Number Of Plaque-forming Cells Research Articles

Astaxanthin Mitigates Thiacloprid-Induced Liver Injury and Immunotoxicity in Male Rats.

Thiacloprid (TCP) is a widely used neonicotinoid insecticide with a probable toxic hazard to animals and human beings. This hazard has intensified the demand for natural compounds to alleviate the expected toxic insults. This study aimed at determining whether astaxanthin (ASX) could mitigate the hepatotoxic effect of TCP and diminish its suppressive effect on immune responses in rats. Animals received TCP by gavage at 62.1 mg/kg (1/10th LD50) with or without ASX at 40 mg/kg for 60 days. Intoxicated rats showed modulation of serum transaminases and protein profiles. The hemagglutination antibody titer to sheep red blood cells (SRBC) and the number of plaque-forming cells in the spleen were reduced. The cell-mediated immunity and phagocytosis were suppressed, while serum interleukins IL-1β, IL-6, and IL-10 were elevated. Additionally, malondialdehyde, nitric oxide, and 8-hydroxy-2′-deoxyguanosine levels were increased in the liver, spleen, and thymus, with depletion of glutathione and suppression of superoxide dismutase and catalase activities. The expressions of inducible nitric oxide synthase and the high mobility group box protein 1 genes were upregulated with histomorphological alterations in the aforementioned organs. Cotreatment with ASX markedly ameliorated the toxic effects of TCP, and all markers showed a regression trend towards control values. Collectively, our data suggest that the protective effects of ASX on the liver and immune system of TCP-treated animals depend upon improving the antioxidant status and relieving the inflammatory response, and thus it may be used as a promising therapeutic agent to provide superior hepato- and immunoprotection.

Toxic effects of atrazine on immune function in BALB/c mice.

This study was aimed to evaluate the toxic effects of different concentrations (23, 90, 360mg/kg BW) of atrazine (ATZ) on immune function in BALB/c mice. Some parameters of general immunotoxicity, humoral immunity, cellular immunity, and non-specific immunity were tested. The studies showed that the high-dose ATZ induced a significant reduction in the final body weight of mice, the absolute and relative weights of spleen, the counts of white blood cell (WBC), lymphocyte (LYM), monocyte (MON), and the number of splenocyte. An increase in the level of alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), and cholesterol (CHO) in the high-dose ATZ group was observed. Pathological examination showed that the medium- and high-doses of ATZ caused atrophy and destruction of thymus, spleen, and hepatorenal toxicity. The serum interleukin-5(IL-5) level of mice and the number of plaque-forming cell (PFC) in spleen cells in the high-dose ATZ group decreased significantly while there was a significant increase of the serum immunoglobulin G (IgG) in the high-dose ATZ group when compared to the negative control group. In the high-dose ATZ group, the proliferation ability of T and B lymphocytes as well as the delayed-type hypersensitivity (DTH) response were significantly decreased. The low-dose ATZ (23mg/kg BW) caused a significant decrease in the number of WBC and neutrophil (NEUT), as well as the proportion of polychromatic and normoblast. In summary, we thought the low-dose ATZ has a slight effect on the immune system; it can be preliminarily concluded that the lowest observed adverse effect level (LOAEL) of atrazine is 23mg/kg BW in mice. Atrazine can cause immunotoxicity mainly through cellular and humoral immunity pathways.

Hawthorn (Crataegus monogyna) Phenolic Extract Modulates Lymphocyte Subsets and Humoral Immune Response in Mice

This study investigated the effect of hawthorn (Crataegus monogyna) phenolic extract on lymphocyte subsets in the lymphoid organs in nonimmunized mice and on humoral immune response in sheep red blood cell-immunized mice. Hawthorn phenolic extract (50, 100, 200 mg/kg) was administered orally five or ten times. Sheep red blood cells were injected 24 h after administration of the last extract dose. The lymphocyte subsets were assessed 24 and 72 h after the last dose. Humoral immune response was determined 4 and 7 days after immunization. Five doses of the extract decreased the percentage of CD4-CD8- and CD4+ thymocytes but elevated the percentage of CD4+CD8+ and CD8+ thymic cells. The extract increased the total number, percentage, and absolute count of T and B splenocytes. When administered five times, it lowered the percentage of T lymphocytes, but boosted the population of B lymphocytes of mesenteric lymph nodes (after 24 h). However, a rise in the population of T lymphocytes was observed 72 h after five and ten doses. The extract administered ten times elevated the number of plaque-forming cells and total anti-sheep red blood cell hemagglutinin titer but reduced the 2-ME-resistant antibody titer (day 7). At the same time, five doses of the extract increased antibody titers. Considering its impact on lymphocyte subsets and humoral immune response, hawthorn extract may be used as an immunomodulator.

Catechin rich butanol fraction extracted from Acacia catechu L. (a thirst quencher) exhibits immunostimulatory potential

Acacia catechu L., (Fabaceae) named as “catechu” is a plant, the decoction of heartwood of which is daily consumed as thirst quencher by a good percentage of the population in South India. The plant is mainly distributed in India and other Asian countries. It has been used in Indian traditional medicine for the treatment of asthma, bronchitis, colic, diarrhea, boils, skin afflictions, sores and stomatitis. The present investigation was aimed to study the immunomodulatory effects of different fractions of ethanol extract of A. catechu heartwood and HPLC analysis of the active fraction. Three fractions namely, butanol, chloroform and ethyl acetate were prepared from ethanol extract of A. catechu heartwood. Each of these fractions was assessed for its immunomodulatory activity. In vivo immunomodulatory activity was analyzed by sheep red blood cells (SRBC) specific hemagglutinating antibody titer, plaque-forming cell assay and delayed type hypersensitivity (DTH) reaction in Swiss albino mice. In vitro immunomodulating potential of the fractions was studied using murine peritoneal macrophages and splenocytes. Non-specific immune functions such as phagocytosis (nitroblue tetrazolium reduction assay and cellular lysosomal enzyme assay), nitric oxide (NO) production and cytokine release (TNF-α and IL-10) were studied in macrophages. In addition, splenocyte proliferation was also studied. In the in vivo experiments, butanol and chloroform fractions showed an increase in antibody titer dose-dependently. At higher dose (400 mg/kg b. w.) treatment the butanol fraction produced an enhancement in the number of plaque-forming cells (antibody producing cells) in the spleen. SRBC induced DTH reaction was significantly increased with butanol fraction in a dose-dependent manner. Peritoneal macrophages showed an increased phagocytic response on treatment with butanol fraction (100 μg/mL) as evidenced by its effect on nitroblue tetrazolium reduction and cellular lysosomal enzyme activity. All three fractions inhibited the production of NO and the release of TNF-α. Interleukin-10 production was significantly increased after treatment with butanol fraction. High-performance liquid chromatography analysis of the butanol fraction showed the presence of high concentration of catechin. The results suggested that butanol fraction of ethanol extract of A. catechu heartwood had immunomodulatory effects on non-specific, humoral, and cell-mediated immune functions. This study may be useful in validating the rationality of daily consumption of decoction of A. catechu and also its use in traditional medicine system. The study also suggests the possible use of A. catechu in the immunostimulatory herbal preparations.

Stimulation of murine immune response by Clerodendrum infortunatum

Background: Clerodendrum infortunatum is a medicinal plant found especially in the Sub-Himalayan regions of West Bengal. Various tribal communities of this region have been using these plants as a source of natural medicine. Objective: Medicinal values of C. infortunatum are well established, but the immunomodulatory properties have never been studied. Therefore, we wanted to investigate various immunomodulatory activities of this plant. Materials and Methods: Several parameters such as plaque-forming cell assay, hemagglutination titer, phagocytic activity of macrophages, and inhibition of lipopolysaccharide (LPS) were performed. Moreover, effects of C. infortunatum on the weight of various organs and total serum protein, albumin, and globulin levels were also determined. The phytochemical fingerprints of C. infortunatum extracts were obtained from Fourier transform infrared and gas chromatography-mass spectrometry analysis. Results: The macrophage stimulation and plaque-forming cell numbers (using sheep red blood cell as antigen) were significantly proliferated and found optimum at 100 and 250 mg/kg doses of leaf and root extracts simultaneously. The extent of stimulation in mural humoral immunity was in the order of leaf > root > stem. The anti-inflammatory activity of C. infortunatum was confirmed by the inhibition of LPS-induced nitric oxide synthesis by macrophages. Conclusion: It can be concluded that 70% hydromethanolic extract of C. infortunatum has profound immunomodulation potentials in the murine model, stimulating both humoral and innate form of the immune system. Abbreviations used: PFC: Plaque-forming cell assay; HA titer: Hemagglutination titer; LPS: Lipopolysaccharide; FTIR: Fourier transform infrared; GC-MS: Gas chromatography-mass spectrometry; SDS: Sodium dodecyl sulfate; sRBC: Sheep red blood cell; PBS: Phosphate buffer saline; PC: Phagocytic capacity; PI: Phagocytic index; NaCl: Sodium chloride; CaCl2: Calcium chloride; NBT: Nitro blue tetrazolium; DMSO: Dimethyl sulfoxide; KOH: Potassium hydroxide; H2SO4: Sulfuric acid; HOCl: Hypochlorous acid; H2O2: Hydrogen peroxide; EDTA: Ethylenediaminetetraacetic acid.

Immunoregulatory effects of 4-(4-chlorophenyl)-1-(5-amino-3-methylisoxazole-4-carbonyl)-thiosemicarbazide (06K) in non-immunized and SRBC-immunized mice.

Immunoregulatory properties of 06K derivative (4-(4-chlorophenyl)-1-(5-amino-3-methylisoxazole-4-carbonyl)-thiosemicarbazide) in mouse in vivo models were investigated. Several in vivo models were used: humoral and cellular immune response, carrageenan inflammatory reaction and determination of lymphocyte subsets in non-immunized mice. The compound administered before or after immunization with sheep erythrocytes (sheep red blood cell (SRBC)) elevated the number of plaque-forming cells (PFC), and this effect was stronger at lower doses. Although total haemagglutinin titres to SRBC decreased upon postimmunization treatment, IgG titre increased. In the model of delayed-type hypersensitivity (DTH) to ovalbumin (OVA), the compound, applied intraperitoneally before an eliciting dose of an antigen but not before immunization, inhibited the magnitude of a cutaneous reaction. Further, 06K significantly diminished carrageenan-induced foot pad inflammation when administered 1 h before carrageenan. The compound, administered intraperitoneally to naïve mice, elicited changes in weight, cell number in lymphoid organs and content of lymphocyte subsets, depending on the dose and number of applications. Phenotypic changes included increased turnover of thymocytes, changes in B-cell distribution in spleens and lymph nodes, increased percentage of CD8+ cells and regulatory CD4+ CD25+ Foxp3+ T cells. Immunoregulatory properties of 06K involve mobilization of lymphopoiesis and generation of regulatory T cells.

Immune response modulatory effect of Emilia sonchifolia (L.) DC: an in vivo experimental study.

This study was performed in order to provide a scientific basis for the conventional use of Emilia sonchifolia in the traditional Indian Ayurvedic medicine possibly through modulation of the host immune defense. Emilia sonchifolia methanolic extract (25 mg/kg body weight) was administered intraperitoneally in mice, and hematological parameters, relative organ weights, bone marrow cellularity, and α-esterase activity were assessed. Humoral immune response was evaluated by hemagglutinating antibody (HA) titer and plaque forming cell (PFC) assay. Blastogenesis assays of lymphoid organs were done in the presence and absence of various mitogens such as phytohemagglutinin, concanavalin A, pokeweed mitogen, and lipopolysaccharide. Cytotoxic T lymphocyte (CTL) production was assessed by Winn's neutralization test. The levels of cytokines interleukin-2 (IL-2) and interferon-γ (IFN-γ) were evaluated by ELISA. Emilia sonchifolia significantly enhanced the total white blood cell count (9995±535 cells/mm3), bone marrow cellularity, α-esterase activity, and weight of lymphoid organs (p<0.001). The effect on humoral immune response was evident from the enhanced HA titer and increased number of PFCs (p<0.001). The blastogenic effects of mitogens were also stimulated to significant levels by E. sonchifolia treatment. Emilia sonchifolia treatment augmented cell-mediated immune response by enhancing the killing activity of CTLs and by enhanced production of IL-2 and IFN-γ. From these results, it was very evident that E. sonchifolia, an indigenous medicinal plant, is a potent immune response modulator, and the present report is so far the first study to demonstrate the immunoregulatory activity of E. sonchifolia.

Dried fruit extract of Terminalia chebula modulates the immune response in mice

Terminalia chebula, traditionally regarded as universal panacea, is known for its pleiotropic effects, including the effects on oxidative stress, malignant tumor growth, wound healing, and insulin sensitivity in Type 2 diabetes. This study reports the effect of dry fruit extract of T. chebula (TCE) on Th1/Th2-mediated immune responses in mice. TCE was administered orally for 10 consecutive days, after which mice were immunized with goat RBC (gRBC) or ovalbumin. TCE enhanced the expression of Th1 cytokine, interferon γ, decreased interleukin 4, and increased the number of plaque-forming cells in gRBC-immunized mice. The percentage of CD4+ cells and delayed-type hypersensitivity response also increased in these mice. Treatment is reported to increase lymphocyte proliferation and macrophage phagocyte response, but decrease nitrite production. The bone marrow cellularity and WBC count also increased in the treated mice. None of the group showed any sign of toxicity. The data indicate that TCE elicits a significant dose-dependent Th1 response.

Stimulation of Murine Immune Response by the Tubers of Dioscorea alata L. of North-Eastern Region of India

Dioscorea alata is a staple food in south-eastern Asia and Africa and also widely consumed in the North-eastern region of India. Its medicinal value is well established, but the immunomodulatory property has never been studied on animal model. Therefore, we have investigated the immunomodulatory activity of D. alata by performing plaque forming cell assay, haemagglutination titer, stimulation of phagocytosis assay, inhibition of lipopolysaccharide (LPS) induced nitric oxide (NO) synthesis, carbon-clearance test, in vitro cell adhesions assay and various cell counts. Effect of D. alata on various organ weight and total serum protein, albumin and globulin levels were also determined. At 100 mg/kg dose the macrophages were highly stimulated (P < 0.001) to proliferate and the plaque forming cell number was also found to be optimum (P < 0.001) at the same dose. Elimination of foreign material from the system was found to be highest at 250 mg/kg dose. Both at 100 and 250 mg/kg doses, the phagocytic activity of the macrophages was increased significantly (P < 0.001). Anti-inflammatory activity of D. alata was proved by the inhibition of LPS induced NO synthesis by macrophages. Therefore, it can be concluded that 70 % hydro-methanolic extract of D. alata has profound immunostimulating potential in the murine model, stimulating both humoral and innate arms of the immune system.

Involvement of (IgG and IgM)-secreting B lymphocytes in severity of autoimmune hepatitis type 1

Autoimmune hepatitis type 1 (AIH1) is an autoimmune disease attacks the liver and characterized by periportal inflammation, elevated immunoglobulins, and autoantibodies. The central role of B lymphocyte in pathogenicity of AIH1 is unclear. Here, the effect of antibody-secreting cells activity in terms of number of plaque-forming cells (PFC) on severity of AIH1 was evaluated. The high number of PFC-(IgG and IgM) in peripheral blood of patients with AIH1 was observed and this was concomitant with increase in the number of CD4+ T lymphocyte, immunoglobulin (Ig) (IgG and IgM) concentrations, and levels of liver function tests (LFTs). However, the negative correlation (r < -0.5, P < 0.05) between the numbers of PFC-(IgG and IgM) and CD8+ T lymphocytes was reported here. The present study showed the positive relationship between the concentrations of Ig (IgG and IgM) and levels of LFTs (r > +0.5, P < 0.05). The high expression of IL-10 mRNA was found in the tissue culture of peripheral blood lymphocytes obtained from patients with AIH1 as compared with that isolated from control group (P < 0.05). The current study proved the direct role of (IgG and IgM)-secreting cells in severity of AIH1. This was associated with CD4+ cell numbers and IL-10 mRNA expression, and mediated by IgG and IgM.

Immunomodulatory Effect of Ganoderma Lucidum Polysaccharides (GLP) on Long-Term Heavy-Load Exercising Mice

Long-term heavy-load exercise can lead to a decrease in the organism's immune response. In this study, we used 100 Kunming (KM) mice to investigate the immune-regulatory effects of Ganoderma lucidum polysaccharides (GLP) on long-term heavy-load exercising mice. Peripheral white blood cells (WBC), the absolute value of neutrophils (NEUT), the phagocytic function of macrophages, serum agglutination valence, and the number of plaque-forming cells (PFC) were evaluated 4 weeks after gavaging long-term heavy-load exercising mice with GLP. After exercise, the WBC count in peripheral blood, absolute neutrophil count, macrophage phagocytic index, serum agglutination valence, and the number of plaque-forming cells were significantly reduced in the mice not fed GLP. Both medium and high doses of GLP drastically increased peripheral WBC, absolute neutrophil count, macrophage phagocytic index, serum agglutination valence, and the number of plaque-forming cells in long-term heavy-load exercising mice. High doses of GLP increased peritoneal macrophage phagocytic rate considerably. With this study, we demonstrate that 4 weeks of heavy-load exercise can lead to exercise-induced immunosuppression in mice. A supplement of GLP fed to these mice improves both non-specific and specific immune responses among these mice. The effect for the high-dose GLP treatment is especially significant.

The effects of bestatin on humoral response to sheep erythrocytes in non-treated and cyclophosphamide-immunocompromised mice

The effects of bestatin on humoral immune response to sheep erythrocytes (SRBC) and restoration of the response impaired by a single cyclophosphamide dose (350 mg/kg) were tested on mice. Bestatin (at doses of 10, 1, and 0.1 mg/kg) was administered intraperitoneally (i.p.) 5 or 10 times. The pharmacological immunosuppression was induced by a single i.p. injection of cyclophosphamide (350 mg/kg) administered 24 h before the first bestatin dose. The mice were immunized i.p. with SRBC 24 h after the last dose of bestatin. It was found that multiple administration of bestatin at all three doses potentiated the humoral response to SRBC in non-treated mice, resulting in an increased number of plaque-forming cells (PFC) and 2-mercaptoethanol (2-ME)–resistant anti-SRBC antibodies. However, five times administration of bestatin at the doses under investigation caused further decreases in total anti-SRBC hemagglutinins. A single injection of cyclophosphamide (350 mg/kg) suppressed humoral response of mice to the antigen. Administration of bestatin after pharmacological immunosuppression partially prevented the suppressive action of cyclophosphamide in the in vivo model of the humoral immune response to SRBC. The protective action of bestatin was both dose- and schedule-dependent. Ten times’ exposure to a bestatin dose of 0.1 mg/kg after a high cyclophosphamide dose partially reduced the suppressive effect of this drug on humoral response of SRBC-immunized mice, increasing PFC on days 4 and 7 after immunization, which coincided with restored ability of the lymphocytes to produce the 2-ME–resistant hemagglutinins on day 7 and the total anti-SRBC hemagglutinins on day 14 after priming.

Modulation of humoral immune responses and inhibition of proinflammatory cytokines and nitric oxide production by 10-methoxycanthin-6-one

Plant-derived natural products such as alkaloids, flavonoids, terpenoids, and polysaccharides have received considerable attention in recent years due to their diverse pharmacological properties such as immunomodulatory, anti-inflammatory, cytotoxic, cancer chemopreventive effects, and so on. 10-Methoxycanthin-6-one, a β-carboline alkaloid from the medicinal plant Aerva lanata, was assessed for immunomodulatory activity in Balb/c mice. Intraperitoneal administration of five doses of the compound at 0.5 mg/kg body weight was found to enhance the total WBC count (13,975.50 ± 324.27 cells/mm3 on the 12th day), bone marrow cellularity (23.08 ± 0.86 × 106 cells/femur), and number of α-esterase-positive cells (1283.16 ± 21.10 cells/4000 cells). Treatment with the compound along with the antigen, sheep red blood cells, produced an enhancement in the circulating antibody titer (1024 on Days 12 and 15) and the number of plaque-forming cells (PFC) in the spleen. In treated group, maximum number of PFC (264.83 PFC/106 spleen cells) was observed on the sixth day after antigen administration. At the same time, administration of 10-methoxycanthin-6-one could significantly reduce the elevated levels of proinflammatory cytokines and nitric oxide production by lipopolysaccharide (LPS)-stimulated macrophages. There was also a significant reduction in the mRNA levels of inducible nitric oxide synthase, cyclooxygenase 2, tumor necrosis factor alpha (TNF)-α, and interleukin (IL)-1β and IL-6 in LPS-stimulated macrophages after treatment with 10-methoxycanthin-6-one.

Germinal Center Texture Entropy as Possible Indicator of Humoral Immune Response: Immunophysiology Viewpoint

In this article, we present the results indicating that spleen germinal center (GC) texture entropy determined by gray-level co-occurrence matrix (GLCM) method is related to humoral immune response. Spleen tissue was obtained from eight outbred male short-haired guinea pigs previously immunized by sheep red blood cells (SRBC). A total of 312 images from 39 germinal centers (156 GC light zone images and 156 GC dark zone images) were acquired and analyzed by GLCM method. Angular second moment, contrast, correlation, entropy, and inverse difference moment were calculated for each image. Humoral immune response to SRBC was measured using T cell-dependent antibody response (TDAR) assay. Statistically highly significant negative correlation was detected between light zone entropy and the number of TDAR plaque-forming cells (r (s) = -0.86, p < 0.01). The entropy decreased as the plaque-forming cells increased and vice versa. A statistically significant negative correlation was also detected between dark zone entropy values and the number of plaque-forming cells (r (s) = -0.69, p < 0.05). Germinal center texture entropy may be a powerful indicator of humoral immune response. This study is one of the first to point out the potential scientific value of GLCM image texture analysis in lymphoid tissue cytoarchitecture evaluation. Lymphoid tissue texture analysis could become an important and affordable addition to the conventional immunophysiology techniques.

Immunomodulatory and antitumor activity of Aerva lanata ethanolic extract

Cancer is responsible for millions of deaths each year worldwide. Pharmacological intervention with plant-derived products alone or in combination to reverse, suppress, or prevent the cancer progression plays a key role in the fight against this terrible disease. Aerva lanata is an important medicinal plant widely used in traditional systems of medicine like ayurveda and siddha. Ethanolic extract of whole plant of A. lanata exhibited immunomodulatory and antitumor activity. Intraperitoneal administration of five doses of the extract (10 mg/kg body weight) was found to enhance the total WBC count (14,238 cells/mm3), bone marrow cellularity (22.33 × 106 cells/femur), and number of α-esterase-positive cells (1276 cells/4000 cells). Aerva treatment also showed enhanced proliferation of splenocytes, thymocytes, and bone marrow cells both in the presence and absence of specific mitogens in vitro and in vivo. The number of plaque-forming cells (PFC) in spleen (243.33 PFC/106 spleen cells) and circulating antibody titer were also increased (P < 0.001). The extract was 100% cytotoxic to Dalton’s lymphoma ascites (DLA) and Ehrlich ascites carcinoma (EAC) cells at a concentration of 500 µg/mL. It was also found to be cytotoxic toward L929 and HELA cells at higher concentrations, whereas the nontoxic concentrations produced a reduction in the rate of proliferation. Simultaneous administration of five doses of A. lanata extract could produce significant inhibition in DLA-induced solid tumor development in mice and increase the life span of mice-bearing EAC tumors by 53.47%.

Arctigenin, a phenylpropanoid dibenzylbutyrolactone lignan, inhibits type I–IV allergic inflammation and pro-inflammatory enzymes

We previously reported that arctigenin, a phenylpropanoid dibenzylbutyrolactone lignan isolated from Forsythia koreana, exhibits anti-inflammatory, antioxidant, and analgesic effects in animal models. In addition, arctigenin inhibited eosinophil peroxidase and activated myeloperoxidase in inflamed tissues. In this study, we tested the effects of arctigenin on type I-IV allergic inflammation and pro-inflammatory enzymes in vitro and in vivo. Arctigenin significantly inhibited the heterologous passive cutaneous anaphylaxis induced by ovalbumin in mice at 15 mg/kg, p.o., and compound 48/80-induced histamine release from rat peritoneal mast cells at 10 microM. Arctigenin (15 mg/kg, p.o.) significantly inhibited reversed cutaneous anaphylaxis. Further, arctigenin (15 mg/kg, p.o.) significantly inhibited the Arthus reaction to sheep's red blood cells, decreasing the hemolysis titer, the hemagglutination titer, and the plaque-forming cell number for SRBCs. In addition, arctigenin significantly inhibited delayed type hypersensitivity at 15 mg/kg, p.o. and the formation of rosette-forming cells at 45 mg/kg, p.o. Contact dermatitis induced by picrylchloride and dinitrofluorobenzene was significantly (p < 0.05) inhibited by surface treatment with arctigenin (0.3 mg/ear). Furthermore, arctigenin dose-dependently inhibited pro-inflammatory enzymes, such as cyclooxygenase-1 and 2, 5-lipoxygenase, phospholipase A2, and phosphodiesterase. Our results show that arctigenin significantly inhibited B- and T-cell mediated allergic inflammation as well as pro-inflammatory enzymes.

Modulation of immune response by Vernonia cinerea L. inhibits the proinflammatory cytokine profile, iNOS, and COX-2 expression in LPS-stimulated macrophages

The effect of methanolic extract of Vernonia cinerea L. on the immune system was studied using BALB/c mice. Intraperitoneal (i.p.) administration of five doses of the extract (20 mg/kg body weight) was found to enhance the total white blood cell (WBC) count (13,700 ± 463 cells/mm3) on 6th day, bone marrow cellularity (27.9 ± 2.1 × 106 cells/femur) and number of α-esterase positive cells (1184 ± 56.29/4000 cells). Treatment with V. cinerea along with the antigen, sheep red blood cells (SRBC), produced an enhancement in the circulating antibody titre and the number of plaque forming cells (PFC) in the spleen. Maximum number of PFC (304.16 ± 12.4) was obtained on the 6th day. It also enhanced the proliferation of splenocytes, thymocytes and bone marrow cells both in the presence and absence of specific mitogens in vitro and in vivo. Administration of V. cinerea significantly reduced the lipopolysaccharide (LPS) induced elevated levels of nitric oxide (NO) and proinflammatory cytokines such as tumor necrosis factor-α, interleukin-1 (IL-1β), and IL-6 in mice. Treatment of V. cinerea methanolic extract also showed an enhancement in the phagocytic activity of peritoneal macrophages. Moreover The extract downregulated the inducible NO synthase and cyclooxygenase-2 (COX-2) mRNA expression in LPS-stimulated macrophages. These results indicate the immunomodulatory activity of V. cinerea.

Immunomodulatory effects of betulinic acid from the bark of white birch on mice

The objective of this study was to explore the immunomodulatory effects of betulinic acid (BA) extracted from the bark of white birch on mice. Female mice were orally administered BA for 14 days in doses of 0, 0.25, 0.5, and 1 mg/kg body weight. We found that BA significantly enhanced the thymus and spleen indices, and stimulated lymphocyte proliferation induced by Concanavalin A and lipopolysaccharide as shown by MTT assay. Flow cytometry revealed that BA increased the percentage of CD4+ cells in thymus as well as the percentage of CD19+ and the ratios of CD4+/CD8+ in spleen. BA increased the number of plaque-forming cell and macrophage phagocytic activity as indicated by a neutral red dye uptake assay, and the peritoneal macrophages levels of TNF-α were also increased. In contrast, serum levels of IgG and IgM and serum concentrations of IL-2 and IL-6 were significantly decreased in BA-treated mice compared to the control as assayed by haemagglutination tests and ELISA, respectively. Taken together, these results suggest that BA enhances mouse cellular immunity, humoral immunity, and activity of macrophages. Thus, BA is a potential immune stimulator and may strengthen the immune response of its host.

Ipomoea obscura (L.) enhances the functions of immunological effector cells, inhibits proinflammatory cytokines and nitric oxide production by LPS induced macrophages

Most of the synthetic chemotherapeutic agents available today are immunosuppressant, cytotoxic and exerts variety of side effects. Botanical based immunomodulators are often employed as supportive or adjuvant therapy to overcome the undesired effects of cytotoxic chemotherapeutic agents and to restore normal health. The methanolic extract of traditionally important medicinal plant Ipomoea obscura exhibited immunomodulatory activity in BALB/c mice. Intraperitoneal administration of five doses of the extract (10 mg/kg body wt) was found to enhance the total WBC count (13912cells/mm3) on the 12th day, bone marrow cellularity (28.9 × 106cells/femur) and number of α-esterase positive cells (1246 cells/4000 cells). Treatment with the extract along with the antigen, sheep red blood cells (SRBC), produced an enhancement in the circulating antibody titer and the number of plaque forming cells (PFC) in the spleen. Maximum number of PFC (267.6 PFC/106 spleen cells) was obtained on the 6th day. At the same time administration of Ipomoea obscura extract significantly reduced the elevated levels of proinflammatory cytokines and nitric oxide production by lipopolysaccharide stimulated macrophages. These results indicate the immunomodulatory activity of the alcoholic extract of Ipomoea obscura.

Immunomodulatory activities of Punarnavine, an alkaloid from Boerhaavia diffusa

The effect of Punarnavine on the immune system was studied using Balb/c mice. Intraperitoneal administration of Punarnavine (40 mg/kg body weight) was found to enhance the total WBC count on 6th day. Bone marrow cellularity and number of α-esterase positive cells were also increased by the administration of Punarnavine. Treatment of Punarnavine along with the antigen, sheep red blood cells (SRBC), produced an enhancement in the circulating antibody titer and the number of plaque forming cells (PFC) in the spleen. Maximum number of PFC was obtained on the 6th day. Punarnavine also showed enhanced proliferation of splenocytes, thymocytes and bone marrow cells both in the presence and absence of specific mitogens in vitro and in vivo. More over administration of Punarnavine significantly reduced the LPS induced elevated levels of proinflammatory cytokines such as TNF-α, IL-1β, and IL-6 in mice. These results indicate the immunomodulatory activity of Punarnavine.