Impact of vitamin D resistance genes on vitamin D deficiency during pregnancy among the South Indian population.

Increasing evidence suggests that vitamin D (Vit-D) could be pivotal in maintaining normal glucose homeostasis. Low levels of Vit-D in early pregnancy are associated with a higher risk of gestational diabetes mellitus (GDM). Though several reports have highlighted the prevalence of vit-D deficiency among pregnant women, its underlying cause has not yet been fully elucidated. In this connection, a few studies have found the development of resistance to Vit-D, including the levels of Vitamin D receptor (VDR) and transcription regulators that modify VDR action, as well as the bioavailability of Vit-D. We aimed to determine the levels of Vit-D resistance genes such as 25-HydroxyVit-D-24-hydroxylase (CYP24A1), VDR repressor genes (SNAIL and SMRT) and their association between Vit-D concentrations in early pregnancy, and the risk of gestational diabetes mellitus (GDM). A prospective observational study was conducted on healthy pregnant women (NGDM; n = 50) and GDM (n = 50) attending routine antenatal care at SRM Medical College Hospital, Chennai, recruited at 12 weeks of gestation. We found that the serum levels of Vit-D were low in GDM subjects and negatively correlated with the fasting glucose levels. Further, increased expressions of Vit-D resistance genes such as CYP24A1, SNAIL, and SMRT were observed in GDM subjects and negatively correlated with the serum levels of Vit-D. Furthermore, we have validated the data using the trophoblast cell line, BeWo, exposed to calcitriol under a hyperglycemic environment. Our finding showed that increased expression of Vit-D resistance genes in pregnancy may be associated with a greater risk of adverse pregnancy outcomes, including GDM.

Exosomes as Theranostic Targets: Implications for the Clinical Prognosis of Aggressive Cancers.

Exosomes are extracellular vesicles produced by various cell types and extensively distributed in physiological fluids. Because of their significant role in cancer progression, they have been a focal point for the novel cancer therapy approach. Exosomes are highly efficient at transporting proteins, RNAs, and small drugs into cancer cells for therapeutic purposes. In addition to their prominent role as potential biomarkers for transporting targeted information from their progenitor cells, exosomes have also emerged as a new avenue for developing more effective clinical diagnostics and therapeutic techniques, also known as exosome theranostics. Lipids, proteins, and nucleic acids transported by exosomes were investigated as potential biomarkers for cancer diagnosis, prognosis, and future cancer treatment targets. The unique mechanism of exosomes and their therapeutic as well as diagnostic uses, also known as theranostic applications of exosomes in malignancies, are discussed in this review.

Toxicoproteomic analysis of human lung epithelial cells exposed to steel industry ambient particulate matter (PM) reveals possible mechanism of PM related carcinogenesis.

Toxicoproteomic analysis of steel industry ambient particulate matter (PM) that contain high concentrations of PAHs and metals was done by treating human lung cancer cell-line, A549 and the cell lysates were analysed using quantitative label-free nano LC-MS/MS. A total of 18,562 peptides representing 1576 proteins were identified and quantified, with 196 proteins had significantly altered expression in the treated cells. Enrichment analyses revealed that proteins associated to redox homeostsis, metabolism, and cellular energy generation were inhibited while, proteins related to DNA damage and repair and other stresses were over expressed. Altered activities of several tumor associated proteins were observed. Protein-protein interaction network and biological pathway analysis of these differentially expressed proteins were carried out to obtain a systems level view of proteome changes. Together it could be inferred that PM exposure induced oxidative stress which could have lead into DNA damage and tumor related changes. However, lowering of cellular metabolism, and energy production could reduce its ability to overcome these stress. This kind of disequilibrium between the DNA damage and ability of the cells to repair the DNA damage may lead into genomic instability that is capable of acting as the driving force during PM induced carcinogenesis.

Preparation of collagen peptide functionalized chitosan nanoparticles by ionic gelation method: An effective carrier system for encapsulation and release of doxorubicin for cancer drug delivery.

In recent years, nanoparticles (NPs) based on biopolymers or peptides are gaining popularity for the encapsulation and release of drug molecules, especially for cancer therapy, due to their ability for targeted and controlled release. The use of collagen peptide (CP) for the preparation of chitosan (CN) NPs is especially interesting as it results in NPs that are stable under physiological conditions. In this work, mono-dispersed pH responsive CPCN NPs of about 100nm were prepared via ionic gelation method by simple and mild co-precipitation of CN and CP. Investigation of NPs with Fourier transform infra-red (FTIR) spectroscopy and dynamic light scattering (DLS) measurements reveals that hydrogen bonding and electrostatic interactions are believed to be major driving forces for NP formation and drug encapsulation, respectively. Scanning electron microscopic (SEM) investigations show that hard and fine CPCN NPs transform to soft and bigger gel like particles as a function of collagen concentration. The unique "polymeric gel" structure of NPs showed high encapsulation efficiency towards doxorubicin hydrochloride (DOX) as well as pH controlled release. Anti-proliferative and cell viability analysis revealed that DOX loaded NPs showed excellent anti-proliferative characteristics against HeLa cells with favorable biocompatibility against normal cells. Such NPs have high potential for use as smart drug delivery carriers in advanced cancer therapy.

Reversibility of endothelial dysfunction in diabetes: role of polyphenols.

The endothelium, a thin single sheet of endothelial cells, is a metabolically active layer that coats the inner surface of blood vessels and acts as an interface between the circulating blood and the vessel wall. The endothelium through the secretion of vasodilators and vasoconstrictors serves as a critical mediator of vascular homeostasis. During the development of the vascular system, it regulates cellular adhesion and vessel wall inflammation in addition to maintaining vasculogenesis and angiogenesis. A shift in the functions of the endothelium towards vasoconstriction, proinflammatory and prothrombic states characterise improper functioning of these cells, leading to endothelial dysfunction (ED), implicated in the pathogenesis of many diseases including diabetes. Major mechanisms of ED include the down-regulation of endothelial nitric oxide synthase levels, differential expression of vascular endothelial growth factor, endoplasmic reticulum stress, inflammatory pathways and oxidative stress. ED tends to be the initial event in macrovascular complications such as coronary artery disease, peripheral arterial disease, stroke and microvascular complications such as nephropathy, neuropathy and retinopathy. Numerous strategies have been developed to protect endothelial cells against various stimuli, of which the role of polyphenolic compounds in modulating the differentially regulated pathways and thus maintaining vascular homeostasis has been proven to be beneficial. This review addresses the factors stimulating ED in diabetes and the molecular mechanisms of natural polyphenol antioxidants in maintaining vascular homeostasis.

Proteomic identification of pterostilbene-mediated anticancer activities in HepG2 cells.

In the present study, we attempt to shed light on the underlying molecular mechanism of the anticancer activity of pterostilbene (PTS) in HepG2 cells through the proteomic approach. PTS was found to induce apoptosis by altering the expression of apoptotic genes and the G2/M phase of cell cycle arrest. Further, the 2-DE map showed the expression of 72 differentially regulated proteins in PTS-treated HepG2 cells, of which 8 spots with >2 fold up- or down-regulated level were identified by MALDI-TOF analysis, which has a regulatory role in apoptosis. These findings for the first time offer valuable insights into the mechanism of apoptotis by PTS in HepG2 cells.

Quercetin ameliorates tunicamycin-induced endoplasmic reticulum stress in endothelial cells.

OBJECTIVE: Endothelial dysfunction highlights that it is a potential contributor in the pathogenesis of vascular complications arising from endoplasmic reticulum stress (ER stress) and has been emerging as a main causative factor in vascular failure. Here, we hypothesize that the natural flavonoid, quercetin plays an effective role in reducing ER stress in human umbilical vein endothelial cells. MATERIALS AND METHODS: Human umbilical vein endothelial cells were pre-treated with different concentrations of quercetin (0-100 µm) before inducing ER stress using tunicamycin (TUN) (0.75 µg/ml); cytotoxicity was assessed by MTT assay. Expression levels of ER stress responsive genes, antioxidant enzymes and apoptotic markers were assessed by qRT-PCR, while roles of caspase-3 and PARP cleavage were measured by western blot analysis. RESULTS: Quercetin pre-treatment at 25 and 50 µm had a cytoprotective effect on cells against TUN-induced toxicity. Quercetin administration modulated expression level of ER stress genes coding for glucose-regulated protein 78 (GRP78) and C/EBP-homologous protein (CHOP), and antioxidant enzymes such as superoxide dismutase and catalase, along with free radical generation assessed by malondialdehyde assay. Induction of apoptosis was prevented with reduction in expression level of Bax, and concomitant increase in Bcl-2 levels, thus proving its potential against ER stress. CONCLUSION: The current study indicates that quercetin modulated stress responsive genes GRP78 and CHOP, helping endothelial cells prevent TUN-induced ER stress.

Modulatory effects of morin on hyperglycemia by attenuating the hepatic key enzymes of carbohydrate metabolism and ß-cell function in streptozotocin-induced diabetic rats.

The present study was aimed to evaluate the effect of morin on blood glucose, insulin level, hepatic glucose regulating enzyme activities and glycogen level in experimental diabetes. Diabetes mellitus was induced by a single intraperitoneal injection of streptozotocin (STZ) (50 mg/kg b.w.). Five days after STZ injection, diabetic rats received morin (25 and 50 mg/kg b.w.) orally for 30 days. Glibenclamide was used as reference drug. Morin treatment significantly reduced the blood glucose and improved the serum insulin levels. Further, a dose-dependent reduction in glucose-6-phosphatase and fructose-1,6-bisphosphatase was observed along with the increase in liver hexokinase and glucose-6-phosphate dehydrogenase activities. Morin supplement were found to be effective in preserving the normal histological appearance of pancreatic islets as well as to preserve insulin-positive ß-cells in STZ-rats. Therefore, these findings suggest that morin displays beneficial effects in the treatment of diabetes, mediated through the regulation of carbohydrate metabolic enzyme activities.

Protective effect of gallic acid on alloxan-induced oxidative stress and osmotic fragility in rats.

In the present study, we investigated the antioxidant effect of gallic acid (GA) on membrane lipid peroxidation and osmotic fragility in alloxan-induced diabetic Wistar rats. GA was administered orally at doses of 5, 10, and 20 mg/kg body weight for 45 days, after which liver and kidney tissues were analyzed for the degree of lipid peroxidation, reduced glutathione, and the activities of antioxidants such as catalase, superoxide dismutase, and glutathione peroxidase. Administration of GA to alloxan-induced diabetic rats reduced the blood glucose level with an increase in the level of insulin. Liver and kidney tissues from diabetic animals exhibited disturbances in antioxidant defense compared with normal rats. GA at a dose of 20 mg/kg b.w. showed a significant effect than that of the other doses. In addition, the results revealed that GA protected the integrity of erythrocyte membrane in diabetic rats as demonstrated by lower percentage of hemolysis and resistance to hydrogen peroxide-induced peroxidation. The anti-hyperglycemic activity of GA in alloxan-induced diabetic rats was also comparable with glibenclamide, a reference drug. These results suggest that GA could provide a beneficial effect on diabetes by decreasing oxidative stress-related diabetic complications.

In vitro cytotoxicity of Gymnema montanum in human leukaemia HL-60 cells; induction of apoptosis by mitochondrial membrane potential collapse.

OBJECTIVES: Gymnema montanum Hook, an Indian Ayurvedic medicinal plant, is used traditionally to treat a variety of ailments. Here, we report anti-cancer effects and molecular mechanisms of ethanolic extract of G. montanum (GLEt) on human leukaemia HL-60 cells, compared to peripheral blood mononuclear cells. MATERIALS AND METHODS: HL-60 cells were treated with different concentrations of GLEt (10-50 µg/ml) and cytotoxicity was assessed by MTT assay. Levels of lipid peroxidation, antioxidants, mitochondrial membrane potential and caspase-3 were measured. Further, apoptosis was studied using annexin-V staining and the cell cycle was analyzed by flow cytometry. RESULTS: GLEt had a potent cytotoxic effect on HL-60 cells (IC50 -20 µg/ml), yet was not toxic to normal peripheral blood mononuclear cells. Exposure of HL-60 cells to GLEt led to elevated levels of malonaldehyde formation, but to reduced glutathione, superoxide dismutase, catalase and glutathione peroxidase activities (P < 0.05). Induction of apoptosis was confirmed by observing annexin-V positive cells, associated with loss of mitochondrial membrane potential. Cell cycle arrest at G0/G1 was observed in GLEt-treated HL-60 cells, indicating its potential at inducing their apoptosis. CONCLUSIONS: Findings of the present study suggest that G. montanum induced apoptosis in the human leukaemic cancer cells, mediated by collapse of mitochondrial membrane potential, generation of reactive oxygen species and depletion of intracellular antioxidant potential.

The impact of oxidative stress on islet transplantation and monitoring the graft survival by non-invasive imaging.

Islet transplantation is an attractive strategy to treat severe diabetic conditions in patients suffering from autoimmune derived diabetes, and it has currently been considered a forefront research arena in diabetes. Major aim of islet transplantation is to achieve successful insulin independent disease free survival. The key challenges in transplanted islets are the generation of reactive oxygen species (ROS) and associated oxidative stress, pro-inflammatory cytokine - (TNFα) mediated apoptotic induction, attack by immune cells, and achieving revascularization with minimal hypoxic microenvironment. Free radicals and their derivatives are constantly produced in living systems, but at relatively low level, and in a balanced state. Oxidative stress, which occurs as a result of an imbalance between the intracellular free radicals production and the cellular antioxidant defense mechanisms in the transplanted islets, can lead to cell death. The balance between oxidants and antioxidants in a cell can be easily disturbed by increase in ROS production or reduction in the level of cellular antioxidant defensive substances, which can cause many metabolic complications, including pancreatic ß-cell damage. Antioxidants function as blockers of radical processes by eliminating harmful ROS produced during normal cellular metabolism. A complex antioxidant defense mechanism has been developed by nature in cells to protect the cellular homeostasis. This system mainly includes antioxidant enzymes, vitamins and minerals. As transplanted islet survival is crucial for achieving successful therapy, most of these antioxidants can be used as a supplement to scavenge the local ROS thereby improving the survival of transplanted islets. Currently, very few techniques have been routinely used to qualitatively and quantitatively assess the survival and function of islet grafts, especially to confirm the success of treatment, which includes metabolic parameters such as blood glucose, insulin and C-peptide levels. These biochemical measurements provide markers at only the late stages of islet rejection. Use of molecular imaging techniques has the potential for real-time non-invasive monitoring of the functional status and viability of transplanted islet grafts in living animals. This review mainly focuses on the current status of islet transplantations, potential preventive strategies used to reduce oxidative stress-mediated toxicity in islet grafts, and use of molecular imaging as a tool to quantitatively evaluate the functional status of the transplanted islets in living animals.

Antigenotoxic potential of Gymnema montanum leaves on DNA damage in human peripheral blood lymphocytes and HL-60 cell line.

In this study we have evaluated the genoprotective effect of the ethanol extract of Gymnema montanum (GLEt) leaves in human peripheral blood lymphocytes and HL-60 cell line in vitro using the comet assay. DNA damage was induced by treating the cells with H(2)O(2) and methyl methane sulphonate (MMS). GLEt treatment effectively protected the lymphocytes and HL-60 cell line from H(2)O(2)-induced oxidative DNA damage in a dose-dependent manner whereas it was not effective against alkylative DNA damage caused by MMS. The global percent repair efficiency also showed that both pre- and post- GLEt treatment provided effective protection against H(2)O(2) induced DNA damage but not as effective against MMS. At 200 microg ml(-1) level, its repair capacity against H(2)O(2) induced DNA damage was comparable to that of vitamin-C (100 microM). Furthermore, exposure to GLEt reduced the formation of apoptotic cells caused by H(2)O(2), which was demonstrated by the decreased sub-G1-DNA content in cell cycle analysis and apoptotic frequencies of lymphocytes in an annexin-V binding assay. In addition, GLEt was found to have effective peroxide scavenging ability in dose-dependent manner. The protective efficiency of the extract was found to be directly proportional to its total phenolic content. The present study indicates that G. montanum leaves are a significant source of phytochemicals with antigenotoxic and antioxidant activity, and thus has potential therapeutic use.

Effect of Gymnema montanum leaves on red blood cell resistance to oxidative stress in experimental diabetes.

The aim of the present study was to evaluate the protective effect of Gymnema montanum on red blood cell (RBC) membrane in diabetic rats during lipid peroxidation. Ethanol extract of G. montanum leaves (GLEt) was administered orally to alloxan-induced diabetic rats for 3 weeks, and the effects on blood glucose, insulin, lipid peroxidation markers, thiobarbituric acid reactive substances, hydroperoxides in plasma and antioxidant enzymes including superoxide dismutase, catalase and glutathione peroxidase activities in erythrocytes were studied. Administration of GLEt to diabetic animals at doses of 50, 100, and 200 mg/kg body weight lowered elevated blood glucose levels by 24, 35, and 66%, respectively, relative to untreated diabetic rats. In comparison, treatment with the known antidiabetic drug, glibenclamide (600 microg/kg body weight) decreased blood glucose concentrations by 51%. Plasma insulin concentrations were increased in the diabetic rat by 73% with GLEt (200 mg/kg body weight) and 45% with glibenclamide (600 microg/kg body weight). Although a significant decrease in the lipid peroxidation markers was observed in plasma on treatment with GLEt and glibenclamide, the RBC antioxidant levels were increased significantly in diabetic rats. Furthermore, erythrocytes from the GLEt-treated animals were found to be more resistant to H2O2-induced peroxidation than that of untreated diabetic animals. The chemical characterization of the polyphenolics of the extract showed the presence of gallic acid (5.29% w/w), resveratrol (2.2% w/w), and quercetin (16.6% w/w). The results of this study suggest that G. montanum may be useful for the control, management, and prevention of oxidative stress associated with diabetes.

Effect of fish oil pretreatment on isoproterenol-induced changes in myocardial membrane phospholipids.

OBJECTIVE: In the present study, the protective effect of fish oil treatment on the fatty acid composition in isoproterenol (IPH)-induced myocardial infarction was studied in male albino Wistar rats. METHODS: Rats were injected for 2 consecutive days with IPH (60 mg/kg body weight) at 24-h intervals to induce myocardial infarction. Fish oil was administered orally at a dose of 0.05 mL/d for 45 d, after which serum and heart tissue were assayed for lipid profile, lipoprotein changes, and myocardial membrane phospholipid fatty acid composition. RESULTS: Biochemical assessment of myocardial infarction was done by measuring the activities of creatinine kinase and lactate dehydrogenase, which were significantly elevated in the rats administered with IPH. Further, the administration of IPH modified the fatty acid composition and analysis of fatty acids showed there was an increase in the omega-3/omega-6 ratio in phospholipid pool. In addition, increased levels of total cholesterol, free cholesterol, ester cholesterol, phospholipids, triacylglycerols and free fatty acid was observed in serum and heart tissue of IPH-induced rats. The fish oil treatment for a period of 45 d decreased the levels of cardiac markers (creatinine kinase and lactate dehydrogenase) and reversed the biochemical lesions induced by IPH. CONCLUSION: Our study suggests that fish oil treatment has a hypolipidemic effect and has potential use in the treatment of myocardial infarction.

Phytochemical and antimicrobial study of an antidiabetic plant: Scoparia dulcis L.

The antimicrobial and antifungal effects of different concentrations of chloroform/methanol fractions of Scoparia dulcis were investigated. The isolated fractions were tested against different bacteria like Salmonella typhii, Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and Proteus vulgaris and fungal strains such as Alternaria macrospora, Candida albicans, Aspergillus niger, and Fusarium oxysporum. The isolated fractions exhibited significant antimicrobial and antifungal activity against all the tested organisms compared with respective reference drugs. The isolated fractions of S. dulcis showed properties like antimicrobial and antifungal activities that will enable researchers in turn to look for application-oriented principles.

Health promotion by dietary restriction--a focus.

Food restriction, although long popular among gerontologists, has emerged as a new challenge in public health in postindustrial societies because this is the only intervention that repeatedly and strikingly increases maximum life span. The practice of food restriction is widespread for cosmetic, health, and economic reasons. The beneficial effects and the molecular mechanism of food restriction have been well established. The present review summarizes the rapidly accumulating evidence on the involvement of food restriction in various diseases and focuses on good dietary practices for health promotion in modern life style.

Modulatory effect of fish oil on the myocardial antioxidant defense system in isoproterenol-induced myocardial infarction.

The effect of fish oil treatment on the activities of antioxidants such as superoxide dismutase, catalase, glutathione peroxidase, glutathione-s-transferase, and glutathione, as well as the level of the lipid peroxidation marker thiobarbituric reactive substance was studied in isoproterenol-induced myocardial infarction (MI). To confirm the induction of MI by isoproterenol, we studied the activities of cardiac marker enzymes like creatinine kinase and lactate dehydrogenase and the level of troponin. The biochemical lesions due to the activation of lipid peroxidation and decrease in antioxidant status are significantly implicated in experimental isoproterenol-induced MI. The results indicate that the protective effect of fish oil is achieved by decreasing the peroxide concentration and normalizing antioxidant defense enzymes.

Short-term dietary restriction modulates liver lipid peroxidation in carbon tetrachloride-intoxicated rats.

We investigated whether dietary restriction (DR) can protect the liver against the acute toxicity of carbon tetrachloride (CCl4). Adult female Wistar rats received a quantum of diet representing 75 and 50 percent of the food intake of control rats fed ad libitum (25% and 50% daily regimen, respectively) for 30 days. A single dose of CCl4 (3 mL kg(-1) b.w.) was administered subcutaneously at the end of the feeding period. Lipid peroxidation, as thiobarbituric acid reactive substance, conjugated dienes, lipid hydroperoxides and the hepatic markers alanine transaminase, aspartic transaminase, and alkaline phosphatase were significantly decreased in food-restricted rats. The enzymic antioxidants superoxide dismutase, catalase, glutathione peroxidase and the non-enzymic antioxidant glutathione were significantly increased in both groups. The magnitude of liver damage after CCl4 treatment was lower in food-restricted animals than in ad libitum-fed animals. The results suggest that dietary restriction increases the resistance of the liver and protects against oxidative insult produced by an acute dose of CCl4.

Modulatory effects of Gymnema montanum leaf extract on alloxan-induced oxidative stress in Wistar rats.

OBJECTIVES: In light of evidence that some complications of diabetes mellitus may be caused or exacerbated by oxidative damage, we investigated the effect of Gymnema montanum leaf extract (GLEt) on tissue antioxidant defense systems in alloxan-induced diabetes in rats. METHODS: GLEt was administered orally at a doses of 50, 100, and 200 mg/kg of body weight for 30 d, after which liver and kidney tissues were assayed for the degree of lipid peroxidation by means of markers, reduced glutathione content and activities of catalase, superoxide dismutase, glutathione peroxidase, and glutathione-S-transferase. RESULTS: Treatment of diabetic rats with GLEt increased the antioxidant levels. Liver and kidney from diabetic animals exhibited disturbances in antioxidant defense when compared with normal rats. GLEt at a dose of 200 mg/kg of body weight exhibited a significant effect as compared with 50 and 100 mg/kg of body weight. These effects were compared with glibenclamide, a reference drug. CONCLUSIONS: It may be concluded that, in diabetes, liver and kidney tissues are more vulnerable to oxidative stress and show increased lipid peroxidation. The antioxidant responsiveness mediated by G. montanum may be anticipated to have biological significance in eliminating reactive free radicals that may otherwise affect normal cell functioning and provide a scientific rationale for the use of G. montanum as an antidiabetic plant.

Antidiabetic effect of Gymnema montanum leaves: effect on lipid peroxidation induced oxidative stress in experimental diabetes.

Gymnema montanum is widely used in ancient medicine for the ailment of various diseases. Oral administration of 200 mg kg(-1) (body weight) BW of the alcoholic extract of the leaf for 3 weeks resulted in a significant reduction in blood glucose and an increase in plasma insulin, whereas the effect of 50 and 100 mg kg(-1) BW was not significant. The alcoholic extract also resulted in decreased free radical formation in plasma of diabetic rats. Thus, this study shows that Gymnema montanum leaf extract (GLEt) possess antihyperglycemic and antiperoxidative effect. The decrease in lipid peroxides and increase in reduced glutathione (GSH), ascorbic acid (Vitamin C) and alpha-tocopherol (Vitamin E) clearly show the antioxidant properties of GLEt. The effect of GLEt was most prominently seen in the case of animals given 200 mg kg(-1) BW. In addition, the results suggest that GLEt was highly effective than the reference drug glibenclamide.