The Hexosamine Biosynthesis Pathway: Regulation and Function.

The hexosamine biosynthesis pathway (HBP) produces uridine diphosphate-N-acetyl glucosamine, UDP-GlcNAc, which is a key metabolite that is used for N- or O-linked glycosylation, a co- or post-translational modification, respectively, that modulates protein activity and expression. The production of hexosamines can occur via de novo or salvage mechanisms that are catalyzed by metabolic enzymes. Nutrients including glutamine, glucose, acetyl-CoA, and UTP are utilized by the HBP. Together with availability of these nutrients, signaling molecules that respond to environmental signals, such as mTOR, AMPK, and stress-regulated transcription factors, modulate the HBP. This review discusses the regulation of GFAT, the key enzyme of the de novo HBP, as well as other metabolic enzymes that catalyze the reactions to produce UDP-GlcNAc. We also examine the contribution of the salvage mechanisms in the HBP and how dietary supplementation of the salvage metabolites glucosamine and N-acetylglucosamine could reprogram metabolism and have therapeutic potential. We elaborate on how UDP-GlcNAc is utilized for N-glycosylation of membrane and secretory proteins and how the HBP is reprogrammed during nutrient fluctuations to maintain proteostasis. We also consider how O-GlcNAcylation is coupled to nutrient availability and how this modification modulates cell signaling. We summarize how deregulation of protein N-glycosylation and O-GlcNAcylation can lead to diseases including cancer, diabetes, immunodeficiencies, and congenital disorders of glycosylation. We review the current pharmacological strategies to inhibit GFAT and other enzymes involved in the HBP or glycosylation and how engineered prodrugs could have better therapeutic efficacy for the treatment of diseases related to HBP deregulation.

Hexosamine pathway activation improves memory but does not extend lifespan in mice.

Glucosamine feeding and genetic activation of the hexosamine biosynthetic pathway (HBP) have been linked to improved protein quality control and lifespan extension. However, as an energy sensor, the HBP has been implicated in tumor progression and diabetes. Given these opposing outcomes, it is imperative to explore the long-term effects of chronic HBP activation in mammals. Thus, we asked if HBP activation affects metabolism, coordination, memory, and survival in mice. N-acetyl-D-glucosamine (GlcNAc) supplementation in the drinking water had no adverse effect on weight in males but increased weight in young females. Glucose or insulin tolerance was not affected up to 20 months of age. Of note, we observed improved memory in young male mice supplemented with GlcNAc. Survival was not changed by GlcNAc treatment. To assess the effects of genetic HBP activation, we overexpressed the pathway's key enzyme GFAT1 and a constitutively activated mutant form in all mouse tissues. We detected elevated levels of the HBP product UDP-GlcNAc in mouse brains, but did not find any effects on behavior, memory, or survival. Together, while dietary GlcNAc supplementation did not extend survival in mice, it positively affected memory and is generally well tolerated.

Time and space-resolved quantification of plasma membrane sialylation for measurements of cell function and neurotoxicity.

While there are many methods to quantify the synthesis, localization, and pool sizes of proteins and DNA during physiological responses and toxicological stress, only few approaches allow following the fate of carbohydrates. One of them is metabolic glycoengineering (MGE), which makes use of chemically modified sugars (CMS) that enter the cellular biosynthesis pathways leading to glycoproteins and glycolipids. The CMS can subsequently be coupled (via bio-orthogonal chemical reactions) to tags that are quantifiable by microscopic imaging. We asked here, whether MGE can be used in a quantitative and time-resolved way to study neuronal glycoprotein synthesis and its impairment. We focused on the detection of sialic acid (Sia), by feeding human neurons the biosynthetic precursor N-acetyl-mannosamine, modified by an azide tag. Using this system, we identified non-toxic conditions that allowed live cell labeling with high spatial and temporal resolution, as well as the quantification of cell surface Sia. Using combinations of immunostaining, chromatography, and western blotting, we quantified the percentage of cellular label incorporation and effects on glycoproteins such as polysialylated neural cell adhesion molecule. A specific imaging algorithm was used to quantify Sia incorporation into neuronal projections, as potential measure of complex cell function in toxicological studies. When various toxicants were studied, we identified a subgroup (mitochondrial respiration inhibitors) that affected neurite glycan levels several hours before any other viability parameter was affected. The MGE-based neurotoxicity assay, thus allowed the identification of subtle impairments of neurochemical function with very high sensitivity.

Wound healing potential of Solanum xanthocarpum in streptozotocin-induced diabetic rats.

OBJECTIVES: The objective of the present study was to evaluate wound healing potential of Solanum xanthocarpum extract in streptozotocin-induced diabetic rats. METHODS: Alcoholic extract of the aerial parts (ESX) was subjected to phytochemical estimations and its standardization with chlorogenic acid using HPLC. ESX was then evaluated for wound healing potential in, streptozotocin-induced diabetic rats using excision and incision wound models on topical and oral treatment Various biochemical evaluations, such as collagen, hexosamine, hyaluronic acid, protein, DNA along with antioxidant parameters, proinflammatory cytokines, VEGF and histopathological examination were also evaluated. KEY FINDINGS: Extract of S. xanthocarpum depicted the presence of mainly alkaloids, polyphenols, steroids, while content of chlorogenic acid was found to be 8.44% w/w. The maximum effective nature of ESX in healing was observed at 10% gel (topical) and 200 mg/kg (orally) in diabetic rats, where highest healing power was observed when treated both orally and topically. Biochemical evaluations showed significant increase in the levels of collagen, hexosamine, hyaluronic acid, protein, DNA followed by significant decline in the levels of blood glucose, lipid peroxidation, nitric oxide and expression of proinflammatory cytokines, supported by histopathology. CONCLUSIONS: The potential healing effect in diabetic rats may be attributed to the presence of chlorogenic acid in combination with other phytoconstituents.

Combination of medicinal honey and 904 nm superpulsed laser-mediated photobiomodulation promotes healing and impedes inflammation, pain in full-thickness burn.

Burn wound is a complex multi-factorial pathophysiology producing excruciating pain and psychological discomfort among patients, which imposes a major burden on the healthcare system. Multi-target therapy focuses on augmented healing by regulating different phases of tissue repair. Recently, photobiomodulation (PBM)-induced wound healing has achieved profound impetus as a non-invasive, drug-free biophysical therapeutic approach. On the other hand, medicinal honey known to possess antibacterial and immunomodulatory properties and is being used as an effective treatment option for infected wounds. The present study aimed to determine whether the combination of medicinal honey and PBM using superpulsed 904 nm laser treatment could additively accelerate full-thickness burn wound repair in rats. Animals were randomly allocated into 4 experimental groups: control (C), PBM superpulsed 904 nm laser treated (PBMT), honey treated (HT) and combined treatment (CT). The dual treatment exhibited an enhanced wound area contraction and hexosamine content as compared to the other groups. Histopathological analysis revealed increased cellular proliferation, extracellular matrix accumulation and decreased inflammation in the CT group. Further, the CT group demonstrated synergistically attenuated inflammation, pain and enhanced cell adhesion, migration as evidenced by significantly reduced protein expression of TNF-α, NF-κB, IL-1ß, COX-2, substance-P receptor and up-regulation of fibronectin, respectively as compared with the other groups. Thus, the findings of present study signify that the combination of medicinal honey and PBMT accelerates the repair process of burn wounds. The study showed that therapeutic efficacy of 904 nm superpulsed laser-mediated PBM augments in the presence of medicinal honey by enhancing cellular proliferation and attenuation of inflammation and pain in burn wound healing.

Phytochemicals: Target-Based Therapeutic Strategies for Diabetic Retinopathy.

Background: A variety of causative factors are involved in the initiation of diabetic retinopathy (DR). Current antidiabetic therapies are expensive and not easily accessible by the public. Furthermore, the use of multiple synthetic drugs leads to severe side effects, which worsen the diabetic patient's condition. Medicinal plants and their derived phytochemicals are considered safe and effective treatment and their consumption can reduce the DR risk. In this article, we discuss a variety of medicinal plants, and their noteworthy bio-active constituents, that will be utilized as target based therapeutic strategies for DR. Methods: A broad-spectrum study was conducted using published English works in various electronic databases including Science Direct, PubMed, Scopus, and Google Scholar. Results: Targeting the multiple pathological factors including ROS, AGEs formation, hexosamine flux, PARP, PKC, and MAPK activation through variety of bioactive constituents in medicinal plants, diabetes progression can be delayed with improved loss of vision. Conclusions: Data reveals that traditional herbs and their prominent bioactive components control and normalize pathological cellular factors involved in DR progression. Therefore, studies should be carried out to explore the protective retinopathy effects of medicinal plants using experimental animal and humans models.

Butyrated ManNAc analog improves protein expression in Chinese hamster ovary cells.

The chemical additive sodium butyrate (NaBu) has been applied in cell culture media as a direct and convenient method to increase the protein expression in Chinese hamster ovary (CHO) and other mammalian cells. In this study, we examined an alternative chemical additive, 1,3,4-O-Bu3 ManNAc, for its effect on recombinant protein production in CHO. Supplementation with 1,3,4-O-Bu3 ManNAc for two stable CHO cell lines, expressing human erythropoietin or IgG, enhanced protein expression for both products with negligible impact on cell growth, viability, glucose utilization, and lactate accumulation. In contrast, sodium butyrate treatment resulted in a ∼20% decrease in maximal viable cell density and ∼30% decrease in cell viability at the end of cell cultures compared to untreated or 1,3,4-O-Bu3 ManNAc treated CHO cell lines for both products. While NaBu treatment enhanced product yields more than the 1,3,4-O-Bu3 ManNAc treatment, the NaBu treated cells also exhibited higher levels of caspase 3 positive cells using microscopy analysis. Furthermore, the mRNA levels of four cell apoptosis genes (Cul2, BAK, BAX, and BCL2L11) were up-regulated more in sodium butyrate treated wild-type, erythropoietin, or IgG expressing CHO-K1 cell lines while most of the mRNA levels of apoptosis genes in 1,3,4-O-Bu3 ManNAc treated cell lines remained equal or increased only slightly compared to the levels in untreated CHO cell lines. Finally, lectin blot analysis revealed that the 1,3,4-O-Bu3 ManNAc-treated cells displayed higher relative sialylation levels on recombinant EPO, consistent with the effect of the ManNAc component of this additive, compared to control while NaBu treatment led to lower sialylation levels than control, or 1,3,4-O-Bu3 ManNAc-treatment. These findings demonstrate that 1,3,4-O-Bu3 ManNAc has fewer negative effects on cell cytotoxicity and apoptosis, perhaps as a result of a more deliberate uptake and release of the butyrate compounds, while simultaneously increasing the expression of multiple recombinant proteins, and improving the glycosylation characteristics when applied at comparable molarity levels to NaBu. Thus, 1,3,4-O-Bu3 ManNAc represents a highly promising media additive alternative in cell culture for improving protein yields without sacrificing cell mass and product quality in future bioproduction processes.

Gastroprotective Effects of PMK-S005 against Ethanol-Induced Acute Gastric Damage in Rats.

BACKGROUND/AIMS: This study aimed to examine the gastroprotective effects of PMK-S005, which is a synthetic S-allyl-Lcysteine (SAC; a sulfur-containing amino acid), against acute ethanol-induced gastric damage in rats. METHODS: Sprague- Dawley rats were divided into six groups, including a nonethanol group, groups treated with absolute ethanol 1 hour after pretreatment with various doses of PMK-S005 (1, 5, and 10 mg/kg) or rebamipide (50 mg/kg), and an absolute ethanolonly group. Ethanol-induced gross ulcer and mucus levels were measured. Myeloperoxidase, tumor necrosis factor a, interleukin 1ß, PGE2, LTB4, cPLA2, COX-1, and COX-2 levels were estimated by enzyme-linked immunosorbent assay or Western blot analysis. Furthermore, the protein expression levels of antioxidant enzymes, including heme oxygenase-1 (HO-1), NAD(P)Hquinine oxidoreductase 1 (NQO-1), GCLC, and GCLM, were assessed. RESULTS: PMK-S005 significantly attenuated the ethanol-induced gastric damage; it reduced mucosal inflammatory cytokine production and increased mucus levels. The expression levels of cPLA2, COX-1, and COX-2 were decreased by PMK-S005. PMK-S005 did not affect PGE2 synthesis, but LTB4 production was significantly suppressed. In addition, long-term administration of PMKS005 significantly increased the expression of HO-1, NQO-1, GCLC, and GCLM. CONCLUSIONS: These results strongly suggest that PMK-S005 prevents gastric mucosal damage and that these gastroprotective activities are due to anti-inflammatory effects and enhancement of the gastric defense system, including antioxidant enzymes.

Alocasia denudata Engler treatment enhance open wound healing activities in Wistar rat's skin.

ETHNOPHARMACOLOGICAL RELEVANCE: A. denudata is traditionally used to treat various skin disorders, including wounds. It is widely used by the traditional healers as an effective wound treatment. AIM OF STUDY: This study was done to determine A. denudata treatment effects on open wound healing activities in Wistar rat's skin. MATERIALS AND METHODS: 120 Wistar rats (250-300 g) were divided into four main groups, 1.5% and 3% A. denudata stem juice treated group, 10% Solcoseryl® gel treated group as positive control and phosphate buffer saline (PBS) treated group as negative control. Six full thicknesses wounds (6mm) were induced bilaterally on the dorsal of the rat's skin. Rats were sacrificed on day 1, 3, 6, 10 and 14. The percentage of wound contraction, biochemical estimations, macroscopic observation and histological examinations were done to evaluate the wound healing activities. RESULTS: Results showed wounds treated with A. denudata stem juice possess a significant higher rate of wound contraction (p<0.001), total protein concentration (p<0.05), hexosamine concentration (p<0.001) and uronic acid concentration (p<0.001). Moreover, cathepsin B (p<0.05) and hydroxyproline (p<0.05) level showed lower concentration in wounds treated with A. denudata stem juice. Histological observation of wounds treated with A. denudata stem juice displayed organized epithelial layer with dense and compact collagen fibers. CONCLUSION: Both doses of A. denudata stem juice were found to enhance wound healing process. However, wounds treated with 3% A. denudata stem juice were reported to be more effective as a wound healing agent thus support its traditional usage.

Trivalent chromium inhibits TSP-1 expression, proliferation, and O-GlcNAc signaling in vascular smooth muscle cells in response to high glucose in vitro.

Trivalent chromium (Cr(3+)) is a mineral nutrient reported to have beneficial effects in glycemic and cardiovascular health. In vitro and in vivo studies suggest that Cr(3+) supplementation reduces the atherogenic potential and lowers the risk of vascular inflammation in diabetes. However, effects of Cr(3+) in vascular cells under conditions of hyperglycemia, characteristic of diabetes, remain unknown. In the present study we show that a therapeutically relevant concentration of Cr(3+) (100 nM) significantly downregulates a potent proatherogenic matricellular protein, thrombospondin-1 (TSP-1), in human aortic smooth muscle cells (HASMC) stimulated with high glucose in vitro. Promoter-reporter assays reveal that this downregulation of TSP-1 expression by Cr(3+) occurs at the level of transcription. The inhibitory effects of Cr(3+) on TSP-1 were accompanied by significant reductions in O-glycosylation of cytoplasmic and nuclear proteins. Using Western blotting and immunofluorescence studies, we demonstrate that reduced protein O-glycosylation by Cr(3+) is mediated via inhibition of glutamine: fructose 6-phosphate amidotransferase, a rate-limiting enzyme of the hexosamine pathway, and O-linked N-acetylglucosamine (O-GlcNAc) transferase, a distal enzyme in the pathway that controls intracellular protein O-glycosylation. Additionally, we found that Cr(3+) attenuates reactive oxygen species formation in glucose-stimulated HASMC, suggesting an antioxidant effect. Finally, we report an antiproliferative effect of Cr(3+) that is specific for high glucose and conditions triggering elevated protein O-glycosylation. Taken together, these findings provide the first cellular evidence for a novel role of Cr(3+) to modulate aberrant vascular smooth muscle cell function associated with hyperglycemia-induced vascular complications.

Hexosamine biosynthetic pathway activity in leptin resistant sucrose-drinking rats.

Rats offered 30% sucrose solution in addition to chow and water become leptin resistant therefore we investigated the effect of sucrose solution consumption on leptin signaling. In Experiment 1 rats were resistant to 3rd ventricle injections of1.5 µg leptin after 36 days of sucrose and western blot indicated that resistance was associated with increased basal levels of signal transducer and activator of transcription 3 phosphorylation (pSTAT3). In Experiment 2 rats were resistant to a peripheral injection of 2mg leptin/kg after 26 days of sucrose. Immunohistochemistry indicated that increased basal pSTAT3 was limited to the medial and lateral arcuate nucleus of the hypothalamus. Increased availability of glucose and fructose can stimulate the hexosamine biosynthetic pathway (HBP) which O-GlcNAc-modifies proteins. This has the potential to change protein bioactivity. We tested whether this pathway could account for the leptin resistance. There was no increase in the expression of HBP enzymes in tissues from sucrose rats in Experiment 1, however, direct activation of the HBP with a 3h intravenous infusion of 30 µmol/kg/min glucosamine significantly increased hypothalamic pSTAT3. Although sucrose consumption and activation of the HBP both increase hypothalamic pSTAT3 experiments described here did not provide evidence of a direct link between sucrose consumption, HBP activity and leptin resistance. Unexpectedly, we found that the HBP enzyme glutamine fructose-6-phosphate amidotransferase (GFAT) in liver and O-GlcNAcase in hypothalamus were increased 30min after leptin injection in leptin responsive animals, implying a complex interaction between activity of the HBP and leptin responsiveness.

Social determinants of hospitalizations for ambulatory care sensitive conditions in Guarulhos, São Paulo / Los determinantes sociales de las hospitalizaciones por condiciones sensibles a la atención primaria en guarulhos, são paulo / Determinantes sociais das Internações por Condições Sensíveis à Atenção Primária em Guarulhos, São Paulo

The study goals present an overview of Hospitalizations for Ambulatory Care Sensitive Conditions (ACSC) in Guarulhos, SP, from 2008 to 2012. This is an ecological study based on secondary data obtained from the Brazilian Hospital Information System, and supported by the Praxical Theory of Intervention of Collective Health Nursing. Applied descriptive statistics for analysis. It was observed that Guarulhos shows an upward trend in hospitalizations by ACSC (20% increase), the most frequent causes of heart failure (11.8%), cerebrovascular disease (10.6%) and angina (9.7%), most frequently in the age group ≥ 65years old, for both sexes. The results are similar to other Brazilian studies, but their analysis should extrapolate the biological limits and the supply of healthcare resources, focusing on the social determinants of the health-disease process.


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El estudio tuvo como objetivo proporcionar una visión general de las Hospitalizaciones por Condiciones Sensibles a la Atención Primaria (ICSAP) en Guarulhos, SP, en el período 2008-2012. Se trata de un estudio ecológico a partir de datos secundarios obtenidos a través del Sistema de Información Hospitalaria, y apoyado por la Teoría de Intervención Práxica de la Enfermería en Salud Colectiva. Se aplicó la estadística descriptiva para el análisis. Se observó que Guarulhos muestra una tendencia al alza en las hospitalizaciones por ICSAP (aumento del 20%), las causas más frecuentes de insuficiencia cardiaca (11,8%), enfermedad cerebrovascular (10,6%) y la angina (9,7% ), con mayor frecuencia en el grupo de edad ≥ 65 años para ambos sexos. Los resultados son similares a otros estudios brasileños, pero su análisis debe extrapolar los límites biológicos y el suministro de los recursos sanitarios, centrándose en los determinantes sociales del proceso salud-enfermedad.
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Objetivo Apresentar o panorama das Internações por Condições Sensíveis à Atenção Primária (ICSAP) no município de Guarulhos, SP, no período de 2008 a 2012. Método Estudo ecológico, com dados secundários obtidos via Sistema de Informações Hospitalares, sustentado pela Teoria de Intervenção Práxica da Enfermagem em Saúde Coletiva. Empregou-se estatística descritiva para análise. Resultados Observou-se que Guarulhos apresenta trajetória crescente nas internações por ICSAP (aumento de 20%), sendo as causas mais frequentes a insuficiência cardíaca (11,8%), as doenças cerebrovasculares (10,6%) e a angina (9,7%), com maior frequência na faixa etária ≥ 65 anos, para ambos os sexos. Conclusão Os resultados encontrados assemelham-se a outros estudos brasileiros, porém sua análise deve extrapolar os limites biológicos e a oferta de recursos assistenciais, atentando para as determinações sociais do processo saúde-doença. .

Effect of growth factors and pro-inflammatory cytokines by the collagen biocomposite dressing material containing Macrotyloma uniflorum plant extract-In vivo wound healing.

Open burn wounds require proper dressings for faster healing and to prevent infection. In the present study, a wound dressing material in sheet form, containing fish scale collagen (FSC), physiologically clotted fibrin (PCF) and Macrotyloma uniflorum plant extract (MPE) was applied on the experimental wounds of rats. It was found that MPE accelerated wound healing, by suppressing the cyclooxygenase-2 (COX-2) and inducible nitric oxide synthases (iNOS) expressions thereby reduced inflammation. It has influenced the regulation of growth factors such as vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), epidermal growth factor (EGF) and transforming growth factor (TGF-ß). The biocomposite sheet has enhanced collagen synthesis and down regulated the matrix metalloproteinases (MMPs), thereby helped faster healing of wounds. The results suggest that the incorporation of MPE played an important role in enhancing the wound healing rate. The FSC-PCF biosheet containing MPE may be further tried on the clinical wounds of small and large animals before application on to humans.

Wound healing activity of the inflorescence of Typha elephantina (Cattail).

Methanolic extracts of Typha elephantina inflorescence (TE) and its bandage were screened for wound healing by incision and excision wound models in Wistar rats. In the incision wound model, incision wounds were topically treated with TE gel (2.0% [w/w], 3.0% [w/w], and 5.0% [w/w]), Typha elephantina inflorescence bandage, and the reference standard 5.0% w/w povidone iodine for a period of 10 days. When the wounds healed thoroughly, sutures were removed on the 8th postwounding day, and the tensile strength of the skin was measured on the 10th day. In the excision wound model, excision wounds were treated with TE gel (3.0% [w/w] and 5.0% [w/w]), inflorescence bandage, and 5.0% w/w povidone iodine till the wounds completely healed. Epithelization time, wound contraction, hydroxyproline and hexosamine content of the scab, and ascorbic acid and malondialdehyde content of the plasma were determined in this model. In the incision wound model, high tensile strength of the skin of the healed wound was observed in rats treated with the TE gels and the inflorescence bandage when compared with wounded control rats. The increase in tensile strength indicates a promotion of collagen fibers and a firm knitting of the disrupted wound surfaces by collagen. In the excision wound model, higher rate of wound contraction, decreased period of epithelization, elevated hydroxyproline, hexosamine, and ascorbic acid levels, and a significant decrease in malondialdehyde content was observed in treated groups when compared with the wounded control animals. It may be concluded that the inflorescence of Typha elephantina possesses a potent wound healing activity, which may be due to an underlying antioxidant mechanism.

[Glycoproteins of mucus of gastric and duodenal wall surface during ulcerogenesis and the impact of fenugreek].

The comparative evaluation of qualitative and quantitative composition of glycoproteins of gastric and duodenal wall surface layer of protective mucus in the normal, at the modeling of ulcers in rats and at the introduction to animals with ulcerative lesions of fenugreek extract carried out. It was shown in control (normally) the general level of glycosylation of glycoproteins gastric mucus is 1.7 times more than the duodenum. Under acute stress model ulceration in the stomach mucus decrease in hexosamine (1.4 times), galactose (2.2 times), fucose (1.3-fold) and an increase in NANA (3.6 times) observed. Under cysteamine model ulceration in duodenal mucus increase galactose (2.7 times), NANA (2.4 times), fucose (1.8-fold) but significant decrease in the amount of hexosamines 3 times compared to the control occurred. It was proved the protective effect of fenugreek extract to the wall surface mucus of the stomach and duodenum mucosa under conditions modeling ulceration in rats.

Evaluation of in vivo wound healing activity of Bacopa monniera on different wound model in rats.

Wound healing effects of 50% ethanol extract of dried whole plant of Bacopa monniera (BME) was studied on wound models in rats. BME (25 mg/kg) was administered orally, once daily for 10 days (incision and dead space wound models) or for 21 days or more (excision wound model) in rats. BME was studied for its in vitro antimicrobial and in vivo wound breaking strength, WBS (incision model), rate of contraction, period of epithelization, histology of skin (excision model), granulation tissue free radicals (nitric oxide and lipid peroxidation), antioxidants (catalase, superoxide dismutase, and reduced glutathione), acute inflammatory marker (myeloperoxidase), connective tissue markers (hydroxyproline, hexosamine, and hexuronic acid), and deep connective tissue histology (dead space wound). BME showed antimicrobial activity against skin pathogens, enhanced WBS, rate of contraction, skin collagen tissue formation, and early epithelization period with low scar area indicating enhanced healing. Healing effect was further substantiated by decreased free radicals and myeloperoxidase and enhanced antioxidants and connective tissue markers with histological evidence of more collagen formation in skin and deeper connective tissues. BME decreased myeloperoxidase and free radical generated tissue damage, promoting antioxidant status, faster collagen deposition, other connective tissue constituent formation, and antibacterial activity.

Inhibition of metastatic lung cancer in C57BL/6 mice by marine mangrove Rhizophora apiculata.

Metastasis is one of the hallmarks of malignant neoplasms and is the leading cause of death in many cancer patients. A major challenge in cancer treatment is to find better ways to specifically target tumor metastasis. In this study, the anti-metastatic potential of the methanolic extract of Rhizophora apiculata (R.apiculata) was evaluated using the B16F-10 melanoma induced lung metastasis model in C57BL/6 mice. Metastasis was induced in C57BL/6 mice by injecting highly metastatic B16F-10 melanoma cells through the lateral tail vein. Simultaneous treatment with R.apiculata extract (10 mg/kg b.wt (intraperitoneal) significantly (p<0.01) inhibited pulmonary tumor nodule formation (41.1 %) and also increased the life span (survival rate) 107.3 % of metastatic tumor bearing animals. The administration of R.apiculata extract significantly (p<0.01) reduced biochemical parameters such as lung collagen hydroxyproline, hexosamine, uronic acid content, serum nitric oxide (NO), γ-glutamyl transpeptidase (GGT) and sialic acid levels when compared to metastasis controls. These results correlated with lung histopathology analysis of R.apiculata extract treated mice showing reduction in lung metastasis and tumor masses. Taken together, our findings support that R.apiculata extract could be used as a potential anti-metastasis agent against lung cancer.

Dietary supplementation of silymarin is associated with decreased cell proliferation, increased apoptosis, and activation of detoxification system in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) incidence rates are increasing in many parts of the world. HCC's limited treatment remedies and the poor prognosis emphasize the importance in developing an effective chemoprevention for this disease. Here, we investigated the molecular mechanisms involved in the chemoprevention of silymarin in N-nitrosodiethylamine (NDEA)-induced rat model of HCC. Liver of the rats treated with NDEA showed higher proliferation index and glycoconjugates. NDEA treatment also increased the level of anti-apoptotic proteins with simultaneous decrease in the level of pro-apoptotic proteins along with increased accumulation of Cytochrome c in mitochondria. The carcinogenic insult also increased microsomal phase I metabolizing enzymes with a simultaneous decrease in the Phase II detoxifying enzyme glutathione-S-transferase (GST). Whereas dietary silymarin administration along with NDEA treatment significantly decreased the proliferation and down regulated the expression of anti-apoptotic proteins with simultaneously increased expression of pro-apoptotic proteins along with the release of Cytochrome c to cytosol there by activating the intrinsic apoptotic pathway. Silymarin administration also decreased the level of glycoproteins and activated the phase II detoxifying enzyme GST. These results demonstrate that suppression of HCC by silymarin in vivo involves inhibition of proliferation, activation of apoptosis, and efficient detoxification.

Silibinin regulates matrix metalloproteinase 3 (stromelysine1) gene expression, hexoseamines and collagen production during rat skin wound healing.

Silibinin (SB), a flavonoid isolated from the milk thistle, Silybum marianum, has been shown to exhibit protective effects against skin damage. The objective of the present study was to investigate the effect of topical application of SB on levels of stromelysine 1 (STM1) gene expression, acetyl hexoseamines and collagen production during skin wound healing. Full-thickness skin wounds were topically treated with 10% and 20% SB extract in acetonitril:olive oil (AOO) (4:1) for 30 days, and expression level of STM1 transcript, n-acetyl glucoseamine (NAGLA), n-acetyl galactoseamine (NAGAA) and collagen contents were analyzed on the 10th, 20th and 30th days post wounding. SB in dose- and time-dependent manner accelerated wound closure time and increased levels of STM1 mRNA, hydroxyproline, NAGLA and NAGAA compared to the untreated and vehicle (AOO)-treated rats. The current study provides evidence that SB, by increasing STM1 gene expression and extracellular matrix constituents including glycosaminoglycans and collagen contents, promotes a faster wound healing process and can be used as a healing agent in future.

Diabetic retinopathy and atherosclerosis: is there a link?

Diabetic retinopathy (DR) is the leading cause of blindness amongst the working-age population, and diabetes accelerated cardiovascular disease (CVD) the commonest cause of death in diabetic patients. Although, there is evidence suggesting a close association between DR and CVD, particularly in patients with Type 2 diabetes, the pathophysiology underlying the link is unclear. Here we review common risk factors and pathogenic mechanisms linking DR and CVD, and aim to highlight the need for a more holistic view of the management of diabetes and its complications. The understanding of the link between the two complications could eventually lead to refined management strategies and improved patient outcomes in the expanding diabetes epidemic.