Screening method of peptic ulcer disease.pptx

Screening method of peptic ulcer disease.pptx
1.Introduction
2.Causes
3.Symptoms
4.Classification of antiulcer drugs
Screening model
(A) In vitro model
(B) In vivo model

A. IN VITRO MODEL
1. H+/K+ ATPase inhibition assay
2. Tiotidine binding assay
3. Gastrin binding assay

B. In Vivo model
1. Pylorus ligation in rats
2. NSAIDs induced gastric ulcer
3. Ethanol induced gastric ulcer in rats
4. Histamine induced gastric ulcer
5. Acetic acid induced gastric ulcer
6. Cysteamine induced duodenal ulcer

1. Screening method of peptic ulcer disease Prepared By – Undhad Tushar C. Masters Of Pharmacy Sem – 1 (Pharmacology) R.K. University Under The Guidance Of – Dr. Pravin R. Tirgar Ph D, M. Pharm - Pharmacology, Professor, School Of Pharmacy, RK University 1

2. contents Introduction Causes Symptoms Classification of antiulcer drugs Screening model (A) In vitro model (B) In vivo model Tushar_Undhad (Screening method of peptic ulcer disease) 2

3. 1.Introduction Gastric ulcers may located at the stomach or duodenum. Stomach ulcers are called peptic ulcers and intestine ulcers are called duodenal ulcers. Stomach ulcer Tushar_Undhad (Screening method of peptic ulcer disease) 3

4. 1.Introduction Studies showed that gastric ulcer occurs at least 10% of the world population. Tushar_Undhad (Screening method of peptic ulcer disease) 4

5. 1.Introduction Peptic ulcer caused by a lack of balance between the gastric aggressive factors and defensive factors. Aggressive Factors Defensive Factors Tushar_Undhad (Screening method of peptic ulcer disease) 5

6. 1.Introduction Aggressive Defensive Acid, Pepsin, Bile, Helicobacter pylori Oily, Spicy, Irregular diet NSAIDS & other drugs Smoking, Alcohol, Stress Prostaglandin secretion Bicarbonate secretion Mucus secretion, Blood flow Rapid mucus turnover Tushar_Undhad (Screening method of peptic ulcer disease) 6

7. 2. causes H. pylori infection, Consumption of alcohol ,smoking chronic consumption of NSAIDs ex aspirin ibuprofen irregulated acid secretion Oily, spicy, irregular diet habit, Stress Tushar_Undhad (Screening method of peptic ulcer disease) 7

8. 3.symptoms Acidity, reduced pain after food Gastric bleeding Or blood vomit Burning sensation, nausea, vomiting, heart burn, weight loss Loss of appetite Tushar_Undhad (Screening method of peptic ulcer disease) 8

9. 4.Classification of antiulcer drugs Class of drugs Example of drugs H2 receptor antagonist Cimetidine, ranitidine, Proton pump inhibitor Omeprazole, pantoprazole, rabeprazole Anticholinergics Pirenzepine, telenzepine Prostaglandin analogue Misoprostol Antacids Sodium bicarbonate, MgOH Ulcer protective Sucralfate, colloidal bismuth Anti H.pylori Amoxicillin, clarithromycin, Metronidazole Tushar_Undhad (Screening method of peptic ulcer disease) 9

10. 5.Screening model A. IN VITRO MODEL 1. H+/K+ ATPase inhibition assay 2. Tiotidine binding assay 3. Gastrin binding assay Tushar_Undhad (Screening method of peptic ulcer disease) 10

11. 1. H+/K+ ATPase inhibition assay PRINCIPLE: It is the final step in the synthesis of acid of the parietal cell. PROCEDURE: Homogenate 80 ng microsomal gastric H+/K+ ATPase incubated with 100 ul buffer, 1 mM ATP and test compound in microtiter plate for 30 min at 37 c. Tushar_Undhad (Screening method of peptic ulcer disease) 11

12. 1. H+/K+ ATPase inhibition assay Reaction is stopped by adding malachite green (colorimetric agent) After 10 sec, 15% of sodium citrate is added for 45 min. Release of orthophosphate by ATP is quantified by colorimeter. Tushar_Undhad (Screening method of peptic ulcer disease) 12

13. 1. H+/K+ ATPase inhibition assay Evaluation: Percentage inhibition of H+/K+ ATPase is calculated. Lower the orthophosphate release, more is the inhibition of H+/K+ ATPase by test compound. Tushar_Undhad (Screening method of peptic ulcer disease) 13

14. B. In vivo model 1. Pylorus ligation in rats 2. NSAIDs induced gastric ulcer 3. Ethanol induced gastric ulcer in rats 4. Histamine induced gastric ulcer 5. Acetic acid induced gastric ulcer 6. Cysteamine induced duodenal ulcer Tushar_Undhad (Screening method of peptic ulcer disease) 14

15. B. In vivo model 7. Reserpine induced gastric ulcer 8. Serotonin induced gastric ulcer 9. Diethyl dithiocarbonate (DDC) induced ulcer 10. Methylene blue induced ulcer Tushar_Undhad (Screening method of peptic ulcer disease) 15

16. 1. Pylorus ligation in rats PRINCIPLE: The Pylorus part of the stomach was ligated , it causes ulcers in rats by stopping the passage of gastric contents from stomach and accumulation of acidic gastric juice in the stomach for longer time. Tushar_Undhad (Screening method of peptic ulcer disease) 16

17. 1. Pylorus ligation in rats PROCEDURE: Wrister rats are used for the experiment. (150 to 180gm weight) Animals are fasted for 48 hours. Tushar_Undhad (Screening method of peptic ulcer disease) 17

18. 1. Pylorus ligation in rats Animals are anaesthetized and a 1 inch midline abdominal incision. The pylorus is carefully lifted out and ligated without damaging its blood supply. The stomach is now replaced and the abdominal wall closed with sutures. The test compound is administered orally Tushar_Undhad (Screening method of peptic ulcer disease) 18

19. 1. Pylorus ligation in rats 10-19 hours later, animals are sacrificed and stomachs are dissected out. Contents of the stomach are drained into a graduated centrifuge tube and their acidity determined by titration with 0.1N NaOH. Stomach is opened and ulcer index is calculated. Tushar_Undhad (Screening method of peptic ulcer disease) 19

20. 1. Pylorus ligation in rats EVALUATION Ulcer index = 10/X Where X = total mucosal area / total ulcer area Tushar_Undhad (Screening method of peptic ulcer disease) 20

21. 2.NSAIDs induced gastric ulcer model PRINCIPLE: NSAIDs cause ulcers by inhibiting prostaglandins synthesis by inhibiting cyclooxygenase enzyme in COX pathway. Prostaglandins play a protective role via stimulating the secretion of bicarbonates and mucous, maintaining blood flow and regulating mucous cell turn over and repair. Tushar_Undhad (Screening method of peptic ulcer disease) 21

22. 2.NSAIDs induced gastric ulcer model PROCEDURE: Animals are fasted for 24-36 hours. NSAID (aspirin or indomethacin) using appropriate vehicle (water or 1% carboxymethylcellulose) is orally administered. After 1 hour, animals are treated with test drug. Tushar_Undhad (Screening method of peptic ulcer disease) 22

23. 2.NSAIDs induced gastric ulcer model 4 hours later, animals are sacrificed, stomach is removed and ulcer is measured. Dose of NSAIDs: Aspirin- 150mg/kg of body weight. Indomethacin- 40-100mg/kg of body weight. Tushar_Undhad (Screening method of peptic ulcer disease) 23

24. 2.NSAIDs induced gastric ulcer model Tushar_Undhad (Screening method of peptic ulcer disease) 24

25. 3.ETHANOL INDUCED GASTRIC ULCER IN RATS PRINCIPLE: Ethanol, being a necrotizing agent. Damages the superficial epithelial layers & inhibits the release of mucosal prostaglandins. PROCEDURE: Wistar rats are using( weighing 150-200 grams). Fasted for 18 hours before experiment. Tushar_Undhad (Screening method of peptic ulcer disease) 25

26. 3.ETHANOL INDUCED GASTRIC ULCER IN RATS Rats are given test drugs or standard drug orally. 30 mins later 1 ml/200gm of 99.% alcohol is administered orally. After 1 hour, Rats are sacrificed and stomachs dissected out. ulcer index are calculated. Tushar_Undhad (Screening method of peptic ulcer disease) 26

27. 4.Histamine induced gastric ulcer model PRINCIPLE: Histamine released from mast cells and binds with receptors present on the surface of cells which leads to activation of adenyl cyclase. This adenyl cylcase converts ATP into c-AMP. This conversion enhances secretion of HCL. Tushar_Undhad (Screening method of peptic ulcer disease) 27

28. 4.Histamine induced gastric ulcer model PROCEDURE: Male guinea pigs are used. (300-400g) Fasting 36-48 hours, 50 mg of histamine sulphate is injected via intraperitoneal route. Tushar_Undhad (Screening method of peptic ulcer disease) 28

29. 4.Histamine induced gastric ulcer model Test drugs are administered after 30-45 mins of histamine injection 5 mg of Promethazine HCl is given before and after histamine injection. And sacrifice the animals after 4 hours. Calculate ulcer index Tushar_Undhad (Screening method of peptic ulcer disease) 29

30. 5.Reserpine induced gastric ulcer model PRINCIPLE: Reserpine acts on cholinergic system. Reserpine increases histamine secretion by causing degranulation of gastric mast cells. Tushar_Undhad (Screening method of peptic ulcer disease) 30

31. 5.Reserpine induced gastric ulcer model PROCEDURE: Dawley rats are used for the experiment. Animals are fasted for 48 hours. Test drug is administered intraperitonially. Tushar_Undhad (Screening method of peptic ulcer disease) 31

32. 5.Reserpine induced gastric ulcer model Half an hour later, reserpine dose of 15mg/kg is administered intraperitonially. 4 hours later, animals are sacrificed, stomach are removed and dissected. Ulcer index is calculated. Tushar_Undhad (Screening method of peptic ulcer disease) 32

33. 6.Serotonin induced gastric ulcer model PRINCIPLE: Serotonin acts as vasoconstrictor which reduces gastric mucosal blood flow and leads to acute mucosal injury. Tushar_Undhad (Screening method of peptic ulcer disease) 33

34. 6.Serotonin induced gastric ulcer model Procedure: Animals are fasted for 24 hours. Serotonin creatin sulfate (20-50mg/kg) is administered subcutaneously. Animals are sacrificed after 6 hours, stomach is dissected out and calculate ulcer index. Tushar_Undhad (Screening method of peptic ulcer disease) 34

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