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Abbas Salihi - One of the best experts on this subject based on the ideXlab platform.

  • In vitro anticancer activity of hydrogen sulfide and nitric oxide alongside nickel nanoparticle and novel mutations in their genes in CRC patients
    Scientific Reports, 2021
    Co-Authors: Zjwan Housein, Tayeb Sabir Kareem, Abbas Salihi
    Abstract:

    This study was carried out to assess the impact of nickel nanoparticles (NiNPs) as well as scorpion venom on colorectal cancer (CRC) cells in the presence and/or absence of 5-fluorouracil (5-FU), hydrogen sulfide (H_2S), and nitric oxide (NO) donors and to determine alterations in endothelial NO synthase (eNOS) and cystathionine γ-lyase (CSE) enzyme-producing genes in CRC patients. The IC_50 of both H_2S and NO donors, along with NiNPs, were determined. The CRC cells were treated for 24hrs, and the cytotoxic activities were assessed using the MTT test. Moreover, the apoptosis was determined after 24hrs and 48hrs using TUNEL assay. Furthermore, the mutations in the eNOS gene (intron 4, -786T>C and 894 G>T) and CSE gene (1364GT) were determined using direct sequencing. The IC_50 values for Sodium Disulfide (Na_2S) and Sodium nitroprusside (SNP) at 24hrs treatment were found to be 5 mM and 10^−6 M, respectively, while the IC_50 value for 5-FU was reached after 5-days of treatment in CRC cell line. Both black and yellow scorpion venoms showed no inhibition of cell proliferation after 24hrs treatment. Furthermore, Na_2S showed a significant decrease in cell proliferation and an increase in apoptosis. Moreover, a co-treatment of SNP and 5-FU resulted in inhibition of the cytotoxic effect of 5-FU, while a combination treatment of NiNPs with Na_2S, SNP, and 5-FU caused highly significant cytotoxicity. Direct sequencing reveals new mutations, mainly intronic variation in eNOS gene that has not previously been described in the database. These findings indicate that H_2S promotes the anticancer efficiency of 5-FU in the presence of NiNPs while NO has antiapoptotic activity in CRC cell lines.

  • The vasodilatory mechanism of nitric oxide and hydrogen sulfide in the human mesenteric artery in patients with colorectal cancer
    Experimental and therapeutic medicine, 2021
    Co-Authors: Awat Y. Hassan, Ismail M. Maulood, Abbas Salihi
    Abstract:

    Recent studies have focused on the role of gasotransmitters in cancer progression and prevention. Therefore, the current study was designed to explore the vasodilator activity of NO and H2S in the human mesenteric arteries of patients with colorectal cancer (CRC) via the activation of K+ channels. A total of two sets of experiments were established for the current investigation. Blood samples from patients with CRC were obtained to detect serum levels of endocan and malondialdehyde (MDA). The role of K+ channels in mediating the vasodilation of the human mesenteric artery in response to Sodium nitroprusside (SNP) and Sodium Disulfide (Na2S) was assessed. The level of serum endocan was indicated to be decreased in patients with CRC compared with healthy individuals, while the level of serum MDA remained unaltered between groups. The arterial rings pre-contracted with norepinephrine were first relaxed by the cumulative addition of increasing concentrations of either SNP (30 nM-30 µM) or (1-6 mM). Maximal relaxation rates were then calculated at 15 min intervals for 60 min. Pre-incubation of arterial rings for 20 min with individual K+ channel blockers was indicated to significantly reduce SNP- and Na2S-induced relaxation at different time points. Pre-treatment of L-nitro-arginine methyl ester did not alter vasodilation that was induced by Na2S. Furthermore, vasodilation of the CRC mesenteric artery was not altered by the synergistic application of SNP and Na2S, while pre-incubation of arterial rings with D,L-propargylglycine significantly enhanced vasodilation induced by SNP. These results indicated that endothelial dysfunction and oxidative stress do not serve roles in the pathogenesis of CRC. The dilatory mechanisms of NO and H2S in mesenteric arteries of patients with CRC were K+ channel- and time-dependent, and the activity of cystathionine γ-lyase enzyme inhibited the ability of exogenous NO in vasodilation processes.

  • activation of inward rectifier potassium channels in high salt impairment of hydrogen sulfide induced aortic relaxation in rats
    Physiology and Pharmacology, 2015
    Co-Authors: Abbas Salihi, Salahaddin Universityerbil
    Abstract:

    Introduction: Hydrogen sulfide (H2S) plays a key role in the regulation of vascular tone and protection of blood vessels against endothelial dysfunction. Since the mechanism of salt impairing H2S-induced vascular relaxation is not fully clear, therefore this study was designed to investigate the role of potassium (K + ) channels in the vasodilatory effects of exogenous H2S in rat aortic rings. Materials and Methods: Isolated thoracic aortic rings of adult male albino rats fed 8% NaCl diet for six weeks were used for isometric tension recording using PowerLab tissue bath system. Results: The relaxation response to Sodium Disulfide (Na2S, an H2S donor) was reduced in aortic rings of rats that were either fed high salt (HS) or incubated in a medium containing 1,3 or 5mM/L of extra NaCl compared with control rings. Na2S-induced relaxation was lower in rings precontracted by high K + than phenylephrine (PE, a selective α1adrenergic receptor agonist). In addition, incubation of aortic rings of HS loaded rats with inward-rectifier K + (KIR) channels blocker individually or simultaneously with either ATP-dependent (KATP) or voltage- sensitive K + (KV) channels blockers inhibited Na2S-induced relaxation in PE-precontracted rings; however it had no effects on rings pretreated with KATP channels blocker. In contrast, incubation of aortic rings of HS loaded rats with Ca +2 activated K + (KCa) channels blocker individually or in combination with KIR channels blocker significantly enhanced Na2S-induced relaxation. Conclusion: These results revealed that HS partially impairs aortic relaxation caused by H2S, and that the mechanism of relaxation is mainly mediated by the stimulation of KIR channels and inhibition of KCa channels.

Serena A. Corr - One of the best experts on this subject based on the ideXlab platform.

  • Selective and Facile Synthesis of Sodium Sulfide and Sodium Disulfide Polymorphs.
    Inorganic chemistry, 2018
    Co-Authors: Hany El-shinawi, Edmund J. Cussen, Serena A. Corr
    Abstract:

    Na2S and Na2S2 were selectively synthesized using a microwave-assisted thermal treatment of a Na+/S solution in tetraglyme between 100 and 200 °C, considerably lower than that of current routes. This novel synthetic pathway yields the Na2S phase in high purity and allows for good selectivity between the polymorphs of Na2S2 (α and β phases). These materials show promising electrochemical properties and are particularly interesting for the continued development of Na–S batteries.

Milad Sheydaei - One of the best experts on this subject based on the ideXlab platform.

Nobuhiro Kihara - One of the best experts on this subject based on the ideXlab platform.

Jiang Cheng - One of the best experts on this subject based on the ideXlab platform.