Synergistic protective effects between docosahexaenoic acid and omeprazole on the gastrointestinal tract in the indomethacin-induced injury model

Antioxidative Action of Alpha-Linolenic Acid during Its Gastroprotective Effect in an Indomethacin-Induced Gastric Injury Model

Polyunsaturated fatty acids (PUFAs) are known to have beneficial effects. In particular, the consumption of omega-3 PUFAs has recently increased because of their effects on human health. Previous studies have investigated the activity of alpha-linolenic acid (ALA; C:18 omega-3) in metabolism and inflammation models. In a murine model of colitis, treatment with ALA effectively reduced inflammation. Previously, our research group identified the protective action of docosahexaenoic acid against gastric damage caused by nonsteroidal anti-inflammatory drugs. The present study aimed to examine the impact of ALA in an indomethacin-induced gastric injury model and to determine its antioxidant activity in gastric tissue. Female Wistar rats were administered ALA over 10 days (20 mg/kg, orally). Two hours after the final ALA administration, the rats were given indomethacin (30 mg/kg, orally) to induce gastric injury. After 3 h, the rats were euthanized, and each stomach lesion was measured to determine the total damage. Stomach tissue samples were collected for the analysis of various antioxidant indicators. The results show ALA's gastroprotective effect following 10-day administration. ALA treatment significantly reduced gastric reactive oxygen species and malondialdehyde levels in the indomethacin-induced injury group. Moreover, ALA treatment decreased the levels of nitric oxide, myeloperoxidase, leukotriene B4, and increased glutathione following indomethacin administration. These results suggest that the gastroprotective effects of ALA are likely attributed to its role in the antioxidant pathway in indomethacin-induced gastric injury.

Thiamine pyrophosphate may protect indomethacin-induced small intestinal enteropathy in rats by inhibiting intestinal inflammation and oxidative stress

Non-steroid anti-inflammatory drug (NSAID)-induced enteropathy is a clinically undesirable but highly prevalent problem. Thiamine pyrophosphate (TPP) has a role in reducing oxidative stress as well as acting as a coenzyme in enzymatic reactions. The aim of this study was to investigate the protective effect of TPP on the damage caused by indomethacin (IND), one of the NSAID group drugs, in the small intestine. In the experiment in which 32 rats were used, four groups were formed randomly (groups 1, 2, 3, 4; control, TPP, IND, IND + TPP group, respectively). Small intestinal injury was induced in group 3 and group 4 rats that were fasted 1 day beforehand by a single intragastric administration of 25 mg/kg IND. Half an hour before the model was created, 20 mg/kg TPP was administered to group 2 and group 4 by intragastric as pretreatment. Tissue changes, proinflammatory cytokines, oxidative stress status, macroscopic appearance, and histopathologic analysis were evaluated. All data were statistically analyzed, and significance was determined (p < 0.05). Prophylactic treatment with TPP resulted in maintenance of antioxidant enzymes (GPX, SOD) and GSH levels in small intestinal tissue analysis. However, the excessive increase in IND-induced lipid peroxidation (MDA) and total oxidant level (TOS) was not downregulated by TPP compared to group 3. Additionally, the treatment had no prophylactic effect on the reduction of proinflammatory cytokine (TNF-α, IL-6) levels in tissue. Histopathologic examination of the tissue revealed that IND disrupted the intestinal villus structure, causing erosive ulceration, degeneration, and inflammation. TPP reduced the inflamed areas and total tissue damage score in the IND group (p < 0.001). In this study, the positive effects of TPP use on some parameters in a short period of time suggested that TPP may produce more significant results with changes in the time and dose of use. Indeed, these beneficial effects obtained with a single dose suggest that TPP may provide protection in small intestinal enteropathy as an antioxidant and anti-inflammatory agent.

Omeprazole attenuates irradiation-induced lung injury through the suppression of apoptosis and oxidative stress in mice

Radiation therapy is an effective treatment for patients with malignant thoracic tumors, but it can cause lung damage. Omeprazole (OM) is a proton pump inhibitor with anticancer, antioxidative, and anti-inflammatory activities. The aim of this study was to examine the effects of OM on oxidative stress and apoptosis through the use of ionizing radiation (IR) in lung tissue. Sixty-four mice were randomized into eight groups: the control, OM (10, 25, and 50 mg/kg/day/oral for 7 consecutive days), IR (single dose of 6 Gy), and IR + OM (10, 25, and 50 mg/kg) groups. The protective effect of OM was determined by histological and immunohistochemical evaluation and assessment of protein carbonyl levels. OM significantly decreased protein carbonyl levels in the lungs of irradiated mice compared with those in the lungs of IR-treated mice. Histological evaluation of the irradiated mice revealed destruction of the alveolar wall, thickening of the alveolar sac wall, enlarged red blood cells, infiltration of inflammatory cells, edema, and capillary, vascular and interstitial hyperemia. OM at all three doses significantly reduced lung injury. Immunohistochemical findings also revealed that OM could reduce the expression of caspase-3. OM at a low dose and short duration of administration had no side effects. OM is able to protect against lung damage caused by IR through reducing oxidative stress and decreasing the expression of caspase-3.

Role of antioxidative activity in the docosahexaenoic acid's enteroprotective effect in the indomethacin-induced small intestinal injury model

Therapeutic effect of non-steroidal anti-inflammatory drugs (NSAIDs) has been related with gastrointestinal injury. Docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid (PUFA), can prevent gastric and small intestinal damage. Nonetheless, contribution of antioxidative action in the protective effect of DHA has not been evaluated before in the small intestine injury after indomethacin treatment. Pathogenesis of NSAID-induced small intestinal injury is multifactorial, and reactive oxidative species have been related to indomethacin's small intestinal damage. The present work aimed to evaluate antioxidative activity in the protective action of DHA in the indomethacin-induced small intestinal damage. Female Wistar rats were gavage with DHA (3 mg/kg) or omeprazole (3 mg/kg) for 10 days. Each rat received indomethacin (3 mg/kg, orally) daily to induce small intestinal damage. The total area of intestinal ulcers and histopathological analysis were performed. In DHA-treated rats, myeloperoxidase and superoxide dismutase activity, glutathione, malondialdehyde, leukotriene, and lipopolysaccharide (LPS) levels were measured. Furthermore, the relative abundance of selective bacteria was assessed. DHA administration (3 mg/kg, p.o.) caused a significant decrease in indomethacin-induced small intestinal injury in Wistar rats after 10 days of treatment. DHA's enteroprotection resulted from the prevention of an increase in myeloperoxidase activity, and lipoperoxidation, as well as an improvement in the antioxidant defenses, such as glutathione levels and superoxide dismutase activity in the small intestine. Furthermore, we showed that DHA's enteroprotective effect decreased significantly LPS levels in indomethacin-induced injury in small intestine. Our data suggest that DHA's enteroprotective might be attributed to the prevention of oxidative stress.

Tesofensine, a novel antiobesity drug, silences GABAergic hypothalamic neurons

Obesity is a major global health epidemic that has adverse effects on both the people affected as well as the cost to society. Several anti-obesity drugs that target GLP-1 receptors have recently come to the market. Here, we describe the effects of tesofensine, a novel anti-obesity drug that acts as a triple monoamine neurotransmitter reuptake inhibitor. Using various techniques, we investigated its effects on weight loss and underlying neuronal mechanisms in mice and rats. These include behavioral tasks, DeepLabCut videotaped analysis, electrophysiological ensemble recordings, optogenetic activation, and chemogenetic silencing of GABAergic neurons in the Lateral Hypothalamus (LH). We found that tesofensine induces a greater weight loss in obese rats than lean rats, while differentially modulating the neuronal ensembles and population activity in LH. In Vgat-ChR2 and Vgat-IRES-cre transgenic mice, we found for the first time that tesofensine inhibited a subset of LH GABAergic neurons, reducing their ability to promote feeding behavior, and chemogenetically silencing them enhanced tesofensine's food-suppressing effects. Unlike phentermine, a dopaminergic appetite suppressant, tesofensine causes few, if any, head-weaving stereotypy at therapeutic doses. Most importantly, we found that tesofensine prolonged the weight loss induced by 5-HTP, a serotonin precursor, and blocked the body weight rebound that often occurs after weight loss. Behavioral studies on rats with the tastant sucrose indicated that tesofensine's appetite suppressant effects are independent of taste aversion and do not directly affect the perception of sweetness or palatability of sucrose. In summary, our data provide new insights into the effects of tesofensine on weight loss and the underlying neuronal mechanisms, suggesting that tesofensine may be an effective treatment for obesity and that it may be a valuable adjunct to other appetite suppressants to prevent body weight rebound.

The influence of different proton pump inhibitors and potassium-competitive acid blockers on indomethacin-induced small intestinal injury

BACKGROUND AND AIM

The influence of gastric acid inhibitors (GAIs) on nonsteroidal anti-inflammatory drug (NSAID)-induced enteropathy is controversial. Herein, the influences of different GAIs on NSAID-induced intestinal injury and the underlying mechanisms are clarified.

METHODS

Indomethacin (IND; 10 mg/kg/day) was administered to mice to induce small intestinal injury. Disease activity was examined macroscopically and histologically. The permeability of small intestine was evaluated by measuring plasma lipopolysaccharide levels. 16S rDNA sequencing was performed to determine the composition of intestinal flora.

RESULTS

Among the four GAIs, ilaprazole (IPZ) significantly attenuated IND-induced small intestinal injury and maintained the integrity of the mucosal barrier. Omeprazole (OPZ) and vonoprazan (VPZ) ameliorated ulceration without significant differences, while rabeprazole (RPZ) failed to protect against the injury. To explore the potential mechanism, we investigated changes in the gut microbiota mediated by GAIs. After 5-day administration, GAIs significantly altered the composition of the gut microbiota. The IND group had a significant decrease in alpha diversity compared with the control group, and this decrease was reversed by OPZ and IPZ treatment, respectively. After IPZ treatment, the community membership was more assembled in the control group than the IND group. Further, we found that Lactobacillus was significantly increased in the groups of OPZ, IPZ, and VPZ, while Bacteroides was significantly increased in the RPZ group.

CONCLUSION

Our results indicated that GAIs have different influences on the mucosal barrier, possibly by altering the composition of intestinal microbiota, and the impacts mediated by various GAIs in the IND-induced intestinal damage model seem different.

Hybrid Nanobeads for Oral Indomethacin Delivery

The oral administration of the anti-inflammatory indomethacin (INDO) causes severe gastrointestinal side effects, which are intensified in chronic inflammatory conditions when a continuous treatment is mandatory. The development of hybrid delivery systems associates the benefits of different (nano) carriers in a single system, designed to improve the efficacy and/or minimize the toxicity of drugs. This work describes the preparation of hybrid nanobeads composed of nanostructured lipid carriers (NLC) loading INDO (2%; w/v) and chitosan, coated by xanthan. NLC formulations were monitored in a long-term stability study (25 °C). After one year, they showed suitable physicochemical properties (size < 250 nm, polydispersity < 0.2, zeta potential of −30 mV and spherical morphology) and an INDO encapsulation efficiency of 99%. The hybrid (lipid-biopolymers) nanobeads exhibited excellent compatibility between the biomaterials, as revealed by structural and thermodynamic properties, monodisperse size distribution, desirable in vitro water uptake and prolonged in vitro INDO release (26 h). The in vivo safety of hybrid nanobeads was confirmed by the chicken embryo (CE) toxicity test, considering the embryos viability, weights of CE and annexes and changes in the biochemical markers. The results point out a safe gastro-resistant pharmaceutical form for further efficacy assays.

Alpha-lipoic acid: A promising adjuvant for nonsteroidal anti-inflammatory drugs therapy with improved efficacy and gastroprotection

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used in a wide variety of diseases due to their analgesic and anti-inflammatory effects, but their usage have been limited due to significant ulcerogenic side effects. In the present study, we aimed to evaluate the effect of α-lipoic acid (ALA) treatment on the anti-inflammatory activity of indomethacin (Indo) as well as the possible therapeutic effect of ALA on high dose Indo-induced gastropathy in female mice. Mice were treated with Indo (5 or 30 mg/kg, p.o) alone or in combination with ALA (50, 100 or 200 mg/kg, i.p). in vivo anti-inflammatory effect was evaluated by formalin-induced paw edema measured as paw thickness and edema. Gastric damage was evaluated macroscopically and histologically by scoring mucosal hemorrhage, erosion, edema and inflammation. To our results, Indo was ineffective at 5 mg/kg, but co-treatment with Indo and ALA significantly reduced paw edema, implying that ALA augmented the anti-inflammatory effect of subtherapeutic dose of Indo. However, ALA was not able to induce a further increase in the anti-inflammatory effect of Indo at 30 mg/kg. Unlike the treatment with Indo at 5 mg/kg, Indo at 30 mg/kg caused severe gastric damage that prevented by co-treatment with ALA. These results suggest that combination of ALA with NSAIDs can both increase anti-inflammatory effect and prevent NSAIDs-induced gastric damage. ALA would be promising adjuvant that can reduce dose for effective NSAID therapy, which improves safety profile of NSAIDs especially in cases long-term administration of high dose needed.