Browsing by Author "Rezk, Ahmed"

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    Enhancement of Vitamin C’s Protective Effect against ThimerosalInduced Neurotoxicity in the Cerebral Cortex of Wistar Albino Rats: An In Vivo and Computational Study
    (American Chemical Society, 2024-01) Hassan, Amr; Mohsen, Reham; Rezk, Ahmed; Bangay, Gabrielle; Rijo, Patrícia; Soliman, Mona F. M; Hablas, Mohamed G. A; Swidan, Khalifa AbdulRazik K; Mohammed, Tahseen S; Zoair, Mohammad A; Mohamed, Abir A. Khalil; Abdalrhman, Tamer I; Desoky, Ahmad M. Abdel-aleem; Mohamed, Dalia D; Mohamed, Doaa D; Abd El Maksoud, Ahmed I; Mohamed, Aly F
    Vitamin C was examined to ameliorate the neurotoxicity of thimerosal (THIM) in an animal model (Wistar albino rats). In our work, oxidative and antioxidative biomarkers such as SOD, LPO, and GSH were investigated at various doses of THIM with or without concurrent vitamin C administration. Furthermore, the adverse effects of THIM on hepatic tissue and cerebral cortex morphology were examined in the absence or presence of associated vitamin C administration. Also, we studied the effect of vitamin C on the metallothionein isoforms (MT-1, MT-2, and MT-3) in silico and in vivo using the RT-PCR assay. The results showed that the antioxidant biomarker was reduced as the THIM dose was raised and vice versa. THIM-associated vitamin C reduced the adverse effects of the THIM dose. The computation studies demonstrated that vitamin C has a lower ΔG of −4.9 kcal/mol compared to −4.1 kcal/mol for THIM to bind to the MT-2 protein, which demonstrated that vitamin C has a greater ability to bind with MT-2 than THIM. This is due to multiple hydrogen bonds that exist between vitamin C and MT-2 residues Lys31, Gln23, Cys24, and Cys29, and the sodium ion represents key stabilizing interactions. Hydrogen bonds involve electrostatic interactions between hydrogen atom donors (e.g., hydroxyl groups) and acceptors (e.g., carbonyl oxygens). The distances between heavy atoms are typically 2.5−3.5 Å. H-bonds provide directed, highaffinity interactions to anchor the ligand to the binding site. The five H-bonds formed by vitamin C allow it to form a stable complex with MT, while THIM can form two H-bonds with Gln23 and Cys24. This provides less stabilization in the binding pocket, contributing to the lower affinity compared to vitamin C. The histopathological morphologies in hepatic tissue displayed an expansion in the portal tract and the hepatocytes surrounding the portal tract, including apoptosis, binucleation, and karyomegaly. The histopathological morphologies in the brain tissue revealed a significant decrease in the number of Purkinje cells due to THIM toxicity. Interestingly, THIM toxicity was associated with hemorrhage and astrogliosis. Both intracellular and vasogenic edema appeared as the concentrations of THIM rose. Finally, vitamin C ameliorated the adverse effect on the cerebral cortex in Wistar albino rats.
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    Phytochemical constitutes and biological activities of essential oil extracted from irradiated caraway seeds ( Carum carvi L)
    (Taylor and Francis, 2022-05) Aly, Amina; Maraei, Rabab; Rezk, Ahmed; Diab, Ayman
    PURPOSE: Essential oils (EOs) obtained from spices, herbs and medicinal plants are well known in traditional medicine and are an area of interest due to their various biological activities. Therefore, present study investigate the chemical composition, phytochemical properties as well as the biological activity of EOs recovered from un-irradiated and irradiated (2.5, 5, and 10 kGy) caraway seeds. MATERIALS AND METHODS: Carum carvi L. seeds were irradiated with gamma irradiation at dose levels 2.5, 5, and 10 kGy, then EOs were recovered from all the samples. The chemical composition, phenols and flavonoids content were evaluated. As well as, antimicrobial and antitumor activities against the two cell lines [colorectal adenocarcinoma (Caco-2) and liver cancer (HepG-2)] were invistigated. RESULTS: The results indicated the percentage of oil increased by radiation, especially at dose of 10 kGy, which gave the highest percentage (3.50%) compared to the control. Also, the Gas Chromatography/Mass Spectrometry (GC-MS) analysis revealed the presence of twenty six compounds in the essential oil extracts . The main constituent of caraway seeds EOs was Carvone followed by Limonene. According to the results, there was an increase in the content of phenols and flavonoids by using gamma rays compared with control, the maximum increase was observed at dose level 10 kGy (13.70 and 7.38mg/g oil, respectively) followed by 5 kGy (11.20 and 5.86mg/g oil, respectively). The antioxidant properties of the caraway essential oils were increased by increasing irradiation dose level (2.5 to 10 kGy) analyzed by DPPH radical and metal chelating activity. Caraway essential oils have an antimicrobial action against Gram positive and Gram negative bacteria as well as fungi. The antimicrobial activity was increased as irradiation dose raised and the10 kGy dose was more effective in suppressing the growth of bacteria and fungi. Aditionally, the caraway essential oils have anticancer activity against the two cell lines studied; colorectal adenocarcinoma (Caco-2) and liver cancer cell line (HepG-2) as reduced the cell viability and density. CONCLUSION: The 10 kGy dose was more effective for oil yield, phenols, flavonoids and antioxidant activity as well as antibacterial and antifungal activities. Furthermore, the caraway essential oils indicated anticancer activity against the two cell lines studied; colorectal adenocarcinoma (Caco-2) and liver cancer cell line (HepG-2) as reduced the cell viability and density. So caraway could be considered an important herb with multiple therapeutic uses.