ovalbumin and Stomach-Ulcer

Licania rigida Benth., a Brazilian endemic plant, has been traditionally used for treating inflammation and stomach pain. This work investigates the anti-inflammatory and gastroprotective activities of the ethanolic extract from L. rigida seeds (EELr) by in vitro and in vivo methods. The phytochemical profile was determined and the in vitro antioxidant activity was investigated by radical scavenging and thiobarbituric acid reactive substances methods. The ovalbumin denaturation method was used with sodium diclofenac as standard for the in vitro anti-inflammatory activity assessment. Acetylsalicylic acid was used to induce gastric ulcers in male mice and then to evaluate the preventive and therapeutic gastroprotective effect of EELr, using omeprazole as the reference drug. The extract exhibited relevant amount of phenolic compounds and flavonoids, in particular, demonstrating in vitro antioxidant capacity. EELr was able to inhibit almost 60% of ovalbumin denaturation at a concentration considered low. It also prevented the decrease of biochemical markers for oxidative stress such as superoxide dismutase (SOD) and reduced glutathione (GSH) in the stomach and SOD and catalase (CAT) in the liver. EELr also significantly decreased the number of lesions as well as reduced the ulcerated area when used as therapy. The observed effect may be due to its phenolic compounds, such as chlorogenic acid, caffeic acid and tannins, as previously reported. EELr is a potential source of compounds with anti-inflammatory activity, protects the liver from oxidative damage and improves healing of aspirin-induced ulcers. This work contributes to the knowledge of L. rigida species.

Topics: Animals; Anti-Inflammatory Agents; Anti-Ulcer Agents; Antioxidants; Aspirin; Chrysobalanaceae; Ethanol; Gastric Mucosa; Mice; Ovalbumin; Phytotherapy; Plant Extracts; Rats; Rats, Wistar; Seeds; Stomach Ulcer; Superoxide Dismutase

There are strong beliefs in the efficacy of traditional medical systems worldwide. Many herbs have been acclaimed to possess antiulcer effects and could be unexplored sources of new lead compounds. Sida corymbosa R. E. Fries (Malvaceae) is used in Northern Nigeria to treat ulcers and wounds. This work aimed to investigate the usefulness of Sida corymbosa in treatments of stomach ulcers and wounds in traditional medicine.. Effect of the aqueous extract was determined on gastric ulceration, rate of wound healing and inflammation using ethanol-induced and diclofenac-induced ulceration, wound excision model and albumin-induced inflammation respectively in rats.. The study demonstrated the anti-ulcer activity of Sida corymbosa as the extract (250, 500 and 1000 mg/kg) showed a dose-dependent, significant (P<0.05) reduction of ulcer indices against gastric ulcers induced by both ethanol and diclofenac. Topical application of a formulation prepared with the extract of Sida corymbosa on surgically created incisions produced an increase in the rate of healing of the wounds. The extract of Sida corymbosa exhibited a significant (P < 0.05), dose-related decrease in inflammation induced by fresh egg albumin. This study showed that Sida corymbosa has constituents with the ability to reduce the severity of haemorrhagic gastric lesions, promote wound healing and reduce inflammation. These actions may be attributed to any one of the active constituents or as a result of synergistic effects of these phytoconstituents.. This study validates the use of the plant in traditional medicine for the treatment of stomach ulcers and wounds.

Topics: Animals; Anti-Inflammatory Agents; Anti-Ulcer Agents; Diclofenac; Dose-Response Relationship, Drug; Ethanol; Inflammation; Malvaceae; Medicine, African Traditional; Ovalbumin; Phytotherapy; Plant Extracts; Rats; Rats, Wistar; Stomach Ulcer; Wound Healing; Wounds, Penetrating

Bovine alpha-lactalbumin (alpha-LA), a major milk protein, exerts strong gastroprotective activity against rat experimental gastric ulcers induced by ethanol or stress. To elucidate the mechanisms underlying this activity, the influence of alpha-LA on gastric mucus metabolism was investigated in vitro and in vivo. For the in vitro study, RGM1 cells (a rat gastric epithelial cell line) were selected for observation of the direct activity of alpha-LA on gastric mucosal cells and cultured in the presence of either alpha-LA or ovalbumin (OVA), a reference protein showing no gastroprotective activity. Amounts of synthesized and secreted mucin, a major component of mucus, were determined using [3H]glucosamine as a tracer, and prostaglandin E2 (PGE2) levels in the culture medium were determined by RIA. For the in vivo study, the thickness of the mucus gel layer, a protective barrier for gastric mucosa, was evaluated histochemically in rat gastric mucosa. alpha-Lactalbumin (3 mg/mL) significantly stimulated mucin synthesis and secretion in RGM1 cells and also increased PGE2 levels in the culture medium. In contrast, OVA showed no enhancing effects under identical conditions. Neither indomethacin, a cyclo-oxygenase inhibitor, nor AH23848, a prostaglandin EP4 receptor antagonist, affected alpha-LA-induced enhancement of mucin synthesis and secretion. In vivo, oral administration of alpha-LA (300 mg/kg x 3 times/d x 7 d) increased the thickness of the mucus gel layer in rats. These results indicate that alpha-LA fortifies the mucus gel layer by stimulating mucin production and secretion in gastric mucus-producing cells, and that this enhancing effect is independent of endogenous PGE2. Comparison of the efficacy of alpha-LA with OVA suggests that the activities observed in RGM1 cells are closely related to the gastroprotective effects in rat gastric ulcer models. In conclusion, alpha-LA stimulates mucus metabolism, and this action may be responsible for its gastroprotective activity.

Topics: Animals; Cattle; Cell Line; Culture Media, Conditioned; Dinoprostone; Gastric Mucosa; Glucosamine; Histocytochemistry; In Vitro Techniques; Lactalbumin; Male; Mucins; Mucus; Ovalbumin; Rats; Rats, Wistar; Stomach Ulcer; Tritium

Formulations consisting of egg albumin, indomethacin (IND), and olive oil or fatty acids, were prepared by vigorous stirring using a high-speed homogenizer and subsequent freeze-drying. To confirm the anti-inflammatory properties and ulcerogenic effects of the formulations, we examined the action of the formulations on carrageenan-induced edema in rats as well as their ulcerogenic actions in the same species. Compared with IND alone, albumin-IND-olive oil (9:1:4.3), albumin-IND-linolenic acid (9:1:4.3), albumin-IND-linolic acid (9:1:4.3), albumin-IND-oleic acid (9:1:4.3), albumin-IND-stearic acid (9:1:4.3), and albumin-IND-tristearin (9:1:4.3) formulations all exhibited a more potent inhibitory effect on carrageenan-induced edema. In addition, the inhibitory effects on edema formation of an albumin-IND (9:1) complex was as strong as that of IND alone. These results suggested that the bioavailability of IND was increased by olive oil, fatty acid, and tristearin as absorbefacient agents. The increase in the bioavailability was evident from the fact that the mean plasma levels, maximum plasma levels (Cmax), and area under plasma concentration-time curve (AUC) values after oral administration of the albumin-IND-olive oil (9:1:4.3) formulation was significantly greater than that after administration of the drug alone. With respect to their ulcerogenic properties, the formulations were significantly less active than IND alone, suggesting that a reduction in the ulcerogenic activity of IND was by produced complexation with egg albumin.

Topics: Administration, Oral; Animals; Biological Availability; Carrageenan; Drug Carriers; Edema; Fatty Acids; Freeze Drying; Indomethacin; Inflammation; Male; Olive Oil; Ovalbumin; Plant Oils; Rats; Rats, Sprague-Dawley; Stomach Ulcer

Under in vitro circumstances, ovalbumin, administered serosally, caused a definite acid secretory response in the isolated whole stomach of sensitized mice. Acid secretion induced by challenge was inhibited by cimetidine or by pretreatment with disodium cromoglycate. It remained, however, unchanged by mepyramine or atropine. It is likely that a local histamine release caused by an anaphylactic reaction of type I might be involved in the pathogenesis of certain kinds of digestive diseases, i.e. peptic ulcer.

Topics: Anaphylaxis; Animals; Calcium; Cromolyn Sodium; Gastric Acid; Gastric Mucosa; Histamine; In Vitro Techniques; Mice; Ovalbumin; Stomach Ulcer

In an attempt to elucidate the pathophysiological mechanisms of gastric anaphylactic ulcer we measured tritiated thymidine incorporation in gastric cells, their mitotic rate and the degranulation of mast cells in the preulcerous phase. The results showed that there is a highly significant increase in cell turnover and mast cell degranulation in the mucosa of sensitized animals. Changes were found at the site of ovalbumin challenge, where point ulceration occurred within 48-72 h. The tissue culture studies demonstrated that the mucosa of sensitized animals produces significantly more histamine when challenged with ovalbumin than the mucosa of nonsensitized animals. Addition of histamine to the tissue culture medium in which normal gastric mucosa was cultured led to an increase in [3H]-thymidine uptake at low concentration, and a decrease at high concentration. Serotonin added to the culture medium had no significant effect on [3H]-thymidine uptake, but heparin at high concentration was found to have a stimulatory effect. These studies show that anaphylactic gastric ulceration is associated with an increase in mucosal cell turnover, and that the mast cell mediator responsible for this increase may be histamine.

Topics: Anaphylaxis; Animals; Cells, Cultured; Disease Models, Animal; Heparin; Histamine; Histamine Release; In Vitro Techniques; Intestinal Mucosa; Mast Cells; Mitosis; Muridae; Ovalbumin; Serotonin; Stomach; Stomach Ulcer

Topics: Anaphylaxis; Animals; Disease Models, Animal; Gastric Mucosa; Ovalbumin; Rodentia; Stomach Ulcer

The development of novel anti-inflammatory drugs (AID) has been claimed to be dependent on the discovery of models of inflammation that differ from those currently used for drug screening, e.g. carrageenen paw oedema and u.v. erythema. We have thus evaluated the effect of a variety of drugs in a number of novel models of inflammation in the rat produced in the hind paw. We have utilized kaolin, zymosan, anti-rat IgG (anti-IgG) and the Reversed Passive Arthus (RPA) reaction to produce these oedema models. We found that the non-steroidal AID's, e.g. aspirin, flufenamic acid, indomethacin, naproxen, and phenylbutazone, were active in all four tests. Of the nine novel AID examined, levamisole and tetramisole demonstrated considerable activity in all four tests and dapsone was especially active in the anti-IgG and RPA tests. In contrast, the anti-rheumatic d-penicillamine was inactive in all four models. Each of the ten compounds tested which has been claimed to influence complement function, was active in the RPA but not in the kaolin model. These results are discussed in the context of the aetiology of each oedema and the suspected mode of action of the various drugs.

Topics: Animals; Anti-Inflammatory Agents; Antibodies, Anti-Idiotypic; Arthus Reaction; Disease Models, Animal; Drug Evaluation, Preclinical; Edema; Immunoglobulin G; Kaolin; Male; Ovalbumin; Rats; Stomach Ulcer; Zymosan

Praomys (Mastomys) natalensis were sensitised by peritoneal injection of ovalbumin mixed with aluminium hydroxide. The animals developed homocytotoropic IgE and IgG 1 antibodies. When presensitised animals were challenged with ovalbumin in the gastric wall, a gastric ulcer appeared. This ulceration, induced by an immunological release of histamine, could be inhibited by the administration of disodium cromoglycate. The present model is useful for producing a gastric ulcer in a determined site. It supports the theory of a possible allergic component in the pathogenesis of the human disease.

Topics: Animals; Antibodies; Antibody Formation; Antigens; Female; Gastric Mucosa; Hypersensitivity, Delayed; Immunoglobulin M; Male; Mast Cells; Ovalbumin; Reagins; Rodentia; Stomach Ulcer

In an attempt to evaluate the role of gastric mucosal defense factors in ulcerogenesis, we measured the levels of glycoproteins in the mucosa as well as mucosal cell turnover in the preulcerous phase and compared these parameters to the normal mucosa in the same animal. Ovalbumin-presensitized Praomys (Mastomys) natalensis were challenged in the gastric wall with ovalbumin and a gastric ulcer developed at the challenge site 3 days later as a result of a mucosal anaphylactic reaction. This model enabled us to study the events occurring at the site of a future ulceration. Gas-liquid chromatographic determination of mucosal glycoproteins showed that the normal and preulcerous mucosae had similar levels. Cell turnover, determined by [3H]thymidine incorporation, was stimulated as a result of the preulcerous anaphylactic reaction at 24 hours postchallenge whereas at 48 hours the values were not different from those obtained in controls. These results suggest that the pathogenesis of anaphylactic gastric ulcer involves a change in cell turnover but no changes in the production of gastric mucus.

Topics: Anaphylaxis; Animals; Disease Models, Animal; Female; Gastric Mucosa; Glycoproteins; Kinetics; Male; Monosaccharides; Ovalbumin; Rodentia; Stomach Ulcer; Thymidine; Time Factors

Studies were performed in animals to establish whether antigen prefeeding could present homocytotropic antibody synthesis and the induction of gastric ulcer resulting from mucosal anaphylaxis. A single digestive exposure to 1 or 10 mg ovalbumin induced a state of specific immunologic tolerance. Inhibition of the formation of specific reagins was shown by the study of mast cell degranulation. Tolerant animals presented a reduced incidence of gastric ulcer after subsequent mucosal challenge. These results are important for the development of methods of prevention and treatment of allergic diseases.

Topics: Anaphylaxis; Animals; Antigens; Female; Gastric Mucosa; Immune Tolerance; Male; Mast Cells; Ovalbumin; Reagins; Rodentia; Stomach Ulcer

Topics: Amines; Analgesics; Animals; Anti-Inflammatory Agents; Benzyl Compounds; Body Temperature; Carrageenan; Edema; Formaldehyde; Guinea Pigs; Lethal Dose 50; Male; Methylamines; Ovalbumin; Oxyphenbutazone; Phenylbutazone; Piperazines; Pyrazoles; Rats; Stomach Ulcer; Structure-Activity Relationship; Thiazoles

Topics: Animals; Anura; Fishes; Glycine; Histidine; Mice; Ovalbumin; Rabbits; Rats; Stomach Ulcer