Novel hypoglycemic effects of Ganoderma lucidum water-extract in obese/diabetic (+db/+db) mice

In this study, we evaluated the pharmacological effects of Ganoderma lucidum (G. lucidum) (water-extract) (0.003, 0.03 and 0.3 g/kg, 4-week oral gavage) consumption using the lean (+db/+m) and the obese/diabetic (+db/+db) mice. Different physiological parameters (plasma glucose and insulin levels, lipoproteins-cholesterol levels, phosphoenolpyruvate carboxykinase (PEPCK), 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG CoA reductase) and isolated aorta relaxation of both species were measured and compared. G. lucidum (0.03 and 0.3 g/kg) lowered the serum glucose level in +db/+db mice after the first week of treatment whereas a reduction was observed in +db/+m mice only fed with 0.3 g/kg of G. lucidum at the fourth week. A higher hepatic PEPCK gene expression was found in +db/+db mice. G. lucidum (0.03 and 0.3 g/kg) markedly reduced the PEPCK expression in +db/+db mice whereas the expression of PEPCK was attenuated in +db/+m mice (0.3 g/kg G. lucidum). HMG CoA reductase protein expression (in both hepatic and extra-hepatic organs) and the serum insulin level were not altered by G. lucidum. These data demonstrate that G. lucidum consumption can provide beneficial effects in treating type 2 diabetes mellitus (T2DM) by lowering the serum glucose levels through the suppression of the hepatic PEPCK gene expression.     

Cleavage of hyaluronan is impaired in aged dermal wounds

Changes in extracellular matrix (ECM) are one of many components that contribute to impaired wound healing in aging. This study examined the effect of age on the glycosaminoglycan hyaluronan (HA) in normal and wounded dermis from young (4–6 month-old) and aged (22–24 month-old) mice. HA content and size were similar in the normal dermis of young and aged mice. Dermal explants labeled with [³H]-glucosamine showed decreased generation of smaller forms of HA in aged explants relative to young explants. Aged mice exhibited delayed wound repair compared with young mice with the greatest differential at 5 days. Expression of hyaluronan synthase (HAS) 2 and 3, and hyaluronidase (HYAL) 1–3 mRNA in wounds of young and aged mice was similar. There was a trend toward a decreased HYAL protein expression in aged wound dermis, which was accompanied by changes in detectable HYAL activity. Total HA content was similar in young and aged wound dermis. There was significantly less HA in the lower MW range (~ 250 kDa and smaller) in 5-day wound dermis, but not in 9-day wound dermis, from aged mice relative to young mice. We propose that decreased cleavage of HA is an additional component of impaired dermal wound healing in aging.     

Interleukin (IL)-19 promoted skin wound healing by increasing fibroblast keratinocyte growth factor expression

BackgroundInterleukin (IL)-19, a member of the IL-10 cytokine family, is involved in keratinocyte proliferation in psoriasis.ObjectivesWe investigated the role of IL-19 in the wound-healing process in vivo and in vitro.MethodsTwo full-thickness circular wounds (4 mm in diameter) were punched into the skin of BALB/C mice. IL-19 and keratinocyte growth factor (KGF) mRNA in wounded skin were determined using real-time PCR. The wounds were treated with PBS, vehicle, IL-19 (400 ng/mL), or IL-20 (400 ng/mL) (n = 6 in each group) twice daily and the percentage of wound healing was measured daily for 7 days. In vitro, human skin fibroblast CCD966-SK cells and keratinocyte HaCaT cells were treated with IL-19 or KGF. Cell proliferation and migration were determined using bromodeoxyuridine (BrdU) and transwell assays, respectively. The expression of IL-19 and KGF mRNA was also analyzed.ResultsIn wounded mouse skin, IL-19 mRNA was upregulated at 12 h, and KGF at 24 h after the injury. Both increases in gene expression declined 72 h after the skin had been wounded. The percentage of wound healing in IL-19-treated mice was higher than in control mice. In vitro, IL-19 upregulated KGF expression in the CCD966-SK cells; IL-19 was upregulated in KGF-treated HaCaT cells. KGF but not IL-19 promoted HaCaT cell proliferation. However, IL-19 significantly increased the migration of HaCaT cells. HaCaT cells treated with the cultured supernatants of IL-19-stimulated CCD966-SK cells showed significantly more proliferation than in controls.ConclusionsIL-19 is important for cutaneous wound healing because it upregulates KGF expression.     

Nesfatin-1 improves oxidative skin injury in normoglycemic or hyperglycemic rats

Hyperglycemia is one of the major causes of suppressed angiogenesis and impaired wound healing leading to chronic wounds. Nesfatin-1 a novel peptide was reported to have antioxidant and anti-apoptotic properties. This study is aimed to investigate the potential healing-promoting effects of nesfatin-1 in non-diabetic or diabetic rats with surgical wounds. In male Sprague-Dawley rats, hyperglycemia was induced by intraperitoneal (ip) injection of streptozotocin (55 mg/kg). Under anesthesia, dorsum skin tissues of normoglycemic (n = 16) and hyperglycemic rats were excised (2 × 2 cm, full-thickness), while control rats (n = 16) had neither hyperglycemia nor wounds. Half of the rats in each group were treated ip with saline, while the others were treated with nesfatin-1 (2 μg/kg/day) for 3 days until they were decapitated. Plasma interleukin-1-beta (IL-1β), transforming growth factor-beta (TGF-β-1), IL–6 levels, and dermal tissue malondialdehyde (MDA), glutathione (GSH) levels, myeloperoxidase (MPO) and caspase-3 activity were measured. For histological examination, paraffin sections were stained with hematoxylin-eosin or Masson’s trichrome and immunohistochemistry for vascular endothelial growth factor (VEGF) was applied. ANOVA and Student’s t-tests were used for statistical analysis. Compared to control rats, skin MPO activity, MDA and caspase-3 levels were increased similarly in saline-treated normo- and hyperglycemic rats. Nesfatin-1 depressed MDA, caspase-3, MPO activity and IL-1β with concomitant elevations in dermal GSH and plasma TGF-β-1 levels. Histopathological examination revealed regeneration of epidermis, regular arrangement of collagen fibers in the dermis and a decrease in VEGF immunoreactivity in the epidermal keratinocytes of nesfatin-1-treated groups. Nesfatin-1 improved surgical wound healing in both normo- and hyperglycemic rats via the suppression of neutrophil recruitment, apoptosis and VEGF activation.     

Healing potential of Pequi (Caryocar coriaceum Wittm.) fruit pulp oil

Caryocar coriaceum Wittm. (Caryocaraceae), popularly known as Pequi, is a common tree frequently used in folk medicine to treat many types of afflictions, such as wound lesions, gastric and inflammatory diseases. The present study was undertaken to evaluate the healing potential of the pulp oil from C. coriaceum (OCC) in rats and mice. OCC was tested by monitoring wound contraction in incised wounds and topical application of OCC accelerated wound contraction in open wounds. The mean values of wound contraction in pulp oil treated rats on day 16 were 6.25 ± 0.51% as against 4.17 ± 0.28% seen in control and the difference was statistically significant (p < 0.01). Gastric lesions induced by ethanol and aspirin were significantly reduced by OCC (200 and 400 mg/kg, p < 0.05). Pretreatment of mice with yohimbine, indomethacin, l-NAME or glibenclamide greatly suppressed the gastroprotective effect of OCC. Thus we provide the first evidence that OCC reduces gastric damage induced by ethanol, at least in part, by mechanisms that involve α₂-receptors, endogenous prostaglandins, nitric oxide and K⁺ATP channels. These results indicate the beneficial effect of C. coriaceum on wound and gastric healing and justify its traditional use for the treatment of wounds and gastric ulcers.     

Replenishment of type VII collagen and re-epithelialization of chronically ulcerated skin after intradermal administration of allogeneic mesenchymal stromal cells in two patients with recessive dystrophic epidermolysis bullosa

In animal models it has been shown that mesenchymal stromal cells (MSC) contribute to skin regeneration and accelerate wound healing. We evaluated whether allogeneic MSC administration resulted in an improvement in the skin of two patients with recessive dystrophic epidermolysis bullosa (RDEB; OMIM 226600). Patients had absent type VII collagen immunohistofluorescence and since birth had suffered severe blistering and wounds that heal with scarring. Vehicle or 0.5 × 10⁶ MSC were infused intradermally in intact and chronic ulcerated sites. One week after intervention, in MSC-treated skin type VII collagen was detected along the basement membrane zone and the dermal–epidermal junction was continuous. Re-epithelialization of chronic ulcerated skin was observed only near MSC administration sites. In both patients the observed clinical benefit lasted for 4 months. Thus intradermal administration of allogeneic MSC associates with type VII collagen replenishment at the dermal–epidermal junction, prevents blistering and improves wound healing in unconditioned patients with RDEB.     

Neurotensin-loaded collagen dressings reduce inflammation and improve wound healing in diabetic mice

Impaired wound healing is an important clinical problem in diabetes mellitus and results in failure to completely heal diabetic foot ulcers (DFUs), which may lead to lower extremity amputations. In the present study, collagen based dressings were prepared to be applied as support for the delivery of neurotensin (NT), a neuropeptide that acts as an inflammatory modulator in wound healing. The performance of NT alone and NT–loaded collagen matrices to treat wounds in streptozotocin (STZ) diabetic induced mice was evaluated. Results showed that the prepared dressings were not-cytotoxic up to 72 h after contact with macrophages (Raw 264.7) and human keratinocyte (HaCaT) cell lines. Moreover, those cells were shown to adhere to the collagen matrices without noticeable change in their morphology. NT–loaded collagen dressings induced faster healing (17% wound area reduction) in the early phases of wound healing in diabetic wounded mice. In addition, they also significantly reduced inflammatory cytokine expression namely, TNF-α (p < 0.01) and IL-1β (p < 0.01) and decreased the inflammatory infiltrate at day 3 post-wounding (inflammatory phase). After complete healing, metalloproteinase 9 (MMP-9) is reduced in diabetic skin (p < 0.05) which significantly increased fibroblast migration and collagen (collagen type I, alpha 2 (COL1A2) and collagen type III, alpha 1 (COL3A1)) expression and deposition. These results suggest that collagen-based dressings can be an effective support for NT release into diabetic wound enhancing the healing process. Nevertheless, a more prominent scar is observed in diabetic wounds treated with collagen when compared to the treatment with NT alone.     

Hypoglycemic effect of aspalathin,a rooibos tea component from Aspalathus linearis,in type 2 diabetic model db/db mice

Effects of aspalathin, a green rooibos tea component, on glucose metabolism were studied in vitro and in vivo. We first examined the effect of aspalathin on glucose uptake by cultured L6 myotubes and on insulin secretion from cultured RIN-5F pancreatic β-cells in vitro, and then investigated the effect of dietary aspalathin on fasting blood glucose level and conducted an intraperitoneal glucose tolerance test (IPGTT) using type 2 diabetes model mice in vivo. Aspalathin dose-dependently and significantly increased glucose uptake by L6 myotubes at concentrations 1–100 μM. It also significantly increased insulin secretion from cultured RIN-5F cells at 100 μM. Dietary aspalathin (0.1–0.2%) suppressed the increase in fasting blood glucose levels of db/db mice for 5 weeks. In IPGTT, aspalathin improved impaired glucose tolerance at 30, 60, 90, and 120 min in db/db mice. These results suggest that aspalathin has beneficial effects on glucose homeostasis in type 2 diabetes through stimulating glucose uptake in muscle tissues and insulin secretion from pancreatic β-cells.     

Efficacy of olmesartan and nifedipine on recurrent hypoxia-induced left ventricular remodeling in diabetic mice

AimsRecurrent hypoxia due to sleep apnea syndrome is implicated in cardiovascular events, especially in diabetic patients, but the underlying mechanisms remain controversial. We previously reported that angiotensin II receptor blockers can improve hypoxia-induced left ventricular remodeling. The aim of this study was to examine the effect on left ventricular remodeling of adding a calcium channel blocker to angiotensin II receptor blocker therapy in diabetic mice exposed to recurrent hypoxia.Main methodsMale db/db mice (8-week-old) and age-matched control db/+ mice were fed a Western diet and subjected to recurrent hypoxia (oxygen at 10 ± 0.5% for 8 h daily during the daytime) or normoxia for 3 weeks. Hypoxic db/db mice were treated with the vehicle, olmesartan (3 mg/kg/day), nifedipine (10 mg/kg/day), or both drugs.Key findingsRecurrent hypoxia caused hypertrophy of cardiomyocytes, interstitial fibrosis, and a significant increase in expression of the oxidative stress marker 4-hydroxy-2-nonenal (4-HNE) in the left ventricular myocardium. Treatment with olmesartan, nifedipine, or both drugs had no effect on systolic blood pressure, and each treatment achieved similar suppression of 4-HNE expression. Olmesartan and the combination with olmesartan and nifedipine significantly prevented cardiomyocyte hypertrophy more than treatment with nifedipine alone. On the other hand, olmesartan combined with nifedipine significantly reduced cytokine expression, superoxide production and matrix metalloproteinase (MMP)-9 activity, and significantly suppressed interstitial fibrosis in the left ventricular myocardium.SignificanceThe combination with olmesartan and nifedipine, as well as a monotherapy with olmesartan, exerts preferable cardioprotection in diabetic mice exposed to recurrent hypoxia.     

Uptake of advanced glycation end products by proximal tubule epithelial cells via macropinocytosis

Chronic hyperglycaemia during diabetes leads to non-enzymatic glycation of proteins to form advanced glycation end products (AGEs) that contribute to nephropathy. We describe AGE uptake in LLC-PK1 and HK2 proximal tubule cell lines by macropinocytosis, a non-specific, endocytic mechanism. AGE–BSA induced dorsal circular actin ruffles and amiloride-sensitive dextran–TRITC uptake, significantly increased AGE–BSA–FITC uptake (167 ± 20% vs BSA control, p < 0.01) and was ezrin-dependent. AGE–BSA–FITC uptake was significantly inhibited by amiloride and inhibitors of Arf6, Rac1, racGEF Tiam1, PAK1 and actin polymerisation. AGE–BSA–FITC, Arf6 and PIP2 co-localised within dorsal circular actin ruffles. AGE–BSA increased PAK1 kinase activity (212 ± 41% vs control, p < 0.05) and protein levels of Tiam1, a Rac1 activator. AGE–BSA significantly increased TGF-β₁ protein levels (160 ± 6%, p < 0.001 vs BSA), which were significantly inhibited by inhibitors of Arf6 (82 ± 19%, p < 0.001 vs AGE) and actin polymerisation (107 ± 11%, p < 0.001 vs AGE), suggesting AGEs partially exert their profibrotic effects via macropinocytosis. PAK1 and PIP5Kγ siRNA significantly decreased AGE–BSA–FITC uptake (81 ± 6% and 64 ± 7%, respectively, p < 0.05 vs control for both), and AGE-stimulated TGF-β₁ protein release (99 ± 15% and 49 ± 8% of control, p < 0.05 and p < 0.001, respectively). Inhibition of AGE uptake by macropinocytosis inhibitors and a neutralising TGF-β antibody, reversed the AGE-induced decrease in surface Na⁺K⁺ATPase, suggesting AGE uptake by macropinocytosis may contribute to diabetic kidney fibrosis and/or EMT by modulating this pump. Understanding methods of cellular uptake and signalling by AGEs may lead to novel therapies for diabetic nephropathy.     

In vivo characterization of the opioid antagonist nalmefene in mice

AimsThe current study assessed the in vivo antagonist properties of nalmefene using procedures previously used to characterize the opioid antagonists naloxone, naltrexone, 6β-naltrexol and nalbuphine.Main methodsICR mice were used to generate antagonist dose–response curves with intraperitoneal (i.p.) nalmefene against fixed A₉₀ doses of morphine in models of morphine-stimulated hyperlocomotion and antinociception. Additional dose–response curves for antagonist precipitated opioid withdrawal were run in mice treated acutely (100 mg/kg, s.c., ? 4 h) or chronically (75 mg pellet, s.c., ? 72 h) with morphine. Comparisons were made between antagonist potency and degree of precipitated withdrawal.Key findingsNalmefene produced dose- and time-related antagonism of morphine-induced increases in locomotor activity with a calculated ID₅₀ (and 95% confidence interval) of 0.014 (0.007–0.027) mg/kg. Nalmefene produced rapid reversal of morphine-induced locomotor activity (5.1 min for 50% reduction in morphine effect). A 0.32 mg/kg dose of nalmefene produced blockade of morphine-induced antinociception in the 55 °C tail-flick test that lasted approximately 2 h. Nalmefene was able to potently precipitate withdrawal in mice treated acutely or chronically with morphine.SignificanceThese results demonstrate that nalmefene is similar to naloxone and naltrexone with respect to its in vivo pharmacology in mice. Specifically, nalmefene produces potent antagonism of morphine agonist effects while precipitating severe withdrawal. The compound has a slower onset and longer duration of action compared to naloxone and naltrexone. The data allows for a more complete preclinical comparison of nalmefene against other opioid antagonists including the putative opioid neutral antagonist 6β-naltrexol.     

Carnosine enhances diabetic wound healing in the db/db mouse model of type 2 diabetes

Diabetes mellitus (DM) is a progressive disorder with severe late complications. Normal wound healing involves a series of complex and well-orchestrated molecular events dictated by multiple factors. In diabetes, wound healing is grossly impaired due to defective, and dysregulated cellular and molecular events at all phases of wound healing resulting in chronic wounds that fail to heal. Carnosine, a dipeptide of alanine and histidine and an endogenous antioxidant is documented to accelerate healing of wounds and ulcers. However, not much is known about its role in wound healing in diabetes. Therefore, we studied the effect of carnosine in wound healing in db/db mice, a mice model of Type 2 DM. Six millimeter circular wounds were made in db/db mice and analyzed for wound healing every other day. Carnosine (100?mg/kg) was injected (I.P.) every day and also applied locally. Treatment with carnosine enhanced wound healing significantly, and wound tissue analysis showed increased expression of growth factors and cytokines genes involved in wound healing. In vitro studies with human dermal fibroblasts and microvascular-endothelial cells showed that carnosine increases cell viability in presence of high glucose. These effects, in addition to its known role as an antioxidant and a precursor for histamine synthesis, provide evidence for a possible therapeutic use of carnosine in diabetic wound healing.     

Effect of long-term exposure of mice to 900 MHz GSM radiation on experimental cutaneous candidiasis

Mobile phones communicate with base stations using 900 MHz microwaves. The current study was aimed to survey the effects of long-term 900 MHz microwave exposure of mice on experimentally induced cutaneous candidiasis. Forty inbred, male, BALB/c mice were randomly divided into four groups. Cutaneous lesions with Candida albicans were experimentally induced on the lateral-back skin of the 20 mice. One group of the diseased mice were exposed (6 h per day and 7 d per week) to 900 MHz microwave radiation, while the other groups were not exposed. Two unexposed control groups were also included. The skin lesions were regularly monitored and the live candida cell density was enumerated using the colony-forming unit (CFU) assay. The process was repeated after a one week resting interval. One week later, all mice were challenged through intra tail veins using LD₉₀ dose of C. albicans. Mortality of the mice was recorded and the candida load of the kidney homogenates from died animals was counted. 900 MHz microwave exposed mice had 1.5 day and 3.7 day delays on wound healing in stages two. Live Candida inoculated Wave exposed (LCW) mice also showed higher yeast loads in skin lesions at days 5, 7 and 9 post inoculation. Survival analysis of live candida challenged mice showed the radiation exposed group is prone to death induced by systemic infection and candida enumeration from the kidney homogenates showed radiation exposed animals have had significantly higher yeast load in the tissue. In collection, long-term 900 MHz radiation exposure of mice led to longevity of skin wounds and susceptibility of the animals to systemic challenge and higher incidences of microorganisms in internal tissues.     

DA-1229, a novel and potent DPP4 inhibitor, improves insulin resistance and delays the onset of diabetes

AimTo characterize the pharmacodynamic profile of DA-1229, a novel dipeptidyl peptidase (DPP) 4 inhibitor.Main methodsEnzyme inhibition assays against DPP4, DPP8 and DPP9. Antidiabetic effects of DA-1229 in HF-DIO mice and young db/db mice.Key findingsDA-1229 was shown to potently inhibit the DPP4 enzyme in human and murine soluble forms and the human membrane-bound form with IC₅₀ values of 0.98, 3.59 and 1.26 nM, respectively. As a reversible and competitive inhibitor, DA-1229 was more selective to human DPP4 (6000-fold) than to human DPP8 and DPP9. DA-1229 (0.1–3 mg/kg) dose-dependently inhibited plasma DPP4 activity, leading to increased levels of plasma GLP-1 and insulin, and thereby lowering blood glucose levels in mice. In high fat diet-fed (HF) mice, a single oral dose of 100 mg/kg of DA-1229 reduced plasma DPP4 activity by over 80% during a 24 h period. Long-term treatment with DA-1229 for 8 weeks revealed significant improvements in glucose intolerance and insulin resistance, accompanied by significant body weight reduction. However, it remains unclear whether there is a direct causal relationship between DPP4 inhibition and body weight reduction. In young db/db mice, the DA-1229 treatment significantly reduced blood glucose excursions for the first 2 weeks, resulting in significantly lower levels of HbA1c at the end of the study. Furthermore, the pancreatic insulin content of the treatment group was significantly higher than that of the db/db control.SignificanceDA-1229 as a novel and selective DPP4 inhibitor improves the insulin sensitivity in HF mice and delays the onset of diabetes in young db/db mice.     

Validation of a model for the study of multiple wounds in the diabetic mouse (db/db)

The genetically diabetic db/db mouse exhibits symptoms that resemble human type 2 diabetes mellitus, demonstrates delayed wound healing, and has been used extensively as a model to study the role of therapeutic topical reagents in wound healing. The purpose of the authors' study was to validate an excisional wound model using a 6-mm biopsy punch to create four full-thickness dorsal wounds on a single db/db mouse. Factors considered in developing the db/db wound model include reproducibility of size and shape of wounds, the effect of semiocclusive dressings, comparison with littermate controls (db/-), clinical versus histologic evidence of wound closure, and cross-contamination of wounds with topically applied reagents. The size of wounds was larger, with less variation in the db/db mice (31.11 +/- 3.76 mm2) versus db/- mice (23.64 +/- 4.78 mm2). Wounds on db/db mice that were covered with a semiocclusive dressing healed significantly more slowly (mean, 27.75 days) than wounds not covered with the dressing (mean, 13 days; p < 0.001), suggesting the dressings may splint the wounds open. As expected, wounds healed more slowly on db/db mice than db/- mice (covered wounds, 27.75 days versus 11.86 days, p < 0.001; wounds not covered, 13 days versus 11.75 days, p = 0.39). Covered wounds, thought to be closed by clinical examination, were confirmed closed by histology only 62 percent of the time in the db/db and 100 percent of the time in the db/- mice. Topical application of blue histologic dye or soluble biotinylated laminin 5 to one of the four wounds did not spread locally and contaminate adjacent wounds. Multiple, uniform, 6-mm wounds in db/db mice heal in a relatively short time, decrease the number of animals needed for each study, and allow each animal to serve as its own control. The db/db diabetic mouse appears to be an excellent model of delayed wound healing, particularly for studying factors related to epithelial migration.     

TGF-beta-induced early gene-1 overexpression promotes oxidative stress protection and actin cytoskeleton rearrangement in human skin fibroblasts

BackgroundTransforming growth factor beta inducible early gene-1 (TIEG-1), a member of the Krüppel-like factor, was identified as a primary response gene for TGF-β. The role of TIEG-1 in skin repair has been mainly addressed in vivo on TIEG-1 null mice model and the mechanism remains unexplored.MethodsWe investigated the modulation of TIEG-1 expression in normal human skin fibroblasts by either down-expressing or overexpressing the gene. We evaluated reactive oxygen species production and the cell viability of treated cells. The effect of TIEG-1 overexpression was monitored by wound healing assay and immunofluorescence staining of actin fibers organization and alpha-smooth muscle actin (α-SMA). Western blots were carried out to identify the level of expression or phosphorylation of key proteins such as cofilin, Rho GTPases, and p38 mitogen-activated protein kinase (p38 MAPK).ResultsTIEG-1 down-regulation had a deleterious effect on the cell viability. It was significantly reduced (65 ± 5%) and exposure to ultraviolet further increased this effect (47 ± 3%). By contrast, cells overexpressing TIEG-1 had a reduced reactive oxygen species production (75%) compared to control and mock-transfected cells. This overexpression also resulted in formation of actin stress fibers and increased α-SMA expression and an enhanced wound healing feature. RhoB GTPase was upregulated and phosphorylation of cofilin and p38 MAPK was observed.ConclusionTIEG-1 overexpression in normal human skin fibroblasts results in improved resistance to oxidative stress, myofibroblast-like conversion that involved RhoB signaling pathway with cofilin and p38 MAPK proteins activation.General significanceThis study enlightens the role of TIEG-1 role in skin biology.     

Optimization of the synthesis of 1-allyloxy-2-hydroxy-propyl-starch through statistical experimental design

The synthesis of 1-allyloxy-2-hydroxy-propyl starches was studied using a statistical experimental design approach. The etherification of two different granular maize starches with allyl glycidyl ether (AGE) in a heterogeneous alkaline suspension was investigated. The optimal reaction conditions were found via experimental design and the obtained response factor, e.g. the degree of substitution (DS) of the starch hydroxyl group, was statistically evaluated. The effects of six process factors on DS, namely the starch concentration, the reaction time, the temperature, and the amount of NaOH, Na₂SO₄ and AGE were investigated. The statistical analysis showed significant impact of the temperature, the amount of NaOH and the amount of AGE on the DS for both starches. Optimum conditions for the highest DS for waxy maize starch were: 0.0166% AGE (based on dry starch (ds)) and 1.0% NaOH (ds) at 34 °C in 4 h; on dent maize starch, these were 0.0099% AGE (ds) and 1.0% NaOH (ds) at 37 °C in 16 h.     

Tetrahydropyridine derivatives with inhibitory activity on the production of proinflammatory cytokines: Part 3

In order to develop a new class of anti-rheumatic drug which inhibits production of proinflammatory cytokines such as TNFα, IL-1β, IL-6, and IL-8, a series of 3-pyridylpyrrole derivatives possessing a bicyclic tetrahydropyridine moiety at the 4-position of the pyrrole ring were synthesized and their pharmacological activities were evaluated. The derivatives were found to have potent inhibitory activities on the production of the cytokines both in vitro and in vivo. Among them, compound 4a, (S)-2-(4-fluorophenyl)-4-(1,2,3,5,6,8a-hexahydroindolizin-7-yl)-3-(pyridin-4-yl)-1H-pyrrole (R-132811), achieved the most promising results in various in vitro and in vivo tests including several rheumatoid arthritis models ((i) inhibition of p38α, p38β, p38γ, and p38δ MAP kinases: IC₅₀ = 0.034, 0.572, >10, and >10 μM, respectively; (ii) inhibition of TNFα, IL-1β, IL-6, and IL-8 production in human whole blood: IC₅₀ = 0.026, 0.020, 0.88, and 0.016 μM, respectively; (iii) inhibition of LPS induced TNFα, IL-1β and IL-6 production in mice: ID₅₀ = 0.93, 8.63, and 0.11 mg/kg, po, respectively; (iv) inhibition of anti-collagen antibody-induced arthritis in mice: ID₅₀ = 2.22 mg/kg, po; (v) inhibition of collagen-induced arthritis in mice: ID₅₀ = 2.38 mg/kg, po; (vi) prophylactic effect on adjuvant-induced arthritis in rats: ID₅₀ = 3.1 mg/kg, po; (vii) therapeutic effect on adjuvant-induced arthritis in rats: ID₅₀ = 4.9 mg/kg, po; (viii) analgesic effect on adjuvant-induced arthritic pain in rats: ID₅₀ = 2.9 mg/kg, po). As a result, compound 4a was chosen as a candidate for further pre-clinical studies.     

Chitosan topical gel formulation in the management of burn wounds

Wound healing properties of chitosan with different molecular weight and degree of deacetylation ranges have been examined. The macroscopic image and histopathology were examined using chitosan, Fucidin^® ointment and to blank. The rate of contraction was evaluated by determination of the unclosed area as a function of time. The treated wounds were found to contract at the highest rate with high molecular weight–high degree of deacetylation chitosan-treated rats as compared to untreated, treated, and Fucidin^® ointment-treated rats. Wounds treated with high molecular weight chitosan had significantly more epithelial tissue (p < 0.05) than wounds with any other treatment and the best re-epithelization and fastest wounds closure were found with the high molecular weight chitosan treatment group. Histological examination and collagenase activity studies revealed advanced granulation tissue formation and epithelialization in wounds treated with high molecular weight chitosan (p < 0.05). High molecular weight with high degree of deacetylation chitosan samples therefore demonstrates potential for use as a treatment system for dermal burns.     

Cytokine expression profile over time in burned mice

The persistent inflammatory response induced by a severe burn increases patient susceptibility to infections and sepsis, potentially leading to multi-organ failure and death. In order to use murine models to develop interventions that modulate the post-burn inflammatory response, the response in mice and the similarities to the human response must first be determined. Here, we present the temporal serum cytokine expression profiles in burned mice in comparison to sham mice and human burn patients. Male C57BL/6 mice were randomized to control (n = 47) or subjected to a 35% TBSA scald burn (n = 89). Mice were sacrificed 3, 6, 9, 12, 24, and 48 h and 7, 10, and 14 days post-burn; cytokines were measured by multi-plex array. Following the burn injury, IL-6, IL-1β, KC, G-CSF, TNF, IL-17, MIP-1α, RANTES, and GM-CSF were increased, p < 0.05. IL-2, IL-3, and IL-5 were decreased, p < 0.05. IL-10, IFN-γ, and IL-12p70 were expressed in a biphasic manner, p < 0.05. This temporal cytokine expression pattern elucidates the pathogenesis of the inflammatory response in burned mice. Expression of 11 cytokines were similar in mice and children, returning to lowest levels by post-burn day 14, confirming the utility of the burned mouse model for development of therapeutic interventions to attenuate the post-burn inflammatory response.