stress-induced cellular damage through the perturbation of cellular redox balance. It has been reported that lipid peroxidation is a persistent process in cells, maintained at basal level, by protective enzymes and antioxidants which prevent it from entering the autocatalytic phase [40]. Inhibition of oxidation of LDL due to the antioxidant potential of the EOC could prevent lipid accumulation within macrophage which in turn could inhibit atherosclerosis. Hishikawa et al. [41] suggested that the antioxidant activities of many polyphenols are responsible for their protection against atherosclerosis. Figueirinha et al. [4], suggested that the anti-inflammatory activity of C. citratus extract is due to its inhibition of NO production and iNOS expression in dendritic cells. Nitric oxide production was independent of the concentration of exogenous L-arginine. In the present study, nitric oxide production and respiratory burst activity were inhibited by EOC. This supports the subsequent depolarization of the plasma membrane, which may lead to the impairment of intracellular signalling steps required for macrophage activation. To conclude, our finding has excavated knowledge on drug formulation of C. citratus which exhibits negligible cytotoxic effect on normal cells and demonstrates antioxidant properties as evidenced from in vitro antioxidant assessment, has anti-inflammatory properties as evidenced by the inhibition of hemolysis of erythrocytes and exhibited cytoprotective properties, when added to PBMC induced with OxLDL and H2O2 LDL. Thus, EOC showed differential response against deleterious action of ROS, suggesting that this can be validated as a therapeutic and preventive agent against coronary artery diseases.
Introduction Presently, extensive studies have been carried out to improve the detection limit of existing sensing protocols in the field of analytical science [1–3]. For example, enzymatic catalysis reactions and in vitro nucleic acid amplification techniques have been widely integrated with conventional detection protocols to improve the sensitivity [4–7]. Meanwhile, due to the intrinsic advantages of nanomaterials, various functional nanoparticles have also been adopted for signal amplification [8–10]. As one of the most classic and efficient techniques, electrochemical biosensors have attracted extraordinary attention since the successful commercialization of the personal glucose meter [11–13]. Furthermore, with the occurrence of aptamers as the recognition probes, the electrochemical aptasensors have been further widely utilized for rapid and sensitive detections in many significant fields [7,14–16]. As mentioned, extensive researches have been executed to improve sensing performances especially detection limit of electrochemical biosensors [4,7,16–18]. However, from the perspective of practical applications, not only the detection limit, but also the dynamic sensing range of methods plays equally significant roles. And previous studies have clearly demonstrated that fixed dynamic range greatly restricts the performance of the electrochemical biosensors in many applications such as the monitoring of viral loading, in which the concentration of the target could vary over many orders of magnitude [19].