124 research outputs found
The influence of age, ethnicity and body anthropometry on the level of serum osteocalcin and terminal-c telopeptides of type I collagen in men
Bone turnover markers (BTMs) are useful in the assessment of bone health status. However, the infl uence of age, ethnicity and body anthropometry on the level of BTMs in men remains understudied. This study aimed to determine the influence of these factors on the level of BTM, namely osteoclacin (OC) and C-terminal telopeptides of type 1 collagen (CTX-1) among Malay and Chinese men (N = 407) aged 20 years and above in Klang Valley. The subjects were recruited using purposive sampling method. Their height, body weight and body mass index were measured. Their blood was collected in the morning for serum OC and CTX-1 analysis using enzyme-linked immunoasorbent assays. Results showed that OC and CTX-1 levels were significantly higher in Malay compared to Chinese men (p 0.005). There were significant and negative correlations between OC and body mass index and weight, which were significant for men aged 20-39 years only (p 0.05). As a conclusion, levels of BTMs in Malaysian men could be infl uenced by age, ethnicity and body anthropometry. Thus, these factors should be taken into consideration in the evaluation of bone health status of men using BTMs
Serum testosterone, sex hormone-binding globulin and total calcium levels predict the calcaneal speed of sound in men
OBJECTIVES: Variations in sex hormones and the calcium balance can influence bone health in men. The present study aimed to examine the relationship between the calcaneal speed of sound and biochemical determinants of bone mass, such as sex hormones, parathyroid hormones and serum calcium. METHODS: Data from 549 subjects from the Malaysian Aging Male Study, which included Malay and Chinese men aged 20 years and older residing in the Klang Valley, were used for analysis. The subjects' calcaneal speed of sound was measured, and their blood was collected for biochemical analysis. Two sets of multiple regression models were generated for the total/bioavailable testosterone and estradiol to avoid multicollinearity. RESULTS: The multiple regression results revealed that bioavailable testosterone and serum total calcium were significant predictors of the calcaneal speed of sound in the adjusted model. After adjustment for ethnicity and body mass index, only bioavailable testosterone remained significant; the total serum calcium was marginally insignificant. In a separate model, the total testosterone and sex hormone-binding globulin were significant predictors, whereas the total serum calcium was marginally insignificant. After adjustment for ethnicity and body mass index (BMI), the significance persisted for total testosterone and SHBG. After further adjustment for age, none of the serum biochemical determinants was a significant predictor of the calcaneal speed of sound. CONCLUSION: There is a significant age-dependent relationship between the calcaneal speed of sound and total testosterone, bioavailable testosterone and sex hormone-binding globulin in Chinese and Malay men in Malaysia. The relationship between total serum calcium and calcaneal speed of sound is ethnicity-dependent
Modulation of collagen synthesis and its gene expression in human skin fibroblasts by tocotrienol-rich fraction
Effect of the tocotrienol-rich fraction on the lifespan and oxidative biomarkers in Caenorhabditis elegans under oxidative stress
OBJECTIVE: This study was performed to determine the effect of the tocotrienol-rich fraction on the lifespan and oxidative status of C. elegans under oxidative stress. METHOD: Lifespan was determined by counting the number of surviving nematodes daily under a dissecting microscope after treatment with hydrogen peroxide and the tocotrienol-rich fraction. The evaluated oxidative markers included lipofuscin, which was measured using a fluorescent microscope, and protein carbonyl and 8-hydroxy-2′-deoxyguanosine, which were measured using commercially available kits. RESULTS: Hydrogen peroxide-induced oxidative stress significantly decreased the mean lifespan of C. elegans, which was restored to that of the control by the tocotrienol-rich fraction when administered before or both before and after the hydrogen peroxide. The accumulation of the age marker lipofuscin, which increased with hydrogen peroxide exposure, was decreased with upon treatment with the tocotrienol-rich fraction (
Palm oil γ-tocotrienol and α-tocopherol act as potent inducers in the immune response of mouse splenocytes in vitro / Narimah Abdul Hamid Hasani, Khalid bin Abdul Kadir and Wan Zurinah Wan Ngah
Vitamin E may have anti carcinogenesis effect in human and animal models
via the mechanism of cell cycle arrest and enhancement of immune system.
The cell-mediated immune inducing properties of palm oil vitamin E, for
example, γ-tocotrienol and α-tocopherol, were investigated by measuring
the mitogenesis response of splenocytes, extracted from normal male Mus
musculus to splenic T-lymphocytes mitogens, phytohemagglutinin (PHA;
0.25 μg/mL) and concanavalin A (Con A; 1.0 μg/mL); and B-lymphocytes
mitogen i.e., lipopolysaccharide (LPS; 1.0 μg/mL). Both γ-tocotrienol
and α-tocopherol enhanced the cell proliferation of mitogen untreated
splenocytes as determined by 5-Bromo-2'-deoxy-uridine (BrdU) detection
method. Both compounds also enhanced the T-lymphocytes response to PHA
and Con A, as well as B-lymphocytes responses to LPS at all concentration
used (0-300 μM). γ-Tocotrienol was observed to affect cell proliferation
more than α-tocopherol. The uptake of γ-tocotrienol and α-tocopherol into
the splenocytes was determined by high performance liquid chromatography
(HPLC). γ-Tocotrienol was absorbed into the cells at markedly higher
levels than α-tocopherol with the ratio of 4.8 : 1 (p<0.01, n=4) at 300
μM of treatment. This may be the reason of the higher proliferation affect
of γ-tocotrienol as compared to α-tocopherol. In conclusion, we are
of the opinion that palm oil γ-tocotrienol and α-tocopherol are able to synergistically influence splenocytes proliferation thus enhancing the cellmediated
immune system
OXIDATIVE CHANGES AND COGNITIVE FUNCTION DECLINE IN AGING RATS
Objective: This study aims to show that impairment of cognitive function occurred during aging is related to increased oxidative stress.
Methods: A total of 36 Sprague Dawley rats were divided into four groups: Young (3 months), middle (14 months), and old age groups (18 and 23 months). Rats were killed and blood was collected for the measurement of oxidative stress which includes deoxyribonucleic acid (DNA) damage and lipid peroxidation (malondialdehyde [MDA] levels). Cognitive function of rats was measured through open-field experiments, Morris water maze (MWM), and object identification.
Results: Increased DNA damage and MDA levels were found in middle age and old rats compared to young rats (3 months old, p<0.05). There was an increase in anxiety with age as indicated by the increased production of fecal boli and decreased activity of grooming and rearing. For the navigation test, older rats took a long time to search for the hidden platform compared to young rats. In the probe test (spatial memory test 24 h after the last training), the middle- and old-age groups spent less time at the quadrant compared to the young age group.
Conclusion: There is a decline in cognitive function with increased oxidative stress in aging rats
Gamma-tocotrienol modulation of senescence-associated gene expression prevents cellular aging in human diploid fibroblasts
OBJECTIVE: Human diploid fibroblasts undergo a limited number of cellular divisions in culture and progressively reach a state of irreversible growth arrest, a process termed cellular aging. The beneficial effects of vitamin E in aging have been established, but studies to determine the mechanisms of these effects are ongoing. This study determined the molecular mechanism of γ-tocotrienol, a vitamin E homolog, in the prevention of cellular aging in human diploid fibroblasts using the expression of senescence-associated genes. METHODS: Primary cultures of young, pre-senescent, and senescent fibroblast cells were incubated with γ-tocotrienol for 24 h. The expression levels of ELN, COL1A1, MMP1, CCND1, RB1, and IL6 genes were determined using the quantitative real-time polymerase chain reaction. Cell cycle profiles were determined using a FACSCalibur Flow Cytometer. RESULTS: The cell cycle was arrested in the G0/G1 phase, and the percentage of cells in S phase decreased with senescence. CCND1, RB1, MMP1, and IL6 were upregulated in senescent fibroblasts. A similar upregulation was not observed in young cells. Incubation with γ-tocotrienol decreased CCND1 and RB1 expression in senescent fibroblasts, decreased cell populations in the G0/G1 phase and increased cell populations in the G2/M phase. γ-Tocotrienol treatment also upregulated ELN and COL1A1 and downregulated MMP1 and IL6 expression in young and senescent fibroblasts. CONCLUSION: γ-Tocotrienol prevented cellular aging in human diploid fibroblasts, which was indicated by the modulation of the cell cycle profile and senescence-associated gene expression
Cytotoxicity and Antioxidant Activity of Zingiber Officinale and 6-Gingerol on HepG2 Cells
The present study was designed to compare the effects of ethanolic extract of ginger (Zingiber officinale) and its phenolic component [6]-Gingerol on viability, antiproliferation and apoptotic levels of human hepatoma cell lines (HepG2) and its antioxidant activity. HepG2 cells were cultured in Eagles minimum essential medium (EMEM) and the percentage of cell cytotoxicity was evaluated by tetrazolium salt (MTS) assay. Antiproliferation and apoptotic levels were measured by 5Bromo-2deoxyuridine (BrdU) colorimetry. Antioxidant capacity was studied by 1.1-diphenyl-2-picryl-hydrazyl radical (DPPH) using spectrophotometry. We found that cytotoxicity and antiproliferative effect of ginger extract and [6]-Gingerol could be associated with induction of apoptosis. The ginger ethanol extract and [6]-Gingerol also showed remarkable antioxidant activities in comparison with ascorbic acid and N-acetyl-L-cysteine
Antioxidant enzyme activity and malondialdehyde levels can be modulated by Piper betle, tocotrienol rich fraction and Chlorella vulgaris in aging C57BL/6 mice
OBJECTIVE: The aim of this study was to determine the erythrocyte antioxidant enzyme activity and the superoxide dismutase, catalase, glutathione peroxidase, and plasma malondialdehyde levels in aging mice and to evaluate how these measures are modulated by potential antioxidants, including the tocotrienol-rich fraction, Piper betle, and Chlorella vulgaris. METHOD: One hundred and twenty male C57BL/6 inbred mice were divided into three age groups: young (6 months old), middle-aged (12 months old), and old (18 months old). Each age group consisted of two control groups (distilled water and olive oil) and three treatment groups: Piper betle (50 mg/kg body weight), tocotrienol-rich fraction (30 mg/kg), and Chlorella vulgaris (50 mg/kg). The duration of treatment for all three age groups was two months. Blood was withdrawn from the orbital sinus to determine the antioxidant enzyme activity and the malondialdehyde level. RESULTS: Piper betle increased the activities of catalase, glutathione peroxidase, and superoxide dismutase in the young, middle, and old age groups, respectively, when compared to control. The tocotrienol-rich fraction decreased the superoxide dismutase activity in the middle and the old age groups but had no effect on catalase or glutathione peroxidase activity for all age groups. Chlorella vulgaris had no effect on superoxide dismutase activity for all age groups but increased glutathione peroxidase and decreased catalase activity in the middle and the young age groups, respectively. Chlorella vulgaris reduced lipid peroxidation (malondialdehyde levels) in all age groups, but no significant changes were observed with the tocotrienol-rich fraction and the Piper betle treatments. CONCLUSION: We found equivocal age-related changes in erythrocyte antioxidant enzyme activity when mice were treated with Piper betle, the tocotrienol-rich fraction, and Chlorella vulgaris. However, Piper betle treatment showed increased antioxidant enzymes activity during aging
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