Exogenous IL-13 exacerbates Leishmania major infection and abrogates acquired immunity to re-infection.

Cutaneous leishmaniasis is a major global health issue, affecting more than 88 countries with 0.7-1.2 million new cases per year. T helper polarization plays a significant role in disease outcome, with Th1 responses being associated with resistance and Th2 responses being associated with susceptibility. IL-13 is an important Th2 cytokine with structural and functional similarities to IL-4. In this study, we demonstrate that administering exogenous IL-13 to Leishmania major-infected BALB/c mice increases parasite load in the infected paw and decreases tissue levels of the key Th1/Th2 cytokines IFN-γ and IL-4, respectively. Infecting BALB/c mice with a low dose of L. major has previously been shown to confer resistance to re-infection with a higher dose. In this study, we demonstrate that administration of exogenous IL-13 early in the course of the initial low-dose infection abrogates acquired resistance to high-dose re-infection, as measured by infected paw thickness.

Cytotoxic effect of Montivipera bornmuelleri's venom on cancer cell lines: in vitro and in vivo studies.

BACKGROUND: Montivipera bornmuelleri's venom has shown immunomodulation of cytokines release in mice and selective cytotoxicity on cancer cells in a dose-dependent manner, highlighting an anticancer potential. Here, we extend these findings by elucidating the sensitivity of murine B16 skin melanoma and 3-MCA-induced murine fibrosarcoma cell lines to M. bornmuelleri's venom and its effect on tumor growth in vivo. METHODS: The toxicity of the venom on B16 and MCA cells was assessed using flow cytometry and xCELLigence assays. For in vivo testing, tumor growth was followed in mice after intratumoral venom injection. RESULTS: The venom toxicity showed a dose-dependent cell death on both B16 and MCA cells. Interestingly, overexpression of ovalbumin increased the sensitivity of the cells to the venom. However, the venom was not able to eradicate induced-tumor growth when injected at 100 µg/kg. Our study demonstrates a cytotoxic effect of M. bornmuelleri's venom in vitro which, however, does not translate to an anticancer action in vivo.

Immunomodulatory effect of natural and modified Citrus pectin on cytokine levels in the spleen of BALB/c mice.

Pectin is present in the cell wall of different vegetables and fruits. Beside its importance in the plant cell wall, pectin has enticed great attention for its beneficial effects on human health. It was shown to decrease cholesterol levels, to possess anti-oxidative, anti-bacterial and anti-cancer activity. The immunomodulatory activity of pectin and its mechanism of action is recently being investigated. In this study, the differential immunomodulatory activities of both CP (citrus pectin) and MCP (modified citrus pectin) were investigated. Females BALB/c mice (20-25 g) were randomly divided into 7 groups and different concentrations of CP and MCP (0%, 1.5%, 3% and 5%) were added to their drinking water for 21 days. Then, the splenic level of IL-1ß, IL-4, IL-10, IL-17, IFN-γ and TNF-α were evaluated using ELISA. Both CP and MCP exhibited immunomodulatory activities by increasing the levels of the pro-inflammatory cytokines IL-17, IFN-γ and TNF-α levels. This tendency seems to be regulated by the up-regulation of IL-4 levels but with no major effect on those of IL-10. Therefore, CP and especially MCP have potential immunomodulatory effects which might be highly beneficial in immunotherapy.

Atenolol Reduces Leishmania major-Induced Hyperalgesia and TNF-α Without Affecting IL-1ß or Keratinocyte Derived Chemokines (KC).

Infection with a high dose of the intracellular parasitic protozoan Leishmania major induces a sustained hyperalgesia in susceptible BALB/c mice accompanied by up-regulation of the pro-inflammatory cytokines IL-1ß and IL-6. Interleukin-13 (IL-13) has been shown to reduce this hyperalgesia (despite increased levels of IL-6) and the levels of IL-1ß during and after the treatment period. These findings favor the cytokine cascade leading to the production of sympathetic amines (involving TNF-α and KC) over prostaglandins (involving IL-lß and IL-6) as the final mediators of hyperalgesia. The aim of this study was to investigate the effect of daily treatment with the ß-blockers atenolol on L. major-induced inflammation in mice with respect to hyperalgesia as well as the levels of TNF-α and KC (the analog of IL-8 in mice). Our data demonstrates that atenolol is able to reduce the L. major induced sustained peripheral hyperalgesia, which does not seem to involve a direct role for neither IL-lß nor KC. Moreover, our results show that TNF-α may play a pivotal and direct role in sensitizing the peripheral nerve endings (nociceptors) since its level was reduced during the period of atenolol treatment, which correlates well with the reduction of the observed peripheral, but not central, hyperalgesia. These findings contribute to a better understanding of the cytokine cascade leading to hyperalgesia and may lead to the development of new and more efficient medications for many types of pain.

Antioxidant and hepatoprotective activities of the oil fractions from wild carrot (Daucus carota ssp. carota).

CONTEXT: Wild carrot, Daucus carota L. ssp. carota (Apiacae), is widely distributed throughout the world and has various uses in traditional medicine in Lebanon. OBJECTIVE: The present study aimed to fractionate and analyze the chemical composition of the Daucus carota oil extract (DCOE) fractions and to evaluate their antioxidant and hepatoprotective properties in vitro and in vivo. MATERIALS AND METHODS: DCOE was chromatographed on silica gel column to produce four fractions: pentane (F1), 50:50 pentane:diethyl ether (F2), diethyl ether (F3), and 93:7 chloroform: methanol (F4). Qualitative and quantitative analyses of oil fractions were performed by GC-MS and HPLC techniques. The in vitro antioxidant properties were assessed using DPPH, FIC, and ferric-reducing antioxidant power (FRAP) assays. The hepatoprotective property was determined by examining the levels of serum markers (alanine transaminase (ALT) and aspartate transaminase (AST)) and hepatic antioxidant (superoxide dismutase (SOD), catalase (CAT), and glutathione-S-transferase (GST)) enzymes in CCl4-intoxicated mice pretreated with intraperitoenal 50, 100, or 200 mg/kg b.w. of the oil fractions for 5 d. RESULTS: GCMS analysis of F2 revealed the presence of 2-himachalen-6-ol (61.4%) which is reported for the first time in Daucus carota species. F3 and F4 were rich in phenolics and flavonoids and demonstrated significant DPPH activity (IC50 = 0.29 and 0.38 mg/ml, respectively) and high FRAP values (225.11 and 437.59 µmol FeSO4/g, respectively). The sesquiterpene-rich fraction F1 had the highest FIC ability (IC50 = 0.28 mg/ml). Pretreatment with F1 and F4 reversed the CCl4-induced decrease in SOD, CAT, and GST levels and reduced significantly hepatic damage. DISCUSSION AND CONCLUSION: The current results suggested that wild carrot oil fractions exhibited a unique chemical composition and possessed significant antioxidant activities as well as hepatoprotective effects against CCl4-induced hepatotoxicity.

In Leishmania major-induced inflammation, interleukin-13 reduces hyperalgesia, down-regulates IL-1ß and up-regulates IL-6 in an IL-4 independent mechanism.

Infection with high dose Leishmania major induces a sustained hyperalgesia in BALB/c mice while low dose induces a short lived hyperalgesia both accompanied with the upregulation of IL-1ß and IL-6. Although IL-13 was shown to reduce the high dose L. major hyperalgesia during the treatment period, this effect was accompanied by a significant decrease in the levels of IL-1ß and a significant increase in the levels of IL-6 in the paws of mice even beyond this period. Those results suggest that IL-13 exerts those effects via the induction of another mediator, IL-4 being a potential candidate due to its known hypoalgesic effects in other models and to its close functional closeness to IL-13 especially at the level of receptors. In this study we correlated the pain thresholds and the levels of IL-1ß, IL-6 and IL-4 with the period of IL-13 treatment and beyond it in mice infected with high and low dose of L. major. The results of both models show that IL-1ß plays no direct role in provoking the observed hyperalgesia after stopping the treatment with IL-13 which is in contrary to IL-6 which might be a key player after the treatment period. Furthermore we demonstrate that there is no correlation between the levels of IL-4, hyperalgesia, the decreased IL-1ß levels and the increased levels of IL-6 in the paws of IL-13 treated and L. major (high and low dose) infected BALB/c mice.

Interleukin-13 reduces hyperalgesia and the level of interleukin-1ß in BALB/c mice infected with Leishmania major with an up-regulation of interleukin-6.

The anti-inflammatory cytokines interleukin-10 (IL-10) and interleukin-13 (IL-13) were shown to reduce hyperalgesia in some models such as rats exposed to UV rays. In addition, IL-10 was also shown to reduce hyperalgesia in high dose of Leishmania major-induced inflammation in BALB/c mice accompanied by a significant decrease in the levels of interleukin-1ß (IL-1ß) in the paws of infected mice, while no effect on the levels of IL-6 was observed. In this study, we injected BALB/c mice with a high dose of L. major and treated them with IL-13 (15 ng/animal) for twelve days (excluding the weekends) and hyperalgesia was assessed using thermal pain tests. Furthermore, the levels of IL-1ß and IL-6 were also assessed at different post-infection days. Our results show that IL-6 and more importantly IL-1ß don't play a direct role in the L. major-induced hyperalgesia and that IL-13 induces this hyperalgesia through the down-regulation of IL-1ß and another proinflammatory cytokine (most probably TNF-α). Furthermore, our data show that IL-13 leads to the upregulation of the level IL-6 which initially seems to have no direct role in the induced hyperalgesia. Therefore, we suggest that the L. major-induced hyperalgesia is mainly mediated by the cytokine cascade leading to the production of sympathetic amines.

Leishmania major: interleukin-13 increases the infection-induced hyperalgesia and the levels of interleukin-1beta and interleukin-12 in rats.

Interleukin-13 (IL-13) is a powerful anti-inflammatory cytokine that was previously shown to be a susceptibility factor for Leishmania major (L. major) infection. In this study we report a different role for IL-13 in rats infected with L. major; rIL-13 stimulates expression of pro-inflammatory cytokines and IL-12 which is a key cytokine in protective immunity against Leishmania. Infected rats received daily injections of rIL-13 for eight consecutive days which resulted in increased pain perception for the first week post-infection assessed by thermal pain tests. This hyperalgesia was accompanied by a sustained early up-regulation of interleukin-1beta followed by an up-regulation of IL-12p70. Real-time PCR showed no negative impact for rIL-13 upon the clearance of the parasites from the infection sites and blood.

Interleukin-10 reduces hyperalgesia and the level of Interleukin-1beta in BALB/c mice infected with Leishmania major with no major effect on the level of Interleukin-6.

Infection with a high dose of Leishmania major has been shown to induce hyperalgesia in BALB/c mice accompanied by a sustained upregulation of Interleukin-1beta (IL-1beta) and an early upregulation of Interleukin-6 (IL-6). On the other hand, Interleukin 10 (IL-10) has been demonstrated to be hypoalgesic in other models such as rats exposed to UV rays. In this study, we injected BALB/c mice with a high dose of Leishmania major and treated them with IL-10 (15 ng/animal) for six consecutive days. Hyperalgesia was assessed using thermal pain tests and the levels of IL-1beta and IL-6 were also assessed at different post-infection days. Our results show that IL-10 can reduce the Leishmania major-induced hyperalgesia during the treatment period through a direct effect on the levels of IL-1beta which seems to play an important role in this hyperalgesia induction since its level was reduced during the period of IL-10 injection and was increased again when this treatment was stopped. On the contrary IL-10 has no direct effect on the levels IL-6 which seems to have no direct role in the induced hyperalgesia.