Search

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. [ABSTRACT FROM AUTHOR]

Green propolis is a resinous substance used in folk medicine given its anti-inflammatory, antibacterial, and anti-ulcer effects. Our research group has already confirmed the gastroprotective activity of hydroalcoholic extract from green propolis (HEGP), as well as of its main isolated compounds. In continuity, this study evaluated the antioxidant mode of action involved in the preventive effect induced by HEGP, and its therapeutic gastric healing potential on installed ulcers. In addition, the healing effect of its main compound Artepillin C was also investigated. Acute and chronic ulcers were induced in rats by given ethanol or acetic acid, respectively. In acute model, the rats were orally pre-treated with vehicle (water plus 1% Tween, 1 mL/kg), HEGP (30–300 mg/kg), or carbenoxolone (200 mg/kg) 1 h prior the ulcer induction. In the chronic ulcer protocol, the rats received vehicle (water plus 1% Tween, 1 mL/kg), HEGP (300 mg/kg), or omeprazole (20 mg/kg) twice a day by 7 days, whereas groups of mice received vehicle (water plus 1% Tween, 1 mL/kg), Artepillin C (18 mg/kg), or ranitidine (20 mg/kg) twice a day by 4 days. Ulcerated tissue was collected for histological, histochemical, immunostaining, oxidative, and inflammatory analyses. The in vitro scavenger activity of HEGP was also verified using the DPPH assay. The oral pre-treatment with HEGP (100 and 300 mg/kg) prevented the gastric epithelial damage promoted by ethanol. Besides, HEGP (100 and 300 mg/kg) reduced SOD activity about 11% and 26%, respectively, and increased the activity of GST around 20% and CAT in 80%. HEGP (300 mg/kg) also reduced the production of reactive oxygen species, as well as lipoperoxidation levels in the ethanol-ulcerated tissue. In the acetic acid-induced chronic ulcer, the daily treatment with HEGP (300 mg/kg) accelerates the healing process by 71%. In this model, HEGP normalized SOD and CAT activity and increased GST activity by 109% when compared to non-ulcerated rats. In both models, the extract administration increased the mucin PAS staining and reduced the myeloperoxidase activity at the ulcer site. Moreover, the treatment with HEGP enhanced the PCNA immunostaining, but did not alter the concentration of collagen in the acetic acid-ulcerated tissue. The extract had a direct DPPH radical-scavenging ability (LogIC50: 0.56). Besides, as expected, HPLC analysis showed Artepillin C as a major compound and its administration at 18 mg/kg also accelerated the gastric healing ulcer process in mice. Our findings confirm that HEGP displays both gastroprotective and gastric healing properties, contributing to the validation of its popular use as preventive and therapeutic approaches. These actions occur through the increase in mucin production and the reestablishment of the oxidative balance due to a reduction in gastric inflammation. [ABSTRACT FROM AUTHOR]

The Bauhinia genus is known as “Pata-de-Vaca” and a wide variety of these species are used in Brazilian folk medicine due to their gastroprotective properties. This study aimed to investigate the antiulcer efficacy of the hydroalcoholic extract from B. curvula (HEBC) leaves, as well as its semi-purified fraction (SPFr) and the contribution of their phytochemicals constituents for this effect. For that, ethanol 60%/HCl 0.3 M- and indomethacin-induced gastric ulcer were performed in rodents. Gastric ulcerated tissues were processed for histological, histochemical and biochemical analysis. The oral treatment with HEBC and SPFr decreased the gastric ulcer induced by ethanol/HCl in mice and by indomethacin (only HEBC) in rats. The gastroprotective effect of HEBC was abolished in mice pretreated with Nω-Nitro-l-arginine methyl ester, N-Ethylmaleimide, glibenclamide or indomethacin. Both HEBC and SPFr reduced myeloperoxidase activity in parallel with a decrease of lipoperoxides content at the site of the lesion. On the other hand, HEBC did not alter volume, pH, total acidity or pepsin activity of acid gastric secretion in rats, and neither inhibited the in vitro H(+),K(+)-ATPase activity. Additionally, the compounds identified and isolated from the SPFr, the flavonoids quercitrin (65%) and kaempferol (35%), were able to diminish the extent of ulcerated area induced by both ethanol/HCl and indomethacin. Taking together, these findings show that B. curvula extracts present gastroprotective effect, mainly explained by the presence of flavonoids quercitrin and kaempferol, which may possibly improve the defensive factors of gastric mucosa. [ABSTRACT FROM AUTHOR]

According to the Brazilian folk medicine, the leaves of Plinia edulis (Vell.) Sobral (Myrtaceae), known as cambuca, are indicated in the treatment of gastric disorders. Infusions of P. edulis leaves were previously demonstrated to contain both maslinic (MA) and ursolic acids (UA). Both triterpenes have also been identified in the methanolic extract of peels from P. edulis fruit (MEPPE); however, the antiulcer effects of MEPPE have not yet been studied. This study therefore evaluates the gastroprotective potential of MEPPE, MA, and UA using ethanol/HCl- and indomethacin-induced gastric ulcers in mice. In addition, the in vitro effects of these compounds on the H, K-ATPase activity and on the free radical DPPH were measured. When used at concentration of 100 μg/mL, both MEPPE and UA were found to reduce the DPPH radical levels by 78.66 and 60.14%, respectively. However, MA did not reduce DPPH radical levels. Our results illustrated the antiulcer effects of MEPPE, MA, and UA against experimental ulcer models when administered by either the oral or the intraperitoneal routes. In addition, MEPPE reduced the size of ethanol/HCl-induced ulcers in a dose-dependent manner (log half-maximal effective oral dose, LogED = 1.09). Interestingly, UA promoted gastroprotection at lower doses than MA by increasing the production of mucin levels at 692%; however, it does not alter the activity of H, K-ATPase. In contrast, both MEPPE and MA, when incubated at concentrations of 10 and 100 μg/mL, inhibited H, K-ATPase activity in 61.81, 68.37, 54.04, and 70.45%, respectively. These results confirm that MEPPE, MA, and UA display gastroprotective activity through different modes of action; MA inhibits H, K-ATPase activity, whereas UA favour the mucus barrier. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the sex-specific effects of a hydroalcoholic extract from Eugenia punicifolia (HEEP) leaves on gastric ulcer healing., Methods: In this rat study involving males, intact (cycling) females, and ovariectomized females, gastric ulcers were induced using acetic acid. A vehicle, lansoprazole, or HEEP was administered for 14 d after ulcer induction. Body weight was monitored throughout the treatment period. At the end of treatment, the rats were euthanized and the following in vivo and in vitro investigations were performed: macroscopic examination of the lesion area and organ weights, biochemical analysis, zymography, and evaluation of protein expression levels. Additionally, the concentration-dependent effect of HEEP was evaluated in terms of subacute toxicity and cytotoxicity., Results: Compared to the vehicle, HEEP demonstrated a great healing capacity by substantially reducing the ulcerative lesion area in males (52.44%), intact females (85.22%), and ovariectomized females (65.47%), confirming that HEEP accelerates the healing of acetic acid-induced gastric lesions and suggesting that this effect is modulated by female sex hormones. The antiulcer effect of HEEP was mediated by prostaglandin E 2 only in male rats. Overall, the beneficial effect of HEEP was the highest in intact females. Notably, HEEP promoted the expression of vascular endothelial growth factor (intact vs ovariectomized females) and decreased the expression of Caspase-8 and Bcl-2 (intact female vs male or ovariectomized female). Additionally, HEEP enhanced fibroblast proliferation and migration into a wounded area in vitro , confirming its healing effect. Finally, no sign of subacute toxicity or cytotoxicity of HEEP was observed., Conclusion: In gastric ulcers, HEEP-induced healing (modulated by female sex hormones; in males, mediated by prostaglandin) involves extracellular matrix remodeling, with gastric mucosa cell proliferation and migration., Competing Interests: Conflict-of-interest statement: The authors declare that they have no commercial, personal, political, intellectual, or religious interests related to the work presented herein.

The gastroprotective effect of the methanol extract of Phyllantus niruri and its main constituent, corilagin, were studied in vivo . The extract (50, 125, or 250 mg/kg, p. o.) inhibited ethanol-induced lesions in rats by 43 % (p < 0.001), 69 % (p < 0.001), and 99 % (p < 0.001), respectively. It also inhibited the formation of indomethacin-induced gastric ulcers in rats by 80 % (p < 0.01), 89 % (p < 0.01), and 97 % (p < 0.01). A decrease in lipid hydroperoxide levels (p < 0.01) and in myeloperoxidase activity (p < 0.05) evidenced a reduction of oxidative damage and neutrophil infiltration in gastric tissues from ulcerated mice using ethanol/HCl. Potent in vitro free radical scavenger activity (IC 50  = 0.07) using the DPPH assay was observed. In contrast, the extract (250 mg/kg, i. d.) did not show antisecretory activity in pylorus-ligated rats, and also failed to inhibit the H + ,K + -ATPase activity in vitro . However, in pylorus-ligated rats, the extract (50, 125, and 250 mg/kg, i. d.) increased adhered mucus content by 22 % (p < 0.05), 28 % (p < 0.01), and 38 % (p < 0.01), respectively. The involvement of prostaglandins, nonprotein endogenous sulfhydryl compounds, α 2 -receptors, and endogenous nitric oxide in the gastroprotection elicited by the extract was also evaluated. Finally, corilagin reduced the lesion area of ethanol-induced gastric ulcers in mice by 88 % (30 mg/kg, p. o.; p < 0.001). Based on these results, it has been concluded that P. niruri methanol extract possesses gastroprotective activity by different and complementary pathways, which together promote an improvement in gastric cytoprotection. The presence of corilagin may partially explain the effectiveness of the extract against gastric damage., (Georg Thieme Verlag KG Stuttgart · New York.)