Perspectives About Ascorbic Acid to Treat Inflammatory Bowel Diseases.

It is known that reactive oxygen species cause abnormal immune responses in the gut during inflammatory bowel diseases (IBD). Therefore, oxidative stress has been theorized as an agent of IBD development and antioxidant compounds such as vitamin C (L-ascorbic acid) have been studied as a new tool to treat IBD. Therefore, the potential of vitamin C to treat IBD was reviewed here as a critical discussion about this field and guide future research. Indeed, some preclinical studies have shown the beneficial effects of vitamin C in models of ulcerative colitis in mice and clinical and experimental findings have shown that deficiency in this vitamin is associated with the development of IBD and its worsening. The main mechanisms that may be involved in the activity of ascorbic acid in IBD include its well-established role as an antioxidant, but also others diversified actions. However, some experimental studies employed high doses of vitamin C and most of them did not perform dose-response curves and neither determined the minimum effective dose nor the ED50. Allometric extrapolations were also not made. Also, clinical studies on the subject are still in their infancy. Therefore, it is suggested that the research agenda in this matter covers experimental studies that assess the effective, safe, and translational doses, as well as the appropriate administration route and its action mechanism. After that, robust clinical trials to increase knowledge about the role of ascorbic acid deficiency in IBD patients and the effects of their supplementation in these patients can be encouraged.

Characterization of Diclofenac-induced Renal Damage in Normotensive and Hypertensive Rats: A Comparative Analysis.

BACKGROUND: Diclofenac is the non-steroidal anti-inflammatory drug (NSAID) mostly prescribed worldwide, but it is highly associated with hypertension and acute kidney injury. Despite that, little information is available about the renal effects of diclofenac in hypertensive individuals, which led us to carry out this comparative study between the renal effects of this NSAID in normotensive (NTR) and spontaneously hypertensive rats (SHR). METHODS: Male Wistar NTR and SHR were orally treated with vehicle (V: 10 mL/kg) or diclofenac sodium (D: 100 mg/kg) once a day for 3 days. Urine volume, electrolytes excretion (Na+, K+, Cl-, and Ca2+), urea, creatinine, pH, and osmolarity were evaluated. Furthermore, blood samples and renal tissue were collected to perform biochemical and histological analysis. RESULTS: Diclofenac increased the renal corpuscle and bowman's space in the SHR, while no microscopic changes were observed in the renal tissue of NTR. Regarding the urinary parameters, diclofenac reduced urine volume, pH, osmolarity, and all electrolytes excretion, followed by decreased urea and creatinine levels in both lineages. Moreover, it also induced hyponatremia, hypokalemia, and hypocalcemia in SHR, while reduced glutathione-S-transferase activity, lipid hydroperoxides, and nitrite levels in renal tissue. CONCLUSIONS: The data presented herein demonstrated that diclofenac induces renal damage and impaired renal function in both NTR and SHR, but those effects are exacerbated in SHR, as seen by the histological changes and electrolytes balance disturbance, therefore, reinforcing that diclofenac may increase the risks of cardiovascular events in hypertensive patients.

3-Demethyl-2-geranyl-4-prenylbellidifoline, a natural xanthone with diuretic and kidney protective properties.

OBJECTIVES: The diuretic and kidney protective effect of the 3-demethyl-2-geranyl-4-prenylbellidifoline (DGP) were evaluated in rats. METHODS: The normotensive (NTR) and spontaneously hypertensive rats (SHR) received, once a day for 7 days, oral treatment with DGP (0.1 mg/kg), hydrochlorothiazide (10 mg/kg), or vehicle (10 ml/kg). Urine, blood, and kidney samples were collected for further analysis. KEY FINDINGS: The urine and Na+ elimination content were significantly higher in the groups that received DGP. Furthermore, a Ca2+-sparing action was detected in the urine of DGP-treated groups, which was consistent with the reduction in calcium oxalate crystal formation. Relevantly, the treatment did not change the parameters examined in the blood. Concerning the renal analyses, DGP treatment recovered the morphological damages of the kidney corpuscle area of SHR. In addition to the differences observed between the NTR and SHR vehicle groups, DGP augmented the amount of reduced glutathione and the activity of glutathione S-transferase GST while reducing the catalase and N-acetyl-ß-D-glucosaminidase activity and nitrite levels. CONCLUSION: Together, this study displayed the prolonged diuretic action of DGP and its natriuretic, Ca2+-sparing, and antiurolytic effects. The antioxidative and anti-inflammatory effects of DGP were evidenced in SHR kidneys, opening perspectives for further studies regarding the benefits of this xanthone.

Are silymarin and N-acetylcysteine able to prevent liver damage mediated by multiple factors? Findings against ethanol plus LPS-induced liver injury in mice.

This study investigated the effect of N-acetylcysteine (NAC) and silymarin (SIL) in the liver of mice exposed to ethanol and lipopolysaccharides (LPS). Mice were divided into four groups (n = 6): naive, vehicle, NAC (200 mg/kg), and SIL (200 mg/kg). Treatments were given orally (po) once daily for 10 days. Liver injury was induced by administration of ethanol (30%, po) for 10 days, once daily, followed by a single administration of LPS (2 mg/kg, ip) 24 h before euthanasia. After the treatment period, animals were euthanized, and liver and blood samples were collected. NAC, but not SIL, prevented the increase in oxalacetic glutamic transaminase (OGT) and pyruvic glutamic transaminase (PGT) serum levels. NAC and SIL did not restore levels of reduced glutathione or hepatic malonaldehyde. The treatments with NAC or SIL showed no difference in the activity of glutathione S-transferase, superoxide dismutase, and catalase compared to vehicle group. Myeloperoxidase and N-acetylglucosaminidase activities are increased, as well as the IL-6 and IL-10 levels in the liver. The treatment with NAC, but not SIL, reduced the N-acetylglucosamines activity and the IL-6 and IL-10 amount in the liver. Histological findings revealed microsteatosis in the vehicle group, which was not prevented by SIL but was partially reduced in animals receiving NAC. Unlike other liver injury models, NAC (200 mg/kg) or SIL (200 mg/kg) did not positively affect antioxidant patterns in liver tissue of animals exposed to ethanol plus LPS, but NAC treatment displays anti-inflammatory properties in this model.

Diuretic, Natriuretic, And Ca2+-Sparing Effect Of The Alkaloid Boldine In Rats.

BACKGROUND: Previous studies indicate the renal vasodilating effects of boldine, an alkaloid found in Peumus boldus. However, its potential to induce diuresis still needs to be studied. METHODS: Wistar rats were used and the urine volume was noted for 8 h and further studied. RESULTS: The acute treatment at 0.1 and 0.3 mg/kg of boldine showed a diuretic, natriuretic, and Ca2+-sparing effect in rats without changing the urinary elimination of K+and Cl-. When boldine was given in combination with hydrochlorothiazide, there was an increase in urinary volume compared to the vehicle group. However, this was not different from the treatments in its isolated form. Urine Ca2+values ​​remained low but were not enhanced by this association. The excretion of Na+and Cl- was significantly increased compared to the group that received only vehicle or boldine. On the other hand, although the association of amiloride plus boldine did not result in a diuretic effect, the increase in Na+and the reduction in K+excretion were significantly potentiated. Furthermore, in the presence of the non-selective muscarinic receptor antagonist atropine, boldine showed reduced capacity to increase urinary volume, maintaining the natriuretic and Ca2+-sparing effect, besides a very evident K+-sparing action. Similar results were obtained in the presence of the non-selective cyclooxygenase inhibitor indomethacin. Furthermore, boldine showed an ex vivo antiurolithiasis activity, reducing calcium oxalate's precipitation and crystallization. CONCLUSIONS: This study reveals the diuretic, natriuretic, Ca2+-sparing, and antiurolithiatic effects of boldine, an action possibly related to muscarinic receptor activation and prostanoid generation.

Role of K+ and Ca2+ Channels in the Vasodilator Effects of Plectranthus barbatus (Brazilian Boldo) in Hypertensive Rats.

Plectranthus barbatus, popularly known as Brazilian boldo, is used in Brazilian folk medicine to treat cardiovascular disorders including hypertension. This study investigated the chemical profile by UFLC-DAD-MS and the relaxant effect by using an isolated organ bath of the hydroethanolic extract of P. barbatus (HEPB) leaves on the aorta of spontaneously hypertensive rats (SHR). A total of nineteen compounds were annotated from HEPB, and the main metabolite classes found were flavonoids, diterpenoids, cinnamic acid derivatives, and organic acids. The HEPB promoted an endothelium-dependent vasodilator effect (~100%; EC50 ~347.10 µg/mL). Incubation of L-NAME (a nonselective nitric oxide synthase inhibitor; EC50 ~417.20 µg/mL), ODQ (a selective inhibitor of the soluble guanylate cyclase enzyme; EC50 ~426.00 µg/mL), propranolol (a nonselective α-adrenergic receptor antagonist; EC50 ~448.90 µg/mL), or indomethacin (a nonselective cyclooxygenase enzyme inhibitor; EC50 ~398.70 µg/mL) could not significantly affect the relaxation evoked by HEPB. However, in the presence of atropine (a nonselective muscarinic receptor antagonist), there was a slight reduction in its vasorelaxant effect (EC50 ~476.40 µg/mL). The addition of tetraethylammonium (a blocker of Ca2+-activated K+ channels; EC50 ~611.60 µg/mL) or 4-aminopyridine (a voltage-dependent K+ channel blocker; EC50 ~380.50 µg/mL) significantly reduced the relaxation effect of the extract without the interference of glibenclamide (an ATP-sensitive K+ channel blocker; EC50 ~344.60 µg/mL) or barium chloride (an influx rectifying K+ channel blocker; EC50 ~360.80 µg/mL). The extract inhibited the contractile response against phenylephrine, CaCl2, KCl, or caffeine, similar to the results obtained with nifedipine (voltage-dependent calcium channel blocker). Together, the HEPB showed a vasorelaxant effect on the thoracic aorta of SHR, exclusively dependent on the endothelium with the participation of muscarinic receptors and K+ and Ca2+ channels.

Dimethyl Cardamonin from Fruits of Campomanesia reitziana D. Legrand Promotes Gastroprotection and Gastric Healing Effects in Rodents.

Campomanesia reitziana D. Legrand (Myrtaceae) displays antiulcer properties when given to rodents. The major active chemical components of C. reitziana are chalcones, including 4',6'-dihydroxy-2'-methoxy-3',5'-dimethylchalcone or dimethyl cardamonin (DMC); therefore, we hypothesized that this compound could have antiulcer effects and the present study aimed to evaluate its gastroprotective and gastric healing properties. DMC was isolated from the fruits of C. reitziana, and its gastroprotective effect was evaluated by ethanol and indomethacin-induced gastric ulcer models in mice (0.1 mg/kg, i.p. and 1 and 3 mg/kg, p.o.). Oxidative stress and inflammatory parameters were analyzed in the gastric tissue. Moreover, its gastric healing effect was evaluated in rats. In addition, the compound's mode of action was evaluated in vivo and in vitro by measuring H+ -K+ -ATPase activity. Finally, the cytotoxic potential of DMC was tested in fibroblasts and human gastric adenocarcinoma cells. The DMC reduced the ethanol-induced gastric ulcer in mice by 77 %, increased the adhered mucus, and reduced lipoperoxides levels. The block of nonprotein sulfhydryls (NP-SH) compounds by pretreatment with N-ethylmaleimide (NEM), the inhibition of nitric oxide synthase with Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME), or the antagonism of α2 receptor using yohimbine reversed the gastroprotective effects of DMC. Furthermore, DMC reduced the acidity of gastric content in pylorus-ligated rats but did not change H+ , K+ -ATPase (isolated from rabbit) activity in vitro. DMC reduced the lesion area in acetic acid-induced ulcers and decreased myeloperoxidase activity. DMC did not change the viability of fibroblast cells (L929) but reduced the viability of human gastric adenocarcinoma cells (AGS). The results confirmed that DMC could significantly enhance the gastric healing process and prevent ulcers due to improving protective factors on the gastric mucosa and reducing gastric acid secretion.

Geraniol accelerates the gastric healing, minimizes ulcers recurrence, and reduces anxiolytic-like behavior in ulcerated rodents by oral or inhaled route.

BACKGROUND: Geraniol (GE) is dietary acyclic monoterpene alcohol found in essential oils from aromatic plants with therapeutic value against gastric ulcers already described. HYPOTHESIS/PURPOSE: To assess whether oral GE accelerates gastric healing or prevents ulcer recurrence, and to evaluate the hypothesis that GE promotes antiulcer effects by the inhaled route and that promotes changes in the behavior of ulcerated rodents. METHODS: Gastric healing effects, underlining mechanisms, and behavioral changes were measured in80% acetic acid-induced gastric ulcer model in rats receiving GE by oral (30 mg/kg) or inhaled route (1 mg/L of air/min); whereas the effects of GE to avoid ulcer recurrence was evaluated in mice submitted to 10% acetic acid plus IL-1ß ulcer. RESULTS: GE administered by both routes accelerates gastric healing, increasing mucin and GSH levels, CAT, and GST activities, and reducing MPO activity. Moreover, oral, and inhaled GE minimized ulcer recurrence reducing gastric TNF and IL-6 levels and preserving mucin levels. Interestingly, the inhalation or oral intake of GE promotes anxiolytic-like effects in ulcerated rats. CONCLUSION: Data altogether suggest that the GE accelerates gastric healing through the strengthening of protective factors of the gastric mucosa, promoting a quality healing that reduces the recurrence of the lesion. Besides, the anxiolytic-like effect of GE may also contribute to its gastric healing action since anxiety is recognized as one of the etiologic agents of ulcers.

Exotic Medicinal Plants Used in Brazil with Diuretic Properties: A Review.

Several exotic plants (non-native) are used in Brazilian traditional medicine and are known worldwide for their possible diuretic actions. Among the wide variety of plants, standing out Achillea millefolium L., Camellia sinensis L. Kuntze, Crocus sativus L., Hibiscus sabdariffa Linn., Petroselinum crispum (Mill.) A.W. Hill, Taraxacum officinale (L.) Weber, and Urtica dioica L., whose effects have already been the subject of some scientific study. In addition, we also discussed other exotic species in Brazil used popularly, but that still lack scientific studies, like the species Arctium lappa L., Carica papaya L., Catharanthus roseus (L.) G. Don, Centella asiatica (L.) Urb, Citrus aurantium L., and Persea americana Mill. However, generally, clinical studies on these plants are scarce. In this context, different plant species can be designated for further comprehensive studies, therefore, promoting support for developing an effective medicine to induce diuresis.

Lupeol Stearate Accelerates Healing and Prevents Recurrence of Gastric Ulcer in Rodents.

Objective: The focus of this study was to evaluate the gastric healing effect of lupeol stearate (LS) and its ability to minimize ulcer recurrence in rodents. Methods: To evaluate the gastric healing properties of LS, rats were subjected to 80% acetic acid-induced ulcer model and treated with vehicle, LS (1 mg/kg, p.o.), or omeprazole (20 mg/kg, p.o.), twice daily by seven days. The gastric ulcers were evaluated macroscopically, histologically, and biochemically. To evaluate the effects of LS in gastric ulcer recurrence, mice were ulcerated with 10% acetic acid and treated with vehicle, LS (1 mg/kg, p.o.), or ranitidine (100 mg/kg, p.o.), twice a day for ten days. Then, ulcer recurrence in these animals was induced by IL-1ß at five days after the treatment period. Results: The oral treatment with LS accelerated gastric healing by 63% in rats compared to the vehicle group, evidenced by histological improvement and increased gastric mucin levels. Moreover, the gastric healing effects of LS in rats were accompanied by an elevation in glutathione S-transferase activity and a reduction in myeloperoxidase activity. Furthermore, the LS treatment reduced the recurred lesions in mice. Conclusions: The oral treatment of LS accelerates gastric healing in rats by favoring mucus production and reducing neutrophil migration, and it also can reduce ulcer recurrence. These data highlighted this compound as promising for developing new pharmacological strategies for the management of gastric ulcer.

Neuroprotective effects of strength training in a neuroinflammatory animal model.

BACKGROUND: The preventive role of muscular strength on diminishing neuroinflammation is yet unknown. In this study, the role of the prophylactic muscular strength exercise was investigated in order to verify whether it would diminish cognitive alterations and modify the antioxidant intracellular scenery in an animal neuroinflammatory model in of the CA1 region of the hippocampus. METHODS: The animals received muscular strength training (SE) three times a week for eight weeks. Subsequently, the stereotaxic surgery was performed with an intra-hippocampal infusion of either saline solution (SAL) or lipopolysaccharide (LPS). Next, we performed the behavioral tests: object recognition and social recognition. Then, the animals were euthanized, and their hippocampus and prefrontal cortex were collected. In another moment, we performed the dosage of the antioxidant activity and histological analysis. RESULTS: The results showed that the muscular strength exercises could show a beneficial prophylactic effect in the cognitive deficiencies caused by acute neuroinflammation. Regarding oxidative stress, there was an increase in catalase enzyme activity (CAT) in the group (SE + LPS) compared to the control groups (p < 0.05). As for the cognitive alterations, there were found in the (SE + LPS) group, diminishing the mnemonic hazard of the discriminative and social memories compared to the control groups (p < 0.05). CONCLUSION: We concluded, therefore, that the exercise performed prophylactically presents a protective effect capable of minimizing such mnemonic deficits and increasing catalase enzyme activity in rats that suffered a local neuroinflammatory process in the hippocampus.

Baccharis dracunculifolia DC Hydroalcoholic Extract Improves Intestinal and Hippocampal Inflammation and Decreases Behavioral Changes of Colitis Mice.

The hydroalcoholic extract of B. dracunculifolia (HEBD) and its major compound p-coumaric acid were evaluated against the severity of intestinal inflammation and behavioral changes like depressive and anxious behavior in colitis mice. Colitis was induced in Swiss mice by oral dextran sulfate sodium (DSS) administration for five days. The mice received vehicle (10 ml/kg), HEBD (3, 30, or 300 mg/kg), or p-coumaric acid (15 mg/kg) orally, once a day for twelve days. Behavioral tests were performed on the 11th and 12th days after the beginning of the treatments. Moreover, the colon, cortex, and hippocampus were collected to analyze oxidative and inflammatory parameters. The treatment with HEBD (300 mg/Kg), but not p-coumaric acid, showed decreased disease activity index (DAI) values compared to the vehicle group and partially preserved the villi architecture and mucin levels. Furthermore, the HEBD increased the antioxidant defenses in the colon and hippocampus and reduced the myeloperoxidase activity and IL-6 levels in the colon from colitis mice. Colitis mice treated with HEBD did not show depressive-like behavior in the tail suspension test. HEBD reduced colon inflammation, while it maintains antioxidant defenses and mucin levels in this tissue. It may reduce neuropsychiatric comorbidities associated with colitis through its antioxidant effects.

Boldine, an Alkaloid from Peumus boldus Molina, Induces Endothelium-Dependent Vasodilation in the Perfused Rat Kidney: Involvement of Nitric Oxide and Small-Conductance Ca2+-Activated K+ Channel.

Boldine, 2,9-dihydroxy-1,10-dimethoxyaporphine, is the main alkaloid found in the leaves and bark of Peumus boldus Molina. In recent years, boldine has demonstrated several pharmacological properties that benefit endothelial function, blood pressure control, and reduce damage in kidney diseases. However, the renal vasodilator effects and mechanisms remain unknown. Herein, perfused rat kidneys were used to study the ability of boldine to induce vasodilation of renal arteries. For that, left kidney preparations with and without functional endothelium were contracted with phenylephrine and received 10-300 nmol boldine injections. The preparations were then perfused for 15 min with phenylephrine plus L-NAME, indomethacin, KCl, tetraethylammonium, glibenclamide, apamin, charybdotoxin, or iberiotoxin. In 30, 100, and 300 nmol doses, boldine induced a dose-and endothelium-dependent relaxing effect on the renal vascular bed. No vasodilator effects were observed in preparations lacking functional endothelium. While the inhibition of the cyclooxygenase enzyme through the addition of indomethacin did not cause any change in the vasodilating action of boldine, the nonselective nitric oxide synthase inhibitor L-NAME fully precluded the vasodilatory action of boldine at all doses tested. The perfusion with KCl or tetraethylammonium (nonselective K+ channels blocker) also abolished the vasodilatory effect of boldine, indicating the participation of K+ channels in the renal action of boldine. The perfusion with glibenclamide (selective ATP-sensitive K+ channels blocker), iberiotoxin (selective high-conductance Ca2+-activated K+ channel blocker), and charybdotoxin (selective high- and intermediate-conductance Ca2+-activated K+ channel blocker) did not modify the vasodilatory action of boldine. On the other hand, the perfusion with apamin (selective small-conductance Ca2+-activated K+ channel blocker) completely prevented the vasodilatory action of boldine at all doses tested. Together, the present study showed the renal vasodilatory properties of boldine, an effect dependent on the generation of nitric oxide and the opening of a small-conductance Ca2+-activated K+ channel.

Preparations from Campomanesia reitziana reduce the gastrointestinal motility and castor oil-induced diarrhea in a non-opioid and non-dopaminergic pathway in mice and display antimicrobial activity in vitro.

BACKGROUND: This study investigated the antidiarrheal potential of the aqueous extract (AECR) and hydroalcoholic extract of Campomanesia reitziana leaves (HECR), its ethyl acetate (EAF) and dichloromethane fractions (DCMF), and myricitrin isolated from EAF. METHODS: The total phenols and flavonoids were measured, followed by chromatography and myricitrin isolation. The 2,2-diphenyl-1-picryl-hydrazyl scavenger activity, the cytotoxicity, and the effects on LPS-induced nitrite production in intestinal epithelial cells (IEC-6) were quantified. The effect of HECR, EAF, DCMF, and AECR on intestinal motility (IT), gastric emptying (GE), and castor oil-induced diarrhea in mice was determined, as well as its antimicrobial activity. KEY RESULTS: The administration of AECR 10% (10 ml/kg, p.o), but not HECR (300 mg/kg), reduced the GE and IT by 52 and 51%. The EAF and DCMF at 300 mg/kg also reduced IT but did not change GE. Moreover, AECR and EAF, but not DCMF, inhibited the castor oil-induced diarrhea and naloxone or metoclopramide pretreatment did not change these effects. Myricitrin did not change IT and the evacuation index of mice. Finally, the dry residue of AECR inhibited bacterial growth and EAF showed bacteriostatic activity against S. aureus, E. coli, and S. typhimurium and antifungal for C. albicans. However, none of the preparations alter the viability of Giardia spp. trophozoites. CONCLUSIONS: The AECR and EAF can be effective to treat diarrhea acting through opioid- or dopaminergic type 2 receptor-independent mechanisms and by its antimicrobial actions.

Herbal Medicines in the Treatment of Dyspepsia: An Overview.

This review focuses on the efficacy of herbal medicines for managing dyspepsia in humans and animals. Searches were conducted on the PubMed, Science Direct, and Medline databases, for publications in the last 3 years. In each database, the search terms used consisted of the 2 key terms describing the disorder and subtypes plus each of the terms relating to the therapy. The key terms used were "natural product" and "medicinal plant" in a cross-over with "dyspepsia" and "functional dyspepsia" (i.e., gastroprotection, Helicobacter pylori infection, prokinetic). We included all human and animal studies on the effects of herbal medicines reporting the key outcome of dyspepsia symptoms. Preclinical studies using critically validated models showed that most medicinal plants with gastroprotective action had antioxidant, anti-inflammatory, anti-apoptotic, and antisecretory effects. Moreover, several species displayed anti Helicobacter pylori and prokinetic efficacy. The data availability of controlled clinical studies is currently minimal. The use of different methodologies and the minimal number of patients raise doubts about the effects of these preparations. Only adequate clinical trials with scientifically validated methods can determine whether different herbal medicines can be used as viable alternatives to the conventional pharmacological treatments used to control dyspepsia symptoms.

Taxifolin and gastro-adhesive microparticles containing taxifolin promotes gastric healing in vivo, inhibits Helicobacter pylori in vitro and proton pump reversibly in silico.

Taxifolin (3,5,7,3,4-pentahydroxy flavanone or dihydroquercetin, Tax) was identified as a gastroprotective compound and a gastroadhesive formulation was recently developed to prolong its residence time and release in the stomach. So, the gastric healing effectiveness of Tax and gastro-mucoadhesive microparticles containing Tax (MPTax) against the acetic acid induced-gastric ulcer in rats was investigated in this study. Moreover, the interactions between Tax and H+/K+-ATPase were investigated in silico, and its anti- H. pylori activity was determined in vitro. The oral treatment with MPTax (81.37 mg/kg, containing 12.29% of Tax) twice a day for seven days reduced the ulcer area by 63%, compared to vehicle-treated group (Veh: 91.9 ± 10.3 mm2). Tax (10 mg/kg, p.o) reduced the ulcer by 40% but with a p = 0.07 versus Veh group. Histological analysis confirmed these effects. Tax and MPTax increased the gastric mucin amount, reduced the myeloperoxidase activity, and increased the glutathione reduced content at ulcer site. However, only MPTax decreased the lipoperoxide accumulation at ulcer site. Besides, Tax and MPTax normalize the catalase and glutathione S-transferase activity. Tax showed reversible interaction with H+/K+-ATPase in silico and its anti-H. pylori effects was confirmed (MIC = 625 µg/mL). These results suggest that the antiulcer property of Tax involves the strengthening of the gastric protective factors in parallel to its inhibitory interaction with H+/K+-ATPase and H. pylori. Considering that ulcer healing action displayed by Tax was favored by gastroadhesive microparticles, this approach seems to be promising for its oral delivery to treat acid-peptic diseases.

Gastric healing effect of p-coumaric acid isolated from Baccharis dracunculifolia DC on animal model.

The p-coumaric acid is a phenolic compound present in large quantities in the extract of Baccharis dracunculifolia DC, a Brazilian medicinal plant used to treat gastric ulcer. Given the necessity for finding new chemical components capable of accelerating gastric healing, in this study, the effects of the p-coumaric acid were evaluated in the acetic acid-induced ulcer model in rats, where histological, inflammatory, and oxidative parameters were analyzed. The healing property was also evaluated in the scratch assay on fibroblast cells (L929) and the cytotoxicity of p-coumaric acid was assessed in both L929 and human gastric adenocarcinoma (AGS) cells by MTT assay. The treatment with p-coumaric acid (10 mg/kg, p.o.) for 7 days, twice a day, decreased by 44.6% the acetic acid-induced gastric ulcer compared with the vehicle-treated group. The vehicle control-treated group showed a larger extension of the ulcer base and an extensive damage into the mucosa and submucosa layers, which were mitigated by the treatment with p-coumaric acid. This beneficial effect was also associated with increased levels of mucin and reduced glutathione, decreased amount of lipid hydroperoxides, and increased superoxide dismutase and catalase activities without interfering with the activity of myeloperoxidase in the gastric tissue. The compound promoted the restructuring of the cell monolayer in the scratch test and did not show toxicity in the L929 cell line, while reduced the viability of the AGS, a lineage of human gastric adenocarcinoma. Thus, p-coumaric acid may be considered a natural source for the treatment of gastric ulcers, by reinforcing protective factors of gastric mucosa and by accelerating gastric healing.

Dual role of eugenol on chronic gastric ulcer in rats: Low-dose healing efficacy and the worsening gastric lesion in high doses.

This study evaluated the gastric healing activity of eugenol, the main bioactive compound from clove (Syzygium aromaticun) essential oil. Five groups of female Wistar rats were submitted to acetic acid-induced ulcer model and treated with Vehicle (1 mL/kg, p.o.), eugenol (1, 10 or 100 mg/kg, p.o) or omeprazole (20 mg/kg, p.o), twice a day, by seven or fourteen days. Macroscopic, microscopic and biochemical analyses were performed in the ulcerated site. Eugenol (1 mg/kg, p.o) administered by 7 or 14 days accelerated the gastric healing process by 33% and 52%, respectively. The healing actions of eugenol were accompanied by the rescue on the histological architecture and the normalization of the superoxide dismutase and catalase activity. Moreover, eugenol (1 mg/kg, p.o) reduced the gastric mucosal myeloperoxidase activity and increased the mucin secretion. In contrast, eugenol at a dose of 100 mg/kg administered by 7 days enhanced 49% the ulcerated area, but at 10 mg/kg did not change the ulcer area after 7 or 14 days of treatment. Thus, despite the undesirable results due to the worsening of the gastric lesion with the use of eugenol in high doses, the antiulcer potential of this compound is evident and manageable in an adequate dose.

The gastroprotective effect of red propolis extract from Northeastern Brazil and the role of its isolated compounds.

ETHNOPHARMACOLOGICAL RELEVANCE: Propolis has been used in folk medicine to treat gastric disorders for centuries. However, although studies have been conducted to validate the gastroprotective and anti-ulcer activity of some types of propolis, red propolis activity remains unknown. AIM OF THE STUDY: The present study aimed to evaluate the gastroprotective effect of the hydroalcoholic extract of red propolis (HERP), its mode of action, and the main compounds involved in its activity, therefore contributing to validate the chemical and pharmacological potential of this product. MATERIAL AND METHODS: The effect of HERP (30, 100 and 300 mg/kg p.o. and 30 mg/kg i.p.), and the isolated compounds vestitol (VS), neovestitol (NV), methylvestitol (MV), medicarpin (MD), and oblongifolin AB (OB) (10 mg/kg p.o.) were evaluated on gastric ulcers induced by 60% ethanol/0.3 M HCl (5 mL/kg, p.o.) in mice. Histological changes and mucin levels were assessed by HE and PAS, respectively. Moreover, oxidative stress parameters and myeloperoxidase activity were analyzed on ulcerated tissue. The effect of HERP on gastric acid secretion was evaluated by pyloric ligature model and the mechanisms involved in its gastroprotective effect were investigated by pretreating mice with L-NAME (a non-selective nitric oxide synthase inhibitor, 70 mg/kg, i.p.), NEM (a sulfhydryl group chelator, 10 mg/kg, i.p.), yohimbine (an alpha-adrenergic receptor antagonist, 2 mg/kg, i.p.) and indomethacin (a non-selective cyclooxygenase inhibitor, 10 mg/kg, i.p.). RESULTS: HERP (300 mg/kg p.o. or 30 mg/kg i.p.), MV, and MD (10 mg/kg p.o.) protected gastric mucosa against the damage induced by ethanol/HCl. Histological changes were attenuated by the HERP, MV, and MD. Moreover, HERP and MV increased mucin levels. Besides, oxidative stress and MPO activity were reduced by the three treatments. HERP did not display anti-secretory action, but its effect was abolished by indomethacin treatment. CONCLUSIONS: HERP displays gastroprotective property against ethanol/HCl-induced damage. Its effect is dependent on prostaglandins and mucin production. The compounds MV and MD may have an essential role in the activity of HERP. Our data contribute to validate the traditional use of propolis for gastric disorders.

Irinotecan-induced intestinal mucositis in mice: a histopathological study.

PURPOSE: Intestinal mucositis is an important adverse effect of antineoplastic therapy, which remains without adequate treatment. The present study aimed to carry out a complete evaluation of the histopathological changes during irinotecan-induced intestinal mucositis, using the protocol most found in the pharmacological reports nowadays to better understand irinotecan toxicity and support future studies on drug discovery. METHODS: Intestinal mucositis was induced by treating swiss mice for 4 days with irinotecan (75 mg/kg, i.p.). After 72 h post irinotecan, the mice were sacrificed and the small intestine and colon were excised to performed histological analysis by stained tissue with hematoxylin/eosin (H&E). RESULTS: Histoarchitecture loss, villus/crypt ratio reduction, atrophy of the muscular layer, hypertrophy in the submucosal and mucous layers, ruptures in the epithelium, as well as extent cellular infiltrate and presence of micro abscesses and the fusion of the crypts were observed in the histological analysis. Moreover, duodenum and colon had increased intraepithelial lymphocytes and mitotic figures. However, submucosal ganglia were decreased in the duodenum and increased in the colon. CONCLUSIONS: The data obtained in the present study provides new evidence that irinotecan-induced intestinal mucositis highly affects small intestine and colon, further contributing to establish criteria in light of the histopathological changes induced by irinotecan during intestinal mucositis and facilitating inter-study comparisons.