Studies On The Toxicity Of Paracetamol With Superoxide Dismutase And Horseradish Peroxidase

Paracetamol is a kind of widely used antipyretic and analgesic of one non-prescription drug. It is quite safe to take paracetamol according to the standard dose, but long-term use, mixed-taking and taking after drink can result in hepatotoxicity and nepHrotoxicity. Recent researches on the toxicity of paracetamol are mostly concentrated in cell and animal experiments, metabolic processes and statistical analysis. However, there are few researchers concentrating on the toxicity of paracetamol at molecular level. Therefore, study on an effect on acetaminopHen toxicological of biological macromolecules in the body at the molecular level, not only perfection of its theoretical research, but also provides more basis for people to use medication more safely.Protein is an important part of the living body, and the enzyme protein is an important manifestation of those life activities, such as:superoxide dismutase is a class of widely exist in vivo oxidation of metal type reductase, the main role is to transfer and remove the body superoxide anion radicals produced during the oxidation process, it catalase and glutathione peroxidase constitute the three most important in vivo antioxidant enzyme together. Superoxide dismutase is a hot topic around the world; peroxidase enzyme is a kind of common protein in nature, depending on their origin can be divided into three categories, including animal peroxidase (GSH-Px enzyme), plant peroxidase (typically horseradish peroxidase HRP, etc.), fungal peroxidase (lignans peroxidase LiP, manganese peroxidase MnP), they are contained back iron porpHyrin heme protein active site, the catalytic reaction mechanism is similar. HRP which is one of the most extensively studied.In this paper, we studied the toxicity mechanism of paracetamol targeted to functional proteins at molecule level. According to the order of reaction between paracetamol and biomacromolecule in human body, we choose Superoxide dismutase (SOD) and horseradish peroxidase (HRP) as the target molecular and studied the toxic mechanism between paracetamol and protein. The dissertation consists of the following two parts.The first part is the introduction of the paper, which described acetaminopHen the the mian object of the article and overviewed the recent research progress at home and abroad. Then, superoxide dismutase and horseradish peroxidase were introduced and briefly overviewed in recent year all over the word. Meanwhile it summariezed the method and techniques used in this study. The important point is the content and the significance was presented at last.In the second part, the binding mechanism between paracetamol and superoxide dismutase was investigated using fluorescence spectroscopy, ultraviolet-visible (UV-Vis), circular dichroism (CD) spectroscopy and molecular docking. The thermodynamic parameters were calculated by fluorescence quenching to determine that the hydropHobic interactions play a major role in the formation of the superoxide dismutase-paracetamol system. According to the result of UV-Vis absorption spectra and CD spectra, the addition of paracetamol changed the microenvironment of superoxide dismutase and the content of a-helix was increased which induced protein skeleton changes in superoxide dismutase. With the addition of paracetamol to superoxide dismutase can cause an increased of the superoxide dismutase activity.In the third part, the binding mechanism between paracetamol and horseradish peroxidase was investigated using multi-spectroscopic techniques. The experimental results indicated that the quenching mechanism between paracetamol and HRP was static quenching process and HRP interactions play a major role in the formation of the horseradish peroxidase-paracetamol system. The UV-vis absorption, synchronous fluorescence and CD spectra results indicated that the microenvironment changes of horseradish peroxidase were induced by the binding paracetamol. The content of a-helix reduced and the backbone chain of horseradish peroxidase became looser.The results of our study indicate that after paracetamol came into the body, it lead to conformational change of the protein. This work can be a useful guideline for understand paracetamol molecular toxicity and provide support for its human health risk assessment.