This study examined the effects of various doses of palm vitamin E and tocopherol with and without aspirin on gastric acid, malondialdehye (MDA) and mucus in rats. The study was divided into two phases: phase 1 determined the effects of various doses of palm vitamin E and tocopherol on the factors affecting mucosal integrity. Sixty-four male rats of Sprague-Dawley species (200-250 g) were randomly divided into eight groups. Group I was fed a normal diet (control), Group II, III and IV were fed a diet supplemented with palm vitamin E in a dose of 60, 100 and 150 mg kg-1 food, respectively. Whereas rats in Group V, VI, VII and VIII were fed with tocopherol in a dose of 20, 30, 50 and 100 mg kg-1 food, respectively for 4 weeks. The rats were killed after four weeks of feeding for the determination of gastric malondialdehyde (MDA), acid and mucus content. There was a significant decrease in gastric MDA and gastric acid in all the palm vitamin E supplemented groups compared to control. However, these doses of palm vitamin E had no significant effect on gastric mucus. Tocopherol in a dose of 100 mg kg-1 food causes a significant increase in gastric mucus and decrease gastric acid content compared to control and other tocopherol groups. Phase 2 study determined the effect of multiple doses of palm vitamin E and tocopherol on gastric parameters and gastric lesions index post aspirin exposure. Fifty-six rats of the same weight and species were randomized into seven groups. Group I was fed a normal diet, Group II to IV were fed with palm vitamin E enriched diet in a dose of 60, 100 and 150 mg kg-1 food, respectively. Whereas Groups V to VII were fed with tocopherol enriched in a dose of 20, 30 and 50 mg kg-1 food, respectively. After four weeks of feeding with the respective diets the rats were challenged with a single intragastric dose of 400 mg kg-1 body weight aspirin suspended in propylene glycol. The rats were killed 6 h post-aspirin exposure for the determination of gastric lesion index and gastric parameters as mentioned in phase I study. Both vitamins E exhibits similar efficacy but less potency on gastric lesions indexes in rats and it was accompanied by a significant decrease in gastric MDAcontent. We conclude that the effect of vitamin E on gastric parameters before and after aspirin administration is not the same and not dose-dependent. Palm vitamin E reduces MDA concentration with and without aspirin administration and at the same time reduces gastric acid secretion without aspirin challenge. Tocopherol reduced gastric MDA post aspirin administration. However, low dose tocopherol reduces MDA and high dose tocopherol reduces acid and increase gastric mucus in the absence of aspirin administration.
Kamsiah Jaarin , Mtgapor and Fazlina Jaafar , 2006. Effect of Various Doses of Palm Vitamin E and Tocopherol on Factors Affecting Gastric Lesions in Rats. International Journal of Pharmacology, 2: 98-103.