OBJECTIVE: In the present study, the standardized extract of P. amarus was investigated for its suppressive effects on type II collagen-induced rheumatoid arthritis (TCIA) in Sprague Dawley rats.
METHOD: The major components of the extracts, lignans and phenolic compounds were analysed by using a validated reversed phase HPLC and LC-MS/MS. A rheumatoid arthritis rat model was induced by administering a bovine type II collagen emulsion subcutaneously at the base of tail, on day 0 and 7 of the experiment. Effects of the extract on severity assessment, changes in the hind paw volume, bone mineral density, body weight and body temperature were measured. Concentrations of cytokines (TNF-α, IL-1β, IL-1α, IL-6) released, matrix metalloproteinases (MMP-1, MMP-3 MMP-9) and their inhibitor (TIMP-1), haematological and biochemical changes were also measured. ELISA was used to measure the cytokines and proteinases in the rat serum and synovial fluid according to manufacturer's instructions.
RESULTS: The extract dose-dependently modulated the progression in physical parameters (i.e. decrease in body weight, increase in body temperature, reduced hind paw volume, reduced the severity of arthritis), bone mineral density, haematological and biochemical perturbations, serum cytokines production and levels of matrix metalloproteinases and their inhibitor in the synovial fluid. Histopathological examination of the knee joint also revealed that the extract effectively reduced synovitis, pannus formation, bone resorption and cartilage destruction.
CONCLUSION: The results suggest that the oral administration of a standardized extract of P. amarus was able to suppress the humoral and cellular immune responses to type II collagen, resulting in the reduction of the development of TCIA in the rats.
OBJECTIVE: In the present study, BBP was investigated for it's in vivo innate and adaptive immune responses mediated by different humoral and cellular immune factors.
METHODS: Male Balb/c mice were orally fed with BBP (5, 10 and 20 mg/kg) for a period of 14 days and immunized with sheep red blood cells (sRBC) on day 0 for the determination of adaptive responses. The effects of BBP on phagocytosis process of neutrophils isolated from blood of treated/untreated animals were determined. The ceruloplasmin and lysozyme serum levels and myeloperoxidase (MPO) plasma level were also monitored. The mechanism was further explored by assessing its effects on the proliferation of T and B lymphocytes, T-lymphocytes subsets CD4+ and CD8+ and on the secretion of Th1/Th2 cytokines as well as serum immunoglobulins (IgG, IgM) and delayed type hypersensitivity (DTH) reaction.
RESULTS: BBP showed a significant dose-dependent reduction on the migration of neutrophils, Mac-1 expression, phagocytic activity and reactive oxygen species (ROS) production. In comparison to the sensitized control group, a dose-dependent inhibition was observed on lymphocyte proliferation along with the downregulation of effector cells expression and release of cytokines. Moreover, a statistically significant decrease was perceived in serum levels of ceruloplasmin, lysozyme and immunoglobulins and MPO plasma level of BBP-treated mice. BBP also dose-dependently inhibited sheep red blood cells (sRBC)-induced swelling rate of mice paw in DTH.
CONCLUSION: These findings suggest the potential of BBP as a potent immunosuppressive agent.
METHODS: per-orally infected C57BL/6 mice with 15-20 cysts of the avirulent T. gondii Beverly strain at 9-11 weeks of age were examined 12 weeks later during parasite establishment. Distributions of the parasite's cysts and the histopathological lesions in the brains were analyzed using Image J software. Relative expression of TNF-α and iNOS of cell-mediated immunity (CMI), Bax (pro-apoptosis) and Bcl-2 (anti-apoptosis) were all assessed using immunohistochemistry.
RESULTS: higher parasite burden was seen in the forebrain with p value <= 0.05. Dramatically increased TNF-α, iNOS, and Bax expressions with Bax/Bcl-2 ratio 2.42:0.52 were reported (p value <= 0.05). The significant correlation between Bax data and different CMI biomarkers including TNF-α and i-NOS was evaluated. Interestingly, no significant correlation was seen between TNF-α, iNOS, Bax and Bcl-2 expressions and location of the parasite. However, Bax/Bcl-2 ratio was statistically correlated with CMI biomarkers and whole sample mean parasite burden, p value <= 0.05.
CONCLUSION: Chronic toxoplasmosis exhibits an immense pro-apoptotic signal on the cerebral tissues of experimental mice.
PURPOSE: In the present study, phyllanthin isolated from Phyllanthus amarus was investigated for its immunosuppressive effects on various cellular and humoral immune responses in Balb/C mice.
METHODS: Male mice were treated daily at 20, 40 and 100mg/kg of phyllanthin for 14 days by oral gavage. The effects of phyllanthin on cellular immune responses in treated /non treated mice were determined by measuring CD 11b/CD 18 integrin expression, phagocytosis, nitric oxide (NO) production, myeloperoxidase activity (MPO), T and B cells proliferation, lymphocyte phenotyping, serum cytokines production by activated T-cells and delayed type hypersensitivity (DTH). Its effects on humoral immune responses were evaluated by determining the serum levels of lysozyme and ceruloplasmin, and immunoglobulins (IgG and IgM).
RESULTS: Phyllanthin dose-dependently inhibited CD11b/CD18 adhesion, the engulfment of E. coli by peritoneal macrophages molecules, NO and MPO release in treated mice. Phyllanthin caused significant and dose-dependent inhibition of T and B lymphocytes proliferation and down-regulation of the Th1 (IL-2 and IFN-γ) and Th2 (IL-4) cytokines. Phyllanthin at 100mg/kg caused a significant reduction in the percentage expression of CD4(+) and CD8(+) in splenocytes and the inhibition was comparable to that of cyclosporin A at 50mg/kg. At 100mg/kg, phyllanthin also dose-dependently exhibited strong inhibition on the sheep red blood cell (sRBC)-induced swelling rate of mice paw in DTH. Significant inhibition of serum levels of ceruloplasmin and lysozyme were observed in mice fed with higher doses (40 and 100mg/kg) of phyllanthin. Anti-sRBC immunoglobulins (IgM and IgG) antibody titer was down-regulated in immunized and phyllanthin-treated mice in a dose-dependent manner with maximum inhibition being observed at 100mg/kg.
CONCLUSION: The strong inhibitory effects of phyllanthin on the cellular and humoral immune responses suggest that phyllanthin may be a good candidate for development into an effective immunosuppressive agent.