Antibacterial and ulcer healing effects of organoselenium compounds in naproxen induced and Helicobacter pylori infected Wistar rat model.

Aim of the present study was to evaluate in vitro toxicity and in vivo antibacterial, anti-inflammatory, antiulcer, and antioxidant activities of two organoselenium compounds, selenocystine (SeCys) and ebselen (Ebs). The study was conducted in experimentally induced ulcers in rodent model infected with Helicobacter pylori (H. pylori). In vitro toxicological studies on normal splenic lymphocytes revealed that SeCys and Ebs were non-toxic to the cells even at 100 µM concentration. Antibacterial activity was observed at 500 µg/mL concentration of either of the compounds against H. pylori. In vivo studies after treatment with SeCys and Ebs (500 µg/kg/day) resulted in significant reduction in ROS production and inhibition of lipid peroxidation in gastric tissue. The antioxidant and anti-inflammatory activities of both the compounds were also confirmed by their ability to lower GSH reduction, to induce the expression of antioxidant genes such as GPx-4, and MnSOD and to suppress inflammatory genes namely COX-2, TNF-α and TGF-ß. In addition, the immunomodulatory activity of both the compounds was evident by enhance of the CD4 levels and maintenance of the IgG, IL-6 and IL-10 levels. Persistent treatment (500 µg/kg, for 28 days) with both the compounds showed considerable (p<0.05) ulcer healing property supporting its role in gastro protection. In conclusion, the results of our study suggest that both SeCys and Ebs possess broad spectrum of activities without any potential toxicity.

Relevance of Helicobacter pylori genotypes in gastric pathology and its association with plasma malondialdehyde and nitric oxide levels.

Persistent infection with Helicobacter pylori confers an increased risk of peptic ulceration and gastric adenocarcinoma. Reactive oxygen and nitrogen species play a crucial role in the progression from normal gastric mucosa to cancer. The aim of the present study was to investigate the plasma malondialdehyde and nitric oxide levels in H. pylori related gastroduodenal diseases and associate their levels with gastric pathology and genotypes of H. pylori. Malondialdehyde and nitric oxide levels in plasma samples of 250 subjects were spectrophotometrically determined. Subsequently, genotypic and histopathological assessment was performed in gastric biopsies obtained during endoscopy. The levels of MDA and NO exceeded in subjects infected with genotype-1 of Hp than those with other genotypes suggesting more precise interaction of highly virulent strains of Hp in eliciting severe tissue damage. In conclusion, the study demonstrates close relationship between the plasma malondialdehyde and nitric oxide levels, gastric histopathology and genotypes of H. pylori.

Anti-unlcer and antimicrobial activities of sodium selenite against Helicobacter pylori: in vitro and in vivo evaluation.

Abstract We examined sodium selenite, an inorganic selenium supplement, for its ulcer healing properties and antimicrobial activity against gastric pathogen Helicobacter pylori. Minimum inhibitory concentrations (MIC) were determined using disk diffusion and flow cytometry. The studies were performed over a concentration range of 1 microg/ml to 500 microg/ml sodium selenite. Mild activity was seen at 10 microg/ml and 50 microg/ml, a moderate response at 100 microg/ml and strong response at 500 microg/ml with a MIC value of 10 microg/ml. The compound was found to be active at low pH without any resistance after 10 passages. Flow cytometry data showed a characteristic shift of the viability peak in comparison with the control, thereby confirming the bactericidal effects of sodium selenite. Sodium selenite administered in Wistar rats, pre-ulcerated with naproxen and infected with H. pylori, showed ulcer healing and anti-H. pylori activity at a concentration range of 10-50 microg/rat; however concentrations of 100 microg/rat and 500 microg/rat were found to be toxic in the in vivo studies. In conclusion, sodium selenite shows both ulcer healing and anti-H. pylori activity at a low concentration (10 microg/rat) without toxicity.

Artemisia herba-alba Asso (Asteraceae) has equivalent effects to green and black tea decoctions on antioxidant processes and some metabolic parameters in rats.

AIMS: The objective was to compare the long-term effects of Artemisia herba-alba Asso decoction with a green or black tea decoction, prepared without sugar, on the antioxidant processes in rats. METHODS: The direct parameters used in the control of antioxidant processes were total antioxidant status, glutathione peroxidase activity and conjugated dienes, as early markers of lipid peroxidation. However, the indirect parameters used in this control were the body weight gains, plasma glucose and lipid concentrations, iron, copper and zinc status. RESULTS: After 9 weeks, artemisia or tea decoctions did not influence the daily food intake of the groups; however, they significantly decreased the weight gains. They significantly increased the total antioxidant status between 83.5 and 111% and the whole blood glutathione peroxidase activity between 23 and 38%. However, only the green tea and artemisia decoctions significantly decreased the plasma conjugated diene levels by 35 and 55.5%, respectively. Regarding the trace element status, artemisia, green or black tea decoctions significantly reduced the blood Fe by 28, 30 and 17%, respectively. Also, liver Fe tended to be lower in all treated groups as compared to the control group. In contrast, artemisia significantly increased both blood and liver Cu by 50 and 28% as compared to the control group. Moreover, they significantly decreased the plasma glucose and triglyceride levels between 29 and 40%. For the cholesterol, only the artemisia decoction significantly reduced the total blood cholesterol by 17%. CONCLUSION: Artemisia as well as green tea decoctions increased the total antioxidant status, whole blood glutathione peroxidase activity and zinc and copper status, and prevented weight gains and increases in conjugated dienes, plasma glucose, lipids and iron status. The beneficial antioxidant effects were in descending order: artemisia decoction > or = green tea decoction > black tea decoction. So, artemisia could constitute a good adjuvant to combat obesity, hyperglycemia, hypertriglyceridemia, hypercholesterolemia and particularly oxidative stress.

Effect of green tea decoction on long-term iron, zinc and selenium status of rats.

AIMS: The objective was to examine the effect of green tea decoction given at two different concentrations on the long-term (6 weeks) iron, zinc and selenium status of rats. METHODS: During the experimental period, the rats were given ad libitum a basic diet + ultra pure water (control group), a basic diet + green tea decoction prepared from 50 g/l (tea 50 group), or a basic diet + green tea decoction prepared from 100 g/l (tea 100 group). The zinc and iron status was evaluated by determining their concentrations in the serum, blood precipitate, liver, spleen, femur, heart and kidney. Selenium status was evaluated by the serum selenium concentration and whole blood glutathione peroxidase activity. RESULTS: Green tea decoction significantly reduced serum iron by 26% in the tea groups (p < 0.01). The blood precipitate of iron was significantly decreased by 25 and 41% in the tea 50 and tea 100 groups (p < 0.01), respectively. The reserve of iron stored in the liver, spleen and femur was significantly reduced in the tea 100 group by 32% (p < 0.02), 20% (p < 0.04) and 35% (p < 0.005), respectively. Moreover, the two concentrations of green tea significantly decreased the reserve of iron stored in the kidney (p < 0.005) and heart (p < 0.02). In contrast with its effects on iron status, green tea decoction significantly increased the serum zinc in the tea 100 group by 24% (p < 0.001). It also increased the blood precipitate of zinc by 50 (p < 0.01) and 75% (p < 0.0001) in tea 50 and tea 100 groups, respectively. In the kidney, heart and femur, zinc significantly increased in the tea groups dependent on the tea dose. Similarly, the high concentration of green tea decoction significantly increased the serum selenium concentration by 16% (p < 0.004). In addition, both concentrations of green tea decoction significantly increased the whole blood glutathione peroxidase activity by 102 and 130% (p < 0.01). CONCLUSION: Green tea decoction reduced the iron status and improved the zinc and selenium status of rats. These effects may constitute another beneficial effect of the green tea decoction which could play an important role in the antioxidant processes.