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.

Honey bee is a potential antioxidant against cyclophosphamide-induced genotoxicity in albino male mice.

The protective effects of honey bee (HB) and pollen grains against cyclophosphamide (CPM) -induced cytotoxic and genotoxic effects in mice were investigated. This was achieved through study the effects of CPM and HB on oxidative status, chromosomal aberrations and gene expression of the tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), interleukin-1ß (IL1ß), interleukin 17A (IL-17A) and interferon-gamma (IFN-γ) in mice. In addition, the levels of reduced glutathione (GSH) and malondialdehyde were determined. The results of this study revealed that CPM decrease in GSH level and increase in malondialdehyde (MDA) level in the liver and kidney tissues. Moreover, CPM induced sperm abnormality, chromosomal aberrations and down regulated the expression of the studied cytokine genes. HB treatment in association with CPM ameliorates GSH, MDA, chromosomal aberrations and regulated the expression of IL-1-ß, IL-17A, IL-6, TNF-α and IFN-γ. Thus, HB inhibits the cytotoxic and genotoxic risks associated with CPM treatment in mice.

Carbon tetrachloride-induced hepatotoxicity in rat is reversed by treatment with riboflavin.

Liver is a vital organ for the detoxification of toxic substances present in the body and hepatic injury is associated with excessive exposure to toxicants. The present study was designed to evaluate the possible hepatoprotective effects of riboflavin against carbon tetrachloride (CCl4) induced hepatic injury in rats. Rats were divided into six groups. Hepatotoxicity was induced by the administration of a single intraperitoneal dose of CCl4 in experimental rats. Riboflavin was administered at 30 and 100mg/kg by oral gavage to test its protective effect on hepatic injury biochemically and histopathologically in the blood/liver and liver respectively. The administration of CCl4 resulted in marked alteration in serum hepatic enzymes (like AST, ALT and ALP), oxidant parameters (like GSH and MDA) and pro-inflammatory cytokine TNF-α release from blood leukocytes indicative of hepatic injury. Changes in serum hepatic enzymes, oxidant parameters and TNF-α production induced by CCl4 were reversed by riboflavin treatment in a dose dependent manner. Treatment with standard drug, silymarin also reversed CCl4 induced changes in biomarkers of liver function, oxidant parameters and inflammation. The biochemical observations were paralleled by histopathological findings in rat liver both in the case of CCl4 and treatment groups. In conclusion, riboflavin produced a protective effect against CCl4-induced liver damage. Our study suggests that riboflavin may be used as a hepato-protective agent against toxic effects caused by CCl4 and other chemical agents in the liver.

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.

Downregulation of pro-inflammatory cytokines by lupeol measured using cytometric bead array immunoassay.

The objective of the study was to investigate the activity of Lupeol (LUP) on proinflammatory and anti-inflammatory cytokines in the pleural exudate from male swiss albino mice. We applied Cytometric bead array technology for simultaneously measurement of these cytokines in pleurisy induced mice treated with lupeol in graded oral doses. Cytometric bead array uses the sensitivity of amplified fluorescence detection by flowcytometer to measure soluble analytes in a particle based immune assay. This assay can accurately quantitate 5 cytokines in a 50 microlitre sample volume. Oral administration of LUP at doses of 25, 50, 100 and 200 mg/kg p.o. produced dose related inhibition of IL-2, IFN-gamma and TNF-alpha in the pleural exudate with the most significant effect at 100 mg/kg oral dose. LUP had a non significant inhibitory effect on the levels of IL-4 and IL-5.

Immunomodulatory activity of isoflavones isolated from Iris germanica (Iridaceae) on T-lymphocytes and cytokines.

The immunomodulatory activities of two isoflavones, 5,7-dihydroxy-6,4'-dimethoxyisoflavone (irisolidone) (1) and 5,4'-dihydroxy-6,7-methylenedioxyisoflavone (irilone) (2) isolated from Iris germanica (Iridaceae) is reported. Their influence on production of T-lymphocytes (CD4+ and CD8+ cells) and T-cell cytokines, namely Th1: IL-2, IFN-gamma and Th2: IL-4 and IL-5 in a dose-dependent manner was studied by flow cytometric method in Balb/c mice. Oral administration of drugs at doses of 0.1-0.8 mg/kg per oral dose showed 1 to possess stimulatory activity on T-cells and Th1 cytokine production, while as 2 acted as an immunosuppressant for both cells and cytokines. The methylated products of 1 and 2 showed a similar trend to that of their parent compounds but their activity was drastically decreased revealing the importance of free phenolic groups for their immunomodulating activities.

Augmentation and proliferation of T lymphocytes and Th-1 cytokines by Withania somnifera in stressed mice.

Stress has been associated with reports of both greater severity and prolongation of diseases in patients with the infectious origin as well as other immune-mediated diseases. Withania somnifera, an Indian medicinal plant used widely in the treatment of many clinical conditions in India, was investigated for its anti-stress properties using BALB/c mice subjected to chronic stress. The study aimed to investigate chronic stress-induced alterations on Th1 lymphocyte subset distribution and corresponding cytokine secretion patterns. Oral administration of chemically standardized and identified aqueous fraction of W. somnifera root (WS) at the graded doses of 25, 50, 100 and 200 mg/kg p.o. caused significant increase in the stress-induced depleted T-cell population and increased the expression of Th1 cytokines in chronically stressed mice.

Suppression of T lymphocyte activity by lupeol isolated from Crataeva religiosa.

Lupeol has been shown to possess antiarthritic activity through possible suppression of the immune system. As seen in the following studies, it was found to suppress various immune factors such as the phagocytic (cell-killing) activity of macrophages, T-lymphocyte activity that included CD4+T cell mediated cytokine generation. Assessment of T cells and their intracellular content of cytokines was carried out by flow cytometric analysis in Balb/c mice. Oral administration of lupeol at doses of 12.5-200 mg/kg p.o. inhibited CD4+ T and CD8+ T cell counts and cytokines IL-2, IFN-gamma (Th1) and IL-4 (Th2). Cytometric bead array (CBA) technology was applied to carry out simultaneous measurement of multiple serum cytokines. The oral LD(0) in mice was more than 2 g/kg body weight.

Immunosuppressive properties of an ethyl acetate fraction from Euphorbia royleana.

The objective of the study was to investigate the activity of the ethyl acetate (EA) fraction of Euphorbia royleana latex on cellular and humoral-mediated immune responses and phagocytic function of the cells of the reticuloendothelial system in mice. Oral administration of EA at doses of 50, 100 and 200 mg/kg p.o. in mice with sheep red blood cells (SRBC) as an antigen-inhibited both the delayed-type hypersensitivity reaction and the production of circulating antibody titre. Reduction of CD4+ T cell counts in the peripheral whole blood and the neutrophil counts in pleural exudates of the animals treated with EA was observed by flowcytometric analysis. Process of phagocytosis was also inhibited in in vivo and in vitro experimental test models. The oral LD50 in both rats and mice was more than 2.5 g/kg body weight.