14 research outputs found
Evaluating of high fructose diet to induce hyperglycemia and its inflammatory complication in rats.
It has been reported that a diet enriched in fructose would present animal models used to emulate diabetes mellitus type 2 in human. This study aimed to examine the effect of high fructose induction on the blood glucose, C-reactive protein, interleukin-6, interleukin-4 and body weight among high fructose diet-induced rats. The HFD was induced through drinking water in 21% (w/v) concentration among male Sprague-Dawley rats. The high fructose diet administration was unable to induce hyperglycemia, hypertriglyceridemia or any classic inflammatory markers. Also, no histological inflammation was observed. It was concluded that healthy Sprague-Dawley rats fed high fructose diet for 2.5 months could not develop signs of diabetes mellitus type 2
The comparative effects between tocotrieonol-rich fraction (TRF) and α-tocopherol on glutamate toxicity in neuron-astrocyte mono- and co-culture systems
Background:
Vitamin E, which can be categorized into tocotrienols and tocopherols, is known to protect cells from glutamate neurotoxicity. Studies have shown that tocotrienol-rich fraction (TRF) protecting the brain against oxidative damage more efficient than α-tocopherol. The role of astrocyte in promoting neuronal survival and recovery after glutamate neurotoxicity is also increasingly appreciated.
Aims:
To elucidate the effects of TRF and α-tocopherol and the synergism between astrocyte and neuron against glutamate neurotoxicity.
Methods:
Astrocyte and neuron were subjected to glutamate injury followed by TRF and α-tocopherol treatments (100 – 300 ng/ml). Effects of TRF and α-tocopherol on nerve cell viability and glutathione contents against glutamate toxicity were examined. The synergism between astrocyte and neuron was elucidated through co-culture model. Statistical analysis was performed using one way ANOVA.
Results:
Both TRF and α-tocopherol improved approximately 10% of glutamate-injured astrocyte and neuronal cell viability. In co-culture model, TRF and α-tocopherol provided nearly complete protection from glutamate toxicity. Besides, TRF and α-tocopherol treatments significantly restored at least 20% of glutathione contents in glutamate-injured neurons. In the presence of astrocyte, 300 ng/ml TRF and α-tocopherol completely restored glutathione contents in glutamate-injured neuron.
Conclusions:
TRF and α-tocopherol had shown promising neuroprotective effects in astrocyte and neuron from glutamate toxicity. Great scavenging effect of both TRF and α-tocopherol against glutamate toxicity was observed in neuron. Similar protective effects between TRF and α-tocopherol were observed. Co-culture model demonstrated the synergistic properties between neuron and astrocyte. Supplementation of TRF and α-tocopherol in co-culture further improved the recovery process
Reduction of aflatoxin level in aflatoxin-induced rats by the activity of probiotic Lactobacillus casei strain Shirota.
Aims:
Aflatoxin B1 (AFB1) is considered as the most toxic food contaminant, and microorganisms, especially bacteria, have been studied for their potential to reduce the bioavailability of mycotoxins including aflatoxins. Therefore, this research investigated the efficacy of oral administration of Lactobacillus casei Shirota (LcS) in aflatoxin-induced rats.
Methods and Results:
Sprague Dawley rats were divided into three groups of untreated control, the group induced with AFB1 only, and the group given probiotic in addition to AFB1. In the group induced with AFB1 only, food intake and body weight were reduced significantly. The liver and kidney enzymes were significantly enhanced in both groups induced with AFB1, but they were lower in the group given LcS. AFB1 was detected from all serum samples except for untreated control group's samples. Blood serum level of AFB1 in the group induced with AFB1 only was significantly higher than the group which received probiotic as a treatment (P < 0·05), and there was no significant difference between the control group and the group treated with probiotic.
Conclusions:
LcS supplementation could improve the adverse effect of AFB1 induction on rats' body weight, plasma biochemical parameters and also could reduce the level of AFB1 in blood serum.
Significance and Impact of the Study:
This study's outcomes contribute to better understanding of the potential of probiotic to reduce the bioavailability ofAFB1. Moreover, it can open an opportunity for future investigations to study the efficacy of oral supplementation of probiotic LcS in reducing aflatoxin level in human
Ultra-high performance liquid chromatographic determination of aflatoxin M1 in urine
The development of analytical methods to detect aflatoxin B1 (AFB1) in foodstuffs and its metabolites in human biological samples is useful for risk assessment. The latter methodology, i.e. the measurement of AFB1 biomarkers, has become important to assess human aflatoxin exposure. AFB1-lysine adduct, AFB1-DNA adduct and urinary aflatoxin M1 (AFM1) are some of the AFB1 biomarkers that can be measured by several analytical methods, such as enzyme-linked immunosorbent assay, radioimmunoassay, and high performance liquid chromatography (HPLC). HPLC coupled to a fluorescence detector is useful and preferable due to its high degree of sensitivity, but the analysis may take time and consume large amount of solvents. Therefore, the present study extrapolated the HPLC method to ultra-HPLC for the determination of urinary AFM1. After the extraction procedure with an immunoaffinity column, chromatographic separation was done using a high performance 1.8 μm microparticulate C18 column. The mean recovery from urine samples spiked with 0.5, 1.0 and 2.0 ng/ml AFM1 was 84.4±4.0%, with acceptable recovery values, interday (6.0±5.3%) and intraday (2.6±0.6%) coefficients of variation. The retention time was 5.7 min. This method was used to measure urinary AFM1 in 71 subjects, of which 13 had AFM1 levels above the limit of detection (0.018 ng/ml). The mean urinary AFM1 level of the positive samples was 18.8±28.6 pg/ml, ranging from 2.4 to 100.4 pg/ml. As this is one of the few studies investigating the occurrence of aflatoxin biomarkers in human biological samples in Malaysia, a study with a larger sample size is necessary to investigate the magnitude of aflatoxin exposure among the population
Expressions of endothelial cells adhesion molecules are significantly reduced in the presence of minute amount of tocotrienols
Comparative effects of palm tocotrienol rich fractions (TRF) and α–tocopherol on the expression of adhesion molecules by human umbilical vein endothelial cells (HUVECs) were investigated in the present study. Cell based ELISA technique using a monospecific, monoclonal antibodies was employed to measure expression of intracellular cell adhesion molecules–1 (ICAM–1) and vascular cell adhesion molecules–1 (VCAM–1). Primary HUVECs, cultured on a96 wells microtiter plate was incubated for 4 hours with different concentration (ng⁄ml) of TRF or α–tocopherol before subjected to inflammatory stimulation by incubating it with 2 ng⁄ml tumour necrosis factor-α (??F-α) and further incubated for 4 hours. MTS assay was carried out to ascertain the effects of the different dosages on the cells viability. VCAM–1 expression was significantly decreased when HUVECs were incubated with palm TRF between 10–50ng⁄ ml concentrations. Similar effects of the palm TRF were also observed on the expression of ICAM–1. The effect of α–tocopherol however was found to be less consistent. At 10ng⁄ml and 20ng⁄ml, α–tocopherol increased VCAM–1 expression. Higher concentration (30–50ng⁄ml) returned the expression to normal. On the other hand, ICAM–1 was significantly decreased when incubated with 10ng⁄ml of α–tocopherol but gradually increased with increased dosage of α–tocopherol. Our findings suggest that TRF are more potent adhesion molecules expression inhibitor compared to α–tocopherol in–vitro
The role of antenatal vitamin e supplementation in the prevention of neonatal jaundice.
Objective:
To determine the effect of maternal antenatal vitamin E supplementation on neonatal jaundice.
Methods:
A randomized double blind controlled trial assessing the role of vitamin E in the prevention of preeclampsia was conducted in a tertiary hospital over two years. From 12-16 weeks gestation until delivery, primigravida mothers with singleton pregnancies received either 100 mg daily vitamin E in the form of tocotrienol rich fraction, or placebo. The newborns were assessed for jaundice.
Results:
Among 262 infants, 136 were in the vitamin E group and 126 in the placebo group. The incidence of neonatal jaundice was similar: 38% (54/136) in the vitamin E group and 36% (45/126) in the placebo group (p= 0.10). Nevertheless, the vitamin E group had a tendency for lower peak serum bilirubin, although not significantly so.
Conclusion:
Maternal antenatal vitamin E supplementation had no effect on the incidence of neonatal jaundice
Genetic determinants of obesity heterogeneity in type II diabetes
Background: Although obesity is considered as the main cause of Type II diabetes (T2DM), non-obese individuals may still develop T2DM and obese individuals may not. Method: The mRNA expression of PI3K/AKT axis from 100 non-obese and obese participants with insulin sensitivity and insulin resistance states were compared in this study toward the understanding of obesity heterogeneity molecular mechanism. Result: In present study, there was no statistically significant difference in gene expression levels of IRS1 and PTEN between groups, whereas PI3K, AKT2 and GLUT4 genes were expressed at a lower level in obese diabetic group compared to other groups and were statistically significant. PDK1 gene was expressed at a higher level in non-obese diabetic group compared to obese diabetic and non-obese non-diabetics groups. No statistically significant difference was identified in gene expression pattern of PI3K/AKT pathway between obese non-diabetics and non-obese non-diabetics. Conclusion: The components of PI3K/AKT pathway which is related to the fasting state, showed reduced expression in obese diabetic group due to the chronic over-nutrition which may induced insensitivity and reduced gene expression. The pathogenesis of insulin resistance in the absence of obesity in non-obese diabetic group could be due to disturbance in another pathway related to the non-fasting state like gluconeogenesis. Therefore, the molecular mechanism of insulin signalling in non-obese diabetic individuals is different from obese diabetics which more investigations are required to study insulin signalling pathways in greater depth, in order to assess nutritional factors, contribute to insulin resistance in obese diabetic and non-obese diabetic individuals
L54 comparative study of the absorption and distribution of tocotrienols to tocopherols
Vitamin E is a potent fat soluble antioxidant that inhibits lipid peroxidation in biological membranes. In nature compounds with vitamin E activity are α, β, γ and δ- tocopherols and α, β, γ and δ- tocotrienols. Tocotrienols have been suggested to exert a hypocholesterolemic, antiatherosclerotic effect, anti-proliferative and suppressive effect on human breast cancer cells. Besides all the positive effects shown by tocotrienols, these compounds are known to have extremely low bioavailability and low bioaccumulation. A comprehensive knowledge of absorption, distribution, metobolism and elimination of this compund is important for the interpretation of pharmacological and toxicological effects it exerts. Therefore, this study was designed to trace the fate of both α- tocopherol and tocotrienols after 30 days' oral ingestion by Sprague Dawley rats. In this study the pharmacokinetic of tocotrienols found to be entirely different compared to tocopherols. Tocotrienols showed an adaption period, which was improved by the end of 30 days' supplementation in order to attain the selectivity of tocotrienols as a source of vitamin E for the body. Tocotrienols, however have a low accumulation pattern compared to tocopherols in various organs studied, except for skin and adipose tissue, suggesting a different mechanism of uptake between α- tocopherol and the tocotrienols involved. An in vitro study study confirmed the finding that a-TTP (α- tocopherol transfer protein) is highly expressed in hepatic cells, which evidently discriminate against bioavailability of tocotrienols in plasma. In an effort to elucidate the mechanism involved in uptake of tocotrienols by the cell, the expression of α-TPP in other cells (HepG2) was investigated. Expression of α-TPP in other cells related to where it is accumulated will be resumed as a continuation of the current work
Estimation of dietary AFB1 exposure through the level of AFM1 detected in human urine samples : a preliminary study.
Aflatoxin B1 (AFB1) is a toxin produced by Aspergillus species of fungi and commonly found contaminating foodstuffs such as cereals, nuts and spices. Once absorbed in the bloodstream, AFB1 is metabolised into aflatoxin M1 (AFM1) and excreted in the urine. This preliminary study
aimed to extrapolate the AFM1 level detected in human urine in estimating dietary AFB1 exposure. Twenty-two adults were recruited randomly and morning urine samples were
collected. The AFM1 level was measured using direct enzyme-linked immunosorbent assay. AFM1 was detected in all urine samples (mean ± SEM = 0.0421 ± 0.006 ng/ml; 95% CI = 0.0299
– 0.0544 ng/ml). The AFM1 value was back-transformed to estimate dietary AFB1 exposure. The mean estimated dietary AFB1 exposure was 0.028 !g/day/kg BW and it was significantly different between educational level (z = -2.242; p = 0.025) and BMI (χ2 = 6.883; p = 0.032). The
estimated dietary AFB1 exposure also showed significant positive correlation with the consumption of powdered milk (r = 0.435; p = 0.021), condensed milk (r = 0.522; p = 0.006) and peanuts (r = 0.390; p = 0.036). It can be postulated that human exposure to aflatoxin may involve many inter-related factors such as dietary habits, environmental and lifestyle factors. Since AFB1 is classified as Group 1 carcinogen by the International Agency for Research on Cancer (IARC), this foodborne contamination could lead to many detrimental health effects.
Therefore, findings from this study warrant further investigations to detect the sources and potential consequences of this contaminant exposure in Malaysia