Antioxidant effect of dry olive (Olea europaea L.) leaf extract on ethanol-induced gastric lesions in rats

Oral administration of chestnut tannins to reduce the duration of neonatal calf diarrhea

BACKGROUND

Neonatal calf diarrhea is generally caused by infectious agents and is a very common disease in bovine practice, leading to substantial economic losses. Tannins are known for their astringent and anti-inflammatory properties in the gastro-enteric tract. The aim of this study was to evaluate the effect of the oral administration of chestnut tannins (Castanea sativa Mill.) in order to reduce the duration of calf neonatal diarrhea. Twenty-four Italian Friesian calves affected by neonatal diarrhea were included. The duration of the diarrheic episode (DDE) was recorded and the animals were divided into a control group (C), which received Effydral® in 2 l of warm water, and a tannin-treated group (T), which received Effydral® in 2 l of warm water plus 10 g of extract of chestnut tannins powder. A Mann-Whitney test was performed to verify differences for the DDE values between the two groups.

RESULTS

The DDE was significantly higher in group C than in group T (p = 0.02), resulting in 10.1 ± 3.2 and 6.6 ± 3.8 days, respectively.

CONCLUSIONS

Phytotherapic treatments for various diseases have become more common both in human and in veterinary medicine, in order to reduce the presence of antibiotic molecules in the food chain and in the environment. Administration of tannins in calves with diarrhea seemed to shorten the DDE in T by almost 4 days compared to C, suggesting an effective astringent action of chestnut tannins in the calf, as already reported in humans. The use of chestnut tannins in calves could represent an effective, low-impact treatment for neonatal diarrhea.

Protective Effects of Selenium, N-Acetylcysteine and Vitamin E Against Acute Ethanol Intoxication in Rats

The aim of this study was to determine possible protective influences of selenium (Se), N-acetylcysteine (NAC), and vitamin E (Vit E) against acute ethanol (EtOH) intoxication. Thirty-six rats were divided into six groups: I (control), II (EtOH), III (EtOH + Se), IV (EtOH + Vit E), V (EtOH + NAC), and VI (EtOH + mix). Except group I, EtOH was given the other pretreated (groups III, IV, V, and VI) and untreated groups (group II). Compared with the EtOH group, serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase, creatine kinase, and creatine kinase-MB levels were significantly decreased in all pretreated groups, whereas slightly diminished amylase and lipase were observed. Compared with the control group, a remarkably lower total antioxidant status (TAS), but higher total oxidant status (TOS), and oxidative stress index (OSI) were seen in brain, liver, and kidney tissues. The values of these parameters were less affected from EtOH-exposed brain tissue of EtOH + NAC and liver of EtOH + mix groups. Both significant decrease of catalase activity and marked increases of adenosine deaminase and myeloperoxidase were determined only in liver tissue of the EtOH group. Activities of these enzymes were restored in almost all pretreated groups. Moreover, an increase of xanthine oxidase activity was prevented in brain tissue of pretreated groups. In histopathological examination of the liver, hydropic degeneration, sinusoidal dilatation, mononuclear cell infiltration, and marked congestion, which were seen in the EtOH group, were prevented in all pretreated groups. Relative protection against acute EtOH toxicity, in both single and combined pretreatments of Se, NAC, and Vit E supplementation, was probably through antioxidant and free radical-neutralizing effects of foregoing materials.

Effect of oleuropein on myocardial dysfunction and oxidative stress induced by ischemic-reperfusion injury in isolated rat heart

Background

Studies have reported antioxidant effect of oleuropein in isolated rat heart.

Objective

This study was conducted to investigate whether perfusion of isolated rat heart with oleuropein, before induction of ischemia or at the onset of reperfusion, had any effect on the hemodynamic parameters, infarct size and biochemical factors following ischemic – reperfusion injury.

Materials and methods

Forty-eight male Wistar rats were divided into 6 groups: the control groups (Con-P and Con-T groups), O10-P and O50-P groups perfused with 10 and 50 μg/g heart oleuropein 5 min before the induction of ischemia and O10-T and O50-T groups perfused with 10 and 50 μg/g heart oleuropein at the beginning of the reperfusion, respectively. All hearts were subjected to 30 min global ischemia and 90 min reperfusion. Hemodynamic parameters were monitored throughout the experiment. The creatine kinase (CK) and malondialdehyde (MDA) level of coronary outflow were assayed and the infarct size measured at the end of reperfusion.

Results

We found hemodynamic parameters namely heart rate, left ventricular end diastolic pressure (LVEDP), left ventricular developed pressure (LVDP), ±dp/dt and coronary outflow significantly improved in all groups that received oleuropein compared to the control groups. Also, the infarct size was smaller and the coronary outflow levels of CK and MDA were lower in the oleuropein groups compared to the control groups.

Conclusions

The findings suggest that perfusion of isolated rat heart with oleuropein would lead to improved myocardial dysfunction following ischemic-reperfusion injury. Our findings confirm the antioxidant potential of oleuropein.

Dry olive leaf extract counteracts L-thyroxine-induced genotoxicity in human peripheral blood leukocytes in vitro

The thyroid hormones change the rate of basal metabolism, modulating the consumption of oxygen and causing production of reactive oxygen species, which leads to the development of oxidative stress and DNA strand breaks. Olive (Olea europaea L.) leaf contains many potentially bioactive compounds, making it one of the most potent natural antioxidants. The objective of this study was to evaluate the genotoxicity of L-thyroxine and to investigate antioxidative and antigenotoxic potential of the standardized oleuropein-rich dry olive leaf extract (DOLE) against hydrogen peroxide and L-thyroxine-induced DNA damage in human peripheral blood leukocytes by using the comet assay. Various concentrations of the extract were tested with both DNA damage inducers, under two different experimental conditions, pretreatment and posttreatment. Results indicate that L-thyroxine exhibited genotoxic effect and that DOLE displayed protective effect against thyroxine-induced genotoxicity. The number of cells with DNA damage, was significantly reduced, in both pretreated and posttreated samples (P < 0.05). Comparing the beneficial effect of all tested concentrations of DOLE, in both experimental protocols, it appears that extract was more effective in reducing DNA damage in the pretreatment, exhibiting protective role against L-thyroxine effect. This feature of DOLE can be explained by its capacity to act as potent free radical scavenger.

Synergistic effect of Se-methylselenocysteine and vitamin E in ameliorating the acute ethanol-induced oxidative damage in rat

The present study was conduced to investigate the synergistic effects of combined treatments with Se-methylselenocysteine (SeMSC) and vitamin E (Vit E) in reversing oxidative stress induced by ethanol in serum and different tissues of rats. Sixty female rats were randomly divided into six groups for 30 days' consecutive pretreatments as followed: control (I), physiological saline (II), 2.8μgkg(-1) Se as SeMSC (III), 2.8μgkg(-1) Se as sodium selenite (Na2SeO3, IV), 5mgkg(-1) α-tocopherol as α-tocopherol acetate (Vit E, V), 5mgkg(-1) α-tocopherol as α-tocopherol acetate and 2.8μgkg(-1) Se as SeMSC (VI). All animals in groups II-VI were treated by ethanol treatment to cause oxidative stress. After 6h of ethanol treatment, the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), the contents of total antioxidant capacity (T-AOC), malondialdehyde (MDA), glutathione (GSH) and carbonyl protein (CP) in the serum, liver, heart and kidney were measured. The result showed that the individual SeSMC, Na2SeO3 and vitamin E could effectively increase the SOD, T-AOC, GSH-Px and GSH contents as well as significantly decrease the MDA and CP concentrations in the tissues of ethanol-induced rats. At the same dose on different forms of Se, SeMSC showed greater antioxidant activity than Na2SeO3. Moreover, group VI (SeMSC and α-tocopherol acetate) showed much better antioxidant activity than individual group III (SeMSC) and V (α-tocopherol acetate) due to the synergistic effect.

Gastroprotective effect of the traditional herbal medicine, Sipjeondaebo-tang water extract, against ethanol-induced gastric mucosal injury

Background

Sipjeondaebo-tang, a traditional herbal medicine, has been reported to activate the immune response. Although, most research has focused on its anticancer activity. The purpose of this study was to determine whether Sipjeondaebo-tang exerts antioxidant activity against ethanol-induced gastric injury.

Methods

Gastric mucosal injury was induced by the oral administration of absolute ethanol at 5 mL/kg to rats after 18 h fast. Sipjeondaebo-tang water extract (SDTW; 200 mg/kg of body weight) was administered to rats 2 h before the oral administration of absolute ethanol. Gastric mucosal injury was evaluated by measuring the gastric injury, such as extent of lesions, malondialdehyde (MDA) concentration, glutathione (GSH) content and activities of antioxidant enzymes including catalase, glutathione peroxidase, glutathione S-transferase, glutathione reductase, and superoxide dismutase in stomach tissue.

Results

Oral administration of SDTW markedly decreased the damage by conditioning the gastric mucosa such as hemorrhage, hyperemia. Pretreatment with SDTW significantly reduced MDA concentration and significantly increased GSH content and the activities of antioxidant enzymes. In an acute toxicity study, no adverse effects of SDTW were observed at doses up to 5000 mg/kg/day.

Conclusions

SDTW may protect the gastric mucosa against ethanol-induced gastric mucosa injury. These results suggested that SDTW might also play an important role in the gastroprotection based on their antioxidant effect.

Anti-ulcerogenic activity of the root bark extract of the African laburnum "Cassia sieberiana" and its effect on the anti-oxidant defence system in rats

BACKGROUND

Despite the widespread use of roots of Cassia sieberiana in managing several health conditions including gastric ulcer disease, there is little scientific data to support the rational phytotherapeutics as an anti-ulcer agent. This paper reports an evaluation of the in vivo anti-oxidant properties of an aqueous root bark extract of C. sieberiana in experimental gastric ulcer rats in a bid to elucidate its mechanism of action.

METHODS

Fisher 344 (F(344)) rats received pretreatment of C. sieberiana root bark extract (500, 750, and 1000 mg/kg body wt.) for 7 days after which there was induction of gastric injury with absolute ethanol. The mean ulcer index (MUI) was calculated and serum total anti-oxidant level determined. Gastric mucosal tissues were prepared and the activity level of the enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and myeloperoxidase (MPO) were measured together with the level of lipid hydroperoxides (LPO). Statistical difference between treatment groups was analysed using one-way analysis of variance (ANOVA) followed by Dunnett's post hoc t test. Statistical significance was calculated at P< 0.05.

RESULTS

The administration of ethanol triggered severe acute gastric ulcer and pretreatment with C. sieberiana root bark extract significantly and dose dependently protected against this effect. The root bark extract also dose dependently and significantly inhibited the ethanol induced decrease in activity levels of the enzymes SOD, CAT and GPx. The extract also inhibited the ethanol-induced decrease in level of serum total anti-oxidant capacity. The increase in ethanol-induced LPO level and MPO activity were also significantly and dose-dependently inhibited by the root bark extract.

CONCLUSIONS

The gastro-cytoprotective effect, inhibition of decrease in activity of gastric anti-oxidant enzymes and MPO as well as the inhibition of gastric LPO level suggests that one of the anti-ulcer mechanisms of C. sieberiana is the anti-oxidant property.