Qom University of Medical Sciences Journal

The liver plays an important role in many physiological processes such as glucose homeostasis, production of essential proteins, production of lipoproteins and lipids, production and secretion of bile acids, and vitamin storage. Oxidative stress is a major risk factor for liver diseases. For this reason, inhibition of oxidation and inflammatory processes by antioxidants plays an important role in preventing or treating liver diseases. Most toxic chemicals cause damage to liver cells by inducing lipid peroxidation and other oxidative effects. Ethylene glycol maybe accidentally ingested, especially by children, due to its sweet taste, or intentionally consumed by adults as an alternative to ethanol or be used for suicide. Although ethylene glycol toxicity is not common, it can have high morbidity and mortality. Nuclear factor kappa B (NF-κB) is a transcription factor and a regulator of innate immunity. The NF-κB signaling pathway links pathogenic signals to cellular danger signals, thus organizing cellular resistance against invading pathogens. NF-κB plays an important role in regulating the expression of genes whose products are involved in tissue damage and inflammation and, therefore, may be detectable as early biomarkers in chemical poisoning.
Myeloperoxidase (MPO) is one of the main components of azurophilic granules in neutrophil granulocytes. The antimicrobial activity of MPO is due to its enzymatic function to produce hypochlorous acid and other toxic oxygen products. It generates reactive oxygen species (ROS) which are involved in processes leading to tissue damage. Hypochlorous acid is an oxidizer of sulfhydryl and thioether groups of proteins. The MPO products are also involved in lipid peroxidation. Accumulation of hydroperoxides that accumulate in lipid compounds strengthens the function of hypochlorous acid. Antioxidants reduce the effects of toxic agents on the liver. Natural antioxidants in many compounds are classified as secondary metabolites. Polyphenols (phenolic acids and flavonoids) and terpenoids (carotenoids) and foods containing these compounds in large amounts play a role in preventing many diseases. Melon (Cucumis melo var. inodorus) has many vitamins A and C and cellulose. Melon has diuretic effects. In this regard, it is effective in removing waste materials and urinary sediments. Melon seeds and peels are usually discarded, while the extracts obtained the seeds have significant antioxidant effects. Considering the antioxidant effects of melon, the present study aims to evaluate the effect of hydroalcoholic extract of melon seeds on the transcription of genes encoding NF-κB and the MPO expression level in male laboratory rats poisoned with ethylene glycol.
Methods
Melon seeds were dried in the shade at a room temperature. Then, the seeds were powdered and hydroethanolic extract was prepared by soaking method. Thirty male Wistar rats weighing 180±20 g were randomly divided into five groups of 6 including healthy control, poisoned control (0.75% ethylene glycol) and three melon extract-treated poisoned groups (0.75% ethylene glycol and 150, 300 and 600 mg/kg body weight of hydroethanolic extract of melon seeds orally) for 38 days. After the treatment period, the rats were first anesthetized using ether and their liver was removed for evaluating the transcription level of genes encoding NF-κB and MPO. The RNA extraction and cDNA synthesis from liver tissue was done using GeneAll kit made in Korea. Transcription level of genes was assessed with real-time PCR technique. The difference between groups was examined using One-way analysis of variance (ANOVA) and t-test.
Results
The performance of the designed primers and the conditions of PCR, the PCR product was evaluated using and agarose gel electrophoresis (1.5%) method. The presence of a single band within the expected range and absence of additional bands indicated the optimal performance of the primers and the conditions of PCR. The results showed that the daily oral ethylene glycol administration significantly increased the expression of the NF-κB encoding gene in the liver tissue of the poisoned groups compared to the healthy control group (P<0.001). Treatment by hydroethanolic extract of melon seeds at concentrations of 300 and 600 mg/kg/body weight caused a significant decrease in the expression of NF-κB encoding gene compared to the poisoned control group. In addition, the ethylene glycol administration caused a significant increase in the MPO gene expression in the poisoned control group compared to the healthy control group (P< 0.001). Treatment by hydroethanolic extract of melon seeds at concentrations of 150, 300 and 600 mg/kg of body weight caused a significant decrease in MPO gene expression compared to the poisoned control group (P< 0.001).
Discussion
The consumption of hydroethanolic extract of melon seeds can reduce the expression level of MPO and NF-κB encoding genes in the liver poisoned by ethylene glycol. Therefore, the hydroethanolic extract of melon seeds has therapeutic and protective effects against ethylene glycol poisoning.
Ethical Considerations
Compliance with ethical guidelines
All stages of animal experiments were carried out after receiving the required permission (Code: IR.IAU.VARAMIN.REC.1399.016) and under the supervision of the National Ethics Committee in Biomedical Research.
Funding
The paper was extracted from the MSc. thesis of the Mohamad-Reza Forouharmanesh, Department of genetic, College of Biological science, Varamin-Pishva Branch of Islamic Azad University.
Authors contributions
Conceptualization, Methodology, Investigation and Supervision: Mehdi Ebrahimi and Maryam Eidi; Writing–Original Draft, Mohamad-Reza Forouharmanesh; Writing–Review & Editing: Mehdi Ebrahimi; Funding Acquisition: Mohamad-Reza Forouharmanesh; Resources: all authors;
Conflicts of interest
The authors declared no conflict of interest.
Acknowledgements
We would like to thank the College of Biological science, Varamin-Pishva Branch of Islamic Azad University, for their help with data collection.