Browsing by Author "Samuel, E. S."

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Dose‑dependent effects of cobalt chloride supplementation in a rat model of acetic acid‑induced ulcerative colitis
(Springer-Verlag London Ltd., 2024) Akinrinde, A. S.; Samuel, E. S.; Adeoye, B. O.
Several recent studies have shown that hypoxia preconditioning, often mimicked by sub-toxic levels of cobalt, can protect body tissues against various types of inflammatory and oxidative injuries. The present study was designed to understand the effects of low-to-moderate doses of cobalt chloride (CoCl2) on ulcerative colitis induced by acetic acid in male Wistar rats. Rats were pre-treated with CoCl2 at 10, 30 and 60 mg/kg BW for 7 days prior to, and later along with intra-rectal administration of 4% acetic acid for another 3 days. Rats were euthanized and the colons were examined macroscopically, and histologically, haematological parameters were evaluated in the blood and various oxidative stress parameters and inflammatory cytokines were studied in the colon and blood. Pre-treatment with CoCl2 at 10 mg/kg caused reduction in colonic levels of hydrogen peroxide (H2O2), nitric oxide (NO), advanced oxidation protein products (AOPP) and reduced serum TNF-α, but increased serum IL-10 levels. Conversely, rats treated with higher doses of CoCl2 showed exacerbation of macroscopic scores and histologic damage in the colon, with significantly elevated levels of oxidants and serum TNF-α along with reduced serum IL-10 levels. Values of all the measured haematological parameters (PCV, Hb, RBC, WBC and platelet count) were dose-dependently increased with increasing doses of CoCl2. The results of this study showed that consumption of cobalt at low doses could play a vital role in the control of ulcerative colitis, while higher doses can contribute to exacerbation of intestinal inflammation. Monitoring of cobalt concentrations in food and water consumed by ulcerative colitis patients is imperative to prevent exacerbation of colonic inflammation by cobalt.
Protective effect of cholecalciferol against cobalt‑induced neurotoxicity in rats: ZO‑1/iFABP, ChAT/AchE and antioxidant pathways as potential therapeutic targets
(Springer Science+Business Media, LLC, 2024) Akinrinde, A. S.; Adeoye, B. O.; Samuel, E. S.; Mustapha, O. A.
Cobalt (Co) toxicity has been reported to produce central nervous system and gastrointestinal abnormalities. This study assessed the therapeutic effect of cholecalciferol (Cho) supplementation against damages caused by sub-acute (14-day) cobalt chloride (CoCl2) exposure in the brain and intestines. Thirty-five male Wistar rats were divided equally into five groups: Group I (control) received no treatment; Group II received oral CoCl2 (100 mg/kg) only; Groups III, IV, and V received 1000, 3000 and 6000 IU/kg of cholecalciferol, respectively by oral gavage, and concurrently with CoCl2. Cobalt-treated rats showed neuronal vacuolation and presence of pyknotic nuclei in the cerebral cortex and hippocampus, depletion of Purkinje cells in the cerebellum, as well as inflammation and congestion in the intestinal mucosa. Cobalt also increased brain and intestinal hydrogen peroxide (H2O2) and malondialdehyde (MDA) concentrations, while simultaneously reducing glutathione (GSH) content, superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione S-transferase (GST) activities. Further, CoCl2 induced increases in brain acetylcholinesterase (AchE) activity and serum zonulin (ZO-1) levels. Conversely, Cho administration suppressed CoCl2-induced damages in the brain and intestines by reducing lipid peroxidation and increasing the activities of antioxidant enzymes. Remarkably, Cho produced stimulation of brain choline acetyltransferase (ChAT) and suppression of AchE activity, along with dose-dependent reduction in serum levels of ZO-1, intestinal fatty acid-binding protein (iFABP) and nitric oxide. In conclusion, the protective role of cholecalciferol against cobalt-induced toxicity occurred via modulation of cholinergic, intestinal permeability and antioxidant pathways. The results may prove significant in the context of the role of gut-brain connections in neuroprotection.
Protective effect of cholecalciferol against cobalt‑induced neurotoxicity in rats: ZO‑1/iFABP, ChAT/AchE and antioxidant pathways as potential therapeutic targets
(Springer Science+Business Media, LLC, 2024) Akinrinde, A. S.; Adeoye, B. O.; Samuel, E. S.; Mustapha, O. A.
Cobalt (Co) toxicity has been reported to produce central nervous system and gastrointestinal abnormalities. This study assessed the therapeutic effect of cholecalciferol (Cho) supplementation against damages caused by sub-acute (14-day) cobalt chloride (CoCl2) exposure in the brain and intestines. Thirty-five male Wistar rats were divided equally into five groups: Group I (control) received no treatment; Group II received oral CoCl2 (100 mg/kg) only; Groups III, IV, and V received 1000, 3000 and 6000 IU/kg of cholecalciferol, respectively by oral gavage, and concurrently with CoCl2. Cobalt-treated rats showed neuronal vacuolation and presence of pyknotic nuclei in the cerebral cortex and hippocampus, depletion of Purkinje cells in the cerebellum, as well as inflammation and congestion in the intestinal mucosa. Cobalt also increased brain and intestinal hydrogen peroxide (H2O2) and malondialdehyde (MDA) concentrations, while simultaneously reducing glutathione (GSH) content, superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione S-transferase (GST) activities. Further, CoCl2 induced increases in brain acetylcholinesterase (AchE) activity and serum zonulin (ZO-1) levels. Conversely, Cho administration suppressed CoCl2-induced damages in the brain and intestines by reducing lipid peroxidation and increasing the activities of antioxidant enzymes. Remarkably, Cho produced stimulation of brain choline acetyltransferase (ChAT) and suppression of AchE activity, along with dose-dependent reduction in serum levels of ZO-1, intestinal fatty acid-binding protein (iFABP) and nitric oxide. In conclusion, the protective role of cholecalciferol against cobalt-induced toxicity occurred via modulation of cholinergic, intestinal permeability and antioxidant pathways. The results may prove significant in the context of the role of gut-brain connections in neuroprotection.