Biological Activity of Extracts of Red and Yellow Fruits of Cornus mas L.-An In Vitro Evaluation of Antioxidant Activity, Inhibitory Activity against α-Glucosidase, Acetylcholinesterase, and Binding Capacity to Human Serum Albumin.

Although extracts are broadly used in order to support the treatment of numerous diseases, only in a limited number of cases is the process of applying and establishing their mechanisms of action scientifically analyzed. Fruits of Cornelian cherry are an abundant source of iridoids, anthocyanins, flavonols and phenolic acids. The aim of the present study was to evaluate the in vitro bioactivity of red and yellow Cornelian cherry fruits' extracts. The biological potential of extracts, in a broad sense, involved antioxidant activity in relation to phosphatidylcholine liposomes, inhibitory ability against α-glucosidase and acetylcholinesterase enzymes, as well as interactions with human serum albumin. Studies showed that both extracts were more effective in protecting liposome membranes against free radicals produced by AAPH in an aqueous environment due to the fact that they can be better eliminated by the hydrophilic components of the extracts than those produced by UVB radiation. Extracts exhibited inhibitory activity against acetylcholinesterase and α-glucosidase, wherein loganic acid extract showed noncompetitive inhibition of the enzyme. Moreover, extracts binded to albumin mainly through hydrogen bonds and van der Waals forces. Taken together, red and yellow cherry fruits' extracts exhibit diverse biological properties and can be exploited as a source of natural therapeutic agents.

Loganic Acid, an Iridoid Glycoside Extracted from Cornus mas L. Fruits, Reduces of Carbonyl/Oxidative Stress Biomarkers in Plasma and Restores Antioxidant Balance in Leukocytes of Rats with Streptozotocin-Induced Diabetes Mellitus.

The various complications related to diabetes are due to the alteration in plasma components and functional activity of blood cells, hence the search for preventive remedies that would ameliorate the clinical condition of patients is a relevant problem today. The main aim of the present study was to examine the antidiabetic potency and antioxidant effects of loganic acid (LA) in blood of diabetic rats. LA showed a restoration of balance between functioning of antioxidant defense system and oxidative stress in leukocytes without notable effects on blood glucose levels when administered orally to rats (20 mg/kg b.w./day) for 14 days. LA ameliorated antioxidant status in leukocytes, as indicated by increasing the content of reduced glutathione and activities of catalase, glutathione peroxidase and glutathione reductase along with decreasing levels of intracellular reactive oxygen species. In addition, we observed the ability of LA to protect against formation and accumulation of glycation and oxidation protein products and malondialdehyde derivates in plasma. Therefore, LA showed antioxidant properties that may have beneficial effects under diabetes. Such results may represent LA as one of the plant components in the development of new drugs that will correct metabolic and functional disorders in leukocytes under diabetes.

Antidiabetic effects of extracts of red and yellow fruits of cornelian cherries (Cornus mas L.) on rats with streptozotocin-induced diabetes mellitus.

The effects of extracts of red and yellow fruits of cornelian cherries have been evaluated in rats with streptozotocin-induced diabetes mellitus. Cornus mas L. active compounds were analyzed by ultra-performance liquid chromatography coupled with electrospray ionization mass spectrometry (UPLC-ESI-qTOF-MS/MS) in positive and negative ion modes and by HPLC-PDA, followed by the identification of iridoids, anthocyanins, phenolic acids and flavonols. Rats with type 1 diabetes mellitus were orally dosed with the extracts in amounts of 20 mg kg-1 of body weight for 14 days. The cornelian cherry extracts lowered blood glucose and improved glucose tolerance. The treatments significantly decreased the amount of glycated hemoglobin (by 25%) and increased erythrocyte resistance to acid hemolysis. Importantly, only treatment with the extract of yellow fruits of the cornelian cherry increased the level of reduced glutathione and mean cell hemoglobin in diabetic rats. The active compounds of Cornus mas L. demonstrated the antidiabetic and antioxidant effects via the attenuation of hyperglycemia and inhibition of oxidative modifications of proteins and lipids, advanced glycation and oxidation protein formation or accumulation. The results suppose that cornelian cherries can be considered as a food supplement to alleviate diabetes mellitus and its complications.

Antidiabetic and Antioxidative Potential of the Blue Congo Variety of Purple Potato Extract in Streptozotocin-Induced Diabetic Rats.

This study was designed to evaluate the effects of purple potato extract of the Blue Congo variety (PP) on diabetes and its antioxidant activities after two-week administration tostreptozotocin (STZ)-induced diabetic rats. The activities of PP were evaluated at a dose of 165 mg/kg body weight (b.w.) by estimating biochemical changes in blood plasma and through a histopathological study of kidney, muscles, and liver tissue. We evaluated the effect of treatment with extract on glucose level, glycated hemoglobin, activities of enzymatic antioxidants (including superoxide dismutase, glutathione peroxidase, and catalase), and lipid peroxidation. Moreover, we determined advanced glycation end-products (AGEs), advanced oxidation protein products (AOPPs), and the level of oxidative modified proteins (OMPs) as markers of carbonyl-oxidative stress in rats with diabetes. Using high-performance liquid chromatography, we identified five anthocyanins and six phenolic acids in the extract from Blue Congo with the dominant acylated anthocyanin as petunidin-3-p-coumaroyl-rutinoside-5-glucoside. The administration of Blue Congo extract lowered blood glucose, improved glucose tolerance, and decreased the amount of glycated hemoglobin. Furthermore, PP demonstrated an antioxidative effect, suppressed malondialdehyde levels, and restored antioxidant enzyme activities in diabetic rats. After administration of PP, we also noticed inhibition of OMP, AGE, and AOPP formation in the rats' blood plasma.

Agmatine Prevents Oxidative-nitrative Stress in Blood Leukocytes Under Streptozotocin-induced Diabetes Mellitus.

Changes in cellular metabolism, development of oxidative-nitrative stress and intensification of glycation and lipid peroxidation (LPO), are significant processes that occur during diabetes mellitus (DM)-associated chronic hyperglycemia. These processes contribute to deviations in the structural organization and functional activity of leukocytes. The development of oxidative-nitrative stress in peripheral blood cells during DM can be prevented by agmatine, an endogenous metabolite of L-arginine, which is a nitric oxide synthase (NOS) inhibitor, and possesses hypoglycemic properties. The administration of agmatine to animals with DM lead to the inhibition of both constitutive and inducible NOS in leukocytes, which in turn decreased total nitrite/nitrate (NOx) levels. Additionally, we observed corresponding increases in reduced glutathione content and activity of antioxidant enzymes (SOD, CAT, GPx, GR), along with decreased levels of the thiobarbituric acid reactive substance, advanced oxidation protein products (AOPPs) and advanced glycosylation end-products (AGEs) as compared to the non-treated diabetic group. Our results indicate that treatment of diabetic animals with agmatine restores redox homeostasis and a balances antioxidant defence system enzymes in leukocytes. This corrective effect on the functional capacity of leukocytes is exerted by preventing oxidative-nitrative stress in animals with DM.

Antidiabetic effects and erythrocyte stabilization by red cabbage extract in streptozotocin-treated rats.

The protective effect of red cabbage extract (RCE) was evaluated in rats with streptozotocin-induced diabetes, assessing a probable role of this extract in the prevention of erythrocyte impairments associated with a high risk of vascular complications in diabetes. RCE was analyzed by ultrahigh performance liquid chromatography and mass spectrometry, and 11 anthocyanins, 3 hydroxybenzoic acids and 9 hydroxycinnamic acids were identified. Type 1 diabetes was induced by streptozotocin (60 mg kg-1) in Wistar male rats (n = 8 per group). After 7 days of acclimatization, streptozotocin-treated rats were given RCE (800 mg kg-1) or vehicle by intragastric administration for 4 weeks. The RCE treatment lowered blood glucose, and glycated and fetal hemoglobin concentrations and improved glucose tolerance as well as considerably raised serum insulin, proinsulin and C-peptide levels in streptozotocin-treated rats. Simultaneously, RCE improved pancreatic islet morphology, increasing the amount of pancreatic ß-cells in diabetic animals. The RCE administration prevented anemia in rats with streptozotocin-induced diabetes, enhanced erythrocyte resistance to acid hemolysis, and normalized reticulocyte production as well as sialic acid content in erythrocyte membranes. The enhanced lectin-induced erythrocyte aggregation in diabetic rats was significantly lowered after the RCE treatment. RCE demonstrated a significant antioxidant effect, decreasing MDA and protein carbonyl contents and increasing catalase and glutathione peroxidase activities in erythrocytes. These results indicate that RCE can be considered as a promising candidate for use as a drug or a food supplement to alleviate diabetes and its vascular complications.

Effect of medicinal mushrooms on blood cells under conditions of diabetes mellitus.

Diabetes mellitus (DM) is the third most common non-infectious disease leading to early disability and high mortality. Moreover, the number of patients is growing every year. The main symptom of DM is hyperglycemia. Increased levels of blood glucose activate polyol, hexosamine, and protein kinase metabolic pathways cause the intensification of non-enzymatic glycosylation and nitration of macromolecules. This, in turn, leads to the development of oxidative and nitrative stresses and secondary complications, such as different kinds of micro- and macroangiopathies. Metabolic disorders caused by insulin deficiency in diabetes significantly impede the functioning of a homeostasis system, which change the physical, biochemical, morphological, and functional properties of blood cells. As a result, the oxygen-transport function of red blood cells (RBCs), rheological properties of the blood, and functions of immunocompetent cells as well as the process of apoptosis are primarily affected. Modern pharmacotherapy focuses on the search for new preparations that aim to decrease blood glucose levels. Undesirable side effects and adverse reactions caused by synthetic medicines led to the search and investigation of new preparations of natural origin. Medicinal mushrooms play an important role among such new preparations. They are a source of a large number of high- and low-molecular compounds with pronounced biological effects. Our investigations show pronounced hypoglycemic and anti-anemic action of submerged cultivated mycelium powder of medicinal mushrooms Agaricus brasiliensis (A. brasiliensis) and Ganoderma lucidum (G. lucidum) on streptozotocin-induced DM in rats. Also, we showed that mycelium powders have membrane protective properties as evidenced by the redistribution of RBC populations towards the growth of full functional cell numbers. Normalization of parameters of leukocyte formula and suppression of apoptosis of white blood cells in diabetic rats treated with A. brasiliensis and G. lucidum mycelia indicates pronounced positive effects of these strains of mushrooms. Thus, the use of medicinal mushrooms for treatment of DM and in prevention development of its secondary complications might be a new effective approach of this disease's cure. This article is aimed at summarizing and analyzing the literature data and basic achievements concerning DM type 1 treatment using medicinal mushrooms and showing the results obtained in our research.

Pituitary tumor transforming gene as a novel regulatory factor of liver fibrosis.

AIMS: Pituitary tumor-transforming gene (PTTG) is involved in multiple cellular pathways. We studied the development of liver fibrosis induced by thioacetamide (TAA) in knockout (PTTG-/-) and wildtype (PTTG+/+) mice. MAIN METHODS: Liver fibrosis in PTTG+/+ and PTTG-/- mice was induced by escalating dose TAA treatment (50-400mg/kg, i.p.) for 12 weeks and assessed by histochemistry, immunohistochemistry, liver hydroxyproline, serum fibrosis markers and fibrosis-related mRNA expression by real-time PCR determination. KEY FINDINGS: Both PTTG+/+ and PTTG-/- mice treated with TAA developed signs of fibrosis and inflammatory cell infiltration. However, histological signs of bridging fibrosis and connective tissue square morphometry were significantly attenuated in mice lacking PTTG. α-SMA immunohistochemistry revealed that hepatic stellate cell activation was markedly reduced in PTTG-/- mice compared to wildtype controls. Hepatic hydroxyproline levels were significantly lower in fibrotic PTTG-/- group. The serum TNFα and hepatic TNFα mRNA expression were significantly lower in fibrotic PTTG-/- animals, as well as hepatic TGFß and VEGF mRNA levels compared to TAA-treated wildtype controls. Serum hyaluronate and TGFß levels were markedly elevated in fibrotic mice of both genotypes, but were not altered by the absence of PTTG. SIGNIFICANCE: TAA-induced fibrosis development is significantly ameliorated in PTTG-/- mice. These animals demonstrated diminished stellate cell activation, suppressed circulating serum markers of inflammation, fibrogenesis and angiogenesis. The presented findings suggest that PTTG is functionally required for hepatic fibrosis progression in an animal model of chronic liver injury. PTTG can be considered as a new important target for prevention and treatment of liver fibrosis/cirrhosis.

LPS induces phosphorylation of actin-regulatory proteins leading to actin reassembly and macrophage motility.

Upon bacterial infection lipopolysaccharide (LPS) induces migration of monocytes/macrophages to the invaded region and production of pro-inflammatory mediators. We examined mechanisms of LPS-stimulated motility and found that LPS at 100 ng/ml induced rapid elongation and ruffling of macrophage-like J774 cells. A wound-healing assay revealed that LPS also activated directed cell movement that was followed by TNF-α production. The CD14 and TLR4 receptors of LPS translocated to the leading lamella of polarized cells, where they transiently colocalized triggering local accumulation of actin filaments and phosphatidylinositol 4,5-bisphosphate. Fractionation of Triton X-100 cell lysates revealed that LPS induced polymerization of cytoskeletal actin filaments by 50%, which coincided with the peak of cell motility. This microfilament population appeared at the expense of short filaments composing the plasma membrane skeleton of unstimulated cells and actin monomers consisting prior to the LPS stimulation about 60% of cellular actin. Simultaneously with actin polymerization, LPS stimulated phosphorylation of two actin-regulatory proteins, paxillin on tyrosine 118 by 80% and N-WASP on serine 484/485 by 20%, and these events preceded activation of NF-κB. LPS-induced protein phosphorylation and reorganization of the actin cytoskeleton were inhibited by PP2, a drug affecting activity of tyrosine kinases of the Src family. The data indicate that paxillin and N-WASP are involved in the reorganization of actin cytoskeleton driving motility of LPS-stimulated cells. Disturbances of actin organization induced by cytochalasin D did not inhibit TNF-α production suggesting that LPS-induced cell motility is not required for TNF-α release.

Metabolic engineering and classic selection of the yeast Candida famata (Candida flareri) for construction of strains with enhanced riboflavin production.

Currently, the mutant of the flavinogenic yeast Candida famata dep8 isolated by classic mutagenesis and selection is used for industrial riboflavin production. Here we report on construction of a riboflavin overproducing strain of C. famata using a combination of random mutagenesis based on the selection of mutants resistant to different antimetabolites as well as rational approaches of metabolic engineering. The conventional mutagenesis involved consecutive selection for resistance to riboflavin structural analog 7-methyl-8-trifluoromethyl-10-(1'-d-ribityl)isoalloxazine), 8-azaguanine, 6-azauracil, 2-diazo-5-oxo-L-norleucine and guanosine as well as screening for yellow colonies at high pH. The metabolic engineering approaches involved introduction of additional copies of transcription factor SEF1 and IMH3 (coding for IMP dehydrogenase) orthologs from Debaryomyces hansenii, and the homologous genes RIB1 and RIB7, encoding GTP cyclohydrolase II and riboflavin synthetase, the first and the last enzymes of riboflavin biosynthesis pathway, respectively. Overexpression of the aforementioned genes in riboflavin overproducer AF-4 obtained by classical selection resulted in a 4.1-fold increase in riboflavin production in shake-flask experiments. D. hansenii IMH3 and modified ARO4 genes conferring resistance to mycophenolic acid and fluorophenylalanine, respectively, were successfully used as new dominant selection markers for C. famata.

Mononuclear and polymorphonuclear leukocytes show increased fructose-1,6-bisphosphatase activity in patients with type 1 diabetes mellitus.

The activity and localization of fructose-1,6-bisphosphatase (FBPase; EC 3.1.3.11) in blood leukocytes of patients with type 1 diabetes mellitus and healthy adults were investigated immunocytochemically. The amount of polymorphonuclear (PMN) and mononuclear (MN) cells with positive FBPase immunocytochemical reaction was 57% and 68%, respectively, in pathological, and 38% and 42%, respectively, in healthy donors. Results of light microscopic investigations were confirmed by measurements of FBPase activity following lysis of PMN and MN cells. The enzyme activity of PMN and MN leukocytes was higher in diabetes mellitus than in healthy adults, by 30% and 127%, respectively. Using immunocytochemistry together with electron microscopy, FBPase was detected not only in the cytoplasm but also in the nucleus of leukocytes of both patients with insulin-dependent diabetes mellitus and healthy donors.