Safety assessment of cocamidopropyl betaine, a cosmetic ingredient.

Cocamidopropyl betaine (CAPB) is a surfactant derived from coconut oil that is widely used in cosmetics and personal products for several purposes, such as a surfactant, foam booster, mildness, and viscosity control. Cocamidopropyl betaine is used at concentrations up to 30% in cosmetics. The acute toxicity, skin irritation, eye irritation, skin sensitization, repeated dose toxicity, genotoxicity, carcinogenicity, and phototoxicity of cocamidopropyl betaine were evaluated. Cocamidopropyl betaine was observed to induce mild skin irritation, eye irritation and skin sensitization. The NOAEL of cocamidopropyl betaine was determined to be 250 mg/kg/day based on the results of a 92-day repeated-dose oral toxicity study in rats. The systemic exposure dose of cocamidopropyl betaine was estimated to range from 0.00120 to 0.93195 mg/kg/day when used in cosmetic products. The margin of safety of cocamidopropyl betaine was calculated to be greater than 100 when used at a maximum concentration of 6% in leave-on products and 30% in rinse-off products, suggesting that its use in cosmetic products is safe under current usage conditions.

Mono-(2-ethylhexyl)-phthalate potentiates methylglyoxal-induced blood-brain barrier damage via mitochondria-derived oxidative stress and bioenergetic perturbation.

Phthalates in contaminated foods and personal care products are one of the most frequently exposed chemicals with a public health concern. Phthalate exposure is related to cardiovascular diseases, including diabetic vascular complications and cerebrovascular diseases, yet the mechanism is still unclear. The blood-brain barrier (BBB) integrity disruption is strongly associated with cardiovascular and neurological disease exacerbation. We investigated BBB damage by di-(2-ethylhexyl) phthalate (DEHP) or its metabolite mono-(2-ethylhexyl) phthalate (MEHP) using brain endothelial cells and rat models. BBB damage by the subthreshold level of MEHP, but not a DEHP, significantly increased by the presence of methylglyoxal (MG), a reactive dicarbonyl compound whose levels increase in the blood in hyperglycemic conditions in diabetic patients. Significant potentiation in apoptosis and autophagy activation, mitochondria-derived reactive oxygen species (ROS) production, and mitochondrial metabolic disturbance were observed in brain ECs by co-exposure to MG and MEHP. N-acetyl cysteine (NAC) restored autophagy activation as well as tight junction protein impairment induced by co-exposure to MG and MEHP. Intraperitoneal administration of MG and MEHP significantly altered mitochondrial membrane potential and tight junction integrity in rat brain endothelium. This study may provide novel insights into enhancing phthalate toxicity in susceptible populations, such as diabetic patients.

Emodin prevents renal ischemia-reperfusion injury via suppression of CAMKII/DRP1-mediated mitochondrial fission.

Acute kidney injury (AKI) is a serious threat to human health. Clinically, ischemia-reperfusion (I/R) injury is considered one of the most common contributors to AKI. Emodin has been reported to alleviate I/R injury in the heart, brain, and small intestine in rats and mice through its anti-inflammatory effects. The present study investigated whether emodin improved AKI induced by I/R and elucidated the molecular mechanisms. We used a mouse model of renal I/R injury and human renal tubular epithelial cell model of hypoxia/reoxygenation (H/R) injury. Ischemia/reperfusion resulted in renal dysfunction. Pretreatment with emodin ameliorated renal injury in mice following I/R injury. Emodin reduced mitochondrial-mediated apoptosis, suppressed the overproduction of mitochondrial reactive oxygen species and accelerated the recovery of adenosine triphosphate both in vivo and in vitro. Emodin prevented mitochondrial fission and restored the balance of mitochondrial dynamics. The phosphorylation of dynamin-related protein 1 (DRP1) at Ser616, a master regulator of mitochondrial fission, was upregulated in both models of I/R and H/R injury, and this upregulation was blocked by emodin. Using computational cognate protein kinase prediction and specific kinase inhibitors, we found that emodin inhibited the phosphorylation of calcium/calmodulin-dependent protein kinase II (https://www.guidetopharmacology.org/GRAC/ObjectDisplayForward?objectId=1554), thereby inhibiting its kinase activity and reducing the phosphorylation of DRP1 at Ser616. The results demonstrated that emodin pretreatment could protect renal function by improving mitochondrial dysfunction induced by I/R.

Comparative study of two isothiazolinone biocides, 1,2-benzisothiazolin-3-one (BIT) and 4,5-dichloro-2-n-octyl-isothiazolin-3-one (DCOIT), on barrier function and mitochondrial bioenergetics using murine brain endothelial cell line (bEND.3).

Isothiazolinone (IT) biocides are potent antibacterial substances used as preservatives and disinfectants. These biocides exert differing biocidal effects and display environmental stability based upon chemical structure. In agreement with our recent study reporting that 2-n-octyl-4-isothiazolin-3-one (OIT) induced dysfunction of the blood-brain barrier (BBB), the potential adverse health effects of two IT biocides 1,2-benzisothiazolin-3-one (BIT) and 4,5-dichloro-2-n-octyl-isothiazolin-3-one (DCOIT) were compared using brain endothelial cells (ECs) derived from murine brain endothelial cell line (bEND.3). BIT possesses an unchlorinated IT ring structure and used as a preservative in cleaning products. DCOIT contains a chlorinated IT ring structure and employed as an antifouling agent in paints. Data demonstrated that DCOIT altered cellular metabolism at a lower concentration than BIT. Both BIT and DCOIT increased reactive oxygen species (ROS) generation at the mitochondrial and cellular levels. However, the effect of DCOIT on glutathione (GSH) levels appeared to be greater than BIT. While mitochondrial membrane potential (MMP) was decreased in both BIT- and DCOIT-exposed cells, direct disturbance in mitochondrial bioenergetic flux was only observed in BIT-treated ECs. Taken together, IT biocides produced toxicity in brain EC and barrier dysfunction, but at different concentration ranges suggesting distinct differing mechanisms related to chemical structure.

A Commonly Used Biocide 2-N-octyl-4-isothiazolin-3-oneInduces Blood-Brain Barrier Dysfunction via Cellular Thiol Modification and Mitochondrial Damage.

Isothiazolinone (IT) biocides are potent antibacterial substances commonly used as preservatives or disinfectants, and 2-n-Octyl-4-isothiazolin-3-one (OIT; octhilinone) is a common IT biocide that is present in leather products, glue, paints, and cleaning products. Although humans are exposed to OIT through personal and industrial use, the potentially deleterious effects of OIT on human health are still unknown. To investigate the effects of OIT on the vascular system, which is continuously exposed to xenobiotics through systemic circulation, we treated brain endothelial cells with OIT. OIT treatment significantly activated caspase-3-mediated apoptosis and reduced the bioenergetic function of mitochondria in a bEnd.3 cell-based in vitro blood-brain barrier (BBB) model. Interestingly, OIT significantly altered the thiol redox status, as evidenced by reduced glutathione levels and protein S-nitrosylation. The endothelial barrier function of bEnd.3 cells was significantly impaired by OIT treatment. OIT affected mitochondrial dynamics through mitophagy and altered mitochondrial morphology in bEnd.3 cells. N-acetyl cysteine significantly reversed the effects of OIT on the metabolic capacity and endothelial function of bEnd.3 cells. Taken together, we demonstrated that the alteration of the thiol redox status and mitochondrial damage contributed to OIT-induced BBB dysfunction, and we hope that our findings will improve our understanding of the potential hazardous health effects of IT biocides.

Methylglyoxal-Induced Dysfunction in Brain Endothelial Cells via the Suppression of Akt/HIF-1α Pathway and Activation of Mitophagy Associated with Increased Reactive Oxygen Species.

Methylglyoxal (MG) is a dicarbonyl compound, the level of which is increased in the blood of diabetes patients. MG is reported to be involved in the development of cerebrovascular complications in diabetes, but the exact mechanisms need to be elucidated. Here, we investigated the possible roles of oxidative stress and mitophagy in MG-induced functional damage in brain endothelial cells (ECs). Treatment of MG significantly altered metabolic stress as observed by the oxygen-consumption rate and barrier-integrity as found in impaired trans-endothelial electrical resistance in brain ECs. The accumulation of MG adducts and the disturbance of the glyoxalase system, which are major detoxification enzymes of MG, occurred concurrently. Reactive oxygen species (ROS)-triggered oxidative damage was observed with increased mitochondrial ROS production and the suppressed Akt/hypoxia-inducible factor 1 alpha (HIF-1α) pathway. Along with the disturbance of mitochondrial bioenergetic function, parkin-1-mediated mitophagy was increased by MG. Treatment of N-acetyl cysteine significantly reversed mitochondrial damage and mitophagy. Notably, MG induced dysregulation of tight junction proteins including occludin, claudin-5, and zonula occluden-1 in brain ECs. Here, we propose that diabetic metabolite MG-associated oxidative stress may contribute to mitochondrial damage and autophagy in brain ECs, resulting in the dysregulation of tight junction proteins and the impairment of permeability.

LRP-1 functionalized polymersomes enhance the efficacy of carnosine in experimental stroke.

Stroke is one of the commonest causes of death with limited treatment options. L-Carnosine has shown great promise as a neuroprotective agent in experimental stroke, but translation to the clinic is impeded by the large doses needed. We developed and evaluated the therapeutic potential of a novel delivery vehicle which encapsulated carnosine in lipoprotein receptor related protein-1 (LRP-1)-targeted functionalized polymersomes in experimental ischemic stroke. We found that following ischemic stroke, polymersomes encapsulating carnosine exhibited remarkable neuroprotective effects with a dose of carnosine 3 orders of magnitude lower than free carnosine. The LRP-1-targeted functionalization was essential for delivery of carnosine to the brain, as non-targeted carnosine polymersomes did not exhibit neuroprotection. Using Cy3 fluorescence in vivo imaging, we showed that unlike non-targeted carnosine polymersomes, LRP-1-targeted carriers accumulated in brain in a time dependent manner. Our findings suggest that these novel carriers have the ability to deliver neuroprotective cargo effectively to the brain.

Mono-PEGylates of exenatide in branched and dimeric structures can improve in vivo stability and hypoglycemic bioactivity.

Exenatide, a synthetic version of exendin-4, is a glucagon-like peptide-1 receptor agonist (GLP-1RA) used for treating diabetes, but its relatively short half-life is a major disadvantage. In this study, we attempted residue-specific mono-PEGylation to the middle of the amino acid backbone to extend its in vivo half-life. Exenatide was point-mutated from Lys to Cys at the 12th residue to yield a variant (K12C), and PEG-maleimide of varying molecular weights (MW) (5, 10, 20, 40 kD) was site-specifically conjugated to yield a mono-PEGylate with branched T-shape molecular structure. In another approach, we conjugated a bis-maleimide PEG (10 kD) to the middle of two K12Cs to yield an H-shape homodimer PEGylate In vitro bioactivity assays indicated that: (1) PEGylates conjugated with higher MW PEG lead to stronger receptor binding, (2) the branched form was superior to the linear configuration in the binding, and (3) both T-shape and H-shape mono-PEGylates demonstrated better potency than the native exenatide, evidenced by lower EC50. Db/db mouse experiments to evaluate in vivo hypoglycemic activity indicated that: (1) all mono-PEGylates resulted in improved glucose tolerance compared to the native exenatide, (2) the homodimer PEGylate demonstrated much stronger hypoglycemic activity, especially during the initial period, and (3) the H-shape and T-shape mono-PEGylates (40 kD) maintained hypoglycemia for up to ca. 168 and 140 h, representing approximately 12- and 14-fold increase, respectively, compared with the native exenatide. Our findings suggest that the exenatide mono-PEGylates in unclassical molecular structures can improve in vivo pharmacokinetics properties.

In-vivo half-life and hypoglycemic bioactivity of a fusion protein of exenatide and elastin-based polypeptide from recombinant Saccharomyces cerevisiae.

Exenatide (Ex) is a 39-amino acid peptide of glucagon-like peptide-1 (GLP-1) receptor agonist that was approved by the FDA in 2005 as a Type II diabetes treatment. It shows a 53% homology with GLP-1 but has an extended half-life (ca. 2.4 h) relative to GLP-1 (ca. 2-3 min). In this study, to further extend its in vivo half-life, we constructed a fusion protein (Ex-(EBP)10-6xHis) using a biocompatible and inert elastin-based polypeptide (EBP) as a fusion partner. Valine was inserted into the guest position of the pentapeptide (VPGXG), no linker sequence was inserted in between the EBPs, and (EBP)10-6xHis tag was attached to the C-terminus of exenatide. By using a recombinant Saccharomyces cerevisiae expression system, the fusion protein was expressed and secreted to the broth and purified by Ni-NTA affinity chromatography. Compared with the native exenatide, the physical half-life of the fusion protein was ca. 3.7-fold extended while approximately 72% of the in-vitro insulin secreting activity was maintained. However, the biological half-life measured by a glucose tolerance test (GTT) and the hypoglycemic test in mice was not significantly different from that of the native form. The effects of EBPylation on bioactivity and half-life of the fusion protein are similar to those of PEGylation. The result suggests that the bioactivity and half-life should be carefully balanced to obtain optimal fusion proteins. We expect that EBPylation using an optimal repeat number of EBP can be an alternative to chemical modification for therapeutic biobetters with extended half-life.

Risk assessment of volatile organic compounds (VOCs) detected in sanitary pads.

Disposable sanitary pads are a necessity for women's health, but safety concerns regarding the use of these products have created anxiety. The aim of this study was to conduct a risk assessment of 74 volatile organic compounds (VOCs), which were expected to be contained within sanitary pads. Of the 74 VOCs, 50 were found in sanitary pads retailed in Korea at concentrations ranging from 0.025 to 3548.09 µg/pad. In order to undertake a risk assessment of the VOCs, the toxicological database of these compounds in the United States Environmental Protection Agency (USEPA), Agency for Toxic Substances and Disease Registry (ATSDR), National Toxicology Program (NTP) and World Health Organization (WHO) was searched. Ethanol was found to exhibit the highest reference dose (RfD) while 1,2-dibromo-3-chloro-propane displayed the lowest RfD. Consequently, a worst-case exposure scenario was applied in this study. It was assumed that there was the use of 7.5 sanitary napkins/day for 7 days/month. In the case of panty liners or overnight sanitary napkins, the utilization of 90 panty liners/month or 21 overnight sanitary napkins/month was assumed, respectively. In addition, 43 kg, the body weight of 12 to 13-year-old young women, and 100% VOCs skin absorption were employed for risk assessment. The systemic exposure dose (SED) values were calculated ranging from 1.74 (1,1,2-trichloroethane) ng/kg/day to 144.4 (ethanol, absolute) µg/kg/day. Uncertainty factors (UFs) were applied ranging from 10 to 100,000 in accordance with the robustness of animal or human experiments. The margin of exposure (MOE) of 34 VOCs was more than 1 (acceptable MOE > 1). Applicable carcinogenic references reported that the cancer risk of five VOCs was below 10-6. Based on our findings, evidence indicates that the non-cancer and cancer risks associated with VOCs detected in sanitary pads currently used in South Korea do not pose an adverse health risk in women.

Inhibitory Effects of a Novel Chrysin-Derivative, CPD 6, on Acute and Chronic Skin Inflammation.

The skin is an important physiological barrier against external stimuli, such as ultraviolet radiation (UV), xenobiotics, and bacteria. Dermal inflammatory reactions are associated with various skin disorders, including chemical-induced irritation and atopic dermatitis. Modulation of skin inflammatory response is a therapeutic strategy for skin diseases. Here, we synthesized chrysin-derivatives and identified the most potent derivative of Compound 6 (CPD 6). We evaluated its anti-inflammatory effects in vitro cells of macrophages and keratinocytes, and in vivo dermatitis mouse models. In murine macrophages stimulated by lipopolysaccharide (LPS), CPD 6 significantly attenuated the release of inflammatory mediators such as nitric oxide (NO) (IC50 for NO inhibition: 3.613 µM) and other cytokines. In cultured human keratinocytes, CPD 6 significantly attenuated the release of inflammatory cytokines induced by the combination of IFN-γ and TNF-α, UV irradiation, or chemical irritant stimulation. CPD 6 inhibited NFκB and JAK2/STAT1 signaling pathways, and activated Nrf2/HO-1 signaling. In vivo relevancy of anti-inflammatory effects of CPD 6 was observed in acute and chronic skin inflammation models in mice. CPD 6 showed significant anti-inflammatory properties both in vitro cells and in vivo dermatitis animal models, mediated by the inhibition of the NFκB and JAK2-STAT1 pathways and activation of Nrf2/HO-1 signaling. We propose that the novel chrysin-derivative CPD 6 may be a potential therapeutic agent for skin inflammation.

Silver nanoparticles promote procoagulant activity of red blood cells: a potential risk of thrombosis in susceptible population.

BACKGROUND: Silver nanoparticles (AgNP) are widely used in medical practices owing to their distinct antibacterial, antiviral and anticancer activities. However, with increasing use of AgNP, concerns over its potential toxicity are also escalating. Here, we demonstrated the potential thrombotic effect of AgNP which was mediated by the procoagulant activity of red blood cells (RBCs). RESULTS: In freshly isolated human RBCs, AgNP, but not silver microparticles (AgMP), elicited morphological changes, phosphatidylserine (PS) exposure and microvesicles (MV) generation, the key indicators of procoagulant activity in RBCs at concentration ranges (≤ 100 µg/mL) that were free of significant hemolysis. In line with this, AgNP potentiated thrombin generation and adherence of RBCs to endothelial cells, while AgMP did not. Oxidative stress, intracellular calcium increase and ATP depletion were found to underlie the procoagulant effects of AgNP, which led to altered activity of membrane aminophospholipid translocases. These in vitro findings were well reproduced in rat in vivo, where intravenously exposure to AgNP promoted venous thrombosis significantly. Of note, RBCs isolated from cancer patients, who inherently convey the risk of thrombogenesis, were more sensitive to the procoagulant effects of AgNP. In addition, AgNP significantly potentiated the procoagulant effects of a chemotherapeutic drug, paclitaxel. CONCLUSION: Collectively, these results suggest that AgNP may have prothrombotic risks by promoting procoagulant activity of RBCs and caution shall be taken for its use in the population sensitive to thrombosis like cancer patients.

Arsenic May Act as a Pro-Metastatic Carcinogen Through Promoting Tumor Cell-Induced Platelet Aggregation.

Arsenic-associated carcinogenesis and related mortality are a major public health concern worldwide; however, the underlying mechanism of action remains unclear. Here, we demonstrated that arsenic promotes tumor metastasis by stimulating tumor cell-platelet aggregation (TCPA), which can ultimately increase cancer-related mortality. In freshly isolated human platelets in vitro, arsenic potentiated TCPA prompted by diverse cancer cell lines, which was attributable to increased platelet reactivity to TCPA with respect to thrombin generation and P-selectin, GPIIb/IIIa expression. Consistently, the co-existence of platelets and arsenic significantly enhanced tumor cell adhesion, extravasation and invasion along with increased metastasis-related markers like metallo-matrix proteinase-2 and -9 in vitro, which was attenuated by platelet activation blockers. Importantly, the exposure to arsenic-contaminated drinking water (2 ppm, 3 weeks) in mice in vivo significantly increased the metastasis of intravenously injected melanoma cells into lung. Furthermore, the exposure to arsenic-contaminated drinking water significantly reduced the survival of melanoma cell-injected mice, which was attenuated by the pretreatment of platelet-activation blockers; aspirin and eptifibatide. All these results provide an important clue to understand the mechanism underlying arsenic-associated cancer mortality and its prevention.

Pro-Coagulant and Pro-Thrombotic Effects of Paclitaxel Mediated by Red Blood Cells.

BACKGROUND: Paclitaxel is one of the most widely used anti-cancer drugs, but numerous case reports of thrombotic events in the cancer patients using paclitaxel raise concern over its pro-thrombotic risk. MATERIALS AND METHODS: We investigated whether paclitaxel can elicit pro-thrombotic properties in red blood cells (RBCs) through phosphatidylserine (PS) exposure and microvesicle (MV) release. RESULTS: In freshly isolated human RBCs, paclitaxel induced thrombin generation through PS exposure and MV release, whereas either coagulation factors or platelets were unaffected. Paclitaxel-induced PS exposure in RBC was mediated by scramblase activation which was induced by calcium-independent protein kinase C (PKC)ζ activation. Paclitaxel also increased RBC-endothelial cell adhesion and RBC aggregate formation which can also contribute to thrombosis. Indeed, intravenous administration of paclitaxel to rats induced PS exposure and PKCζ activation in RBCs in vivo which ultimately promoted venous thrombus formation. CONCLUSION: These results demonstrated that paclitaxel may elicit pro-thrombotic properties in RBCs through PS exposure and MV release, which can ultimately promote thrombus formation.

Effects of cigarette smoke extracts on apoptosis and oxidative stress in two models of ovarian cancer in vitro.

Cigarette smoke contains thousands of harmful components, many of which exert toxic effects on reproductive organs, including the ovaries, and their development. In this study, we investigated the effects of cigarette smoke extract (CSE) on cell proliferation, apoptosis and oxidative stress in the SKOV3 and OVCAR3 ovarian cancer cell lines. A water soluble tetrazolium (WST) assay revealed that the cell proliferation of both ovarian cells was significantly inhibited by three types of CSE in a concentration-dependent manner. Western blot analysis showed that the inhibition of cell proliferation was related to regulation of cell cycle-related protein expression. To determine the effects of cigarette smoke on the death of ovarian cells, we conducted a TUNEL assay, which revealed a time-dependent increase in TUNEL-stained cells in response to CSE exposure. Moreover, the protein expression of the Bcl-2 family signaling pathway observed upon Western blot analysis were consistent with the results of the TUNEL assay. We also examined the reactive oxygen species (ROS) generation in two ovarian cell lines using DCF-DA (5(6)-Carboxy-2',7'-dichlorofluorescein diacetate) assay and ROS-Glo™ H2O2 assay to investigate the oxidative stress caused by CSE. Both ROS detection assays demonstrated an increase in the amount of ROS by CSE in ovarian cells, which was consistent with the results observed for the Keap1-Nrf2 pathway upon Western blot analysis. Taken together, these results suggest that CSE may induce cell proliferation inhibition and oxidative stress in ovarian cells.

Ginsenoside Rg3 disrupts actin-cytoskeletal integrity leading to contractile dysfunction and apoptotic cell death in vascular smooth muscle.

Ginseng and its major active ingredients, ginsenosides are widely consumed for various health benefits including the prevention or treatment of cancer without any special precaution. Previously, we demonstrated that Rg3, one of ginsenosides with a potent anti-cancer activity, may cause contractile dysfunction, and structural damage against normal vascular smooth muscle through apoptotic cell death. However, mechanism underlying the vascular toxicity of Rg3 was not fully elucidated. Here we demonstrated that the vascular toxicity of Rg3 occurs through actin disruption and Bmf-initiated mitochondrial apoptotic pathway, the mechanism which may be shared with its anti-cancer effects. In normal rat primary vascular smooth muscle cells, Rg3 induced apoptosis and contractile dysfunction as determined by caspase-3 activation, TUNEL staining, and insufficient myosin light chain phosphorylation. Rg3 induced actin degradation with RhoA inactivation, followed by mitochondrial translocation of Bmf and dissociation of mitochondrial membrane potential (φ). Pre-treatment of jasplakinolide, an inhibitor of actin depolymerization, significantly blocked Rg3-induced φ dissipation and apoptosis. Notably, Rg3 also induced actin disruption in hepatoma cell line, HepG2, which was reversed by jasplakinolide, confirming that the anti-cancer effects of Rg3 shares the mechanism at least in part. Collectively, these results demonstrated that Rg3 may induce vascular toxicity as well as anti-cancer effects through disrupting actin, suggesting the potential toxicity associated with inadvertent use of ginseng and its products.

Methylglyoxal induced advanced glycation end products (AGE)/receptor for AGE (RAGE)-mediated angiogenic impairment in bone marrow-derived endothelial progenitor cells.

Endothelial cells (ECs) maintain the structure and function of blood vessels and are readily exposed to exogenous and endogenous toxic substances in the circulatory system. Bone marrow-derived endothelial progenitor cells (EPCs) circulate in the blood and differentiate to EC, which are known to participate in angiogenesis and regeneration of injured vessels. Dysfunction in EPC contributes to cardiovascular complications in patients with diabetes, but the precise molecular mechanisms underlying diabetic EPC abnormalities are not completely understood. The aim of this study was to investigate the mechanisms underlying diabetic EPC dysfunction using methylglyoxal (MG), an endogenous toxic diabetic metabolite. Data demonstrated that MG decreased cell viability and protein expression of vascular endothelial growth factor receptor (VEGFR)-2 associated with functional impairment of tube formation in EPC. The generation of advanced glycation end (AGE) products was increased in EPC following exposure to MG. Blockage of receptor for AGE (RAGE) by FPS-ZM1, a specific antagonist for RAGE, significantly reversed the decrease of VEGFR-2 protein expression and angiogenic dysfunction in MG-incubated EPC. Taken together, data demonstrated that MG induced angiogenic impairment in EPC via alterations in the AGE/RAGE-VEGFR-2 pathway which may be utilized in the development of potential therapeutic and preventive targets for diabetic vascular complications.

Enhanced anti-rheumatic activity of methotrexate-entrapped ultradeformable liposomal gel in adjuvant-induced arthritis rat model.

The aim of this study is to investigate in vivo anti-rheumatic activity of methotrexate-entrapped ultradeformable liposomal gel (MTX-UDLs-gel) in adjuvant-induced arthritis rat model. Methotrexate-entrapped ultradeformable liposomes (MTX-UDLs) with the optimal phosphatidylcholine to Tween 80 ratio (7:3, w/w) were incorporated into 1% Carbopol gel. MTX-UDLs-gel was characterized in terms of appearance, clarity, homogeneity, pH and drug content. The permeation of MTX-UDLs-gel across rat skin was investigated using Franz diffusion cell. In vivo anti-rheumatic activity of MTX-UDLs-gel was assessed in terms of edema volume, paw edema and leukocyte infiltration scores, histopathological analysis and inflammatory cytokines level in complete Freund's adjuvant (CFA)-induced arthritis rat model. MTX-UDLs-gel showed good homogeneity and clarity, neutral pH and about 99.5% drug content. The cumulative amount of MTX permeated for 24h from MTX-UDLs-gel (164.6µg) was 1.5 and 2.15 times higher than that of MTX-CLs-gel (113.3µg) and MTX-plain-gel (76.6µg), respectively. MTX-UDLs-gel significantly alleviated the severity of inflammation by reducing edema volume, histological scores and accumulation of neutrophils and improving tissue architecture in CFA-induced arthritis rat model. MTX-UDLs-gel effectively suppressed the expression of pro-inflammatory cytokines, TNF-α and IL-1ß, in paw tissues. In conclusion, the developed MTX-UDLs-gel has a great potential for effective delivery of MTX into the inflamed joints in rheumatoid arthritis.

Pre-elafin is Involved in Ultraviolet-induced Keratinocyte Apoptosis via Pro-caspase-3 Activation Associated with Cystatin-A Down-regulation.

Pre-elafin controls keratinocyte integrity via cornified envelope formation and inhibition of desquamation, but its role in ultraviolet (UV)-induced keratinocyte apoptosis is unknown. This study examined the role of pre-elafin in volunteer skin samples and primary cultured normal human keratinocytes irradiated with phototoxic doses of UVA/narrow-band UVB, and in keratinocytes with pre-elafin overexpression/knockdown, under conditions of low and high calcium. Phototoxic doses of UV increased pre-elafin mRNA and protein expression in inverse proportion to keratinocyte survival. Pre-elafin overexpression under conditions of low calcium, which, in contrast to conditions of high calcium, was localized to the cytoplasm, increased keratinocyte apoptosis, whereas knockdown inhibited UV-induced apoptosis. Pre-elafin was co-localized with, but not bound to, cleaved caspase-3. Pre-elafin reduced cystatin-A expression, which was bound to pro-caspase-3. In conclusion, UV phototoxicity-induced pre-elafin inside keratinocytes prior to cornified envelope formation could be involved in UV-induced keratinocyte apoptosis via cystatin-A downregulation resulting in pro-caspase-3 activation.

Enhanced acute anti-inflammatory effects of CORM-2-loaded nanoparticles via sustained carbon monoxide delivery.

The aim of this study was to enhance the anti-inflammatory effects of carbon monoxide (CO) via sustained release of CO from carbon monoxide-releasing molecule-2-loaded lipid nanoparticles (CORM-2-NPs). CORM-2-NPs were prepared by hot high pressure homogenization method using trilaurin as a solid lipid core and Tween 20/Span 20/Myrj S40 as surfactant mixture. The physicochemical properties of CORM-2-NPs were characterized and CO release from CORM-2-NPs was assessed by myoglobin assay. In vitro anti-inflammatory effects were evaluated by nitric oxide assay in lipopolysaccharide-stimulated RAW 264.7 macrophages. In vivo anti-inflammatory activity was investigated by measuring paw volumes and histological examination in carrageenan-induced rat paw edema. Spherical CORM-2-NPs were around 100nm with narrow particle size distribution. The sustained CO release from CORM-2-NPs was observed and the half-life of CO release increased up to 10 times compared with CORM-2 solution. CORM-2-NPs showed enhanced in vitro anti-inflammatory effects by inhibition of nitric oxide production. Edema volume in rat paw was significantly reduced after treatment with CORM-2-NPs. Taken together, CORM-2-NPs have a great potential for CO therapeutics against inflammation via sustained release of CO.