High versus Moderate Dosage of Daily and Weekly Administration of Vitamin D Supplements in the Form of Oil Drop in Nursing Home Residents.

OBJECTIVE: To investigate the effectiveness of daily (800 IU), weekly-moderate (5600 IU) and weekly-high (8000 IU) supplementation of Vitamin D in nursing home residents. STUDY DESIGN: A descriptive study. PLACE AND DURATION OF STUDY: Nursing Home, MEVA, Istanbul, Turkey, from July 2016 to July 2017. METHODOLOGY: Nursing home residents were divided into 3 groups for supplementation of Vitamin D: Daily Dose Group (DDG), Weekly Dose Group-moderate (WDG-moderate) and Weekly Dose Group-high (WDG-high). Blood and physical performance tests were done initially to obtain a baseline value and the tests were repeated at 13th and 26th weeks of supplementation. Statistical analysis was conducted only on patients who were able to complete the 6-month-long study. RESULTS: WDG-moderate (5600 IU/week) supplementation is found to be the most effective intervention in our study [25 (OH) D from 23.50 ±12.67 ng/mL to 37.38 ±14.42 ng/mL]. In WDG-moderate, the resulting Vitamin D level was found to reach near-optimum therapeutic levels. Only a limited increase was observed in 25 (OH) D level of DDG and WDG- high at the end of 26 weeks. CONCLUSION: Weekly (5600 IU/week) moderate supplementation of Vitamin D could be more beneficial than weekly (8000/week) high supplementation among nursing home residents. Multi-drug use among nursing home residents may hinder the therapeutic efficiency of Vitamin D administration. Physical performance tests may fail to demonstrate increased performance in mobility after Vitamin D administration in nursing home residents.

Galactose-induced Aging Model in Rat Testicular Tissue.

OBJECTIVE: To examine whether the D-galactose induced aging model is an appropriate model for further aging research. STUDY DESIGN: Experimental study. PLACE AND DURATION OF STUDY: Aziz Sancar Institute of Experimental Medicine, Istanbul University, Turkey, June 2015- June 2017. METHODOLOGY: The study comprises 3 groups of rats. Group I is young control (YC) 5-month-old rats. Group II is 5-month- old rats, which were mimetically aged (MA) for 6 weeks via intraperitoneal D-galactose (60 mg/kg body weight/day, 0.5 mL) administration. Group III is naturally aged (NA) 24-month-old rats. Group I and III received intraperitoneal saline (0.9% 0.5 mL) for 6 weeks as vehicle. Group I and Group II received injections at 21 weeks age and Group III rats 6 weeks before 24 months age. Tissues were harvested when rats became 6.5-month-old (Group I and Group II) and 24-month-old (Group III). Quantitative biochemical analyses of proteins, lipids, DNA biomarkers and Cu, Zn-SOD were conducted. Statistical analysis of the data was conducted using ANOVA, followed by post-hoc Bonferroni test. RESULTS: Higher magnitude of oxidative damage and diminished antioxidant defence capacity were found in both mimetically aged and naturally aged testicular tissues. It is observed that D-galactose aging model group shares significant similarities in terms of impaired redox homeostasis with the naturally aged rats. CONCLUSION: D-galactose induced testicular aging model successfully mimics aging process. Therefore, D-galactose induced aging model may be used as an accelerated aging model to study the age related alterations and interventions.

The effects of lipoic acid on redox status in brain regions and systemic circulation in streptozotocin-induced sporadic Alzheimer's disease model.

While the deterioration of insulin-glucose metabolism (IGM), impaired redox homeostasis (IRH), ß-amyloid accumulation was reported in Sporadic Alzheimer's Disease (SAD) model, aforementioned factors related to lipoic acid administration and anthropometric indexes (AIs) are not yet studied with integrative approach. ß-amyloid accumulation, redox homeostasis biomarkers and AIs are investigated in SAD model. Streptozotocin-induced inhibition of insulin-signaling cascade but not GLUT-2 and GLUT-3 transporters takes a role in ß-amyloid accumulation. Inhibition types are related to IRH in cortex, hippocampus and systemic circulation. Lipoic acid (LA) shows both antioxidant and prooxidant effect according to the anatomical location. LA administration also leads to improved AIs during GLUT-2 inhibition and cortical redox status in GLUT-3 inhibited group. Optimal LA action could be possible if its redox behavior is balanced to antioxidant effect. Diagnostic usage of systemic IRH parameters as biomarkers and their possible correlations with deteriorated IGM should be investigated. Graphical abstract ᅟ.

Gender and chronological age affect erythrocyte membrane oxidative indices in citrate phosphate dextrose adenine-formula 1 (CPDA-1) blood bank storage condition.

It is well known that in vitro storage lesions lead to membrane dysfunction and decreased number of functional erythrocytes. As erythrocytes get older, in storage media as well as in peripheral circulation, they undergo a variety of biochemical changes. In our study, the erythrocytes with different age groups in citrate phosphate dextrose adenine-formula 1 (CPDA-1) storage solution were used in order to investigate the possible effect of gender factor on oxidative damage. Oxidative damage biomarkers in erythrocyte membranes such as ferric reducing antioxidant power, pro-oxidant-antioxidant balance, protein-bound advance glycation end products, and sialic acid were analyzed. Current study reveals that change in membrane redox status during blood-bank storage condition also depends on both gender depended homeostatic factors and the presence of CPDA-1. During the storage period in CPDA-1, erythrocytes from the male donors are mostly affected by free radical-mediated oxidative stress but erythrocytes obtained from females are severely affected by glyoxidative stress.

Ameliorative Effects of Testosterone Administration on Renal Redox Homeostasis in Naturally Aged Rats.

BACKGROUND: Testosterone biosynthesis gradually decreases with age. Impaired redox homeostasis-related oxidative damage in cellular macromolecules has a high risk for the development of renal insufficiency. Our aim was to study the effects of testosterone replacement therapy on redox homeostasis. METHODS: We investigated various oxidative damage biomarkers in kidney. Experimental animals were separated into three groups-naturally aged rats, testosterone-administered naturally aged rats (single dose of 25 mg/kg testosterone enanthate), and their respective young controls. RESULTS: Our results showed that the testosterone-administered naturally aged group shared significant similarities with the young rats with respect to their redox status. In testosterone-administered naturally aged rats, kynurenine, protein carbonyl, advanced oxidation protein products, lipid peroxidation markers, and xanthine oxidase activities were significantly lower and Cu-Zn superoxide dismutase activities and testosterone levels were higher than naturally aged rats. In testosterone-administered naturally aged rats, catalase activities, ferric reducing anti-oxidant power, and testosterone levels were significantly lower and dityrosine, N-formyl kynurenine, protein carbonyl, and protein hydroperoxides were significantly higher than in young rats. On the other hand, in naturally aged rats, Cu-Zn superoxide dismutase, catalase activities, ferric reducing anti-oxidant power, and testosterone levels were lower and dityrosine, kynurenine, protein carbonyl, protein hydroperoxide, advanced oxidation protein products, lipid peroxidation markers, advanced glycation end products, and xanthine oxidase activities were higher than controls. CONCLUSIONS: Our results showed that a single dose of testosterone administration has a positive effect on the redox status of the aged kidney. Future studies are needed to clarify the exact molecular mechanism(s) involved in the action of testosterone in maintaining kidney redox homeostasis.

Age-related changes in rat prostate tissue; perspective of protein oxidation.

BACKGROUND: Increased systemic oxidative stress is considered as an important risk factor for prostate cancer occurrence; however, the relationship between impaired redox homeostasis of prostate tissue and aging remains unclear. OBJECTIVE: In our study, we hypothesized that age-related deterioration of redox homeostasis in prostate tissue may be considered as a predisposing factor for prostate cancer occurrence. METHODS: Sprague-Dawley rats were divided into two groups as young control (5 months) and naturally aged (24 months). We investigated the levels of oxidant and antioxidant parameters in prostate tissue. RESULTS: Advanced oxidation protein products, protein carbonyl, non-protein thiol and lipid hydroperoxides levels of aged rats were significantly higher than in the young control rats (p < 0.01, p < 0.05, p < 0.001, p < 0.05, respectively). Additionally, antioxidant activity of Cu-Zn-superoxide dismutase in elderly group was significantly lower than young controls (p < 0.05). CONCLUSIONS: We suggest that increased non-protein thiol levels found in aged rats may prevent further dissemination of oxidative protein damage. We also propose that the increased levels of oxidative protein damage markers and decreased Cu-Zn superoxide dismutase activity in aged prostate may be considered as a predisposing factor for prostate cancer. Further studies are warranted to clarify all these oxidative changes as initiation factors for prostate cancer in the association of aging with prostate cancer.

A comprehensive study of myocardial redox homeostasis in naturally and mimetically aged rats.

Age-related myocardial dysfunction has important implications with impaired redox homeostasis. Current study focused on investigation of redox homeostasis and histopathological changes in the myocardium of mimetically (MA), naturally aged (NA), and young control (YC) rats. Chronic D-galactose administration to young male Wistar rats (5 months old) was used to set up experimental aging models. We investigated 16 different oxidative damage biomarkers which have evaluated redox homeostasis of cellular macromolecules such as protein, lipid, and DNA. As a protein oxidation biomarker, advanced oxidation end products, protein carbonyl groups, protein-bound advanced glycation end products, dityrosine, kynurenine, and N-formylkynurenine concentrations in MA and NA rats were found to be significantly higher compared to those in YC rats. On the other hand, the levels of protein thiol groups were not significantly different between groups, whereas lipid peroxidation biomarkers such as conjugated diens, lipid hydroperoxides, and malondialdehyde in MA and NA rats were found to be significantly higher in comparison to those in YCs. For the assessment of oxidative DNA damage, we analyzed eight hydroxy-5'-deoxyguanosine concentrations of MA and NA groups which were higher than YCs. As an antioxidant status in the MA and NA groups, Cu-Zn superoxide dismutase, ferric reducing antioxidant power, and total thiol levels were lower than those in the YCs. Only nonprotein thiol levels were not significantly different. We also observed similar histopathological changes in MA and NA rats. We concluded that the mimetic aging model could be considered as a reliable experimental model for myocardial senescence.

Oxidation scrutiny in persuaded aging and chronological aging at systemic redox homeostasis level.

BACKGROUND: The effect of the natural aging process on systemic redox homeostasis is previously documented. However, none of the studies specify the effect of experimental aging on systemic redox homeostasis. The purpose of this study is to clarify the ambiguity raised in preliminary reports as to mimetic aging dependency of the type and magnitude of oxidative damage on constituents of plasma. METHODS: In the current study, we investigated the interrelationship among various groups of the systemic oxidative damage markers such as protein oxidation products (protein carbonyl groups, protein hydroperoxides, advanced oxidation protein products, protein thiol groups), lipid peroxidation products (malondialdehyde, lipid hydroperoxides, conjugated dienes), glycoxidation adducts (advanced glycation end products), and antioxidant capacity (ferric reducing/antioxidant power, Cu,Zn-superoxide dismutase, total thiol, non-protein thiol). All these markers were measured in plasma of mimetically aged (MA) rats (5-month-old rats subjected to d-galactose-induced experimental aging), naturally aged (NA) rats (24-month-old), and their corresponding young controls (YC) (5months old). RESULTS AND CONCLUSIONS: Our current results show that systemic oxidation markers of the MA group share significant similarities in terms of impaired redox homeostasis with the NA rats and may be considered as a reliable experimental aging model for intravascular aging. Additional methodological studies including d-galactose dosage and application time are warranted to clarify the potential involvement of all these systemic redox variations as mechanistic factors in the development of mimetic aging related intravascular deterioration. Reversing or preventing systemic oxidative damage in experimental and natural aging should therefore be considered the primary target for the development of effective therapeutic strategies to prevent or treat age-related vascular disorders.

Oxidative damage parameters in renal tissues of aged and young rats based on gender.

PURPOSE: Aging is characterized by a gradual functional decrease of all systems including the kidneys. Growing evidence links altered lipid protein redox-homeostasis with renal dysfunction. The effect of sexual dimorphism on the lipid protein redox-homeostasis mechanisms in the aging kidney is obscure. In the current study, we aimed to investigate redox homeostasis as it related to sexual dimorphism on protein oxidation and lipid peroxidation parameters, as protein carbonyl (PCO), total thiol (T-SH), advanced oxidation protein products (AOPP), malondialdehyde, glutathione (GSH), and superoxide dismutase (SOD) activity, as potential aging biomarkers, which may contribute to an analysis of the free radical theory of aging. MATERIALS AND METHODS: The study was carried out with 16 naturally aged rats (24 months old; eight males and eight females) and their corresponding young rat groups as controls (6 months old; eight males and eight females). All of the aforementioned parameters (PCO, T-SH, AOPP, MDA, GSH, SOD) were measured manually instead of automated devices or ELISA kits. RESULTS: PCO, AOPP, and malondialdehyde levels in aged rats were significantly higher in the older rat group than in the younger rat group, whereas SOD activities were significantly lower in old rats. T-SH levels were not significantly different in male groups; however, T-SH levels were lower in the aged female group than in the young female control group. In addition, GSH levels were significantly different between the aged rat group and the corresponding young control group for both genders. CONCLUSION: With respect to PCO and AOPP, impaired redox homeostasis is substantially more prominent in males than females. The decrease of G-SH levels in male groups could be attributed to stabilizing the redox status of protein thiol groups by the depletion of the GSH groups. Considering the results, the renal tissue proteins and lipids in different genders may have different susceptibilities to oxidative damage.