Prevention of peptic ulcer by aqueous extract of Aegle marmelos leaf in rats

Background and objectives: Aegle marmelos (Bael), a medicinal plant, has been widely used indigenously to treat many diseases in Bangladesh and other countries. The present study was carried out to evaluate the efficacy of A. marmelos leaf to prevent ethanol induced gastric ulcer in a rat model. Methods: Thirty two Wister albino rats of either sex, weighing between 100-150g, were fed 200 mg/kg or 400 mg/kg aqueous extract of A. marmelos leaves one hour prior to oral administration of 90% ethanol (1 ml/200 gm body weight) to induce gastric ulcer. The animals were sacrificed after one hour and ulcer scores and index were determined. The protective efficacy of A. marmelos aqueous extract was expressed as percentage protection of ulcer. Results: Aqueous extract exhibited significant (p<0.05) dose dependent protection against gastric ulcer formation by ethanol in rat stomach. Percentage protection of ulcer with 200 mg/kg and 400 mg/kg of aqueous extract of A. marmelos leave were 19.3% and 37.2% respectively compared to standard anti-peptic ulcer drug omeprazole (50.4%). Conclusion: Thus, crude extracts of A. marmelos leave have been shown to have potential ability to prevent experimentally induced peptic ulcer formation in animal model. IMC J Med Sci 2018; 12(1): 11-14


Introduction
Peptic ulcer refers to ulceration in the lower esophagus, stomach, duodenum, and jejunum, and rarely in the ileum adjacent to a diverticulam.Herbal medicine is fast emerging as an alternative treatment to available synthetic drugs for the treatment of peptic ulcer possibly due to lower costs, easy availability, fewer adverse effects and perceived effectiveness. A. marmelos, commonly known as 'Bael' in Bengali language, is one such plant that grows wildly all over Bangladesh and also in many countries of South East Asia including India, Sri Lanka, Myanmar, Thailand and Indochina [1].Extensive chemical investigations on various parts of the tree have been carried out.Many active constituents has been isolated from A. marmelos and reported to have anti-ulcer, anti-inflammatory and antimicrobial properties [1].The present study was designed to demonstrate the protective effect of aqueous extract of A. marmelos leaves on ethanol induced gastric ulcer in rat model.

Materials and Methods
The study was conducted at the Department of Pharmacology, Dhaka Medical College, Bangladesh.Leaves of A. marmelos were collected from Botanical garden, Mirpur, Dhaka and authenticated by the Bangladesh National Herbarium.

Preparation of plant extract:
Collected leaves (1kg) of A. marmelos were sun dried and the dried material was crushed to coarse powder with mechanical grinder.Aqueous extract was prepared at the Drug Research Laboratory, Center for Advanced Research of Science (CARS), Dhaka University.The dried powdered plant part was soaked in distilled water at room temperature for 72 hour and filtered.The filtrate was concentrated under vacuum rotator evaporator (40-50 0 C) and semi-liquid extract of A. marmelos was obtained and preserved at 4 0 C until used.The extract was diluted with measured amount of distilled water prior to use to get the required concentration.
Animals: Thirty two Wister albino rats of either sex, weighing between 100-150g were kept under standard condition of light and temperature, fed with standard rat pellet diet and allowed to drink water ad libitum.
Experiment Design: Preventive anti-peptic ulcer activity of aqueous extracts of A. marmelos leaves was assessed in ethanol induced gastric ulcer in rat model [2,3].Experimental animals were randomly selected irrespective of sex and divided into 4 groups, each group comprising of 8 rats.Rats in group-I served as control and the other three comprised study groups.All the animals were kept fasting for 24 hours prior to administration of drugs.Rats in group-I received distilled water 5 ml/kg body weight and served as negative control.Rats in group-II and III received aqueous extract of A. marmelos leaves 200 mg/kg and 400 mg/kg body weight respectively in 1-2 ml distilled water by baby Ryle's tube.Rats in group-IV received omeprazole 20 mg/kg body weight orally as standard reference drug.One hour after administration of A. marmelos leave extract and omeprazole, gastric ulcer was induced in rats by administering 90% ethanol (1 ml/200 gm body weight) orally.One hour after ethanol administration rats were sacrificed.Their stomachs were isolated, washed gently under clean water and cut open along the greater curvature.The stomachs were then fixed in 10% formalin and the ulcers were scored as: no ulcer-0, red coloration of mucosa-0.5,spot hemorrhage-1, hemorrhagic streaks-1.5,ulcer-2 and perforation-3.
Ulcer index (UI) was calculated using the following formula: UI =UN+US+UP × 10 -1 , where UN= average of number of ulcers/lesions per animal, US = average number of severity score of lesions and UP = percentage of animal with ulcers incidence.Percentage protection of ulcer was calculated by the following formula:

Statistical Analysis
All the results have been expressed as the mean ± standard error of mean (SEM).The significance of the differences between treatment and control group were calculated using student's t-test.

Results
The ulcer score, UI and protective effect of aqueous extract of A. marmelos leaves and omeprazole on ethanol induced gastric ulcer is shown in Table-1.The mean ulcer score and UI of rats fed with distilled water only (Group-I: control) were 2.83±0.21and 18.16±0.21respectively.Aqueous extract in doses of 200 mg/kg body weight (Group-II) and 400 mg/kg body weight (Group-III) produced a significant dose dependent decrease in ulcer score to 1.58±0.15and 0.83±0.25 while ulcer index to 14.66±0.15and 11.40±0.25 respectively.The