Naringenin modulates Cobalt activities on gut motility through mechanosensors and serotonin signalling.

IntroductionCobalt chloride-(CoCl2) exerts beneficial and toxic activities depending on dose however Naringenin-(Nar) a flavonoid, chelates heavy metals. Absorption of ingested heavy metals, or chelates are dependent on gut motility (gastric emptying and intestinal transit time) and mechanosensor regulation. Literature is vague on CoCl2 activities on gut motility and mechanosensor nor probable chelating actions with naringenin which was investigated in this study.MethodOne hundred male Wistar rats were grouped viz; A to D (25, 62, 150 and 300 mg/kg CoCl2), E to H doses of CoCl2+Nar (50 mg/kg), I-Narigenin and J-Control. Gastric emptying and intestinal transit time were evaluated by day eight, intestinal tissue assayed for biochemical, histological and immunohistochemistry reactivity.ResultCoCl2 significantly increased Gastric emptying (150 and 300 mg/kg) and Intestinal transit time unlike Naringenin. CoCl2 (150 mg/kg) significantly increased Catalase and Nitric oxide but ameliorated by Naringenin. ATPase activities significantly increased in 150 mg/kg-CoCl2 but ameliorated by Naringenin. Carbonyl levels increased in all CoCl2+Nar groups. High Enterochromaffin-cell count in 25 and 62 mg/kg-CoCl2 were ameliorated by Naringenin. Serotonin immunoreactivity increased in CoCl2 (25, 62, 300 mg/kg) but reduced in CoCl2+Nar groups.ConclusionCobalt chloride enhanced gastric motility via increased mechanosensor activities and serotonin expression at low doses. Naringenin ameliorated toxicity of high cobalt chloride via metal-flavonoid chelates.

Low-dose Potassium bromate enhances ischemia-reperfusion-induced gastric ulcer healing in Thyroidectomised Rats.

Gastric ulcer healing is impaired in both hypothyroid and hyperthyroid conditions.  Thyroid hormones regulate growth, energy metabolism and mitochondrial oxidative metabolism. Xenobiotics have been documented to negatively impact the thyroid gland at high doses but the redox and cellular interactions at low doses during wound healing process remains unclear. Potassium bromate has been documented to be toxic at high doses but there is dearth of information on its activities at a low dose in varied thyroid states which was evaluated in this study. 60 male Wistar rats (g, n=10) were randomised into 2 conditions: Normal, ulcerated untreated, ulcerated treated with 12.5mg/kg p.o KBrO3 and thyroidectomised groups: thyroidectomised ulcerated, thyroidectomised ulcer treated with KBrO3 and thyroidectomised treated with thyroxine (100µg/kg) Total thyroidectomy was used to model hypothyroidism, and ischaemia-reperfusion-induced gastric ulcers were monitored for healing. Daily body weights, Levels of thyroxine, Gastric mucin content, redox and sodium pump activity were examined alongside other markers of hepatic and haematological toxicity by days 3 and 7 post ulceration. Data were analysed using descriptive statistics and ANOVA α 0.05. The bromate-exposed hypothyroid rats showed increased gastric ulcer healing potential with reduced gastric epithelial oedema and inflammation; hepatic steatosis, and periportal inflammation. Haematological variables and markers of hepatic functions were normal. There were reduced levels of gastric and hepatic malondialdehyde levels. Thyroxine and potassium bromate treatment resolved the redox and cellular toxicity possibly via increasing catalase and sulfhydryl levels and increased Na+ K+ pump activity. We conclude that potassium bromate enhanced gastric ulcer healing in hypothyroid state, similar to thyroxine treatment.

Cement Dust Exposure Alters Secretory Functions, Biochemical Profile and Morphology of Gastrointestinal Tissues in Rats Exposed to Cement Dust.

Asides direct gastrointestinal exposure, inhalation route is another major xenobiotic exposure pathway to the gastrointestinal tract via mucociliary escalator. This triphasic study assesses cement dust inhalatory exposure effect on the possible alterations of the gastrointestinal tissues and secretion. 72 male, sixteen (16) weeks old Wistar rats were randomized into 3 different phases of 24 animals. Each phase comprised of 3 group of 8 animals. Group 1 (control) were sham-operated with clean ambient air, group 2 (14-days exposed) were exposed to cement dust for 14days, and group 3 (28-day exposed) were exposed to cement dust for 28 days. Biochemical indices including superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), sulfhydryl group, carbonyl group, Na+-K+ATPase pump activity, Nitric oxide (NO) were investigated spectrophotometrically in gastric and hepatic tissues while histopathology was studied using standard procedure. There was significant increase in the level of MDA, NO and carbonyl- an observation that contrasts with the level of CAT, SOD and sulfhydryl; no significant difference in Na+-K+-ATPase pump was observed in the exposed groups compared with control. Histopathological alterations in salivary gland and gastric tissues includes edema, inflammatory cell infiltration and vascular congestion. There was significant alteration in basal salivary, gastric and biliary secretions; increased stimulated salivary and gastric secretion via cholinergic stimulation. Conclusively, histopathological and spectrophotometric analyses reflect that inhalatory experimental exposure to cement dust significantly alter gastrointestinal secretions and predisposes the gastrointestinal tract to an array of deleterious effects via protein oxidation and antioxidant depletion and tissue peroxidation.

Potassium bromate (KBrO3) modulates oxidative stress and inflammatory biomarkers in sodium hydroxide (NaOH) - induced Crohn's colitis in Wistar rats.

Potassium bromate (KBrO3) present in consumed ozonised water was recently documented to exacerbate experimental gastric ulcer. Information, however, is vague as regards its effects in the colon where water reabsorption occurs. In this study, we observed the possible effects of KBrO3 on oxidative stress and inflammatory biomarkers in sodium hydroxide (NaOH) - induced Crohn's colitis (CC). Wistar rats (180-200 g) were divided into six groups (n = 10): (i) control; (ii) untreated CC (induced by 1.4% NaOH; intra-rectal administration); and (iii-vi) CC treated with vitamin E, KBrO3, vitamin E+KBrO3, and sulphazalazine, respectively, for 7 days. Body weight and stool score were monitored daily. By day 3 and 7, excised colon was evaluated for ulcer scores and biochemical and histological analysis. Blood samples collected on days 3 and 7 were assayed for haematological indices using standard methods. Data were subjected to analysis of variance (ANOVA) and p ≤ 0.05 considered significant. Platelet/lymphocyte ratio, colonic ulcer score, malondialdehyde, and mast cells were significantly decreased while colonic sulfhydryl, and Ca2+- and Na+/K+-ATPase activities were increased following KBrO3 treatment compared with untreated CC. These findings suggest that KBrO3 may mitigate against NaOH-induced CC via inhibiting mast cell population and oxidative and inflammatory content but stimulating colonic sulfhydryl and Ca2+- and Na+/K+-ATPase activities.

Attenuation of ischemia-reperfusion-induced gastric ulcer by low-dose vanadium in male Wistar rats.

AIM: Vanadium, a trace element found in food and water sources has been previous reported to attenuate ulcer formation without much insight into its mechanism of action. This study highlights the mechanism by which vanadium exhibits its gastro-protective activity. MAIN METHODS: Eighty male Wistar rats (80-100 g) were randomized into 8 equal groups. Groups 1 (control) and 2 (Ulcerated control) received water only, groups 3-8 received vanadium at 5, 10, 25, 50, 100 and 200 ppm respectively in their drinking water for ten weeks. Gastric ulcer was thereafter induced in groups (2-8) via ischaemia-reperfusion (IR) technique. The stomachs were excised for macroscopic examination, evaluation of mucous content, oxidative stress markers, hydrogen/potassium (H+/K+) and calcium (Ca++) ATPases activities plus expression of induced nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Vanadium at low doses inhibited IR induced gastric ulcer by 62.62% (10 ppm), 54.80% (25 ppm) and 43.50% (50 ppm). KEY FINDINGS: Low dose vanadium increased mucous content, superoxide dismutase, catalase, glutathione activities and nitrite concentrations compared to ulcerated control group. The observed increase in malondialdehyde, Ca++ and H+/K+ ATPase activities, iNOS and COX-2 expression following IR were significantly reduced by pretreatment with vanadium. SIGNIFICANCE: This study demonstrated that vanadium at low doses exhibit gastro-protective activities on IR induced gastric ulcer in rat model by inhibiting proton pump activities and decreasing expressions of iNOS and COX-2, thereby giving more insight into the protective action of vanadium.

Seeds of Buchholzia coriacea in Diet Mitigate Ischemic Reperfusion-Induced Gastric Ulceration in Experimental Rats.

Buchholzia coriacea (B. coriacea) seeds, in folk medicine, have been documented to prevent gastric ulceration though the mechanism is not fully elucidated. To clarify this, the gastro-healing activities were investigated using graded incorporation of B. coriacea seeds in the diet. Male Wistar rats (150-200 g) were divided into 7 groups (n = 15): unulcerated untreated control, ulcerated untreated control, unulcerated B. coriacea low (10%), ulcerated B. coriacea low (10%), nulcerated B. coriacea high (25%), ulcerated B. coriacea high (25%), and ulcerated omeprazole-treated groups. Rats were fed with B. coriacea diets for 7 weeks; thereafter, ulcer was induced by ischemic reperfusion method. Daily body weight, gastric acid secretion, hematological parameters, stomach ulcer score, and biochemical and histological analyses were evaluated on days 0, 3, and 7 post-ulcer induction. Results were subjected to one-way analysis of variance (ANOVA) and presented as mean ± standard error of the mean (SEM); p ≤.05 was considered significant. Significant decreases were observed in mean body weight of B. coriacea-fed compared with control and omeprazole-treated groups from week 7. Ulcerated B. coriacea-fed showed significant decrease in gastric acid secretion by days 3 and 7 compared with ulcerated control groups. Malondialdehyde content was significantly decreased in ulcerated B. coriacea-fed compared with control and omeprazole-treated groups. Significant increases in hematological variables (notably platelet count), superoxide dismutase, catalase, and nitric oxide levels of B. coriacea-fed compared with control and omeprazole-treated groups by days 0 and 3 were observed. Histological evaluations further confirmed these observations. B. coriacea diet enhanced gastric healing activities on ischemic reperfused gastric ulcer. Increased platelet count and nitric oxide levels may play significant roles in this process.

Kolaviron attenuates ischemia/reperfusion injury in the stomach of rats.

Kolaviron (KV), an active complex of at least 3 compounds in Garcinia kola seed, which is known for its antioxidant and anti-inflammatory activity, was investigated for its gastro-protective effect in the stomach of rats subjected to ischemia/reperfusion-induced gastric ulceration. Male adult Wistar rats (180-210 g) were randomized into 6 groups (n = 15) as follows: (i) control, (ii) ulcerated untreated (UU), (iii) KV alone (KVA), (iv) KV + ulcer (KVU), (v) ulcer + KV (UKV), and (vi) ulcer + omeprazole (20 mg/kg). Ulcer was induced through ischemia/reperfusion method after 2 weeks of daily oral KV (100 mg/kg). Rats were weighed daily, and gastric acid secretion, ulcer scores, hematological, biochemical, and histological variables were assessed 1 h after induction at 3 and 7 days post-ulceration. Body weight decreased in KVA (179.1 ± 1.6 g), and KVU (170.1 ± 2.2 g) compared with UU (199.0 ± 1.4 g). Gastric acid secretion decreased significantly in KVU after 1 h and 3 days post-ulceration (0.27 ± 0.03 mEq/L; 0.49 ± 0.02 mEq/L) compared with UU (0.60 ± 0.06 mEq/L; 0.85 ± 0.29 mEq/L), respectively. There was significant reduction in neutrophil/lymphocyte ratio of KVA (0.29 ± 0.06) and KVU (0.35 ± 0.02) compared with UU (0.54 ± 0.04). Malondialdehyde level decreased significantly with concomitant increase in anti-oxidative activities and nitric oxide level in the KV treated groups (KVA, KVU, UKV) compared with UU. In conclusion, treatment with KV protects the stomach by reducing gastric acid secretion, promoting antioxidant activity and suppressing action of reactive oxygen species.