Monthly Archives: August 2013

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

Nur Azlina MF, Kamisah Y, Chua KH, Qodriyah HM.

Evid Based Complement Alternat Med. 2013;2013:804796. doi: 10.1155/2013/804796. Epub 2013 Jul 22.

SUMMARY

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 thattocotrienol supplementation protected rat gastric mucosa against stress-induced lesions possibly by reducing gastric acidity and preserving gastric PGE2 by increasing COX-1 mRNA.

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Vitamin E δ-tocotrienol prolongs survival in the LSL-KrasG12D/+;LSL-Trp53R172H/+;Pdx-1-Cre (KPC) transgenic mouse model of pancreatic cancer.

Husain K, Centeno BA, Chen DT, Hingorani S, Sebti SM, Malafa MP.

Cancer Prev Res (Phila). 2013 Aug 20. [Epub ahead of print]

Summary

Previous work has shown that vitamin E δ-tocotrienol (VEDT) prolongs survival and delays progression of pancreatic cancer in the LSL-KrasG12D/+;Pdx-1-Cre mouse model of pancreatic cancer. However, the effect of VEDT alone or in combination with gemcitabine in the more aggressive LSL-KrasG12D/+;LSL-Trp53R172H/+;Pdx-1-Cre (KPC) mouse model is unknown. Here, we studied the effects of VEDT and the combination of VEDT and gemcitabine in the KPC mice. KPC mice were randomized into 4 groups: 1) vehicle (olive oil, 1.0 mL/kg PO twice/day and PBS 1.0 mL/kg IP twice/week), 2) gemcitabine (100 mg/kg IP twice/week), 3) VEDT (200 mg/kg PO twice/day), and 4) gemcitabine + VEDT. Mice received treatment until they displayed symptoms of impending death from pancreatic cancer, at which point animals were euthanized. At 16 weeks, survival was 10% in the vehicle group, 30% in the gemcitabine group, 70% in the VEDT group (P<0.01), and 90% in the VEDT combined with gemcitabine group (P<0.05). VEDT alone and combined with gemcitabine resulted in reversal of epithelial-to-mesenchymal transition in tumors. Biomarkers of apoptosis (plasma CK18), PARP1 cleavage, and Bax expression were more greatly induced in tumors subjected to combined treatment versus individual treatment. Combined treatment induced cell cycle inhibitors (p27Kip1 and p21Cip1) and inhibited VEGF, vascularity (CD31), and oncogenic signaling (pAKT, pMEK, and pERK) greater than individual drugs. No significant differences in body weight gain between drug treatment and control mice were observed. These results strongly support further investigation of VEDT alone and in combination with gemcitabine for pancreatic cancer prevention and treatment.

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Comparative effect of Piper betle, Chlorella vulgaris and tocotrienol-rich fraction on antioxidant enzymes activity in cellular ageing of human diploid fibroblasts.

Makpol S, Yeoh TW, Ruslam FA, Arifin KT, Yusof YA.

BMC Complement Altern Med. 2013 Aug 16;13(1):210.

Summary

BACKGROUND:

Human diploid fibroblasts (HDFs) undergo a limited number of cellular divisions in culture and progressively reach a state of irreversible growth arrest, a process termed cellular ageing. Even though beneficial effects of Piper betle, Chlorella vulgaris and tocotrienol-rich fraction (TRF) have been reported, ongoing studies in relation to ageing is of interest to determine possible protective effects that may reverse the effect of ageing. The aim of this study was to evaluate the effect of P. betle, C. vulgaris and TRF in preventing cellular ageing of HDFs by determining the activity of antioxidant enzymes viz.; catalase, superoxide dismutase (SOD) and glutathione peroxidase.

METHODS:

Different passages of HDFs were treated with P. betle, C. vulgaris and TRF for 24 h prior to enzymes activity determination. Senescence-associated beta-galactosidase (SA beta-gal) expression was assayed to validate cellular ageing.

RESULTS:

In cellular ageing of HDFs, catalase and glutathione peroxidase activities were reduced, but SOD activity was heightened during pre-senescence. P. betle exhibited the strongest antioxidant activity by reducing SA beta-gal expression, catalase activities in all age groups, and SOD activity. TRF exhibited a strong antioxidant activity by reducing SA beta-gal expression, and SOD activity in senescent HDFs. C. vulgaris extract managed to reduce SOD activity in senescent HDFs.

CONCLUSION:

P. betle, C. vulgaris, and TRF have the potential as anti-ageing entities which compensated the role of antioxidant enzymes in cellular ageing of HDFs.

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Gamma tocotrienol, a potent radioprotector, preferentially upregulates expression of anti-apoptotic genes to promote intestinal cell survival

Suman S, Datta K, Chakraborty K, Kulkarni SS, Doiron K, Fornace AJ Jr Sree Kumar K, Hauer-Jensen M, Ghosh SP.

Food Chem Toxicol. 2013 Aug 10

Summary

Gamma tocotrienol (GT3) has been reported as a potent ameliorator of radiation-induced gastrointestinal (GI) toxicity when administered prophylactically. This study aimed to evaluate the role of GT3 mediated pro- and anti-apoptotic gene regulation in protecting mice from radiation-induced GI damage.

Male 10- to 12-weeks-old CD2F1 mice were administered with a single dose of 200 mg/kg of GT3 or equal volume of vehicle (5% Tween-80) 24 h before exposure to 11 Gy of whole-body γ-radiation. Mouse jejunum was surgically removed 4 and 24 h after radiation exposure, and was used for PCR array, histology, immunohistochemistry, and immunoblot analysis.

Results were compared among vehicle pre-treated no radiation, vehicle pre-treated irradiated, and GT3 pre-treated irradiated groups. GT3 pretreated irradiated groups, both 4 h and 24 h after radiation, showed greater upregulation of anti-apoptotic gene expression than vehicle pretreated irradiated groups. TUNEL staining and intestinal crypt analysis showed protection of jejunum after GT3 pre-treatment and immunoblot results were supportive of PCR data.

Our study demonstrated that GT3-mediated protection of intestinal cells from a GI-toxic dose of radiation occurred via upregulation of antiapoptotic and downregulation of pro-apoptotic factors, both at the transcript as well as at the protein levels.

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Supplementation with natural forms of vitamin e augments antigen-specific Th1-type immune response to tetanus toxoid.

Radhakrishnan AK, Mahalingam D, Selvaduray KR, Nesaretnam K.

Biomed Res Int. 2013;2013:782067. doi: 10.1155/2013/782067. Epub 2013 Jul 7.

Summary

This study compared the ability of three forms of vitamin E [tocotrienol-rich fraction (TRF), alpha-tocopherol (α-T), and delta-tocotrienol (δ-T3)] to enhance immune response to tetanus toxoid (TT) immunisation in a mouse model. Twenty BALB/c mice were divided into four groups of five mice each. The mice were fed with the different forms of vitamin E (1 mg) or vehicle daily for two weeks before they were given the TT vaccine [4 Lf] intramuscularly (i.m.). Booster vaccinations were given on days 28 and 42. Serum was collected (days 0, 28, and 56) to quantify anti-TT levels. At autopsy, splenocytes harvested were cultured with TT or mitogens. The production of anti-TT antibodies was augmented (P < 0.05) in mice that were fed with δ-T3 or TRF compared to controls. The production of IFN-γ and IL-4 by splenocytes from the vitamin E treated mice was significantly (P < 0.05) higher than that from controls. The IFN-γ production was the highest in animals supplemented with δ-T3 followed by TRF and finally α-T. Production of TNF-α was suppressed in the vitamin E treated group compared to vehicle-supplemented controls. Supplementation with δ-T3 or TRF can enhance immune response to TT immunisation and production of cytokines that promote cell-mediated (TH1) immune response.

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Antioxidant Activity of Tocotrienol Rich Fraction Prevents Fenitrothion-induced Renal Damage in Rats.

Budin SB, Han KJ, Jayusman PA, Taib IS, Ghazali AR, Mohamed J.

J Toxicol Pathol. 2013 Jun;26(2):111-8. doi: 10.1293/tox.26.111. Epub 2013 Jul 10

Summary:

Fenitrothion (FNT) is an organophosphate compound widely used as pesticide in Malaysia. The present study aims to investigate effects of palm oiltocotrienol rich fraction (TRF) on the renal damage of FNT-treated rats. A total of 40 male Sprague Dawley rats were divided into 4 groups randomly, the control, TRF, FNT and FNT+TRF groups. FNT (20 mg/kg b.w.) and TRF (200 mg/kg b.w.) were given orally for 28 days continuously. Rats from the FNT+TRF group were supplemented with TRF 30 minutes prior to administration of FNT. Rats were sacrificed after 28 days, and the kidneys were removed for determination of oxidative stress and histological analysis. Plasma was collected for determination of blood creatinine and urea level. Statistical analysis showed that palm oil TRF has a protective effect against renal oxidative damage induced by FNT. In the FNT+TRF group, malondialdehyde and protein carbonyl levels were significantly lower, while the glutathione level as well as superoxide dismutase and catalase activities were significantly higher compared with the FNT-treated group (p<0.05). As for renal function, there was a markedly lower urea level (p<0.05) in the FNT+TRF group compared with the FNT-treated group, but there was no significant difference in creatinine level. Besides, total protein also showed no significant difference for all groups of rats (p>0.05). Histological evaluation also revealed that the FNT+TRF group had less glomerulus and renal tubule damage than the FNT-treated group. In conclusion, palm oil TRF was able to reduce oxidative stress and renal damage in FNT-treated rats.

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The effects of prenatal and early postnatal tocotrienol-rich fraction supplementation on cognitive function development in male offspring rats.

Gowri Nagapan, Goh Yong Meng, Intan Shameha Abdul Razak, Kalanithi Nesaretnam and Mahdi Ebrahimi

BMC Neurosci. 2013 Jul 31;14(1):77. [Epub ahead of print]

Summary

BACKGROUND:

Recent findings suggest that the intake of specific nutrients during the critical period in early life influence cognitive and behavioural development profoundly. Antioxidants such as vitamin E have been postulated to be pivotal in this process, as vitamin E is able to protect the growing brain from oxidative stress. Currently tocotrienols are gaining much attention due to their potent antioxidant and neuroprotective properties. It is thus compelling to look at the effects of prenatal and early postnatal tocotrienols supplementation, on cognition and behavioural development among offsprings of individual supplemented with tocotrienols. Therefore, this study is aimed to investigate potential prenatal and early postnatal influence ofTocotrienol-Rich Fraction (TRF) supplementation on cognitive function development in male offspring rats. Eight-week-old adult female Sprague Dawley (SD) rats were randomly assigned into five groups of two animals each. The animals were fed either with the base diet as control (CTRL), base diet plus vehicle (VHCL), base diet plus docosahexanoic acid (DHA), base diet plus Tocotrienol-Rich fraction (TRF), and base diet plus both docosahexaenoic acid, and tocotrienol rich fraction (DTRF) diets for 2 weeks prior to mating. The females (F0 generation) were maintained on their respective treatment diets throughout the gestation and lactation periods. Pups (F1 generation) derived from these dams were raised with their dams from birth till four weeks post natal. The male pups were weaned at 8 weeks postnatal, after which they were grouped into five groups of 10 animals each, and fed with the same diets as their dams for another eight weeks. Learning and behavioural experiments were conducted only in male off-spring rats using the Morris water maze.Eight-week-old adult female Sprague Dawley (SD) rats were randomly assigned into five groups of two animals each. The animals were fed either with the base diet as control (CTRL), base diet plus vehicle (VHCL), base diet plus docosahexanoic acid (DHA), base diet plus Tocotrienol-Rich fraction (TRF), and base diet plus both docosahexaenoic acid, and tocotrienol rich fraction (DTRF) diets for 2 weeks prior to mating. The females (F0 generation) were maintained on their respective treatment diets throughout the gestation and lactation periods. Pups (F1 generation) derived from these dams were raised with their dams from birth till four weeks post natal. The male pups were weaned at 8 weeks postnatal, after which they were grouped into five groups of 10 animals each, and fed with the same diets as their dams for another eight weeks. Learning and behavioural experiments were conducted only in male off-spring rats using the Morris water maze.

RESULTS:

Results showed that prenatal and postnatal TRF supplementation increased the brain (4–6 fold increase) and plasma alpha-tocotrienol(0.8 fold increase) levels in male off-springs. There is also notably better cognitive performance based on the Morris water maze test among these male off-springs.

CONCLUSION:

Based on these results, it is concluded that prenatal and postnatal TRF supplementation improved cognitive function development in male progeny rats.

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Effects of late administration of pentoxifylline and tocotrienols in an image-guided rat model of localized heart irradiation.

Sridharan V, Tripathi P, Sharma S, Corry PM, Moros EG, Singh A, Compadre CM, Hauer-Jensen M, Boerma M.

PLoS One. 2013 Jul 22;8(7):e68762. doi: 10.1371/journal.pone.0068762. Print 2013.

Summary:

Radiation-induced heart disease (RIHD) is a long-term side effect of radiotherapy of intrathoracic, chest wall and breast tumors when radiation fields encompass all or part of the heart. Previous studies have shown that pentoxifylline (PTX) in combination with α-tocopherol reduced manifestations of RIHD in rat models of local heart irradiation. The relative contribution of PTX and α-tocopherol to these beneficial effects are not known. This study examined the effects of PTX alone or in combination with tocotrienols, forms of vitamin E with potential potent radiation mitigation properties. Rats received localized X-irradiation of the heart with an image-guided irradiation technique. At 3 months after irradiation rats received oral treatment with vehicle, PTX, or PTX in combination with a tocotrienol-enriched formulation. At 6 months after irradiation, PTX-treated rats showed arrhythmia in 5 out of 14 animals. PTX alone or in combination with tocotrienols did not alter cardiac radiation fibrosis, left ventricular protein expression of the endothelial markers von Willebrand factor and neuregulin-1, or phosphorylation of the signal mediators Akt, Erk1/2, or PKCα. On the other hand, tocotrienolsreduced cardiac numbers of mast cells and macrophages, but enhanced the expression of tissue factor. While this new rat model of localized heart irradiation does not support the use of PTX alone, the effects of tocotrienols on chronic manifestations of RIHD deserve further investigation. Read More