Hiliaras Rodovičius

Protective effect of selenium on aluminium-induced oxidative stress in mouse liver in vivo.

The aim of the study was to evaluate possible protective effects of selenium (Se) against systemic aluminium (Al) toxicity and the redox status of mouse liver after short-term (16 h) exposure to Al in vivo. BALB/c mice were injected i.p. with AlCl(3) (25mg Al(3+) per kg of body mass) or/and Na(2)SeO(3) (1.25mg Se per kg of body mass). The 4-fold increased activity of ALT in serum showed systemic hepatotoxicity that Se could not prevent by competitive mechanisms. The protective effects of Se could only be observed on intracellular oxidative stress events as determined by glutathione status. Exposure to Al leads to the decrease in the total glutathione (GSH(tot)) and GSH/GSSG redox ratio to about 50% of the control. Upon co-exposure to Se+Al, the concentration of GSH(tot) and the redox ratio was restored to the control values. Our results indicate that Se did not have a protective effect on Al-linked liver toxicity, but did ameliorate intracellular oxidative stress processes mediated by glutathione.

Antioxidant effects of Camellia sinensis L. extract in patients with type 2 diabetes

The prevalence of diabetes mellitus (DM) has dramatically increased in the past decade. Furthermore, increasing evidence from research shows that oxidative stress (OS) plays a crucial role in the pathogenesis of diabetes and in its complications. A search for ways to reduce oxidative damage has become the focus of interest for the majority of scientists. In this study, we determined the radical scavenging activity of single green tea constituents by using an on-line high performance liquid chromatography (HPLC)-2,2-diphenyl-1-picrylhydrazyl (DPPH) method and evaluated the antioxidant effects on type 2 diabetic patients by performing a double-blind, placebo-controlled study. Epigallocatechin gallate was identified as the most potent antioxidant, contributing approximately 50% of the total antioxidant capacity of green tea extract. We also found a statistically significant decrement of lipid peroxidation markers in patients treated with green tea extract after 9 months or after 18 months of follow-up. Overall, these findings are attractive for diabetic patients, helping them to keep a high level of performance and well-being, which ultimately may delay the time of disability and reduce mortality.

Selective induction of IL-6 by aluminum-induced oxidative stress can be prevented by selenium

In this study the acute toxic effects of aluminum (Al) on mice have been investigated, including the interactions of Al and selenium (Se). Focus was put on the systemic effects of (co)exposure to Al and Se as a reflection of the redox status in the liver, kidney and brain. Short-term exposure (16 h) to Al resulted in an increase in the systemic inflammation parameters IL-6 and PAI-1, whereas serum levels of TNF-α remained unaffected. The different response pattern of IL-6 and TNF-α probably indicates an increased intracellular oxidative stress and altered redox status in the liver, because the selective increase in IL-6 serves as a protective intrahepatocellular process driven by oxidative stress. The intracellular glutathione concentration GSHtot decreased significantly upon Al exposure. Both the increase in IL-6 and decrease in glutathione status could be prevented by co-exposure to Se, but not the increase in PAI-1. The redox status of the kidney and brain was not markedly affected. Therefore it was concluded that short-term exposure to Al causes adverse effects on the intracellular oxidative stress processes in the liver, as reflected by the selective increase in the IL-6 concentration. This process can be restored by co-administration of the trace element Se as a part of the glutathione redox system.

Mineral Element and Total Phenolic Composition and Antioxidant Capacity of Seeds and Aerial Plant Parts of Perennial Legumes

ABSTRACT Naturally derived bioactive compounds with antioxidant activity and mineral component have a positive effect on human health. Consequently, legumes, including perennial species, have been used as healthy food or medicinal plants. Red clover (Trifolium pratense) and lucerne (Medicago sativa) have been researched more thoroughly for food components and supplements than zigzag clover (T. medium), black medick (M. lupulina), liquorice milkvetch (Astragalus glycyphyllos), cicer milkvetch (A. cicer), and sainfoin (Onobrychis viciifolia). However, information is scarce about the distribution of mineral elements and phenolics in plants of these species as well as the antioxidant capacity of their extracts. In this study, we determined the mineral composition and total phenolic concentration in seeds and whole aerial plant parts and morphological fractions of these perennial legumes, as well as the antioxidant activity of extracts of the above-mentioned plant parts. The legume accessions chosen for this study were rich in potassium (K), calcium (Ca), magnesium (Mg), phosphorus (P), zinc (Zn), and iron (Fe), especially at branching growth stage, and thus could be used for mineral fortification of staple foods. Astragalus species, particularly seeds of A. glycyphyllos, were the richest source of Fe. Trifolium pratense, T. medium, O. viciifolia, and A. cicer were valuable source of total phenolics and antioxidants. The flower and leaf extracts of red clover exhibited very strong 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. In general, the tested perennial legumes and their plant parts have rich mineral composition and bioactive properties, and they can be used as functional ingredients to accommodate the need for a particular mineral element or a bioactive property.

Biomarkers of Selenium Toxicity after Sub-Acute Exposure in Mice

Selenium (Se) is a trace element, essential for human health but it can be toxic at moderately higher intake levels. In this study biomarkers of Se toxicity after sub-acute intra-peritoneal exposure to Se (62.5 µg Se/kg bw/ day; 14 days) were investigated in mice. Such exposure corresponds to high human Se-intake levels. Focus was put on the biomarkers of systemic effects and on the toxicity in liver, kidney and brain. The sub-acute exposure to Se resulted in an increase in the concentrations of systemic inflammation biomarkers IL-6 (p=0.025) and resistin (p=0.049) and in a decrease of TNF-α (p=0.008). No effect on concentrations of MCP-1, tPAI-1, leptin and insulin was observed in serum. Also biomarkers of oxidative stress, anti-oxidant parameters and enzymes ALT and AST were not affected. In the tissue homogenates of liver, kidney and brain changes were observed in the activities of enzymes LDH (p=0.013), ALP (p=0.0009) and GGT (p=0.0047). In the brain homogenate an influx of TG (p=0.0044) and a decrease in the total GSH concentration (p=0.008) was observed. It was concluded that although the sub-acute exposure to a relatively high concentration of Se causes an increase in concentration of some biomarkers of intracellular processes, especially in the brain, the effect of Se can be considered as low toxicity.

Effect of ginkgo extract on eye microcirculation in patients with diabetes

The prevalence of Diabetes mellitus has increased around the world in the last decade. Anyone with diabetes is at risk of diabetic eye complications. The aim of the study was to compare effects of standardized Ginkgo biloba (Ginkgo biloba L.) dry extract (Ex.Gb) with the placebo on the microcirculation lesions of the eye in randomized double-blind placebo-controlled trial. 44 patients with type 2 diabetes mellitus were randomized to Ex.Gb 160 mg per day or placebo, and were followed up for nine months. Dose of Ex.Gb was increased to 240 mg in next nine months. Total Antioxidant Status (TAS) of plasma was measured using the Trolox equivalent antioxidant capacity assay. Ophthalmologic examination was performed by the biomicroscopic method. Vascular, intravascular and perivascular alterations were evaluated, and total conjunctival index was calculated. Though the values of the total conjunctival index and its constituent decreased (P<0.05) during the study in Ex.Gb group, there were no significant differences between these parameters as compared with placebo group. Evaluation of plasma TAS showed gradually increment, although insignificant and very small, in Ex.Gb group. The significance of Ex.Gb on development of the alterations of eye microcirculation, especially in elder patients needs to be explored further.

Effect of Acanthopanax senticosus on the Accumulation of Cadmium and on the Immune Response of Spleen Cells

Exposure to cadmium (Cd) is known to alter immune responses. Acanthopanax senticosus (Rupr. et Maxim.) Harms (AS) extract, an antioxidant-containing complex of phenolic compounds, tetracyclic triterpenoids/steroids, and polysaccharides, is known to produce Cd mobilization and excretion in vivo. Building upon earlier findings, the aim of the study was to evaluate the effects of an AS extract on Cd accumulation and changes in the presence of splenic immune cells in hosts during a chronic metal exposure. Chronic Cd exposure of BALB/c mice was induced by providing them solutions containing different levels of CdCl2 (25 or 250 mg/L) in double-distilled water, with/without a concurrent presence of AS root extract (approximately 151 g material/L), for 8 wk. At the study end, Cd levels in spleen were measured. Levels of key splenic immune cells, including macrophages, T-lymphocytes, and B-lymphocytes, were determined by immunohistochemistry using, respectively, CD68, CD3, and CD20 antibodies. The results indicated that chronic consumption of AS extract in the presence of the high dose of CdCl2 led to a significant decrease in Cd levels in mouse spleen. The effects of AS on the lower CdCl2 dose were less apparent. In addition, the presence of AS and Cd increased the amount of macrophages and both B and T lymphocytes in mouse spleen relative to concentrations that were lowered as a result of chronic metal only intake.