Inhibition of non-receptor tyrosine kinase LCK partially mitigates mixed granulocytic airway inflammation in a murine model of asthma.

Asthma affects millions of people worldwide and is one of the most common inflammatory airway diseases. Asthma phenotypes are quite complex and categorized as eosinophilic, mixed granulocytic (presence of both eosinophils and neutrophils in the airways) and neutrophilic. Mixed granulocytic asthma requires large doses of inhaled corticosteroids, which are often insufficient in controlling airway inflammation. Therefore, there is a medical need to test newer therapies to control granulocytic inflammation. Lymphocyte specific protein tyrosine kinase (LCK) signaling has gained momentum in recent years as a molecular target in inflammatory diseases such as asthma. LCK is expressed in lymphocytes and is required for inflammatory intracellular signaling in response to antigenic stimulation. Therefore, efficacy of LCK inhibitor, A770041 was tested in cockroach (CE)-induced corticosteroid insensitive murine model of asthma. The effect of LCK inhibitor was investigated on granulocytic airway inflammation, mucus production, p-LCK and downstream signaling molecules such as p-PLCγ, GATA3, p-STAT3 in CD4+ T cells. Moreover, its effects were also studied on Th2/Th17 related cytokines and oxidative stress parameters (iNOS/nitrotyrosine) in neutrophils/macrophages. Our study shows that CE-induced p-LCK levels are concomitant with increased neutrophilic/eosinophilic inflammation and mucus hypersecretion which are significantly mitigated by A770041 treatment. A770041 also caused marked attenuation of CE-induced pulmonary levels of IL-17A levels but not completely. However, A770041 in combination with dexamethasone caused complete downregulation of mixed granulocytic airway inflammation as well as Th2/Th17 related immune responses. These results suggest that combination of LCK inhibition along with corticosteroids may be pursued as an alternative strategy to completely treat mixed granulocytic asthma.

Inhibition of Bruton's tyrosine kinase and IL-2 inducible T-cell kinase suppresses both neutrophilic and eosinophilic airway inflammation in a cockroach allergen extract-induced mixed granulocytic mouse model of asthma using preventative and therapeutic strategy.

Asthma is a complex airways disease with a wide spectrum which ranges from eosinophilic (Th2 driven) to mixed granulocytic (Th2/Th17 driven) phenotypes. Mixed granulocytic asthma is a cause of concern as corticosteroids often fail to control this phenotype. Different kinases such as Brutons's tyrosine kinase (BTK) and IL-2 inducible T cell kinase (ITK) play a pivotal role in shaping allergic airway inflammation. Ibrutinib is primarily a BTK inhibitor, however it is reported to be an ITK inhibitor as well. In this study, we sought to determine the effect of Ibrutinib on Th1, Th17 and Th2 immune responses in a cockroach allergen extract (CE)-induced mixed granulocytic (eosinophilic and neutrophilic) mouse model in preventative mode. Ibrutinib attenuated neutrophilic inflammation at a much lower doses (25-75 µg/mouse) in CE-induced mixed granulocytic asthma whereas Th2/Th17 immune responses remained unaffected at these doses. However, at a much higher dose, i.e. 250 µg/mouse, Ibrutinib remarkably suppressed both Th17/Th2 and lymphocytic/neutrophilic/eosinophilic airway inflammation. At molecular level, Ibrutinib suppressed phosphorylation of BTK in neutrophils at lower doses and ITK in CD4 + T cells at higher doses in CE-treated mice. Further, effects of Ibrutinib were compared with dexamethasone on CE-induced mixed granulocytic asthma in therapeutic mode. Ibrutinib was able to control granulocytic inflammation along with Th2/Th17 immune response in therapeutic mode whereas dexamethasone limited only Th2/eosinophilic inflammation. Thus, Ibrutinib has the potential to suppress both Th17/Th2 and neutrophilic/eosinophilic inflammation during mixed granulocytic asthma and therefore may be pursued as alternative therapeutic option in difficult-to-treat asthma which is resistant to corticosteroids.

Resveratrol Improves Neuroimmune Dysregulation Through the Inhibition of Neuronal Toll-Like Receptors and COX-2 Signaling in BTBR T+ Itpr3tf/J Mice.

Autism is a neurodevelopmental disorder characterized by deficits in qualitative impairments in communication, repetitive and social interaction, restricted, and stereotyped patterns of behavior. Resveratrol has been extensively studied pharmacologically and biologically and has anti-inflammatory, antioxidant, and neuroprotective effects on neuronal damage in neurodegenerative disorders. The BTBR T+ Itpr3tf/J (BTBR) autistic mouse model has been explored for treatment of autism, which shows low reciprocal social interactions, impaired juvenile play, and decreased social approach. Here, we explored whether resveratrol treatment decreases neuroimmune dysregulation mediated through toll-like receptor (TLR4) and nuclear factor-κB (NF-κB) signaling pathway in BTBR mice. We investigated the effect of resveratrol treatment on TLR2, TLR3, TLR4, NF-κB, and inducible nitric oxide synthase (iNOS or NOS2) levels in CD4 spleen cells. We also assessed the effect of resveratrol treatment on TLR2, TLR3, TLR4, NF-κB, iNOS, and cyclooxygenase (COX-2) mRNA expression levels in the brain tissue. We further explored TLR2, TLR4, NF-κB, iNOS, and COX-2 protein expression levels in the brain tissue. Resveratrol treatment on BTBR mice significantly decreased CD4+TLR2+, CD4+TLR3+, CD4+TLR4+ CD4+NF-κB+, and CD4+iNOS+ levels in spleen cells. Resveratrol treatment on BTBR mice decreased TLR2, TLR3, TLR4, NF-κB, iNOS, and COX-2 mRNA expression levels in brain tissue. Moreover, resveratrol treatment resulted in decreased protein expression of TLR2, TLR3, TLR4, NF-κB, iNOS, and COX-2 in brain tissue. Taken together, these results indicate that resveratrol treatment improves neuroimmune dysregulation through the inhibition of proinflammatory mediators and TLRs/NF-κB transcription factor signaling, which might be help devise future therapies for neuroimmune disorders.

The tyrosine kinase inhibitor tyrphostin AG126 reduces activation of inflammatory cells and increases Foxp3+ regulatory T cells during pathogenesis of rheumatoid arthritis.

Protein tyrosine kinases are key mediators of the signal transduction cascades that control expression of many genes involved in the induction of inflammation caused by arthritis. Here we investigate the effect of the tyrosine kinase inhibitor tyrphostin AG126 on a mouse model of adjuvant-induced arthritis (AIA). We report that when given at 5mg/kg i.p. every 48h from days 0-21, AG126 exerts potent anti-arthritic effects. Further, we investigated the role of AG126 on the key mediators of arthritic inflammation, namely, edema, arthritic score, presence of immunophenotypes including Foxp3+, CD4+Foxp3+, and CD25+Foxp3+ T regulatory (Treg) cells, as well as pro- and anti-inflammatory mediators. AG126 treatment significantly attenuated the severity of AIA and caused a substantial reduction in the percentage of CD2+, CD3+, CD4+, CD8+, CD23+, CD80+, CD86+ CD122+, CD195+, TCRß+, and GITR+ cells in whole blood. Moreover, administration of AG126 under arthritis-inducing conditions resulted in suppression of IL-17A+, IFN-γ+, CD4+ and CD25+ populations while causing an increase in the Foxp3+, CD4+Foxp3+, and CD25+Foxp3+ Treg populations in the spleen. In addition, RT-PCR analysis revealed increased expression of CD4, CD8, IL-17A, IFN-γ, TNF-α, and NF-κB p65 mRNAs and decreased IL-4 mRNA in the arthritic control (AC) mice, while treatment of animals with AG126 reversed these effects. Western blot analysis confirmed the decreased expression of IL-17, GITR, NF-κB p65 proteins and increased Foxp3 and IL-4 proteins following AG126 treatment of knee tissue. Thus, our findings provide new evidence that inhibition of protein tyrosine kinase activity decreases the progression of arthritis.

Amelioration of autoimmune arthritis by naringin through modulation of T regulatory cells and Th1/Th2 cytokines.

Naringin, a well-known flavanone glycoside found in grapefruit and other citrus fruits, was determined to be an effective anti-inflammatory compound. We investigated the effect of naringin on the key mediators of arthritic inflammation, namely T cell subsets, CD4(+)GITR(+) expressing cells, CD4(+)CD25(+)Foxp3(+) (Treg), Th1/Th2 cytokines and inflammatory mediators. We treated Balb/c mice (p.o.) with naringin (20, 40 and 80 mg/kg) for 14 days. Compared with the vehicle-treated and arthritic-control mice, the naringin treatment demonstrated a considerable decrease in the level of T cells, CD4(+)GITR(+), Th1 cytokine and inflammatory mediator expressions. In contrast, naringin treatment resulted in significantly up-regulated Treg and Th2 cytokine levels. Therefore, the naringin-induced inhibition of the T cells, various pro-inflammatory cytokines and inflammatory mediators that facilitate cellular infiltration into the joints might have contributed to its anti-arthritic activity. Our data suggest that naringin diminished the AIA in mice and it could be a potential alternative/adjunct treatment for RA.

Anti-inflammatory effect of Euphorbia hirta in an adjuvant-induced arthritic murine model.

Despite extensive research into inflammatory diseases to date, no drugs with favourable safety profiles are available for treatment. Euphorbia hirta (E. hirta) is a tree that is locally used as a traditional medicine in Africa and Australia to treat numerous diseases such as hypertension, antipyretic and anti-inflammatory activities. The aim of the present study was to determine the potential anti-arthritic effects of E. hirta in mouse models of adjuvant induced arthritis (AIA). We treated BALB/c mice with (p.o.) E. hirta (25, 50, 100, and 200 mg/kg) daily (13 days) beginning at the onset of AIA. We examined the effect of E. hirta on key mediators of arthritic-inflammation, including pro-inflammatory (IL-2, IFN-γ, and TNF-α) and anti-inflammatory (IL-4 and IL-5) cytokines, T-cell activation markers (CD25/CD69), and co-stimulatory molecules (CD80/CD86). We also examined the inflammatory mediators (PGE2 and LTB4) response. E. hirta-treated mice showed a substantial reduction in the levels of pro-inflammatory cytokines, down regulated cell activation markers and co-stimulatory molecules, and up regulated anti-inflammatory cytokines. E. hirta decreased the levels of inflammatory-mediators in AIA animals. Supplementation with an E. hirta extract may be a promising treatment for arthritic and inflammatory diseases.

Grape seed proanthocyanidin extract protects against carrageenan-induced lung inflammation in mice through reduction of pro-inflammatory markers and chemokine expressions.

Proanthocyanidins are the most abundant phenolic compounds and have been reported to exert anti-inflammatory actions. The aim of this study was to investigate the effects of grape seed proanthocyanidin extract (GSPE) in a mouse model of carrageenan-induced pleurisy. Following the induction of pleurisy using λ-carrageenan (Cg, 1 %), GSPE (25, 50 and 100 mg/kg) was administered per-oral (p.o.), and the glucocorticoid-induced tumour necrosis factor receptor (GITR), IL-17A expressing cells and other markers, such as cytokines (Th1/Th2 and Th17), were studied. We evaluate the effects of GSPE on the mRNA expression of pro-inflammatory and anti-inflammatory mediators. The results illustrated that the cell numbers of IL-17A and GITR expressing cells and the cytokine levels in Th1/Th17 cells were markedly increased in the Cg-group, whereas the cytokines produced by Th2 cells were significantly decreased in the same group. Treatment with GSPE reversed these effects. Histological examinations revealed anti-inflammatory effects of GSPE.

Grape seed proanthocyanidin extract has potent anti-arthritic effects on collagen-induced arthritis by modifying the T cell balance.

Rheumatoid arthritis (RA) is an autoimmune disease characterised by chronic inflammation of the synovial joints, joint malformations, and disability. The continuous use of conventional anti-inflammatory drugs is associated with severe adverse effects. Grape seed proanthocyanidin extract (GSPE) is considered to have protective effects against several diseases. In this study based on the mouse adjuvant-induced-arthritis (AIA) model, we examined the effects of GSPE on the key mediators of arthritic inflammation, namely T cell subsets, glucocorticoid-induced tumour necrosis factor receptor (GITR) expressing cells, CD4(+)CD25(+)Foxp3(+) regulatory T (Treg) cells, Th17 cells, Th1/Th2 cytokines, and inflammatory mediator gene expression. We treated BALB/c mice with 25, 50, or 100 mg/kg GSPE or saline daily (14 days) per orally (p.o.) at the onset of AIA. At the peak phase of AIA (day 14), the heparinised whole blood and ankle joints of all groups were collected and tested. GSPE-treated mice showed a substantial reduction in the levels of T cell subsets, GITR-expressing cells, and Th1 cytokines as well as the inflammatory mediators (MCP-1, MIP-2, and ICAM-1) that induce them compared with the vehicle-treated (saline) and arthritic mice. However, GSPE significantly upregulated the number of Tregs and Th2 cytokine producing cell number or it also induced Th17/Treg rebalance and orchestrated various pro-inflammatory and anti-inflammatory cytokines and the gene expression of their mediators that mediate cellular infiltration into the joints. This might, contribute to its anti-arthritic activity. Our results suggest that p.o. treatment with GSPE attenuated AIA in mice might offer a promising alternative/adjunct treatment for RA.

TNF-α inhibitory effect of Euphorbia hirta in rats.

CONTEXT: Euphorbia hirta L. (Euphorbiaceae) (E. hirta) is a tree locally used as a traditional medicine in Africa and Australia to treat numerous diseases such as hypertension, respiratory ailments, tumors, and wounds, and it has reported antiallergic, antipyretic, anti-inflammatory activities, etc. OBJECTIVE: This study evaluated the ability of fresh leaves of E. hirta ethanol extract to inhibit the intracellular tumor necrosis factor α (TNF-α) level in the synovial fluid and neutrophils in lipopolysaccharide (LPS)-induced inflamed rat knees. MATERIALS AND METHODS: Female Wister albino rats 140-160 g were used. E. hirta ethanol extract was given orally at 25, 50, 100, and 200 mg/kg, 2 h before an intra-articular (i.a.) injection of LPS. Two and three hours later, synovial fluid and neutrophils levels of intracellular TNF-α production were measured. RESULTS: In the time course of the experiment, E. hirta maximum inhibition at 100 and 200 mg/kg (p.o.) dose showed 16.5 ± 1.34 and 14.4 ± 1.30% of synovial fluid, 4.26 ± 0.36 and 3.78 ± 0.29% of neutrophils levels of intracellular TNF-α productions at 2 h after LPS injection. LPS control displayed 22.97 ± 1.61 and 6.78 ± 0.34% of synovial fluid and neutrophils levels of intracellular TNF-α at 2 h after LPS injection. Intracellular TNF-α was also estimated at 3 h after LPS injection. DISCUSSION AND CONCLUSION: The LPS-injected rat knee model gives a comparative study of acute anti-inflammatory responses. E. hirta inhibition of proinflammatory intracellular cytokine TNF-α production with LPS-induced inflamed rat knee is of great importance in defining the anti-arthritic potential of E. hirta.

Immunosuppressive effects of Euphorbia hirta in experimental animals.

Euphorbia hirta L. (Euphorbiaceae) (E. hirta) is a tree locally used as a traditional medicine in Africa and Australia to treat numerous diseases such as hypertension, respiratory ailments, tumors, wounds, antipyretic, anti-inflammatory activities, etc. Therefore, we undertook to investigate their immunomodulatory effect on T lymphocytes (CD3+, CD4+ and CD8+ receptors) and Th1 cytokines (IL-2, TNF-α, IFN-γ) in a dose-dependent manner. E. hirta ethanol extract at 25, 50, 100 and 200 mg/kg doses was given orally for 7 days from the day of immunization. E. hirta maximum inhibition at 100 and 200 mg/kg p.o. was found to significantly block the production of the cell-mediated immune response, (CD3+, CD4+ and CD8+ receptors) and (IL-2, TNF-α, IFN-γ) and also prolongs graft rejection. E. hirta also showed a decrease of delayed hypersensitivity (DTH) response and dose-related decrease in the primary antibody response, respectively. Based on the data, it can be suggested that E. hirta is a potent and non-toxic immunosuppressor, which can be further explored for the development of potent immunosuppressor.

Modulation of Th1 cytokines and inflammatory mediators by Euphorbia hirta in animal model of adjuvant-induced arthritis.

Euphorbia hirta L. (Euphorbiaceae) (E. hirta) is a tree locally used as a traditional medicine in Africa and Australia to treat numerous diseases such as hypertension, respiratory ailments, tumors, antipyretic, anti-inflammatory activities. In the present study, we investigated the anti-arthritic activity of fresh leaves of E. hirta ethanol extract that was found to inhibit the production of inflammatory mediators and cytokines of adjuvant arthritis in rats. Adjuvant arthritis was induced in rats (Wistar) by the subplantar injection of 0.05 ml freshly prepared suspension (5.0 mg/ml) of steam killed Mycobacterium tuberculli in liquid paraffin. Animals were treated with graded doses of 25, 50, 100 and 200 mg/kg of E. hirta ethanol extract, p.o. E. hirta significantly inhibited the swelling of the adjuvant-induced arthritis. Moreover, E. hirta at higher dose (200 mg/kg) showed 40.54 ± 1.09 % of CD3+, 15.1 ± 0.76 % of CD4+, 12.2 ± 1.18 % of CD8+ T cell receptor and 17.6 ± 1.11 % gated of CD19+ B cell receptor revealing a down regulation of adjuvant-induced arthritis as compared to the corresponding valves of the arthritic control rats. According to the results shown in Tables 1, 2, the production of IL-1ß, TNF-α, IL-2 and IFN-γ were increased in splenocytes of arthritic rats and this increased level was reduced by E. hirta. Also, E. hirta significantly down regulated lipopolysaccharide (LPS)-induced production of nitric oxide production in peritoneal macrophages. These results suggest that E. hirta exhibits an improvement in adjuvant-induced arthritis through down regulation of activated macrophages and T lymphocytes functions. Such unique effects of E. hirta shown on adjuvant arthritis rat model may be advantageous to the long-term treatment of clinical rheumatoid arthritis. Table 1 Effect of E. hirta and prednisolone (Pred) on LPS-induced IL-1ß and TNF-α productions from splenocytes in Mycobacterium tuberculli-induced inflammatory arthritic rats Treatment Dose (mg/kg) IL-1ß (pg/ml) TNF-α (pg/ml) Arthritic control (AC) - 323.56 ± 31.65 180.91 ± 24.12 E. hirta 25 311.19 ± 29.08* 171.43 ± 22.54* E. hirta 50 287.12 ± 26.98* 164.54 ± 21.76** E. hirta 100 243.12 ± 19.21*** 157.30 ± 18.54*** E. hirta 200 215.21 ± 16.05*** 138.43 ± 17.98*** Prednisolone (Pred) 5 187.18 ± 15.21*** 123.77 ± 15.12*** Normal control (NC) - 54.12 ± 12.54 71.94 ± 12.12 Each value indicates the mean ± SEM of six animals AC arthritic control, NC normal control; E. hirta (25, 50, 100 and 200 mg/kg) and prednisolone (5 mg/kg) were given p.o. from day 0 to day 21 after Mycobacterium tuberculli injection, respectively * p < 0.05; ** p < 0.01; *** p < 0.001, compared to arthritic control Table 2 Effect of E. hirta and Prednisolone (Pred) on Con A-induced IL-2 and IFN-γ productions from splenocytes in Mycobacterium tuberculli-induced inflammatory arthritic rats Treatment Dose (mg/kg) IL-2 (pg/ml) IFN-γ (pg/ml) Arthritic control (AC) - 235.98 ± 15.23 165.95 ± 13.87 E. hirta 25 225.12 ± 14.76** 154.76 ± 11.07** E. hirta 50 207.76 ± 13.87** 134.76 ± 11.01** E. hirta 100 189.98 ± 12.65 *** 110.64 ± 10.98*** E. hirta 200 157.84 ± 14.32 *** 98.54 ± 10.76*** Prednisolone (Pred) 5 131.08 ± 13.31*** 87.65 ± 10.61*** Normal control (NC) - 78.12 ± 12.04 31.87 ± 10.12 Each value indicates the mean ± SEM of six animals AC arthritic control, NC normal control; E. hirta (25, 50, 100 and 200 mg/kg) and prednisolone (5 mg/kg) were given p.o. from day 0 to day 21 after Mycobacterium tuberculli injection, respectively * p < 0.05; ** p < 0.01; *** p < 0.001, compared to arthritic control.

Comparative aneugenicity of doxorubicin and its derivative idarubicin using fluorescence in situ hybridization techniques.

The present study was designed to evaluate and compare the aneugenicity of idarubicin and doxorubicin, topoisomerase-targeting anticancer anthracyclines, using fluorescence in situ hybridization techniques. It was found that idarubicin and doxorubicin treatment (12 mg/kg) induced sperm meiotic delay of 24h. To determine the frequencies of disomic and diploid sperm, groups of 5 male Swiss albino mice were treated with 3, 6 and 12 mg/kg idarubicin or doxorubicin. Significant increases in the frequencies of disomic and diploid sperm were caused by treatment with all doses of idarubicin and the two highest doses of doxorubicin compared with the controls. Moreover, both compounds significantly increased the frequency of diploid sperm, indicating that complete meiotic arrest occurred. The observation that XX- and YY-sperm significantly prevailed XY-sperm indicates missegregation during the second meiotic division. The results suggest also that earlier prophase stages contribute relatively less to idarubicin and doxorubicin-induced aneuploidy. Effects of the same doses were investigated by the bone-marrow micronucleus test. Significant increases in the frequencies of micronuclei were found after treatment with all doses of both compounds. The responses were also directly correlated with bone marrow suppression. Idarubicin was more toxic than doxorubicin. Exposure to 12 mg/kg of idarubicin and doxorubicin yielded 3.82 and 2.64% micronuclei, respectively, and of these an average of 58.3 and 62.8%, respectively, showed centromeric signals, indicating their formation by whole chromosomes and reflecting the aneugenic activity of both compounds. Correspondingly, about 41.7 and 37.2% of the induced micronuclei, respectively, were centromere-negative, demonstrating that both compounds not only induce chromosome loss but also DNA strand breaks. Based on our data, aneuploidy assays such as sperm-fluorescence in situ hybridization assay and micronucleus test complemented by fluorescence in situ hybridization with centromeric DNA probes have been to some extent validated to be recommended for the assessment of aneuploidogenic effects of chemicals.

Synthesis and biological evaluation of some novel cyclic-imides as hypoglycaemic, anti-hyperlipidemic agents.

Certain new halogenated cyclic-imides related to N-substituted phthalimide moiety were synthesized. Spacers of one or two carbon atom distances were inserted to connect the N-terminus of the cyclic-imide nuclei to the used heteroaryl groups to evaluate the effect of such alteration on biological activity. The synthesized compounds were subjected to hypoglycaemic and anti-hyperlipidemic evaluation. Some of the tested compounds proved to be more potent than the reference drugs glibenclamide and clofibrate. Compound 5e remarkably reduced serum glucose level by 55%; while 5c, 5e, 7d and 8e reduced total serum cholesterol by 58, 56, 54 and 53%, respectively. Those new cyclic-imides could be considered as useful template for future development to obtain more potent hypoglycaemic and anti-hyperlipidemic agents.