Joanna Suliburska

Green tea extract reduces blood pressure, inflammatory biomarkers, and oxidative stress and improves parameters associated with insulin resistance in obese, hypertensive patients.

Green tea (GT) consumption is known to be associated with enhanced cardiovascular and metabolic health. The purpose of this study is to examine the hypothesis that supplementation with GT alters insulin resistance and associated cardiovascular risk factors in obese, hypertensive patients. In a double-blind, placebo-controlled trial, 56 obese, hypertensive subjects were randomized to receive a daily supplement of 1 capsule that contained either 379 mg of GT extract (GTE) or a matching placebo, for 3 months. At baseline and after 3 months of treatment, the anthropometric parameters, blood pressure, plasma lipid levels, glucose levels, creatinine levels, tumor necrosis factor α levels, C-reactive protein levels, total antioxidant status, and insulin levels were assessed. Insulin resistance was evaluated according to the homeostasis model assessment-insulin resistance protocol. After 3 months of supplementation, both systolic and diastolic blood pressures had significantly decreased in the GTE group as compared with the placebo group (P < .01). Considerable (P < .01) reductions in fasting serum glucose and insulin levels and insulin resistance were observed in the GTE group when compared with the placebo group. Serum tumor necrosis factor α and C-reactive protein were significantly lower, whereas total antioxidant status increased in the GTE group compared with the placebo (P < .05). Supplementation also contributed to significant (P < .05) decreases in the total and low-density lipoprotein cholesterol and triglycerides, but an increase in high-density lipoprotein cholesterol. In conclusion, daily supplementation with 379 mg of GTE favorably influences blood pressure, insulin resistance, inflammation and oxidative stress, and lipid profile in patients with obesity-related hypertension.

Dietary Intake and Serum and Hair Concentrations of Minerals and their Relationship with Serum Lipids and Glucose Levels in Hypertensive and Obese Patients with Insulin Resistance

Inadequate minerals intake, as well as disruption of some metabolic processes in which microelements are cofactors, are suggested to lead to the development of hypertension. The role of minerals in the pathogenesis of hypertension still remains to be explained. In the present study, we sought to determine associations between serum and hair mineral concentrations and serum lipids and glucose levels. Forty obese hypertensive subjects with insulin resistance and 40 healthy volunteers were recruited in the study. Blood pressure, BMI, and insulin resistance were recorded in all subjects. Levels of lipids, glucose, sodium and potassium, iron, copper, zinc, magnesium, and calcium were assessed in serum. Iron, copper, zinc, magnesium, and calcium were assessed in hair. Dietary intake of the analyzed minerals was estimated. We found distinctly higher concentrations of serum iron and serum and hair calcium as well as markedly lower levels of hair zinc in the hypertensive subjects. The study group manifested also significantly lower daily intake of calcium, magnesium, and iron. We observed a relationship between the concentrations of iron, zinc, and copper in serum and hair and high and low range of cholesterol, triglycerides, and glucose serum levels in the studied patients. Moreover, this study demonstrated significant correlation between serum and hair concentrations of selected minerals and their dietary intake and levels of serum lipids and glucose and blood pressure in the study and the control groups. The obtained results seem to indicate the association between lipid and glucose metabolism and iron, copper, zinc, and calcium concentrations in blood and hair of hypertensive and obese patients with insulin resistance.

Interactions of iron with manganese, zinc, chromium, and selenium as related to prophylaxis and treatment of iron deficiency

Iron (Fe) deficiency is considered as the most common nutritional deficiency. Iron deficiency is usually associated with low Fe intake, blood loss, diseases, poor absorption, gastrointestinal parasites, or increased physiological demands as in pregnancy. Nutritional Fe deficiency is usually treated with Fe tablets, sometimes with Fe-containing multimineral tablets. Trace element interactions may have a significant impact on Fe status. Existing data demonstrate a tight interaction between manganese (Mn) and Fe, especially in Fe-deficient state. The influence of Mn on Fe homeostasis may be mediated through its influence on Fe absorption, circulating transporters like transferrin, and regulatory proteins. The existing data demonstrate that the influence of zinc (Zn) on Fe status may be related to their competition for metal transporters. Moreover, Zn may be involved in regulation of hepcidin production. At the same time, human data on the interplay between Fe and Zn especially in terms of Fe-deficiency and supplementation are contradictory, demonstrating both positive and negative influence of Zn on Fe status. Numerous data also demonstrate the possibility of competition between Fe and chromium (Cr) for transferrin binding. At the same time, human data on the interaction between these metals are contradictory. Therefore, while managing hypoferremia and Fe-deficiency anemia, it is recommended to assess the level of other trace elements in parallel with indices of Fe homeostasis. It is supposed that simultaneous correction of trace element status in Fe deficiency may help to decrease possible antagonistic or increase synergistic interactions.

Effects of green tea supplementation on inflammation markers, antioxidant status and blood pressure in NaCl-induced hypertensive rat model

ABSTRACT Background: Recent studies indicate the important role of chronic inflammation and oxidative stress in the pathogenesis of hypertension. Green tea, due to the high content of catechins, shows high antioxidant activity. Objective: To determine the effect of supplementation with green tea extract on the blood pressure, on the concentration of selected parameters of inflammation and antioxidant status in the model of high-sodium-diet induced hypertension. Design: The study lasted 42 days. The experimental population consisted of 30 rats. The rats were divided into three groups. The rats in the control group were fed a standard diet with 35 g of NaCl per kg of diet, in the second group hypertensive rats were fed a standard diet with NaCl (35 g/kg diet) and with an extract of green tea (2 g/kg diet). The third group consisted of hypertensive rats fed a standard diet with NaCl (35 g/kg diet), and 4 g of green tea extract/kg diet. Results: Supplementation with green tea had no effect on body mass of rats on a high-sodium diet. At the end of the experiment systolic blood pressures in SH2 and SH4 groups were significantly lower than in the control group SK. The SH4 group was characterized by a significantly lower diastolic blood pressure value and concentration of TNF-α in comparison to the SK group. The rats from both SH2 and SH4 groups were characterized by higher total antioxidant status values compared to the control group. Discussion: The mechanism of the beneficial effects of green tea on blood pressure is not clear, but it is believed that it is related to its omnidirectional properties. Conclusions: Supplementation of green tea has a beneficial effect on blood pressure, markers of inflammation and antioxidant status in an experimental model of hypertension.

The genetic basis of obesity complications

Intensive research is currently being performed into the genetic background of excess body mass compli- cations such as diabetes, cardiovascular disorders, especially atherosclerosis and coronary heart disease. Chronic inflammation is an important process in the pathogenesis of obesity, wherein there is an aberrant ex- pression of genes encoding adipokines. Visceral tissue is characterized by a higher expression and secretion of interleukin-8, interleukin-1ß and plasminogen activator inhibitor 1 in the subcutaneous tissue secretion of leptin prevails. An important complication of obesity is obstructive sleep apnea, often observed in Prader- Willi syndrome. The genetic background of sleep apnea may be a polymorphism of the SREBF1 gene. The consequence of excess body mass is metabolic syndrome, which may be related to the occurrence of the rs926198 variant of gene encoding caveolin-1. The genes of transcription factor TCF7L2 and PPAR-γ2 take part in the pathogenesis of diabetes development. It has been demonstrated that oncogenes FOS, FOSB, and JUN may be co-responsible not only for obesity but also for osteoporosis and colorectal cancer. It has been shown that weight loss causes a modification in the expression of about 100 genes involvedt in the production of substances such as cytokines and other responsible for chronic inflammation in obesity. In future studies on the complications of obesity, such scientific disciplines as proteomics, peptidomics, metabolomics and transcriptomics should be used. The aim of this study is to present the current state of knowledge about the genetic basis of obesity complications.

The influence of selected antihypertensive drugs on zinc, copper, and iron status in spontaneously hypertensive rats.

Mineral homeostasis in hypertensive patients may be affected by hypotensive drugs. The aim of this study was to assess the influence of selected antihypertensive drugs on mineral homeostasis in a rat model of hypertension. Eight-week-old male spontaneously hypertensive rats (SHRs) were treated with perindopril, metoprolol, indapamide, amlodipine, or no drug for 45 days. In another experiment, the SHRs were treated with indapamide or amlodipine in the presence of zinc and copper gluconate supplement. Lipids, glucose, and insulin levels along with superoxide dismutase and catalase activities were assayed in serum. Iron, zinc, and copper concentrations in serum, erythrocytes, and tissues were determined using the flame atomic absorption spectrometry. Blood pressure was measured using a tail-cuff plethysmograph. Treatment with indapamide and amlodipine was found to significantly lower zinc levels in serum, erythrocytes, livers, and spleens of the SHRs, as well as copper levels in the kidneys, compared with the control no-drug group. A markedly higher concentration of glucose was found in the indapamide-treated rats. Supplementing the indapamide-treated SHRs with zinc and copper gluconate resulted in a significant decrease in both systolic and diastolic blood pressure, and also lowered serum glucose and triglyceride concentrations and HOMA (homeostasis model assessment-insulin resistance) values. The results show that indapamide and amlodipine disturb zinc and copper homeostasis in SHRs. Supplementation with zinc and copper restores mineral homeostasis in SHRs treated with indapamide and amlodipine, and also corrects metabolic imbalances while improving the antihypertensive efficiency of indapamide.

Association between the gut microbiota and mineral metabolism

The aim of this review is to present the most recent scientific evidence of interactions between the intestinal microbiota and minerals, and the effect of this interaction on the health of the host. The Web of Science database from the years 2013-2017 on this topic was reviewed. Numerous in vitro studies have shown that iron significantly affects the intestinal microbiota. However, Bifidobacteriaceae are capable of binding iron in the large intestine, thereby limiting the formation of free radicals synthesized in the presence of iron, and thus reducing the risk of colorectal cancer. Animal studies have revealed that supplementation with probiotics, prebiotics and synbiotics has a significant effect on bone calcium, phosphate and bone metabolism. The dynamic interaction between microbiota and zinc was shown. Human studies have provided evidence of the influence of probiotic bacteria on parathormone, calcium and phosphate levels and thus on bone resorption. Recent studies have produced new information mainly on the impact of the intestinal bacteria on the metabolism of calcium and iron. From a scientific perspective, the most urgent fields that remain to be investigated are the identification of all human gut microbes and new therapies targeting the interaction between intestinal bacteria and minerals.

L-Arginine and vitamin C attenuate pro-atherogenic effects of high-fat diet on biomarkers of endothelial dysfunction in rats.

High-fat diet (HFD) is known to cause endothelial dysfunction and contribute to atherosclerosis progression. The objective of this study was to evaluate the efficacy of L-arginine (L-Arg) and vitamin C supplementation as a potentially useful strategy for modulation of serum homocysteine (Hcy) levels, tumor necrosis factor alpha (TNF-α), oxidative stress, and insulin resistance induced by HFD in rats. Six weeks-old female and male Wistar rats were divided into five groups of twelve rats each and treated for six weeks with: group 1, standard diet; group 2, HFD; group 3, HFD supplemented with L-Arg (20g/kg diet); group 4, HFD supplemented with L-Arg (20g/kg diet) plus vitamin C (100mg/kg diet); group 5, HFD supplemented with vitamin C (100mg/kg diet). HFD significantly elevated TNF-α, reduced total antioxidant status (TAS), and increased insulin resistance (HOMA-IR). Significant increases of total cholesterol (TCH), LDL cholesterol (LDL), triglyceride (TG) and a decrease of HDL cholesterol (HDL) were observed in HFD rats. Supplementation with l-Arg prevented the decrease of TAS and the increases in HOMA-IR, LDL, and TG levels. Moreover, Hcy and TNF-α levels were reduced in L-Arg supplemented group. Supplementation with vitamin C significantly atenuated TAS decrease and lowered LDL levels. L-Arg plus vitamin C enhanced L-Arg effect on TAS and protected against TNF-α increase. Western blot analysis showed that l-Arg supplementation of HFD rats reduced the level of protein carbonyls. Taken together, these findings indicate that supplemental l-arginine and/or vitamin C, by their abilities to modulate biomarkers of HFD-induced endothelial dysfunction, are anti-atherogenic.

Comparative Analysis of the Trace Element Content of the Leaves and Roots of Three Plantago Species.

The primary objective of this study is to perform a comparative analysis of the trace element content of the leaves and roots of three Plantago species (P. maxima Juss. ex Jacq., P. major L., and P. lanceolata L.). Trace element levels were assessed by inductively coupled plasma mass spectrometry. The data indicate that the leaves of P. lanceolata are characterized by the highest Co, Cr, and Se content, whereas P. maxima leaves contained the greatest levels of Si and Zn. In contrast, the highest concentrations of Co, Cr, Fe, I, Mn, Si, and V were detected in the roots of P. major. Zn content was also higher in P. maxima roots than in the other species analyzed. The toxic trace elements were differentially distributed across the studied species. In particular, P. lanceolata leaves contained significantly higher Al, As, Li, Ni, Pb, and Sr levels, whereas the B and Cd content was elevated in P. major as compared to the other species. Surprisingly, the leaf Hg level was the lowest in P. major, whose levels of Al, As, B, Cd, Ni, Li, and Sr were significantly higher than the other two species. The data indicate that the concentration of most of the essential trace elements was higher in the leaves and roots of P. major and P. lanceolata than in P. maxima, while P. maxima had less toxic metals. The obtained data on trace elements content in Plantago tissues may be taken into account while using plant preparations in practical medicine.

Evaluation of nutritional and biochemical parameters in spontaneously hypertensive rats following antihypertensive treatment.

INTRODUCTION One side effect of antihypertensive drugs is their impact on nutritional status and metabolism. The purpose of this study was to assess the nutritional and biochemical parameters in spontaneously hypertensive rats following treatment with antihypertensive drugs. MATERIAL AND METHODS The experiment was performed on 50 male spontaneously hypertensive rats (SHR), which were assigned to five groups: control (C), with perindopril (PR), with metoprolol (MT), with indapamide (ID), and with amlodipine (AM). All rats were provided ad libitum standard diet (with or without drugs) and distilled water. After 45 days, the animals were weighed and killed. Liver, kidney, heart, spleen, pancreas, and blood samples were collected. Concentrations of glucose, cholesterol, triglycerides, and albumin were assayed in serum. Morphology parameters, such as white blood cell, red blood cell, hematocrit, and lymphocyte counts were measured in the blood. Blood pressure was measured using a tail-cuff plethysmograph. RESULTS The results obtained indicate that the hypotensive drugs under investigation had no effect on the selected nutritional parameters. Perindopril significantly decreased the relative mass of the heart and amlodipine markedly decreased the relative mass of the pancreas. A markedly higher concentration of glucose in the group with indapamid, and a significantly lower concentration of triglycerides in the group with metoprolol, were observed. Indapamide and amlodipine markedly increased the value of red blood cells and hematocrit in the blood of SHR. CONCLUSIONS Long-term therapy with antihypertension drugs may influence tissue mass and biochemical and morphological status in the body.