Alpha-lipoic acid protects against indomethacin-induced gastric oxidative toxicity by modulating antioxidant system

Investigation of the protective activity of baicalein on the lungs via regulation of various cellular responses in rats exposed to experimental sepsis

Backgrounds

In the present study, a cecal ligation and puncture (CLP)-induced experimental sepsis rat model was used to explore the effects of baicalein on inflammatory cytokine levels and oxidative stress as well as the possible regulatory role of nuclear factor-kappa B (NF-κB).

Methods

For that purpose, 42 Wistar albino rats were equally divided into control, sham, sepsis, B50 + S, B100 + S, S + B50, and S + B100 groups. The B50 + S and B100 + S groups received baicalein before the induction of sepsis, while the S + B50 and S + B100 groups received baicalein afterwards. Experimental sepsis in related groups is generated through ligation of cecum and a puncture in cecal wall. Serum samples were used for tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) analyses, and tissue Malondialdehyde (MDA), Superoxide dismutase (SOD), Glutathione (GSH), IL-6, and NF-κB levels were measured.

Results

Compared to the control group, there were significantly increases in the serum TNF-α, IL-6, tissue MDA, and NF-κB levels and decreases in the tissue SOD and GSH levels in the septic group (P < 0.05). Compared to the septic group, inflammation and oxidative stress were reduced in the baicalein-treated groups. Although all of the pre- and post-treatment protocols alleviated inflammation and oxidative stress to varying degrees, pre-treatment with 100 mg/kg was the most successful.

Conclusions

Findings of this study indicated that baicalein has the potential to reduce sepsis-related oxidative stress and inflammation in the lungs and that pathological outcomes could be regulated via NF-κB transcription factor activity.

Effect of indomethacin on embryo implantation and histomorphology of uterus, ovary, kidney, and liver of rats

Background

This study aimed to determine the effects of Indomethacin (IMC) treatment on embryo implantation and histomorphology of uterus, ovary, and other vital organs and its effective dosage in establishing embryo implantation dysfunction model in Sprague-Dawley (SD) rats.

Materials and Methods

The experiments were performed on 24 (6 × 4 groups) adult female SD rats aged 12 weeks old. G1 was the control group and received a normal diet with normal saline. However, on pregnancy days 3 (Pd3) and 4 (Pd4), G2, G3, and G4 were given normal saline and subcutaneously administered IMC twice daily at different doses of 4.33, 4.66 and 5.00 mg/kg body weight, respectively. The rats were euthanized on day 8 of pregnancy (Pd8). The uterus was excised and examined for signs of pregnancy, followed by tissue samples from liver, kidney, and ovary (for histomorphological examination using haematoxylin and eosin stain).

Results

All IMC treatment doses disrupted the implantation process and caused a significant reduction in embryo development. Analysis for histopathological changes revealed that IMC doses above 4.33 mg/kg body weight caused more adverse reproductive health effects in rats. Vasoconstriction and micro vascularization were detected in the liver, while degenerative Bowman's capsules and inflammatory cells were observed in kidney sections from IMC-treated rats.

Conclusion

IMC therapy interfered with implantation and embryo development in rats, resulting in significant uterine vasoconstriction and atrophy, 4.33 mg/kg bwt dose appeared to be optimum to establish embryo implantation dysfunction in SD rats.

Protective Effects of Alpha-Lipoic Acid against 5-Fluorouracil-Induced Gastrointestinal Mucositis in Rats

Alpha-lipoic acid (ALA) is extensively utilized in multivitamin formulas and anti-aging products. The purpose of this study was to investigate the potential protective benefits of ALA on 5-fluorouracil (5-FU)-induced gastrointestinal mucositis in Wistar albino rats. Tissues from the stomach, small intestine, and large intestine were excised, and blood sera were obtained to identify biochemical indices such as TNF-α, IL-1β, MDA, GPx, SOD, MMP-1, -2, -8, and TIMP-1. A histopathological study was also performed. The results revealed mucositis-elevated TNF-, IL-1, MDA, MMP-1, -2, -8, and TIMP-1 levels in both tissues and sera, and these values dropped dramatically following ALA treatment. Reduced SOD and GPx activities in mucositis groups were reversed in ALA-treated groups. The damage produced by mucositis in the stomach and small intestine regressed in the ALA-treated group, according to histopathological evaluation. Consequently, the implementation of ALA supplementation in 5-FU therapy may act as a protective intervention for cancer patients with gastrointestinal mucositis. In light of the findings, ALA, a food-derived antioxidant with pleiotropic properties, may be an effective treatment for 5-FU-induced gastrointestinal mucositus, and prevent oxidative stress, inflammation, and tissue damage in cancer patients receiving 5-FU therapy.

Gastroprotective effect of vitamin U in D-galactosamine-induced hepatotoxicity

Galactosamine (GalN) is a well-known agent for inducing viral hepatitis models in rodents, but it can cause toxicity on different organs. Vitamin U (Vit U) has been proved as a powerful antioxidant on many toxicity models. The present study was designed to investigate the protective effects of Vit U on GalN-induced stomach injury. Rats were divided into four groups as follows: control (group I), Vit U given animals (50 mg/kg per day; group II), GalN administered animals (500 mg/kg at a single dose; group III), GalN + Vit U given animals (at the same dose and time, group IV). At the end of the 3rd day, animals were killed, and stomach tissues were taken. They were homogenized and centrifuged. In comparison to the control group, glutathione, total antioxidant capacity levels, catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, and Na⁺ /K⁺ -ATPase activities of GalN group were found to be decreased. On the contrary, lipid peroxidation, advanced oxidized protein products, hexose-hexosamine, fucose, sialic acid, reactive oxygen species levels, as well as the activities of myeloperoxidase, xanthine oxidase, and lactate dehydrogenase were elevated. Administration of Vit U reversed these abnormalities in the GalN group. It can be concluded that Vit U exerts its unique antioxidant effect and prevents GalN-induced gastric damage.

Sodium R-lipoate and enzymatically-modified isoquercitrin suppressed IgE-independent anaphylactic reactions and stress-induced gastric ulceration in mice

Anaphylaxis is a life-threatening allergic reaction, for which the worldwide prevalence is rapidly increasing. The currently used synthetic antiallergic drugs have a high tendency to cause adverse effects, like gastric ulcers, in long-term use. Therefore, a great deal of attention has been given to develop new safer and more effective antiallergic agents from natural compounds that are chemically/enzymatically-modified. Here, we evaluated/compared the efficacy of two different doses (50 and 100 mg/kg body weight "b.w", given orally) of sodium R-lipoate (NaRLA) and enzymatically-modified isoquercitrin (EMIQ) in alleviating both local/systemic non-immunological anaphylactic reactions and stress-induced gastric ulceration in mice, in comparison with sulfasalazine (SSZ) as a reference drug. The results indicated that the pre-treatment of animals with NaRLA or EMIQ (especially at 100 mg/kg b.w) completely succeeded, as SSZ, in alleviating the hind paw edema induced by either histamine or compound 48/80 (Cpd 48/80). Furthermore, NaRLA and EMIQ prevented the mast cell degranulation and anaphylactic shock caused by Cpd 48/80 (in a dose-dependent manner) and reduced significantly (P < 0.001) the histamine release from the mouse peritoneal mast cells, like SSZ. Moreover, their use was associated with alleviating both gastric histopathological and biochemical alterations in the water-restraint stress (WRS) mice model towards the control values. They also decreased the percentage of degranulated mesenteric mast cells in the WRS mice model. In conclusion, our findings provide possibility that both NaRLA and EMIQ may serve as an effective therapeutic agents for mast cells-dependent anaphylactic reactions without risks of inducing gastric ulcers.

Optimized Self-Nanoemulsifying Delivery System Based on Plant-Derived Oil Augments Alpha-Lipoic Acid Protective Effects Against Experimentally Induced Gastric Lesions

Peptic ulcer disease is an injury of the alimentary tract that leads to a mucosal defect reaching the submucosa. Alpha-lipoic acid (ALA), a natural potent antioxidant, has been known as a gastroprotective drug yet its low bioavailability may restrict its therapeutic efficacy. This study aimed to formulate and optimize ALA using a self-nanoemulsifying drug delivery system (SNEDDS) with a size of nano-range, enhancing its absorption and augmenting its gastric ulcer protection efficacy. Three SNEDDS components were selected as the design factors: the concentrations of the pumpkin oil (X1, 10–30%), the surfactant tween 80 (X2, 20–50%), and the co-surfactant polyethylene glycol 200 (X3, 30–60%). The experimental design for the proposed mixture produced 16 formulations with varying ALA-SNEDDS formulation component percentages. The optimized ALA-SNEDDS formula was investigated for gastric ulcer protective effects by evaluating the ulcer index and by the determination of gastric mucosa oxidative stress parameters. Results revealed that optimized ALA-SNEDDS achieved significant improvement in gastric ulcer index in comparison with raw ALA. Histopathological findings confirmed the protective effect of the formulated optimized ALASNEDDS in comparison with raw ALA. These findings suggest that formulation of ALA in SNEDDS form would be more effective in gastric ulcer protection compared to pure ALA.

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.

Anti-ulcerogenic effect of osajin on indomethacin-induced gastric damage in rats

Ulcer is the most common undesirable result of using non-steroid anti-inflammatory drugs such as indomethacin. In the present study, osajin was experimentally used on indomethacin-induced gastric ulcer in rats. Osajin was purified from Maclura pomifera (Raf.) C. K. Schneid fruits by using the chromatographic methods. Thirty six rats were divided into six groups as follows: healthy (control), IND (indomethacin), RAN (ranitidine, 25 mg/kg), OSJ 100 (osajin, 100 mg/kg), OSJ 200 (200 mg/kg) and OSJ 400 (osajin, 400 mg/kg). Following a 24-h fasting, IND was administered to the treatment groups at a dose of 25 mg/kg. RAN and OSJ were given orally to rats following 5 min of IND administration. Then, gastric tissues were taken 6 h after the IND administration. Determination of the ulcer area, pathological evidence, and biochemical indices such as lipid peroxidation, superoxide dismutase, glutathione, and catalase were performed. IND generated diffuse ulcer areas, severe hyperaemia, oedema, necrotic epithelium, and mononuclear cell infiltration in the mucosa, and significantly increased lipid peroxidation while also decreasing the glutathione concentration, superoxide dismutase and catalase activities of the tissue. OSJ and RAN showed significant amelioration on ulcer area and biochemical indices. Therefore, OSJ may be potentially therapeutic for gastric ulcers.

LP44 (4-[2-(methylthio)phenyl]-N-(1,2,3,4-tetrahydronaphthalen-1-yl)-1-piperazinehexanamide) exerts anti-ulcer effects via 5-hydroxytryptamine receptor 7 activation on indomethacin-induced gastric ulcers in rats

AIM

This study aimed to demonstrate the role of serotonin 7 receptor (5-HT₇) and the effects of 5-HT₇ agonists and antagonists in an indomethacin-induced gastric ulcer.

MATERIAL AND METHOD

Male albino Wistar rats (n = 60) were used in the experiments. LP44 (5-HT₇ agonist) and SB269970 (5-HT₇ antagonist) were administered at 10 mg/kg as a pre-treatment. One hour after the drug treatments, 25 mg/kg of indomethacin (INDO) was administered to all groups except the healthy control group. Six hours after indomethacin administration, all the rats were euthanized.

RESULTS

We analyzed the iNOS, eNOS, and 5-HT₇ receptor mRNA levels in the stomach tissue of rats by real-time PCR. 5-HT₇ mRNA expression was increased in the INDO group compared to the healthy group. LP44 administration exerted a significant upregulatory effect on eNOS mRNA expression and downregulatory effects on iNOS and 5-HT₇ mRNA expression compared to the INDO group. However, antagonist (SB269970) administration did not result in such difference in gene expression, but even partially decreased the agonist's effect in combination. Famotidine and agonist exerted similar effects. Histopathological findings supported the beneficial effects of 5-HT₇ agonist on gastric tissue.

CONCLUSION

The study suggested that activation of 5-HT₇ receptor showed a significant anti-ulcerogenic effect in the indomethacin-induced gastric ulcer model.

Evaluation of gastroprotective and ulcer healing activities of yellow mombin juice from Spondias mombin L

Spondias mombin L. (yellow mombin) is a tree with a nutritional fruit that is commonly consumed in the North and Northeast of Brazil, as the juice of its pulp is rich in antioxidant compounds. This study aimed to investigate the gastroprotective and ulcer healing activities of yellow mombin juice (YMJ) in Wistar rats, and to elucidate the possible involved mechanisms. Phytochemical characterization of the lyophilized fruit juice was performed by high-performance liquid chromatography (HPLC). The gastroprotective activity of YMJ was investigated in ethanol (25, 50, and 100% YMJ) and indomethacin (100% YMJ) models of acute gastric ulcer in rats. Then, the effect of YMJ on mucus production and gastric secretions, and the involvement of non-protein sulfhydryl groups and prostaglandins in the gastroprotective process were examined. Moreover, the ulcer healing effect of YMJ was investigated in a model of acetic acid-induced chronic ulcer through histological and immunohistochemical analyses. HPLC results identified the presence of epicatechin (7.1 ± 1.6 μg/mL) and quercetin (17.3 ± 2.5 μg/mL) in YMJ. Ethanol-induced gastric lesions were inhibited by YMJ (25, 50, and 100%) by 42.42, 45.09, and 98.21% respectively, and indomethacin-induced lesions were inhibited by YMJ (100%) by 58.96%, compared to control group. Moreover, YMJ reduced gastric content and total acidy by 57.35 and 71.97%, respectively, compared to the control group. Treatment with YMJ also promoted healing of chronic ulcer, regeneration of the gastric mucosa, and restoration of mucus levels in glandular cells, as confirmed by histological analysis. It also increased cellular proliferation, as demonstrated by high reactivity to Ki-67 and bromodeoxyuridine. In conclusion, YMJ was found to possess gastroprotective and ulcer healing activities that are correlated to its antisecretory action. These results support the commercial exploration of YMJ as a functional food.

Antioxidant and anti-inflammatory activities of alpha lipoic acid protect against indomethacin-induced gastric ulcer in rats

Little is known about the role of tumor necrosis factor-alpha (TNF-α), plasminogen activator inhibitor-1 (PAI-1), and inducible nitric oxide synthase (iNOS) in the gastric ulcer and the effect of alpha lipoic acid (ALA) in their modulation. Hence, this experimental study was designed to assess the possible protective effect of ALA against indomethacin (IND)-induced gastric ulcer in rats, as well as to determine the possible underlying mechanisms with a special focus on TNF-α, PAI-1, and iNOS. Adult male rats (n = 28) were divided into four equal groups: the control group received distilled water, the vehicle group received 0.5% carboxymethylcellulose, the ulcer group received a single oral dose of IND (50 mg/kg) and the ALA-treated group received ALA (100 mg/kg) orally for 3 days before ulcer induction. Four hours after IND administration, all rats were sacrificed. The ulcer index, and gastric tissue homogenate contents of total antioxidant capacity (TAC), malondialdehyde (MDA), TNF-α, and PAI-1 were evaluated. Immunohistochemical evaluation of iNOS protein expression and histopathological examination of gastric tissue were investigated. The results revealed that ALA pretreatment significantly decreased the ulcer index, the gastric levels of MDA, TNF-α, PAI-1, and iNOS protein expression while increased the gastric levels of TAC as well as improved the histopathological appearance of gastric tissues. In conclusion, ALA ameliorated the IND-induced gastric ulceration. This could be attributed to its antioxidant and anti-inflammatory activities via suppression of TNF-α-induced elevation of both PAI-1 level and iNOS expression in the gastric tissue.

Comparative evaluation of the electrophysiological, functional and ultrastructural effects of alpha lipoic acid and cyanocobalamin administration in a rat model of sciatic nerve injury

BACKGROUND

Vitamin B12 and alpha lipoic acid (ALA) are known to promote functional and morphological recovery after peripheral nerve injury.

OBJECTIVE

To compare the regenerative and neuroprotective effects of vitamin B12 and ALA treatment after sciatic nerve injury.

METHODS

A total of 40 rats were randomly assigned to control (sciatic nerve exposure without injury or anastomosis), sham (sciatic nerve injury and epineural anastomosis were performed but no treatment was administered), PS (isotonic saline was administered for 12 weeks after surgery), ALA (2 mg/kg ALA was administered for 12 weeks after surgery), and vitamin B12 groups (2 mg/kg cyanocobalamin was administered for 12 weeks after surgery). Functional recovery was determined by footprint analysis, in vivo neurophysiology, and ex vivo histopathological examination.

RESULTS

ALA treatment produced significant improvements in sciatic functional index values and non-significant improvements on electroneuromyography compared to vitamin B12 treatment. Upon histopathological examination, the regenerative effects of ALA were relevant to axonal structural recovery whereas vitamin B12 produced greater improvements in edema and myelination.

CONCLUSIONS

While both vitamin B12 and ALA produced improvements after sciatic nerve injury, ALA was more functionally effective. The unique ultrastructural effects of vitamin B12 and ALA treatment should be considered in future studies.

Alleviation of bone markers in rats induced nano-zinc oxide by qurecetin and α-lipolic acid

The purpose of this study was to evaluate the potential protective effect of qurecetin (Qur) and α-lipolic acid (ALA) to modulate the perturbation of bone turnover which is induced by nano-zinc oxide (n-ZnO). Rats were fasted overnight and randomly divided into two groups: G1, normal healthy animals and the other rats were administered zinc oxide nanoparticles orally by guava in a dose of 600 mg/kg body weight/d for 5 sequential days in Wistar albino male rats. N-ZnO-exposed animals were randomly sub-divided into three groups: G2, n-ZnO-exposed animals; G3, n-ZnO-exposed animals co-treated with Qur (200 mg/kg daily); and G4, n-ZnO-exposed animals co-treated with ALA (200 mg/kg). Qur and ALA were administered orally by guava daily for three sequential weeks from the beginning of the experiment. The results revealed a significant reduction of nitiric oxide (NO) and serum level and comet assay in n-ZnO exposure rats after treatment of Qur and ALA. It was found the alteration of pro-inflammatory markers (tumor necrosis factor alpha; TNF-α, interleukin-6; IL-6 and C-reactive protein; CRP), bone alkaline phosphatase (B-ALP, bone formation marker), and C-terminal peptide type I collagen (CTx, bone resorption marker) levels compared with the normal group. Co-administration of Qur and ALA in n-ZnO-exposed rats significantly alleviated the mentioned alterations of biochemical parameters. These results suggest that Qur and ALA as antioxidant agents may be a candidate for preventive and treatment applications of impaired bone markers induced bone loss caused by nano-particles of metal oxide.

Autism genes are selectively targeted by environmental pollutants including pesticides, heavy metals, bisphenol A, phthalates and many others in food, cosmetics or household products

The increasing incidence of autism suggests a major environmental influence. Epidemiology has implicated many candidates and genetics many susceptibility genes. Gene/environment interactions in autism were analysed using 206 autism susceptibility genes (ASG's) from the Autworks database to interrogate ∼1 million chemical/gene interactions in the comparative toxicogenomics database. Any bias towards ASG's was statistically determined for each chemical. Many suspect compounds identified in epidemiology, including tetrachlorodibenzodioxin, pesticides, particulate matter, benzo(a)pyrene, heavy metals, valproate, acetaminophen, SSRI's, cocaine, bisphenol A, phthalates, polyhalogenated biphenyls, flame retardants, diesel constituents, terbutaline and oxytocin, inter alia showed a significant degree of bias towards ASG's, as did relevant endogenous agents (retinoids, sex steroids, thyroxine, melatonin, folate, dopamine, serotonin). Numerous other suspected endocrine disruptors (over 100) selectively targeted ASG's including paraquat, atrazine and other pesticides not yet studied in autism and many compounds used in food, cosmetics or household products, including tretinoin, soy phytoestrogens, aspartame, titanium dioxide and sodium fluoride. Autism polymorphisms influence the sensitivity to some of these chemicals and these same genes play an important role in barrier function and control of respiratory cilia sweeping particulate matter from the airways. Pesticides, heavy metals and pollutants also disrupt barrier and/or ciliary function, which is regulated by sex steroids and by bitter/sweet taste receptors. Further epidemiological studies and neurodevelopmental and behavioural research is warranted to determine the relevance of large number of suspect candidates whose addition to the environment, household, food and cosmetics might be fuelling the autism epidemic in a gene-dependent manner.

Pharmacological reports about gastroprotective effects of methanolic extract from leaves of Solidago chilensis (Brazilian arnica) and its components quercitrin and afzelin in rodents

Solidago chilensis Meyenmost (Asteraceae), popularly known as "Brazilian arnica" or "arnica-do-campo," is widely used in the folk medicine to treat gastric disorders. Based on this, the gastroprotective activity of S. chilensis methanolic extract was investigated. Besides, a phytochemical study allowed isolation of two flavonoids (quercitrin and afzelin). The gastroprotective effects were investigated in acute gastric ulcer models, and the antisecretory activity was assessed in vivo and in vitro. The adhered mucus levels, reduced glutathione (GSH) content and myeloperoxidase (MPO) activity were quantified in ulcerated tissues. The contribution of isolated compounds in extract effects was evaluated, and its doses were calculated according to its yield. To evaluate the in vivo healing properties of S. chilensis methanolic extract, a chronic gastric ulcer was induced in mice by 10 % acetic acid. Evaluation of tumor necrosis factor (TNF) levels was also performed at the site of the acetic acid-induced gastric ulcer. In parallel, effects on cell viability and cell proliferation of fibroblasts (L929 cells) were determined by in vitro trials. Firstly, the S. chilensis methanolic extract (100 or 300 mg/kg) reduced the ulcer area induced by ethanol/HCl in mice when compared to the vehicle group. Moreover, the S. chilensis extract (300 mg/kg) prevented the mucus depletion, the increase in MPO activity and the decrease in the GSH levels in the ulcerated gastric tissue. The S. chilensis extract also was able to decrease the indomethacin-induced gastric ulcer in rats at a dose of 100 mg/kg. The antisecretory effect of the extract (100 mg/kg, intraduodenal (i.d.)) was confirmed by the reduction in the volume and acidity in parallel to an increase in the pH of gastric content. In addition, quercitrin (1.38 mg/kg, but not 0.46 mg/kg) and afzelin (0.026 and 0.078 mg/kg) decreased the ethanol/HCl-induced gastric ulcer. In this model, quercitrin (1.38 mg/kg) prevented the depletion of gastric GSH content and both quercitrin (1.38 mg/kg) and afzelin (0.078 mg/kg) reduced the MPO activity. These compounds also inhibited the H(+),K(+)-ATPase activity at a concentration of 1-100 μg/ml. In addition, the participation of quercitrin and afzelin in these effects also was confirmed. Furthermore, after 4 days of the treatment, an oral administration of S. chilensis methanolic extract (100 mg/kg) reduced the area of the gastric ulcer induced by acetic acid and the regeneration of the gastric mucosa was accompanied by a reduction in gastric TNF levels. The healing properties of the extract also were confirmed by enhancement of proliferation and coverage of scratched wounds in a fibroblast monolayer. Together, our results confirmed the gastroprotective effect of S. chilensis methanolic extract as well as its gastric healing potential and provided some support to the traditional use of S. chilensis for prevention and treatment of gastric lesions in complementation to its known anti-inflammatory properties.

Alpha-lipoic acid treatment of acetaminophen-induced rat liver damage

Acetaminophen (paracetamol) is a well-tolerated analgesic and antipyretic drug when used at therapeutic doses. Overdoses, however, cause oxidative stress, which leads to acute liver failure. Alpha lipoic acid is an antioxidant that has proven effective for ameliorating many pathological conditions caused by oxidative stress. We evaluated the effect of alpha lipoic acid on the histological and histochemical alterations of liver caused by an acute overdose of acetaminophen in rats. Livers of acetaminophen-intoxicated rats were congested and showed centrilobular necrosis, vacuolar degeneration and inflammatory cell infiltration. Necrotic hepatocytes lost most of their carbohydrates, lipids and structural proteins. Liver sections from rats pre-treated with lipoic acid showed fewer pathological changes; the hepatocytes appeared moderately vacuolated with moderate staining of carbohydrates and proteins. Nevertheless, alpha lipoic acid at the dose we used did not protect the liver fully from acetaminophen-induced acute toxicity.

Neurotoxic effects of nickel chloride in the rainbow trout brain: Assessment of c-Fos activity, antioxidant responses, acetylcholinesterase activity, and histopathological changes

The aim of this study was to determine the biochemical, immunohistochemical, and histopathological effects of nickel chloride (Ni) in the rainbow trout brain. Fish were exposed to Ni concentrations (1 mg/L and 2 mg/L) for 21 days. At the end of the experimental period, brain tissues were taken from all fish for c-Fos activity and histopathological examination and determination of acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT) enzyme activities, lipid peroxidation (LPO), and glutathione (GSH) levels. Our results showed that Ni treatment caused a significant increase in the brain SOD activity and in LPO and GSH levels (p < 0.05), but it significantly decreased AChE and CAT enzyme activities (p < 0.05). Strong induction in c-Fos was observed in some cerebral and cerebellar regions of fish exposed to Ni concentrations when compared with the control group. However, c-Fos activity was decreased in necrotic Purkinje cells. Brain tissues were characterized by demyelination and necrotic changes. These results suggested that Ni treatment causes oxidative stress, changes in c-Fos activity, and histopathological damage in the fish brain.

Gastroprotective Effects of Glutinous Rice Extract against Ethanol-, Indomethacin-, and Stress-induced Ulcers in Rats

This study was designed to evaluate the efficacy of an orally administered aqueous extract of glutinous rice (GRE) to protect against acute gastric mucosal lesions induced by ethanol, indomethacin, and water immersion restraint stress in rats and to characterize the active substances responsible for the protection. GRE was shown to dose-dependently prevent the gastric lesions induced by the above ulcerogenic treatments at doses of 30 to 300 mg/kg. GRE treatment increased the gastric mucin content and partially blocked the ethanol-induced depletion of the gastric mucus layer. Also, it increased the nonprotein sulfhydryl concentration in the gastric mucosa. The gastroprotective action of GRE was markedly enhanced by co-treatment with 4-8 mg/kg tea extracts. The activity of GRE was completely lost by heat treatment at 80℃ for 3 min or treatment with 0.01% pepsin at 37℃ for 1 h. Protein extraction studies indicated that prolamins are involved in the gastroprotective activity of GRE. Our results suggest that glutinous rice proteins are useful for the prevention and treatment of gastritis and peptic ulcer.

Protective effects of alpha-lipoic acid on experimental sciatic nerve crush injury in rats: assessed with functional, molecular and electromicroscopic analyses

AIM

The present study aimed to demonstrate protective effects of alpha lipoic acid on experimental sciatic nerve crush injury model assessed with functional and electronmicroscopy analyses.

METHODS

In this study, groups were; Group 1; sham operated, Group 2; applied only sciatic nerve crush (Control), Group 3; Sciatic nerve crush + treated ALA 25 mg/kg (received orally) and Group 4; Sciatic nerve crush + treated ALA 50 mg/kg. Subsequently, sciatic nerves crush injury induced by forceps. At the second and fourth week, all animals were evaluated for sciatic functional index (SFI) and histomorphometric analyses with electronmicroscopy.

RESULTS

The SFI was significantly increased for both ALA-treated groups 30 days post-injury compared with control groups. The elecronmicroscopy results demonstrated that the axon diameter, the myelin diameter, the area of regenerating axon and miyelin were better in the treatment group than in the control group. Also ALA decreased IL-1β and Caspase 3 levels that increased in SNC group.

CONCLUSIONS

These results suggest that ALA neuroprotective agent for peripheral nerve injury (PNI) and promoted peripheral nerve regeneration via its anti-inflammatory and antiapoptotic effects.

Gastroduodenal mucosal defense

PURPOSE OF REVIEW

To review recent developments in the field of gastroduodenal mucosal defense.

RECENT FINDINGS

Research in the field of gastroduodenal mucosal defense has focused on continued elucidation of molecular mechanisms that protect the mucosa and influence healing at the cellular level. Review of literature over the past year reveals focus on familiar processes such as superoxide dismutase, nitric oxide, heme oxygenase-1, neutrophil infiltration, cysteamine, mucin, hydrogen sulfide, ghrelin, adiponectin and the influence of Helicobacter pylori, but also brings into light new processes such as the balance between apoptosis and cellular proliferation, as well as the influence of other organ systems such as the bone marrow and central nervous system on the gastrointestinal tract.

SUMMARY

These new published findings contribute to our overall understanding of gastroduodenal defense and suggest innovative avenues of future research and possible novel therapeutic targets.

The effect of alpha-lipoic acid in ovariectomy and inflammation-mediated osteoporosis on the skeletal status of rat bone

Osteoporosis is a high mortality and morbidity ranged skeletal disease and results in high costs of medical care in the European Union. We evaluated the possible protective effect of alpha-lipoic acid (ALA) on rat bone metabolism in ovariectomy and inflammation-mediated osteoporosis models. Groups were designed as: (1) sham; (2) sham+inflammation; (3) ovariectomy (OVX); (4) ovariectomy+ALA-25mg/kg; (5) ovariectomy+ALA-50mg/kg; (6) ovariectomy+inflammation; (7) ovariectomy+inflammation+ALA-25mg/kg; and (8) ovariectomy+inflammation+ALA-50mg/kg groups. OVX groups were allowed to recover for two months. Then, inflammation was induced in inflammation groups by subcutaneous talc injection. ALA-25mg/kg and 50mg/kg were administered to drug groups chronically. The skeletal response was assessed by bone mineral density (BMD), osteopontin and osteocalcin measurements. Pro-inflammatory cytokine measurements (interleukin (IL)-1 beta, interleukin-6, and tumor necrosis factor-alpha) were performed to observe inflammatory process. In OVX, INF and OVX+INF groups, BMD levels were lowest and osteocalcin, osteopontin, IL-1 beta, IL-6, and TNF-alpha levels were highest when compared to sham group. ALA administration increased BMD levels and decreased osteocalcin, osteopontin, IL-1 beta, IL-6, and TNF-alpha levels versus OVX and OVX+INF control groups. Both in senile and postmenopausal osteoporosis, the balance in coupling were destroyed on behalf of bone resorption. ALA had a protective effect on both senile and postmenopausal osteoporosis. The positive effect of this drug in these osteoporosis models might originate from its positive effects on bone turnover markers and cytokine levels. From this perspective, ALA may be a candidate for radical osteoporosis treatment both in senile and postmenopausal types clinically at the end of advanced studies.