Trichloroethylene induced cutaneous irritation in BALB/c hairless mice: Histopathological changes and oxidative damage

Exploring the therapeutic potential of sodium deoxycholate tailored deformable-emulsomes of etodolac for effective management of arthritis

The current piece of research intends to evaluate the potential of combining etodolac with deformable-emulsomes, a flexible vesicular system, as a promising strategy for the topical therapy of arthritis. The developed carrier system featured nanometric dimensions (102 nm), an improved zeta potential (- 5.05 mV), sustained drug release (31.33%), and enhanced drug deposition (33.13%) of DE-gel vis-à-vis conventional system (10.34% and 14.71%). The amount of permeation of the developed nano formulation across skin layers was demonstrated through CLSM and dermatokinetics studies. The safety profile of deformable-emulsomes has been investigated through in vitro HaCaT cell culture studies and skin compliance studies. The efficacy of the DE-gel formulation was sevenfold higher in case of Xylene induced ear edema model and 2.2-folds in CFA induced arthritis model than that of group treated with conventional gel (p < 0.01). The main technological rationale lies in the use of phospholipid and sodium deoxycholate-based nanoscale flexible lipoidal vesicles, which effectively encapsulate drug molecules within their interiors. This encapsulation enhances the molecular interactions and facilitates the transportation of the drug molecule effectively to the target-site. Hence, these findings offer robust scientific evidence to support additional investigation into the potential utility of flexible vesicular systems as a promising drug delivery alternative for molecules of this nature.

Casearia decandra leaves present anti-inflammatory efficacy in a skin inflammation model in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Casearia decandra (guaçatonga) is popularly used as an anti-inflammatory. We investigated the antioxidant and anti-inflammatory effect of C.decandra leaves (CdE) ethanolic extract and of the rutin standard (present in the CdE).

MATERIALS AND METHODS

Male adult Swiss mice were used (25-30 g; 5-6 animals by a group). CdE phytochemical analysis was performed by HPLC method. The antioxidant potential of CdE and rutin was assessed by different methods. Topical anti-inflammatory effect of CdE (0.001-1mg/ear) and rutin (0.003-0.03mg/ear) was evaluated by ear edema formation and inflammatory cells infiltration (MPO activity and histology) on a skin inflammation model induced by topical application of croton oil (1mg/ear).

RESULTS

Rutin (27.81 ± 1.11 mg/g) was identified in CdE by HPLC analysis. The required amounts of CdE, rutin and ascorbic acid to reduce the initial concentration of radical DPPH by 50% (IC₅₀) were 7.77 (6.31-9.57) μg/mL, 3.62 (3.26-4.01) μg/mL and 3.74 (3.37-4.14) μg/mL with a radical DPPH reduction of 91 ± 1.2%, 91 ± 0.5%, and 96 ± 0.44% (at 30 μg/mL), respectively. Moreover, CdE and rutin presented H₂O₂ scavenging activity with H₂O₂ levels reduction of 41 ± 7% and 46 ± 6%, respectively and SOD-like activity of 60 ± 4% and 51 ± 14%, respectively. On the other hand, just rutin presented nitric oxide scavenging activity of 54 ± 6%. CdE and rutin topically applied inhibited the ear edema with a maximum inhibition of 70 ± 5% (1 mg/ear) and 78 ± 10% (0.03 mg/ear), respectively. Treatments reduced the MPO activity (42 ± 4% to CdE; 1mg/ear and 30 ± 8% to rutin; 0.03 mg/ear). Histologically, the topical treatments also reduced the dermis thickness and the inflammatory cells infiltration.

CONCLUSION

We demonstrated the antioxidant and anti-inflammatory effect of C.decandra leaves and rutin. Its antioxidant potential may contribute to inflammatory process attenuation, supporting the C.decandra leaves used as a promising alternative in the therapy of the inflammatory diseases.

Role of selective blocking of bradykinin B1 receptor in attenuating immune liver injury in trichloroethylene-sensitized mice

Trichloroethylene (TCE) is able to induce trichloroethylene hypersensitivity syndrome (THS) with multi-system immune injuries. In our previous study, we found kallikrein-kinin system (KKS) activation, including the bradykinin B1 receptor (B1R), which contributed to immune organ injury in TCE sensitized mice. However, the mechanism of B1R mediating immune dysfunction is not clarified. The present study initiates to investigate the potential mechanism of B1R on liver injury. We establish a TCE sensitized BALB/c mouse model to explore the mechanism with or without a B1R inhibitor R715. We found B1R expression was increased in TCE sensitization-positive mice. As expect, hepatocyte intracellular organelles and mitochondria disappeared, glycogen particles reduced significantly as well in TCE sensitization-positive mice via the transmission electron microscopic examination, meanwhile, R715 alleviated the deteriorate above. The blockade of B1R resulted in a significant decreased p-ERK1/2 and increased p-AKT expression. The expression of CD68 kupffer cell and its relative cytokine, including IL-6 and TNF-α, increased in TCE sensitization-positive mice and decreased in R715 pretreatment TCE sensitization-positive mice. Together, the results demonstrate B1R plays a key role in ERK/MAPK and PI3K/AKT signal pathway activation and inflammation cytokine expression in immune liver injury induced by TCE. B1R exerts a pivotal role in the development of TCE induced liver injury.

Development of triptolide-nanoemulsion gels for percutaneous administration: physicochemical, transport, pharmacokinetic and pharmacodynamic characteristics

Background

This work aimed to provide useful information on the use of nanoemulsions for the percutaneous administration of triptolide. Lipid nanosystems have great potential for transdermal drug delivery. Nanoemulsions and nanoemulsion gels were prepared to enhance percutaneous permeation. Microstructure and in vitro/in vivo percutaneous delivery characteristics of triptolide (TPL)-nanoemulsions and TPL-nanoemulsion gels were compared. The integrity of the nanoemulsions and nanoemulsion gels during transdermal delivery and its effects on the surface of skin were also investigated. The penetration mechanisms of nanoemulsions and nanoemulsion gels were investigated by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The transport characteristics of fluorescence-labelled nanoemulsions were probed using laser scanning confocal microscopy. A chronic dermatitis/eczema model in mice ears and the pharmacodynamic of the TPL-nanoemulsion gels were also investigated.

Results

Compared to TPL gels, significantly greater cumulative amounts of TPL-nanoemulsion gels and TPL-nanoemulsions penetrated rat skin in vitro. The in vivo microdialysis showed the concentration–time curve AUC_0–t for TPL-NPs is bigger than the TPL-gels. At the same time, TPL-NPs had a larger effect on the surface of skin. By hydrating keratin and changing the structure of both the stratum corneum lipids and keratin, nanoemulsions and nanoemulsion gels influence skin to promote percutaneous drug penetration. Both hairfollicles and the stratum corneum are also important in this transdermal drug delivery system. Moderate and high dosages of the TPL-nanoemulsion gels can significantly improve the symptoms of dermatitis/eczema inflammation and edema erythematic in mice ears and can reduce the expression of IFN-γ and IL-4. Moreover, the TPL-nanoemulsion gels cause less gastrointestinal damage than that of the Tripterygium wilfordii oral tablet does.

Conclusions

Nanoemulsions could be suitable for transdermal stably releasing drugs and maintaining the effective drug concentration. The TPL-nanoemulsion gels provided higher percutaneous amounts than other carriers did. These findings suggest that nanoemulsion gels could be promising percutaneous carriers for TPL. The TPL-nanoemulsion gels have a significant treatment effect on dermatitis/eczema in the mice model and is expected to provide a new, low-toxicity and long-term preparation for the clinical treatment of dermatitis/eczema in transdermal drug delivery systems.

Electronic supplementary material

The online version of this article (10.1186/s12951-017-0323-0) contains supplementary material, which is available to authorized users.

Developmental neurotoxic effects of a low dose of TCE on a 3-D neurosphere system

Trichloroethylene (TCE) is one of the industrial toxic byproducts that now persist in the air, soil, and water. Several studies have already illustrated the toxic effect of high doses of TCE on the biological functions of several organs. This study aims to highlight the toxic impact of a low dose of TCE (1 μmol/L) on the development of rat neural stem cells (NSCs). The subventricular zones (SVZ) of rat pup's brains were collected and minced, and the harvested cells were cultured in the presence of neural growth factors B27/N2 to develop neurospheres. The cells were then exposed to a dose of 1 μmol/L TCE for 1 or 2 weeks. The outcomes indicated a remarkable inhibitory effect of TCE on the differentiation capacity of NSCs, which was confirmed by down-regulation of the astrocyte marker GFAP The inhibitory effect of TCE on the proliferation of NSCs was identified by the reductions in neurosphere diameter, Ki67 expression, and cell cycle arrest at the G1/S phase. Immunolabelling with annexin V indicated the proapoptotic effect of TCE exposure. PCR results revealed a TCE-mediated suppression of the expression of the antioxidant enzyme SOD1. This paper illustrates, for the first time, a detailed examination of the toxic effects of an environmentally low dose of TCE on NCSs at the transcriptional, translational, and functional levels.

Potential immunotoxic effects of trichloroethylene-induced IV allergic reaction in renal impairment

Trichloroethylene (TCE) is known to induce allergic contact dermatitis and subsequent occupational medicamentosa-like dermatitis (OMLD) with multi-system injuries, including liver, kidney, and skin injuries. However, the mechanisms underlying immune system dysfunction that result in organ injury have not yet been clearly elucidated. In the present study, we measured the levels of secreted cytokines by effect or T cells in TCE-treated guinea pigs to better understand the contribution of allergic disorders in renal injuries. We immunized guinea pigs with trichloroethylene using the Guinea Pig Maximization Test (GPMT) and scored the inflammation on the guinea pigs' skin. The kidney function and ultra-structural changes in the kidneys were detected using biochemical methods and electron microscopy. The deposition of cytokines was determined using immunohistochemistry. The sensitization rate was 63.16% in the TCE-sensitized groups. The electron microscopy results showed tubular epithelial cell mitochondrial swelling, vacuolar degeneration, and atrophy of the microvillus in the sensitized groups. A high degree of cytokine deposition was observed in the renal tubular proximal epithelial cells in the TCE-sensitized groups. As observed in this study, the variation in the level of immune system activation not only indicates that TCE can largely magnify the immune reaction but also suggests a potential role of immune dysfunction in renal impairment.

Aceclofenac cocrystal nanoliposomes for rheumatoid arthritis with better dermatokinetic attributes: a preclinical study

AIM

The aim of present research was to complex aceclofenac with lysine (LYS) and the developed aceclofenac-LYS cocrystal was encapsulated in lipid bilayers of liposomes by employing dual carrier approach for the treatment of pain-related disorders in rheumatoid arthritis (RA).

MATERIALS & METHODS

The developed carriers were characterized for particle size, drug release, ex vivo and in vivo studies, dermatokinetic modeling, complete freund's adjuvant (CFA)-induced RA rat model, radiant heat tail-flick method, formalin-induced paw-licking model, paw edema model and xylene-induced ear edema model in mice.

RESULTS

The developed nanoliposomes offered nanometric size, controlled drug release and enhanced drug permeation. Further, hydrogel incorporated nanoproduct was found to be rheologically acceptable and substantially compatible with rodent skin.

CONCLUSION

The studies indicated the superiority of LYS-conjugated liposome-entrapped nanocarriers for improved management of conditions like RA over the marketed product.

Effective transdermal delivery of methotrexate through nanostructured lipid carriers in an experimentally induced arthritis model

Rheumatoid arthritis (RA), an autoimmune and inflammatory pathology, is resulted due to the disruption of immune-homeostasis and failure of host immune-surveillance mechanism leading to cartilage degradation and bone erosion. Orally and parenterally administered methotrexate (MTX) have had adverse systemic complications in RA therapeutics. Therefore, transdermal application of MTX is recommended for the treatment of RA [1]. Present study is designed to develop MTX loaded nanostructured lipid carriers and chemical enhancer co-incorporated hydrogel (gel-(MTX-NLCs+CE)) for an efficient transdermal delivery of MTX in a Freund's adjuvants induced experimental animal model of RA. A gel-(MTX-NLCs+CE) was formulated and evaluated for its biocompatibility in hyper keratinocytes (HaCaT) and human monocytic cells (U937). Further, systemic and local inflammation was assessed by the estimation of pro-inflammatory cytokines & joint-destructive enzymes (TNF-α, IL-6, MMP-1 & IL-1β,; iNOS & COX-2) in the serum and synovial fluid, respectively in an experimentally induced RA animal model. Prepared formulations were also evaluated with respect to arthritis index, arthritis score and histopathology of paw and ankle bones. The biocompatibility study of formulation on U937 and HaCaT is suggestive of safe and greater therapeutic efficacy of the developed formulations. Our results show that transcutaneous ability of MTX loaded nanostructured lipid carries (NLCs) and chemical enhancer (CE) co-incorporated hydrogel significantly (p<0.001) decreases the inflammation in RA animal model. In conclusion, developed NLCs-based gel formulation loaded with MTX opens new avenues for developing novel therapeutic modality for RA patients with the acceptably minimum adverse effects.

Knowledge of Occupational Chemical Exposure and Smoking Behavior in Korean Immigrant Drycleaners

To examine the association between knowledge of chemical exposure at work and cigarette smoking among Korean immigrant drycleaners. A cross-sectional survey was conducted with a total of 151 Korean immigrant drycleaners (mean age = 49 years, 64 % male) from 96 drycleaning shops in a Midwestern state. The data were collected on demographic and work-related characteristics, knowledge of occupational chemical exposure, health concerns associated with chemical exposure, and smoking status. Approximately 25 % of participants were current smokers. The multivariate regression showed that greater knowledge of occupational chemical exposures was significantly associated with a lower likelihood of current smoking [odds ratio (OR) .63; 95 % confidence interval (CI) .41-.95]. Furthermore, male gender (OR 6.32; 95 % CI 1.66-24.00), shorter-term residence in the US (OR .93; 95 % CI .88-.98), and having multiple duties (OR 2.76; 95 % CI 1.01-7.51) were important covariates associated with current smoking among Korean immigrant drycleaners. Knowledge on occupational chemical exposure was significantly associated with smoking among Korean immigrant drycleaners. Smoking cessation programs for this population should consider integrated approaches that incorporate work environment factors into individual and sociocultural components.

Complement Activation and Liver Impairment in Trichloroethylene-Sensitized BALB/c Mice

Our recent studies have shown that trichloroethylene (TCE) was able to induce multisystem injuries in the form of occupational medicamentosa-like dermatitis, including skin, kidney, and liver damages. However, the role of complement activation in the immune-mediated liver injury is not known. This study examined the role of complement activation in the liver injury in a mouse model of TCE-induced sensitization. Treatment of female BALB/c mice with TCE under specific dosing protocols resulted in skin inflammation and sensitization. Skin edema and erythema occurred in TCE-sensitized groups. Trichloroethylene sensitization produced liver histopathological lesions, increased serum alanine aminotransferase, aspartate transaminase activities, and the relative liver weight. The concentrations of serum complement components C3a-desArg, C5a-desArg, and C5b-9 were significantly increased in 24-hour, 48-hour, and 72-hour sensitization-positive groups treated with TCE and peaked in the 72-hour sensitization-positive group. Depositions of C3a, C5a, and C5b-9 into the liver tissue were also revealed by immunohistochemistry. Immunofluorescence further verified high C5b-9 expression in 24-hour, 48-hour, and 72-hour sensitization-positive groups in response to TCE treatment. Reverse transcription–polymerase chain reaction detected C3 messenger RNA expression in the liver, and this was significantly increased in 24-hour and 48-hour sensitization-positive groups with a transient reduction at 72 hours. These results provide the first experimental evidence that complement activation may play a key role in the generation and progression of immune-mediated hepatic injury by exposure to TCE.

Assessment of an imiquimod-induced psoriatic mouse model in relation to oxidative stress

Psoriasis is a chronic inflammatory skin disease that is thought to be related to oxidative stress. Much progress has been made in understanding the pathophysiology of psoriasis in relation to the immunologic and antioxidant systems. However, this progress has been hindered by the lack of an appropriate animal model for psoriasis. Recently, imiquimod (IQM)-induced psoriasis-like cutaneous inflammation has been reported in mice and humans. We verified the usefulness of an IQM-induced mouse model in relation to the antioxidant system. BALB/C female mice at 8-10 weeks of age were treated with IQM cream in this study. We analyzed clinical and histopathological changes. Increased reactive oxygen species production was measured by glutathione assay. Levels of myeloperoxidase (MPO) and superoxide dismutase-1 (SOD1) were determined by western blotting and immunohistochemical analyses. The activity of SOD was measured by a SOD activity assay kit. Application of IQM-induced skin inflammation similar to psoriasis in clinical and histopathological aspects. Accumulation of immune cells was confirmed. Oxidative stress was increased, the antioxidant enzyme MPO levels were increased, and both SOD levels and activity were decreased. In conclusion, the IQM-induced mouse model showed an aberrant antioxidant system. Levels of MPO and oxidative stress were increased, and the level and activity of SOD were decreased. Since this model seemed to be an appropriate model for psoriasis, it can be used to further study the pathogenic role of redox imbalance in psoriasis.