OBJECTIVE: The aim of this work was to summarize documented reports on the effects of tocopherol and tocotrienol on various pathological changes induced by stress.
RESULTS AND CONCLUSION: This review will reveal the scientific evidence of enteral supplementation of vitamin E in the forms of tocotrienol and tocopherol in animal models of stress. These models mimic the stress endured by critically ill patients in a clinical setting and psychological stress in individuals. Positive outcomes from enteral feeding of vitamin E in reducing the occurrence of stress-induced pathological changes are discussed in this review. These positive findings include their ability to reduced stress-induced gastric ulcers, elevated liver enzymes and improved locomotors activity. Evidences showing tocotrienol and tocopherol effects are not just related to its ability to reduce oxidative stress but also acting on other mechanism, are discussed.
Material and methods: The methanolic extract of PS was prepared in the dose of 500 mg/kg. Twenty-eight male Wistar rats were assigned to 4 equal sized groups: two control groups and two treated groups which were supplemented with either PS or OMZ orally at a dose of 500 mg/kg and 20 mg/kg body weight respectively. After 28 days of treatment, one control group, the PS and OMZ group were subjected to a single exposure of water-immersion restraint stress for 3.5 h. After the last exposure to stress, the stomach was excised for evaluation of the parameters.
Results: Oral supplementation of PS was as effective in preventing the formation of gastric lesion when compared with OMZ (p < 0.05). The increased gastric acidity and MDA due to stress was also reduced with supplementation of PS and OMZ. Only PS had the ability to reduce prostaglandin E2 loss (p = 0.0067) and have the ability to down regulate cyclooxygenase-2 (COX-2) mRNA expression (p = 0.01) with stress exposure.
Conclusions: Piper sarmentosum possesses a similar protective effect against stress-induced gastric lesions as omeprazole. The protective effect was associated with decreased lipid peroxidation, increased prostaglandin E2, reduction in gastric acidity and reduction in COX-2 mRNA expression which was altered by stress.