Tocotrienol Attenuates Stress-Induced Gastric Lesions via Activation of Prostaglandin and Upregulation of COX-1 mRNA

Abstract

The present study aims to distinguish the effect of tocotrienol on an important gastric protective factor, prostaglandin E2 (PGE2), in stress-induced gastric injury. Twenty-eight Wistar rats were divided into four groups of seven rats each. Two control groups were fed commercial rat diet, and two treatment groups were fed the same diet but with additional dose of omeprazole (20 mg/kg) or tocotrienol (60 mg/kg). After 28 days, rats from one control group and both treated groups were subjected to water-immersion restraint stress for 3.5 hours once. The rats were then sacrificed, their stomach isolated and gastric juice collected, lesions examined, and gastric PGE2 content and cyclooxygenase (COX) mRNA expression were determined. Both the regimes significantly attenuated the total lesion area in the stomach compared to the control. Gastric acidity, which was increased in stress, was significantly reduced in rats supplemented with omeprazole and tocotrienol. The PGE2 content was also significantly higher in the rats given tocotrienol supplementation compared to the control followed by an increase in COX-1 mRNA expression. We conclude that tocotrienol supplementation protected rat gastric mucosa against stress-induced lesions possibly by reducing gastric acidity and preserving gastric PGE2 by increasing COX-1 mRNA.

Effect of vitamin K2 on the development of stress-induced osteopenia in a growing senescence-accelerated mouse prone 6 strain

“…WRS is often used as a stress treatment to induce stress response syndromes in animals (8)(9)(10)(11)(12)(13)24). In the present study, WRS successfully reduced the BMD via a high bone turnover rate; WRS induced an increase in bone resorption and formation.…”

“…VK2 has been shown to exhibit the novel function of binding to the pregnane X receptor (PXR), and PXR-dependent biological functions have been demonstrated in bone (6); however the biological effect of VK2 remains controversial, Effect of vitamin K2 on the development of stress-induced osteopenia in a growing senescence-accelerated mouse prone 6 strain since Fu et al (7) reported that VK2 failed to prevent bone loss in ovariectomized rats. Water-immersion restraint stress (WRS), which involves both psychological and physical stress, is widely used to induce reproducible stress ulcers in experimental animals (8)(9)(10)(11)(12). WRS consists of immobilization and cold stress, in which the exposure temperature is usually 24˚C.…”

Potential Role of Tocotrienols on Non-Communicable Diseases: A Review of Current Evidence

“…Rats exposed to water-immersion restraint stress (WIRS) developed stress ulcers, which mimics ulcer development in critically ill patients [220]. Pre-treatment with pure T3 mixtures before exposure to WIRS for 28 days significantly reduced gastric acidity, an important aggressive factor in the pathogenesis of stress-induced gastric injuries [221].…”

“…Exposure to restraint stress also resulted in high gastric oxidative stress content, accompanied by the formation of stress ulcers [220,222,223]. T3 was able to significantly reduce oxidative stress product (MDA) and this was associated with improved gastric ulcers [221,223,224]. Endogenous prostaglandin, in particular prostaglandin E 2 (PGE 2 ), is important in maintaining gastric mucosal integrity.…”

“…Interestingly, Rodzian et al (2013) found that the supplementation annatto T3, which mainly contains δT3 isomer, suppressed gastric PGE 2 level [229]. On the other hand, palm pure T3 mixture was able to protect the gastric mucosa with the elevation of PGE 2 level, which was associated with an increased in cyclooxygenase-1 (COX-1) expression [221]. Therefore, the composition of T3 mixture is important in determining the effects on PGE 2 level.…”