The Effects of Palm Oil Tocotrienol-Rich Fraction Supplementation on Biochemical Parameters, Oxidative Stress and the Vascular Wall of Streptozotocin-Induced Diabetic Rats

Abstract

The effects of palm oil tocotrienol-rich fraction supplementation on biochemical parameters, oxidative stress and the vascular wall of streptozotocin-induced diabetic rats. Clinics. 2009;64(3):235-44. OBJECTIVE:This study examined the effects of palm oil tocotrienol-rich fractions on streptozotocin-induced diabetic rats. METHODS: Animals were divided into three groups: (i) normal non-diabetic (NDM), (ii) diabetic treated (tocotrienol-rich fractions -TRF) and (iii) diabetic untreated (non-TRF). The treatment group received oral administration of tocotrienol-rich fractions (200 mg/kg body weight) daily for eight weeks. The normal non-diabetic and the diabetic untreated groups were fed standard rat feed. Blood glucose and lipid profiles, oxidative stress markers and morphological changes of the thoracic aorta were evaluated. RESULTS: Tocotrienol-rich fractions treatment reduced serum glucose and glycated hemoglobin concentrations. The tocotrienolrich fractions group also showed significantly lower levels of plasma total cholesterol, low-density lipoprotein cholesterol, and triglyceride, as compared to the untreated group. The tocotrienol-rich fractions group had higher levels of high-density lipoprotein cholesterol, as compared to the untreated group. Superoxide dismutase activity and levels of vitamin C in plasma were increased in tocotrienol-rich fractions-treated rats. The levels of plasma and aorta malondealdehyde + 4-hydroxynonenal (MDA + 4-HNE) and oxidative DNA damage were significant following tocotrienol-rich fractions treatment. Electron microscopic examination showed that the normal morphology of the thoracic aorta was disrupted in STZ-diabetic rats. Tocotrienol-rich fractions supplementation resulted in a protective effect on the vessel wall. CONCLUSION: These results show that tocotrienol-rich fractions lowers the blood glucose level and improves dyslipidemia. Levels of oxidative stress markers were also reduced by administration of tocotrienol-rich fractions. Vessel wall integrity was maintained due to the positive effects mediated by tocotrienol-rich fractions.

Therapeutic potential of d-δ-tocotrienol rich fraction on excisional skin wounds in diabetic rats

“…The lower mean values of TC, TG, LDL and VLDL levels and high HDL level were recorded in DTT after 3 weeks treatments. This result is in agreement with related study [45].…”

Fenitrothion Alters Sperm Characteristics in Rats: Ameliorating Effects of Palm Oil Tocotrienol-Rich Fraction

“…melatonin has been proposed to protect germ cells from oxidative stress rather than to have a direct effect on sperm in the epididymis, thus reducing the percentage of dna damaged in diazonin-treated rats [37]. our results are also consistent with previous research that found TRF from palm oil reduced dna damage by inhibiting the formation of RoS in diabetic rats [8]. Furthermore, supplementation with TRF in human adults has been found to decrease dna damage through its antioxidant function and by activation of signaling molecules in repairing the dna [10].…”

“…mixtures of tocotrienol and tocopherol from palm oil showed better protection against free radical-induced bone damage in rats compared with pure α-tocopherol [1]. Palm oil TRF at the dose of 200 mg/kg also showed a protective effect against many pathological conditions including diabetes-induced atherosclerosis and red blood cells membrane damage [8,26] and oP-induced toxicity in the kidney and pancreas [6,7]. besides, TRF at the same dose did not cause any oxidative damage in normal rats [6,7,26].…”

Anti-hyperglycaemic and anti-hyperlipidaemic effects of black and red rice in streptozotocin-induced diabetic rats

“…The antidiabetic effects of vitamin E and γ-oryzanol have been reported in STZ-induced diabetic rats. It had previously shown that the STZ-induced diabetic rats treated with tocotrienol-rich fraction from palm oil could potentially stabilize the level of total cholesterol, LDLcholesterol, and triglycerides 31 . In addition, cholesterol synthesis and fuel oxidation were increased in STZ/nicotinamide-induced diabetic rats treated with γ-tocotrienol and γ-oryzanol rich fractions of rice bran oil as a result of hyperlipidaemic and hyperinsulinemic response suppression 32 .…”