Lifelong exposure to dietary fish oil alters macrophage responses in Walker 256 tumor-bearing rats

Fish oil supplementation in obese rats ameliorates metabolic syndrome response

Accumulation of visceral adipose tissue is associated with metabolic syndrome (MS), insulin resistance, and dyslipidemia. Here we examined several morphometric and biochemical parameters linked to MS in a rodent litter size reduction model, and how a 30-day fish oil (FO) supplementation affected these parameters. On day 3 post-birth, pups were divided into groups of ten or three. On day 22, rats were split into control (C) and small litter (SL) until 60 days old. Then, after metabolic disturbance and obesity were confirmed, FO supplementation started for 30 days and the new groups were named control (C), FO supplemented (FO), obese (Ob), and obese FO supplemented (ObFO). Comparison was performed by Student t-test or 2-way ANOVA followed by Tukey post hoc test. At the end of the 60-day period, SL rats were hyperphagic, obese, hypoinsulinemic, normoglycemic, and had high visceral fat depot and high interleukin (IL)-6 plasma concentration. Obese rats at 90 days of age were fatter, hyperphagic, hyperglycemic, hypertriacylgliceromic, hipoinsulinemic, with low innate immune response. IL-6 production ex vivo was higher, but in plasma it was not different from the control group. FO supplementation brought all biochemical changes to normal values, normalized food intake, and reduced body weight and fat mass in obese rats. The innate immune response was improved but still not as efficient as in lean animals. Our results suggested that as soon MS appears, FO supplementation must be used to ameliorate the morpho- and biochemical effects caused by MS and improve the innate immune response.

Microgramma vacciniifolia Frond Lectin: In Vitro Anti-leishmanial Activity and Immunomodulatory Effects Against Internalized Amastigote Forms of Leishmania amazonensis

PURPOSE

The treatment of leishmaniasis, an anthropozoonosis caused by Leishmania protozoa, is limited by factors, such as adverse effects, toxicity, and excessive cost, which has highlighted the importance of novel drugs. In this context, natural products have been considered as sources of antileishmanial agents. This study investigated the leishmanicidal activity of Microgramma vacciniifolia frond lectin (MvFL) on promastigotes and amastigotes of Leishmania amazonensis.

METHODS

The effects of MvFL on promastigote proliferation and macrophage infection by amastigotes were evaluated and mean inhibitory concentrations (IC50) were calculated. As a safety assessment, the hemolytic capacity of MvFL (6.25-200 µg/mL) against mouse and human erythrocytes was determined. Additionally, the ability of MvFL (6.25-100 µg/mL) to modulate lysosomal and phagocytic activities and the nitric oxide (NO) production by murine peritoneal macrophages was also investigated.

RESULTS

After 24 h, MvFL inhibited the proliferation of L. amazonensis promastigotes, with an IC50 of 88 µg/mL; however, hemolytic activity was not observed. MvFL also reduced macrophage infection by amastigotes with an IC50 of 52 µg/mL. Furthermore, treatment with MvFL reduced the number of amastigotes internalized by infected murine peritoneal macrophages by up to 68.9% within 48 h. At a concentration of 25 µg/mL, MvFL stimulated lysosomal activity of macrophages within 72 h, but did not alter phagocytic activity or induce NO production at any of the tested concentrations.

CONCLUSION

MvFL exerts antileishmanial activity and further studies are needed to assess its therapeutic potential in in vivo experimental models of leishmaniasis.

Antileishmania and immunomodulatory potential of cashew nut shell liquid and cardanol

Conventional treatments for leishmaniasis have caused serious adverse effects, poor tolerance, development of resistant strains. Natural products have been investigated as potential therapeutic alternatives. The cashew nut shell liquid (CNSL) is a natural source of phenolic compounds with several biological activities, where cardanol (CN) is considered one of the most important and promising compounds. This study aimed to evaluate antileishmanial, cytotoxic and immunomodulatory activities of CNSL and CN. Both showed antileishmanial potential, with IC₅₀ for CNSL and CN against Leishmania infantum: 148.12 and 56.74 μg/mL; against Leishmania braziliensis: 85.71 and 64.28 μg/mL; against Leishmania major: 153.56 and 122.31 μg/mL, respectively. The mean cytotoxic concentrations (CC₅₀) of CNSL and CN were 37.51 and 31.44 μg/mL, respectively. CNSL and CN significantly reduced the percentage of infected macrophages, with a selectivity index (SI) >20 for CN. CNSL and cardanol caused an increase in phagocytic capacity and lysosomal volume. Survival rates of Zophobas morio larvae at doses of 3; 30 and 300 mg/kg were: 85%, 75% and 60% in contact with CNSL and 85%, 60% and 40% in contact with CN, respectively. There was a significant difference between the survival curves of larvae when treated with CN, demonstrating a significant acute toxicity for this substance. Additional investigations are needed to evaluate these substances in the in vivo experimental infection model.

Cytotoxic and Antileishmanial Effects of the Monoterpene β-Ocimene

Leishmaniasis is a group of infectious-parasitic diseases with high mortality rates, and endemic in many regions of the globe. The currently available drugs present serious problems such as high toxicity, costs, and the emergence of drug resistance. This has stimulated research into new antileishmania drugs based on natural products and their derivatives. β-Ocimene is a monoterpene found naturally in the essential oils of many plant species which presents antileishmanial activity, and which has not yet been evaluated for its potential to inhibit the etiological agent of leishmaniasis. The aim of this work was to evaluate the activity of β-ocimene against Leishmania amazonensis, its cytotoxicity, and potential mechanisms of action. β-Ocimene presented direct activity against the parasite, with excellent growth inhibition of promastigotes (IC50 = 2.78 μM) and axenic amastigotes (EC50 = 1.12 μM) at concentrations non-toxic to RAW 264.7 macrophages (CC50 = 114.5 µM). The effect is related to changes in membrane permeability and resulting abnormalities in the parasitic cell shape. These were, respectively, observed in membrane integrity and atomic force microscopy assays. β-Ocimene was also shown to act indirectly, with greater activity against intra-macrophagic amastigotes (EC50 = 0.89 μM), increasing TNF-α, nitric oxide (NO), and reactive oxygen species (ROS), with lysosomal effects, as well as promoting decreases in IL-10 and IL-6. Against intra-macrophagic amastigote forms the selectivity index was higher than the reference drugs, being 469.52 times more selective than meglumine antimoniate, and 42.88 times more selective than amphotericin B. Our results suggest that β-ocimene possesses promising in vitro antileishmania activity and is a potential candidate for investigation in in vivo assays.

Effects of Vitamin D3 and Marine Omega-3 Fatty Acids Supplementation on Biomarkers of Systemic Inflammation: 4-Year Findings from the VITAL Randomized Trial

Background: The VITAL study was a nationwide, randomized, double-blind, placebo-controlled, 2 × 2 factorial trial of vitamin D3 (2000 IU/day) and marine n-3 FAs (1 g/day) supplements. We recently reported that vitamin D supplementation with or without omega 3 fatty acids reduced autoimmune disease by 22% in the VITAL study. Objective: To investigate the effects of vitamin D3 and/or n-3 FAs on changes in systemic inflammatory biomarkers including pro- and anti-inflammatory cytokines over a 4-year period in the VITAL sub-cohort with in-person evaluations at the Center for Clinical Investigations (CCI) in Boston. Design: Serum levels of four inflammatory biomarkers (high-sensitivity C-reactive protein [hs-CRP], interleukin-6, interleukin-10, and tumor necrosis factor-α) were measured in a total of 2713 samples from those 1054 VITAL/CCI participants (aged 64.9 ± 6.5 years, 49% female, 84% white, and 9% black) at baseline, year 2, and year 4 follow-up visits. Results: In multiple-adjusted models, vitamin D3 supplementation decreased serum hs-CRP levels by 19% at 2-year follow-up (nominal p = 0.007; p-value after multiple comparison adjustment = 0.028), but not at 4-year follow-up (nominal and adjusted p-values > 0.05). The effects of vitamin D3 on other inflammatory markers were not statistically significant either at year 2 or year 4 (all adjusted p-values > 0.05). Marine n-3 FAs were not significantly associated with changes of all the above inflammatory markers either at years 2 and 4, after multiple comparison adjustment (all p-values > 0.05). Conclusions: Vitamin D3 supplementation with or without n-3 FAs decreased hs-CRP by 19% at year 2, but not other inflammatory biomarkers at year 2 or year 4, while n-3 FAs with or without vitamin D3 did not significantly affect these biomarkers at either time point. Our findings support a potential role of vitamin D supplementation in modulating the chronic inflammatory process, systemic inflammation, and possibly autoimmune disease progression.

Curzerene antileishmania activity: Effects on Leishmania amazonensis and possible action mechanisms

Leishmaniasis is a set of infectious diseases with high rates of morbidity and mortality, it affects millions of people around the world. Treatment, mainly with pentavalent antimonials, presents significant toxicity and many cases of resistance. In previous works we have demonstrated the effective and selective antileishmanial activity of Eugenia uniflora L. essential oil, being constituted (47.3%) by the sesquiterpene curzerene. Considering the high rate of parasite inhibition demonstrated for E. uniflora essential oil, and the significant presence of curzerene in the oil, this study aimed to evaluate its antileishmania activity and possible mechanisms of action. Curzerene was effective in inhibiting the growth of promastigotes (IC₅₀ 3.09 ± 0.14 µM) and axenic amastigotes (EC₅₀ 2.56 ± 0.12 µM), with low cytotoxicity to RAW 264.7 macrophages (CC₅₀ 83.87 ± 4.63 µM). It was observed that curzerene has direct effects on the parasite, inducing cell death by apoptosis with secondary necrotic effects (producing pores in the plasma membrane). Curzerene proved to be even more effective against intra-macrophage amastigote forms, with an EC₅₀ of 0.46 ± 0.02 µM. The selectivity index demonstrated by curzerene on these parasite forms was 182.32, being respectively 44.15 and 8.47 times more selective than meglumine antimoniate and amphotericin B. The antiamastigote activity of curzerene was associated with immunomodulatory activity, as it increased TNF-α, IL-12, and NO levels, and lysosomal activity, and decreased IL-10 and IL-6 cytokine levels detected in macrophages infected and treated. In conclusion, our results demonstrate that curzerene is an effective and selective antileishmanial agent, a candidate for in vivo investigation in models of antileishmanial activity.

Biflavones from Platonia insignis Mart. Flowers Promote In Vitro Antileishmanial and Immunomodulatory Effects against Internalized Amastigote Forms of Leishmania amazonensis

Leishmaniasis is an infectious disease that affects millions of people worldwide, making the search essential for more accessible treatments. The species Platonia insignis Mart. (Clusiaceae) has been extensively studied and has gained prominence for its pharmacological potential. The objective of this work was to evaluate the antileishmania activity, cytotoxic effect and activation patterns of macrophages of hydroalcoholic extract (EHPi), ethyl acetate fractions (FAcOEt) and morelloflavone/volkensiflavone mixture (MB) from P. insignis flowers. EHPi, FAcOEt and MB demonstrated concentration-dependent antileishmania activity, with inhibition of parasite growth in all analyzed concentrations. EHPi exhibited maximum effect at 800 μg/mL, while FAcOEt and MB reduced the growth of the parasite by 94.62% at 800 μg/mL. EHPi, FAcOEt and MB showed low cytotoxic effects for macrophages at 81.78, 159.67 and 134.28 μg/mL, respectively. EHPi (11.25 µg/mL), FAcOEt (11.25 and 22.5 µg/mL) and MB (22.5 µg/mL) characterized the increase in lysosomal activity, suggesting a possible modulating effect. These findings open for the application of flowers from a P. insignis flowers and biflavones mixture thereof in the promising treatment of leishmaniasis.

In vitro cytotoxic effect of a chitin-like polysaccharide produced by Mortierella alpina on adrenocortical carcinoma cells H295R, and its use as mitotane adjuvant

This study presents an in vitro evaluation of the antitumor potential of a chitin-like exopolysaccharide (EPS, produced by Mortierella alpina) on Adrenocortical carcinoma cells (ACC) compared to mitotane, a commercial drug commonly used in ACC treatment, and known for its side effects. Techniques of cellular viability determination such as MTT and fluorescence were used to measure the cytotoxic effects of the EPS and mitotane in tumoral cells (H295R) and non-tumoral cells (VERO), observing high cytotoxicity of mitotane and a 10% superior pro-apoptotic effect of the EPS compared to mitotane (p < 0.05). The cytotoxic effect of the EPS was similar to the effect of 50 μM mitotane on tumoral cells (p < 0.05). A decrement of the lysosomal volume was also noted in tumoral cells treated with the EPS. To enhance the antitumor effect, a combination of mitotane at a lower dosage and the EPS (as adjuvant) was also tested, showing a slight improvement of the cytotoxicity effect on tumoral cells. Therefore, the results indicate a cytotoxic effect of the EPS produced by Mortierella alpina on adrenocortical carcinoma, and a possible application in biomedical formulations or additional treatments.

In vitro antileishmanial and immunomodulatory activities of the synthetic analogue riparin E

Leishmaniases are infectious diseases caused by protozoa of the genus Leishmania, that may have different clinical manifestations. First line drugs used in the treatment of leishmaniosis are high costly, and are very aggressive requiring medical monitoring. Thus new therapeutic alternatives are needed and, in this context, natural products have been considered as a source of new antileishmania agents. Riparins are alkamides found in the unripe fruits of Aniba riparia. Several biological activities are described for this group of compounds, such as antimicrobial and antiparasitic potential. The objective of this work was to evaluate the anti-leishmania activity riparin E (Rip-E) in vitro, against promastigotes and internalized amastigotes of Leishmania amazonensis. Rip-E was able to inhibit promastigote cell growth (IC₅₀ 4.7 μg/ml) and to reduce the percentage of macrophages infected with amastigotes, reducing its infectivity (survival index) (IC₅₀ 1.3 μg/ml). The cytotoxicity against BALB/c murine macrophages was also assessed (CC₅₀ 50.6 μg/ml) and the selectivity index was 38.9. Rip-E also demonstrated immunomodulatory activity, evidenced by the increase of the phagocytic capacity and lysosomal activity. However, Rip-E did not affect directly the production of nitric oxide. These results suggest that Rip-E has antileishmania potential, by both its direct inhibitory effect and its ability to activate macrophages.

β-Lapachone Increases Survival of Septic Mice by Regulating Inflammatory and Oxidative Response

Sepsis is characterized by a dysregulated immune response to infection characterized by an early hyperinflammatory and oxidative response followed by a subsequent immunosuppression phase. Although there have been some advances in the treatment of sepsis, mortality rates remain high, urging for the search of new therapies. β-Lapachone (β-Lap) is a natural compound obtained from Tabebuia avellanedae Lorentz ex Griseb. with several pharmacological properties including bactericidal, anti-inflammatory, and antioxidant activity. Thus, the aim of this study was to evaluate the effects of β-Lap in a mouse sepsis model. To this, we tested two therapeutic protocols in mice submitted to cecal ligation and puncture- (CLP-) induced sepsis. First, we found that in pretreated animals, β-Lap reduced the systemic inflammatory response and improved bacterial clearance and mouse survival. Moreover, β-Lap also decreased lipid peroxidation and increased the total antioxidant capacity in the serum and peritoneal cavity of septic animals. In the model of severe sepsis, the posttreatment with β-Lap was able to increase the survival of animals and maintain the antioxidant defense function. In conclusion, the β-Lap was able to increase the survival of septic animals by a mechanism involving immunomodulatory and antioxidant protective effects.

Gallic and Ellagic Acids Are Promising Adjuvants to Conventional Amphotericin B for the Treatment of Cutaneous Leishmaniasis

In this study, we demonstrated the potential associative effect of combining conventional amphotericin B (Amph B) with gallic acid (GA) and with ellagic acid (EA) in topical formulations for the treatment of cutaneous leishmaniasis in BALB/c mice. Preliminary stability tests of the formulations and in vitro drug release studies with Amph B, GA, Amph B plus GA, EA, and Amph B plus EA were carried out, as well as assessment of the in vivo treatment of BALB/c mice infected with Leishmania major After 40 days of infection, the animals were divided into 6 groups and treated twice a day for 21 days with a gel containing Amph B, GA, Amph B plus GA, EA, or Amph B plus EA, and the negative-control group was treated with the vehicle. In the animals that received treatment, there was reduction of the lesion size and reduction of the parasitic load. Histopathological analysis of the treatments with GA, EA, and combinations with Amph B showed circumscribed lesions with the presence of fibroblasts, granulation tissue, and collagen deposition, as well as the presence of activated macrophages. The formulations containing GA and EA activated macrophages in all evaluated parameters, resulting in the activation of cells of the innate immune response, which can generate healing and protection. GA and EA produced an associative effect with Amph B, which makes them promising for use with conventional Amph B in the treatment of cutaneous leishmaniasis.

Antileishmanial activity of cordiaquinone E towards Leishmania (Leishmania) amazonensis

Leishmaniasis is caused by several protozoan species of Leishmania, and being endemically present in 98 countries around the world, it is also a severe public-health problem. The available antileishmanial drugs are toxic and yet present risks of recurrent infection. Efforts to find new, effective, and safe oral agents for the treatment of leishmaniasis are continuing throughout the world. This work aimed to evaluate the antileishmania activity of cordiaquinone E (CORe), isolated from the roots of Cordia polycephala (Lam.) I. M. Johnston. Cytotoxicity, and possible mechanisms of action against promastigote and amastigote forms of Leishmania amazonensis were examined. CORe was effective in inhibiting promastigote (IC₅₀ 4.5 ± 0.3 µM) and axenic amastigote (IC₅₀ 2.89 ± 0.11 µM) growth in concentrations found non-toxic for the host cell (CC₅₀ 246.81 ± 14.5 µM). Our results revealed that CORe presents direct activity against the parasite, inducing cell death by apoptosis. CORe present greater activity against intracellular amastigotes (EC₅₀ 1.92 ± 0.2 µM), yet with much higher selectivity indexes than the reference drugs, being respectively more benign towards RAW 264.7 macrophages than meglumine antimoniate and amphotericin B, (respectively by 4.68 and 42.84 fold). The antiamastigote activity was associated with increased TNF-α, IL-12, NO, and ROS levels, as well as decreased IL-10 levels. These results encourage the progression of studies on this compound for the development of new leishmanicidal agents.

Modulatory Effect of Dietary Polyunsaturated Fatty Acids on Immunity, Represented by Phagocytic Activity

Lately, dietary polyunsaturated fatty acids (PUFAs) have shown substantial importance in human and animal nutrition, especially those of the n-3 group. Development and optimal functioning of the immune system are directed affected by diet. These dietary fatty acids have an important impact on the health and immune competence of various species including human beings. They are essential for the modulation of immune responses in health and disease. Fatty acid composition of immune cells can be modulated by the action of dietary fats and the outcomes in the composition can produce functional effects on reactivity and functioning of immune cells in a short period. There are several mechanisms involved in impacting dietary fatty acids on immune function; however, lipid mediator synthesis from PUFAs is of great importance in terms of inflammation. The objectives of this article are reviewing studies on the impact of PUFA in the diet on phagocytosis of chickens, murine, rats, ruminants, and humans. It also sheds light on the possible mechanism by which this immunomodulation occurs.

Agaricus brasiliensis Mushroom Protects Against Sepsis by Alleviating Oxidative and Inflammatory Response

Sepsis is characterized by the host's dysregulated immune response to an infection followed by a potentially fatal organ dysfunction. Although there have been some advances in the treatment of sepsis, mainly focused on broad-spectrum antibiotics, mortality rates remain high, urging for the search of new therapies. Oxidative stress is one of the main features of septic patients, so antioxidants can be a good alternative treatment. Agaricus brasiliensis is a nutraceutical rich in bioactive compounds such as polyphenols and polysaccharides, exhibiting antioxidant, antitumor, and immunomodulatory activities. Here, we investigated the immunomodulatory and antioxidant effects of A. brasilensis aqueous extract in the cecal ligation and puncture (CLP) sepsis model. Our data showed that aqueous extract of A. brasiliensis reduced systemic inflammatory response and improved bacteria clearance and mice survival. In addition, A brasiliensis decreased the oxidative stress markers in serum, peritoneal cavity, heart and liver of septic animals, as well as ROS production (in vitro and in vivo) and tert-Butyl hydroperoxide-induced DNA damage in peripheral blood mononuclear cells from healthy donors in vitro. In conclusion, the aqueous extract of A. brasiliensis was able to increase the survival of septic animals by a mechanism involving immunomodulatory and antioxidant protective effects.

Consumption of latex from Euphorbia tirucalli L. promotes a reduction of tumor growth and cachexia, and immunomodulation in Walker 256 tumor-bearing rats

ETHNOPHARMACOLOGICAL RELEVANCE

Euphorbia tirucalli L. is an African plant that grows well in Brazil. Individuals diagnosed with cancer frequently consume latex from E. tirucalli, dissolved in drinking water. In vitro studies confirm the antitumor potential of E. tirucalli latex, but in vivo evaluations are scarce.

AIM OF THE STUDY

To evaluate the effect of intake of an aqueous solution of E. tirucalli latex on tumor growth, cachexia, and immune response in Walker 256 tumor-bearing rats.

MATERIALS AND METHODS

Latex from E. tirucalli was collected and analyzed by LC-MS. Sixty male Wistar rats (age, 90 days) were randomly divided into four groups: C, control group (without tumor); W, Walker 256 tumor-bearing group; SW1, W animals but treated with 25 μL latex/mL water; and SW2, W animals but treated with 50 μL latex/mL water. Animals received 1 mL of latex solution once a day by gavage. After 15 d, animals were euthanized, tumor mass was determined, and glucose and triacylglycerol serum levels were measured by using commercial kits. Change in the body weight during tumor development was calculated, and proliferation capacity of tumor cells was assessed by the Alamar Blue assay. Phagocytosis and superoxide anion production by peritoneal macrophages and circulating neutrophils were analyzed by enzymatic and colorimetric assays. Data are analyzed by one-way ANOVA followed by Tukey's post-hoc test, with the significance level set at 5%.

RESULTS

The analysis of the latex revealed the presence of triterpenes. The ingestion of the latex aqueous solution promoted 40% and 60% reduction of the tumor mass in SW1 and SW2 groups, respectively (p < 0.05). The proliferative capacity of tumor cells from SW2 group was 76% lower than that of cells from W group (p < 0.0001). Animals treated with latex gained, on average, 20 g (SW1) and 8 g (SW2) weight. Glucose and triacylglycerol serum levels in SW1 and SW2 animals were similar to those in C group rats. Peritoneal macrophages and blood neutrophils from SW1 and SW2 animals produced 30-40% less superoxide anions than those from W group animals (p < 0.05), but neutrophils from SW2 group showed an increased phagocytic capacity (20%, vs. W group).

CONCLUSIONS

E. tirucalli latex, administered orally for 15 d, efficiently reduced tumor growth and cachexia in Walker 256 tumor-bearing rats. Decreased tumor cell proliferative capacity was one of the mechanisms involved in this effect. Further, the data suggest immunomodulatory properties of E. tirucalli latex. The results agree with folk data on the antitumor effect of latex ingestion, indicating that it may be useful as an adjunct in the treatment of cancer patients. For this, further in vivo studies in animal and human models need to be conducted.

Phytochemical analysis and biological activities of in vitro cultured Nidularium procerum, a bromeliad vulnerable to extinction

This study reports the first phytochemical and biological characterization in treatment of adrenocortical carcinoma cells (H295R) of extracts from Nidularium procerum, an endemic bromeliad of Atlantic Forest vulnerable to extinction. Extracts of dry leaves obtained from in vitro-grown plants were recovered by different extraction methods, viz., hexanoic, ethanolic, and hot and cold aqueous. Chromatography-based metabolite profiling and chemical reaction methods revealed the presence of flavonoids, steroids, lipids, vitamins, among other antioxidant and antitumor biomolecules. Eicosanoic and tricosanoic acids, α-Tocopherol (vitamin E) and scutellarein were, for the first time, described in the Nidularium group. Ethanolic and aqueous extracts contained the highest phenolic content (107.3 mg of GAE.100 g-1) and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging activity, respectively. The immunomodulatory and antitumoral activities of aqueous extracts were assessed using specific tests of murine macrophages modulation (RAW 264.7) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay against adrenocortical carcinoma cell line, respectively. The aqueous extract improved cell adhesion and phagocytic activities and phagolysossomal formation of murine macrophages. This constitutes new data on the Bromeliaceae family, which should be better exploited to the production of new phytomedicines for pharmacological uses.

Garcinielliptone FC: Selective anti-amastigote and immunomodulatory effects on macrophages infected by Leishmania amazonensis

The present study was directed to the in vitro antileishmanial, cytotoxic and immunomodulatory effects of Garcinielliptone FC (GFC) against promastigote and macrophage-internalized amastigote forms of Leishmania amazonensis. GFC showed in vitro cytotoxicity against BALB/c peritoneal macrophages with CC₅₀ of 74.90 μM. The hemolytic activity against sheep erythrocytes only demonstrated a decrease of 20.42% in cell viability at the highest tested concentration tested (1326.0 μM). GFC promoted in vitro growth inhibition of both promastigote and intracellular amastigotes with IC₅₀ values of 14.06 and 1.91 μM, respectively, with 7.3-fold higher Selectivity Index (SI) for intracellular amastigotes (SI = 39.21) than for promastigotes (SI = 5.33). Interestingly, the pre-treatment of macrophages or promastigotes with GFC promoted decrease of infected macrophages and number of recovered amastigotes, respectively. Also, GFC was able to markedly promote macrophages activation by increase of phagocytic capability and nitrite production at concentrations able to solve infection of macrophages by L. amazonensis, suggesting the possible involvement of immunomodulatory modulation of macrophages leading to solve the infection. GFC is an emerging and promising chemical compound for the studies focused on the assessment of its therapeutic potential on in vivo experimental models of leishmaniasis.

Dietary arachidonate in milk replacer triggers dual benefits of PGE2 signaling in LPS-challenged piglet alveolar macrophages

Background

Respiratory infections challenge the swine industry, despite common medicinal practices. The dual signaling nature of PGE₂ (supporting both inflammation and resolution) makes it a potent regulator of immune cell function. Therefore, the use of dietary long chain n-6 PUFA to enhance PGE₂ effects merits investigation.

Methods

Day-old pigs (n = 60) were allotted to one of three dietary groups for 21 d (n = 20/diet), and received either a control diet (CON, arachidonate = 0.5% of total fatty acids), an arachidonate (ARA)-enriched diet (LC n-6, ARA = 2.2%), or an eicosapentaenoic (EPA)-enriched diet (LC n-3, EPA = 3.0%). Alveolar macrophages and lung parenchymal tissue were collected for fatty acid analysis. Isolated alveolar macrophages were stimulated with LPS in situ for 24 h, and mRNA was isolated to assess markers associated with inflammation and eicosanoid production. Culture media were collected to assess PGE₂ secretion. Oxidative burst in macrophages was measured by: 1) oxygen consumption and extracellular acidification (via Seahorse), 2) cytoplasmic oxidation and 3) nitric oxide production following 4, 18, and 24 h of LPS stimulation.

Results

Concentration of ARA (% of fatty acids, w/w) in macrophages from pigs fed LC n-6 was 86% higher than CON and 18% lower in pigs fed LC n-3 (P < 0.01). Following LPS stimulation, abundance of COX-2 and TNF-α mRNA (P <  0.0001), and PGE₂ secretion (P < 0. 01) were higher in LC n-6 PAM vs. CON. However, ALOX5 abundance was 1.6-fold lower than CON. Macrophages from CON and LC n-6 groups were 4-fold higher in ALOX12/15 abundance (P < 0.0001) compared to LC n-3. Oxygen consumption and extracellular acidification rates increased over 4 h following LPS stimulation (P < 0.05) regardless of treatment. Similarly, increases in cytoplasmic oxidation (P < 0.001) and nitric oxide production (P <  0.002) were observed after 18 h of LPS stimulation but were unaffected by diet.

Conclusions

We infer that enriching diets with arachidonic acid may be an effective means to enhance a stronger innate immunologic response to respiratory challenges in neonatal pigs. However, further work is needed to examine long-term safety, clinical efficacy and economic viability.

Electronic supplementary material

The online version of this article (10.1186/s40104-019-0321-1) contains supplementary material, which is available to authorized users.

Platonia insignis Mart., a Brazilian Amazonian Plant: The Stem Barks Extract and Its Main Constituent Lupeol Exert Antileishmanial Effects Involving Macrophages Activation

Platonia insignis Mart., popularly known as “bacurizeiro,” is used in traditional medical practices based on its diverse biological properties. This study was aimed at evaluating the antileishmanial effects of the ethanol extract (EtOH-Ext), hexane fraction (Hex-F), and its main isolated Lupeol obtained from stem barks of P. insignis against Leishmania (Leishmania) amazonensis, as well as their cytotoxicity and possible mechanisms of action. The EtOH-Ext, Hex-F, and Lupeol inhibited the growth of L. amazonensis promastigote forms at IC₅₀ of 174.24, 45.23, and 39.06 µg/mL, respectively, as well as L. amazonensis axenic amastigote forms at IC₅₀ of 40.58, 35.87, and 44.10 µg/mL, respectively. The mean cytotoxic concentrations for macrophages (CC₅₀) were higher than those for amastigotes (341.95, 71.65, and 144.0 µg/mL, resp.), indicating a selective cytotoxicity towards the parasite rather than the macrophages. Interestingly, all treatments promoted antileishmanial effect against macrophage-internalized amastigotes at concentrations lower than CC₅₀. Furthermore, increases of lysosomal volume of macrophages treated with EtOH-Ext, Hex-F, and Lupeol were observed. On the other hand, only Lupeol stimulated increase of phagocytic capability of macrophages, suggesting this compound might be characterized as the biomarker for the antileishmanial effect of P. insignis stem bark, as well as the involvement of immunomodulatory mechanisms in this effect.

Wound healing treatment by high frequency ultrasound, microcurrent, and combined therapy modifies the immune response in rats

BACKGROUND

Therapeutic high-frequency ultrasound, microcurrent, and a combination of the two have been used as potential interventions in the soft tissue healing process, but little is known about their effect on the immune system.

OBJECTIVE

To evaluate the effects of therapeutic high frequency ultrasound, microcurrent, and the combined therapy of the two on the size of the wound area, peritoneal macrophage function, CD4+ and CD8+, T lymphocyte populations, and plasma concentration of interleukins (ILs).

METHOD

Sixty-five Wistar rats were randomized into five groups, as follows: uninjured control (C, group 1), lesion and no treatment (L, group 2), lesion treated with ultrasound (LU, group 3), lesion treated with microcurrent (LM, group 4), and lesion treated with combined therapy (LUM, group 5). For groups 3, 4 and 5, treatment was initiated 24 hours after surgery under anesthesia and each group was allocated into three different subgroups (n=5) to allow for the use of the different therapy resources at on days 3, 7 and 14 Photoplanimetry was performed daily. After euthanasia, blood was collected for immune analysis.

RESULTS

Ultrasound increased the phagocytic capacity and the production of nitric oxide by macrophages and induced the reduction of CD4+ cells, the CD4+/CD8+ ratio, and the plasma concentration of IL-1β. Microcurrent and combined therapy decreased the production of superoxide anion, nitric oxide, CD4+-positive cells, the CD4+/CD8+ ratio, and IL-1β concentration.

CONCLUSIONS

Therapeutic high-frequency ultrasound, microcurrent, and combined therapy changed the activity of the innate and adaptive immune system during healing process but did not accelerate the closure of the wound.

Anti-Leishmania activity of essential oil of Myracrodruon urundeuva (Engl.) Fr. All.: Composition, cytotoxity and possible mechanisms of action

Myracrodruon urundeuva (Engl.) Fr. All., commonly known as "aroeira-do-sertão", is a medicinal plant from Anacardiaceae family. In this study, the chemical composition of M. urundeuva essential oil (MuEO) was evaluated by gas chromatography-mass spectrometry (GC-MS), as well as its anti-Leishmania potential, cytotoxicity, and macrophage activation capability as possible antiprotozoal mechanism of action were assessed. Fourteen compounds were identified, which constituted 94.87% of total oil composition. The most abundant components were monoterpenes (80.35%), with β-myrcene (42.46%), α-myrcene (37.23%), and caryophyllene (4.28%) as the major constituents. The MuEO inhibited the growth of promastigotes (IC₅₀ 205 ± 13.4 μg mL^-1), axenic amastigotes (IC₅₀ 104.5 ± 11.82 μg mL^-1) and decreased percentage of macrophage infection and number of amastigotes per macrophage (IC₅₀ of 44.5 ± 4.37 μg⋅mL^-1), suggesting significant anti-Leishmania activity. The cytotoxicity of MuEO was assessed by MTT test in Balb/c murine macrophages and by human erythrocytes lysis assay and low cytotoxicity for these cells was observed. The CC₅₀ value against macrophages were 550 ± 29.21 μg mL^-1, while cytotoxicity for erythrocytes was around 20% at the highest concentration assessed, with HC₅₀ > 800 μg mL^-1. While MuEO-induced anti-Leishmania activity is not mediated by increases in both lysosomal activity and nitric oxide production in macrophages, the results suggest the antiamastigote activity is associated with an immunomodulatory activity of macrophages due to an increase of phagocytic capability induced by MuEO. Thus, MuEO presented significant activity against Leishmania amazonensis, probably modulating the activation of macrophages, with low cytotoxicity to murine macrophages and human erythrocytes.

INTERVAL TRAINING IS INSUFFICIENT TO ATTENUATE METABOLIC DISTURBANCES IN DIABETIC RATS

ABSTRACT Introduction: Type 1 diabetes is a metabolic disease associated to blood disturbances and disorder of the innate immune system functionality. Objective: This study investigated the effect of two weeks interval training on blood biochemistry and immunological parameters in rats with type 1 diabetes. Methods: Male Wistar rats were divided into three groups: sedentary (SE, n = 10), diabetic sedentary (DI, n = 10), diabetic interval training (DIT, n = 10). IV injection of streptozotocin (45 mg/kg) induced diabetes. Interval training consisted of swimming exercise for 30 seconds with 30 seconds of rest for 30 minutes three times a week during two weeks, with an overload of 15% of the total body mass. The evaluations performed were fasting blood glucose, triglycerides, very low-density lipoprotein cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and total cholesterol concentrations, phagocytic capacity, cationic vesicles content, superoxide anion, and production of hydrogen peroxide of blood neutrophils and peritoneal macrophages. Results: The results showed that two weeks interval training did not attenuate the hyperglycemic state at rest and did not decrease blood lipids in the DIT group. Diabetes increased the functionality of blood neutrophils and peritoneal macrophages in the DI group. Interval training increased the content of cationic vesicles and the phagocytic capacity of blood neutrophils and peritoneal macrophages in the DIT group. Conclusion: It was found that two weeks of interval training increased the functionality parameters of innate immune cells, although this has been insufficient to attenuate the biochemical disorders caused by diabetes.

Inhibitory effects of Zanthoxylum rhoifolium Lam. (Rutaceae) against the infection and infectivity of macrophages by Leishmania amazonensis

ABSTRACT Zanthoxylum rhoifolium Lam. (Rutaceae) has been traditionally used in the treatment of microbial infections and parasitic diseases. In the present study, the antileishmanial effect induced by the ethanol extract of stem barks from Z. rhoifolium (ZR-EEtOH) and its n-hexane fraction (ZR-FHEX) on infection and infectivity of murine macrophages by promastigote forms of Leishmania amazonensis were investigated. In different set of experiments, macrophages or promastigotes were pretreated with ZR-EEtOH or ZR-FHEX at non-lethal concentrations for 24 hours, and then macrophages were submitted to infection by promastigotes. Moreover, their effects on activation of macrophages, as well as on the DNA content, size and number of promastigotes by flow cytometry were also evaluated. The infection rate and the number of internalized amastigote forms were markedly decreased after pretreatment of macrophages or promastigotes when compared with non-treated cells. The increase in phagocytic capability and nitrite content was also observed. Furthermore, the decrease of DNA content, size and number of promastigotes was also observed. In conclusion, ZR-EEtOH and ZR-FHEX promoted a markedly significant antileishmanial effect and reduction of infection of macrophages, probably underlying defense mechanisms activation in macrophages. These findings reinforce the potential application of Z. rhoifolium in the treatment of leishmaniasis.

Diet composition as a source of variation in experimental animal models of cancer cachexia

BACKGROUND

A variety of experimental animal models are used extensively to study mechanisms underlying cancer cachexia, and to identify potential treatments. The important potential confounding effect of dietary composition and intake used in many preclinical studies of cancer cachexia is frequently overlooked. Dietary designs applied in experimental studies should maximize the applicability to human cancer cachexia, meeting the essential requirements of the species used in the study, matched between treatment and control groups as well as also being generally similar to human consumption.

METHODS

A literature review of scientific studies using animal models of cancer and cancer cachexia with dietary interventions was performed. Studies that investigated interventions using lipid sources were selected as the focus of discussion.

RESULTS

The search revealed a number of nutrient intervention studies (n = 44), with the majority including n-3 fatty acids (n = 16), mainly eicosapentaenoic acid and/or docosahexaenoic acid. A review of the literature revealed that the majority of studies do not provide information about dietary design; food intake or pair-feeding is rarely reported. Further, there is a lack of standardization in dietary design, content, source, and overall composition in animal models of cancer cachexia. A model is proposed with the intent of guiding dietary design in preclinical studies to enable comparisons of dietary treatments within the same study, translation across different study designs, as well as application to human nutrient intakes.

CONCLUSION

The potential for experimental endpoints to be affected by variations in food intake, macronutrient content, and diet composition is likely. Diet content and composition should be reported, and food intake assessed. Minimum standards for diet definition in cachexia studies would improve reproducibility of pre-clinical studies and aid the interpretation and translation of results to humans with cancer.

Influence of fish oil supplementation and strength training on some functional aspects of immune cells in healthy elderly women

Immune function changes with ageing and is influenced by physical activity (strength training, ST) and diet (fish oil, FO). The present study investigated the effect of FO and ST on the immune system of elderly women. Forty-five women (64 (sd 1·4) years) were assigned to ST for 90 d (ST; n 15), ST plus 2 g/d FO for 90 d (ST90; n 15) or 2 g/d FO for 60 d followed by ST plus FO for 90 d (ST150; n 15). Training was performed three times per week, for 12 weeks. A number of innate (zymosan phagocytosis, lysosomal volume, superoxide anion, peroxide of hydrogen) and adaptive (cluster of differentiation 4 (CD4), CD8, TNF-α, interferon-γ (IFN-γ), IL-2, IL-6 and IL-10 produced by lymphocytes) immune parameters were assessed before supplementation (base), before (pre-) and after (post-) training. ST induced no immune changes. FO supplementation caused increased phagocytosis (48 %), lysosomal volume (100 %) and the production of superoxide anion (32 %) and H2O2 (70 %) in the ST90. Additional FO supplementation (ST150) caused no additive influence on the immune system, as ST150 and ST90 did not differ, but caused greater changes when compared to the ST (P< 0·05). FO increased CD4+ and CD8+ lymphocytes in the ST150, which remained unchanged when training was introduced. The combination of ST and FO reduced TNF-α in the ST150 from base to post-test. FO supplementation (ST150, base–pre) when combined with exercise (ST150, pre–post) increased IFN-γ, IL-2, IL-6 and IL-10 production. The immune parameters improved in response to FO supplementation; however, ST alone did not enhance the immune system.

Syzygium cumini (L.) Skeels essential oil and its major constituent α-pinene exhibit anti-Leishmania activity through immunomodulation in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Syzygium cumini (L.) Skeels (Myrtaceae), commonly known as "jambolão" in Brazil is widely used in folk medicine against leishmaniasis, inflammation, chronic diarrhea, and ulcers. It is one of the most commonly used plants for the treatment of diabetes worldwide. In previous studies, Syzygium cumini was shown to possess antihyperlipidemic and anti-allergic properties, and to exhibit good performance as an antimicrobial agent against bacteria, fungi, and protozoa parasites of the genus Leishmania and Trypanosoma. This study was aimed at evaluating the effects of S. cumini essential oil (ScEO) and its major component α-pinene on Leishmania (Leishmania) amazonensis, as well as their cytotoxicity and possible mechanisms of action.

MATERIALS AND METHODS

To evaluate the anti-proliferative effect on Leishmania, effects on promastigote and axenic amastigote forms were assessed using tetrazolium salt (MTT) assay. The intramacrophagic amastigotes were exposed to ScEO and α-pinene to determine the survival index. To gain insight into the mechanism of action involved in the effect on the samples, we evaluated the modulation of macrophage activation state by observing structural (phagocytic and lysosomal activities) and cellular (nitric oxide increase) changes. To assess the safety profile of ScEO and α-pinene, murine macrophages and human red blood cells were treated with ScEO and α-pinene and the selectivity index was calculated for each treatment.

RESULTS

α-Pinene was effective against Leishmania amazonensis promastigote forms, with a half-maximal inhibitory concentration (IC50) value of 19.7µg/mL. α-Pinene was more active (IC50 values of 16.1 and 15.6µg/mL against axenic and intracellular amastigotes, respectively) than ScEO (IC50 values of 43.9 and 38.1µg/mL against axenic and intracellular amastigotes, respectively). Our results showed that the anti-Leishmania effects were mediated by immunomodulatory activity, as evidenced by the observed increases in both phagocytic and lysosomal activity, and the elevated NO levels. ScEO and α-pinene exhibited low cytotoxicity against murine macrophages and human erythrocytes. The 50% cytotoxicity concentration (CC50) values for the macrophages in the MTT assay were 614.1 and 425.2µg/mL for ScEO and α-pinene, respectively, while the corresponding half-maximal hemolytic concentration (HC50) values were 874.3 and 233.3µg/mL.

CONCLUSIONS

Taken together, the results demonstrate that ScEO and its major constituent α-pinene have significant anti-Leishmania activity, modulated by macrophage activation, with acceptable levels of cytotoxicity in murine macrophages and human erythrocytes. Further work is warranted, involving more in-depth mechanistic studies and in vivo investigations.

Interval training attenuates the metabolic disturbances in type 1 diabetes rat model

OBJECTIVE

This study investigated the effect of interval training on blood biochemistry and immune parameters in type 1 diabetic rats.

MATERIALS AND METHODS

Male Wistar rats were divided into four groups: sedentary (SE, n = 15), interval training (IT, n = 17), diabetic sedentary (DSE, n = 17), diabetic interval training (DIT, n = 17). Diabetes was induced by i.v. injection of streptozotocin (60 mg/kg). Swimming Interval Training consisted of 30-s exercise with 30-s rest, for 30 minutes, during 6 weeks, four times a week, with an overload of 15% of body mass. Plasma glucose, lactate, triacylglycerol and total cholesterol concentrations, phagocytic capacity, cationic vesicle content, and superoxide anion and hydrogen peroxide production by blood neutrophils and peritoneal macrophages were evaluated. Proliferation of mesenteric lymphocytes was also estimated.

RESULTS

Interval training resulted in attenuation of the resting hyperglycemic state and decreased blood lipids in the DIT group. Diabetes increased the functionality of blood neutrophils and peritoneal macrophages in the DSE group. Interval training increased all functionality parameters of peritoneal macrophages in the IT group. Interval training also led to a twofold increase in the proliferation of mesenteric lymphocytes after 6 weeks of exercise in the DIT group.

CONCLUSION

Low-volume high-intensity physical exercise attenuates hyperglycemia and dislipidemia induced by type 1 diabetes, and induces changes in the functionality of innate and acquired immunity.

Anti-inflammatory, analgesic, and immunostimulatory effects of Luehea divaricata Mart. & Zucc. (Malvaceae) bark

Luehea divaricata (Malvaceae) is a plant widely used for treatment of various inflammatory and infectious conditions; however few reports discuss its biological properties. The aim of this study was to evaluate the anti-inflammatory and analgesic effects as well as the macrophage activity in mice treated with the hydroalcoholic crude extract of L. divaricata(CLD). Thin layer chromatography revealed presence of epicathequin, stigmasterol, lupeol and α,β-amyrin in the extract. To evaluate the anti-inflammatory and analgesic activities, animals were subjected to paw edema induced by carrageenan test, writhing, formalin and capsaicin tests. Immunomodulatory activity was evaluated by adhesion and phagocytic capacity, lysosomal volume, and reactive oxygen species (ROS) production by peritoneal macrophages, after daily treatment with CLD for 15 days. CLD promoted reduction in paw edema (36.8% and 50.2%; p<0.05 at doses of 100 and 300 mg/kg, respectively), inhibited writhing behavior at the higher dose (64.4%, p<0.05), reduced formalin reactivity (81.2% and 91.6% at doses of 100 and 300 mg/kg, respectively, p<0.05), and reduced capsaicin reactivity by 63.9% (300 mg/kg). CLD (200 mg• kg-1• day-1) increased phagocytosis capacity of macrophages (~3 fold, p<0.05), neutral red uptake (~50%, p<0.001), and ROS production (~90%, p<0.001). These data suggest that CLD possesses anti-inflammatory, analgesic and immunostimulatory properties.

Galactofuranosyl glycosides: immunomodulatory effects on macrophages and in vivo enhancement of lethality on sepsis

Galactofuranoside derivatives were synthesised by the classic Fischer glycosydation method, and their immune modulation properties were studied in vitro and in vivo. NMR spectroscopic and ESI-MS analyses confirmed the purity and authenticity of all derivatives. Their phagocyte capacities were tested in resident macrophages. Methyl β-galactofuranoside (GFB-Me) and n-octyl β-galactofuranoside (GFB-O) had an immune stimulant effect at 25μmolml(-1) with an enhancement of 35.12%±0.06 SD and 17.49%±0.11 SD, respectively, but Methyl α-galactofuranoside (GFA-Me) and n-octyl α-galactofuranoside (GFA-O) gave a low immune response. Methyl α-galactofuranoside 5,6-O-isopropylidene (GFA-IP) and Methyl β-galactofuranoside 5,6-O-isopropylidene (GFB-IP) had negative values relative to the control group of minus 4.96%±0.10 SD and -40.72%±0.07 SD, respectively. Furthermore, GFB-Me and GFB-Me-IP were evaluated in vivo on the lethality induced by cecal ligation and puncture. Cytokine levels and iNOS expression were determined and correlated to mortality data. The results showed that the free HO-5 and HO-6 and the β-configuration are essential for the induction of phagocytic activity by the galactofuranosyl units. The methyl β-galactofuranosides also enhanced lethality during sepsis, increasing the levels of pro-inflammatory cytokines and iNOS expression.

Fish oil supplementation improves neutrophil function during cancer chemotherapy

Cancer chemotherapy is associated with neutropenia and impaired neutrophil function. This study aimed to investigate whether supplementation with low dose fish oil (FO), providing n-3 polyunsaturated fatty acids, in cancer patients receiving chemotherapy after surgical tumor (mainly gastrointestinal) removal is able to improve the function of blood neutrophils. Patients (n = 38) receiving chemotherapy (5-fluorouracil and leucovorin) were randomized into two groups; one group (control) did not receive a supplement, while the other group (FO) received 2 g FO/day for 8 weeks; the FO provided 0.3 g eicosapentaenoic acid plus 0.4 g docosahexaenoic acid per day. Patients in the control group lost an average of 2.5 kg of weight over the 8 weeks of the study. The number of blood polymorphonuclear cells (PMNC), mainly neutrophils, and their functions (phagocytosis and hydrogen peroxide production) decreased in the control group (average decreases of approximately 30, 45 and 17%, respectively). FO prevented these decreases and actually increased body weight (average of 1.7 kg weight gain; p < 0.002 vs. control group), PMNC number (average 29% increase), phagocytosis (average 14% increase) and superoxide production (average 28% increase). FO may be useful in preventing chemotherapy-induced decline in neutrophil number and function.

Walker-256 tumor growth is inhibited by the independent or associative chronic ingestion of shark liver and fish oil: a response linked by the increment of peritoneal macrophages nitrite production in Wistar rats

Fish oil (FO) is widely known by its capacity to positively modulate immune parameters and decrease the growth of some tumors. Despite the enormous number of studies addressing the effects of FO, there are few reports showing similar results using other marine sources of lipid compounds with biologic importance. This study aimed to compare the effects of shark liver oil (SLO), which is a source of omega-3 fatty acids and alkylglycerols, with those obtained with FO administration, or the association of both, on tumor growth and the innate immune system in Walker-256 tumor-bearing rats. Beginning at 21 days of age, Wistar rats were fed regular chow and/or FO and/or SLO supplement (1 g/kg body weight per day) for 14 weeks. Walker-256 tumor cells were inoculated on the 90th day. As expected, 14 days after inoculation, rats fed with FO presented tumor weights that were 50% lower than the control tumors (P < .05). The association of both FO and SLO and ingestion of SLO alone also reached the same reduction level. Except for adhesion, all macrophage parameters assayed were 200% higher in rats fed with FO and those supplemented with both FO and SLO compared with control rats. Only reactive nitrogen species production was increased by SLO. These results suggest that SLO might also have indirect antitumor properties. Conversely, there were no additive effects when SLO was administered with FO. Therefore, SLO is another marine compound with in vivo antitumor effects, but its action mechanisms seem not to be related to major modifications on macrophage function.

Modulatory effect of fatty acids on fungicidal activity, respiratory burst and TNF-α and IL-6 production in J774 murine macrophages

The reported effects of different families of fatty acids (FA; SFA, MUFA, n-3 and n-6 PUFA) on human health and the importance of macrophage respiratory burst and cytokine release to immune defence led us to examine the influence of palmitic acid (PA), oleic acid (OA), linoleic acid, arachidonic acid, EPA and DHA on macrophage function. We determined fungicidal activity, reactive oxygen species (ROS) and cytokine production after the treatment of J774 cells with non-toxic concentrations of the FA. PA had a late and discrete stimulating effect on ROS production, which may be associated with the reduced fungicidal activity of the cells after treatment with this FA. OA presented a sustained stimulatory effect on ROS production and increased fungicidal activity of the cells, suggesting that enrichment of diets with OA may be beneficial for pathogen elimination. The effects of PUFA on ROS production were time- and dose-dependently regulated, with no evident differences between n-3 and n-6 PUFA. It was worth noting that most changes induced after stimulation of the cells with lipopolysaccharide were suppressed by the FA. The present results suggest that supplementation of the diet with specific FA, not classes of FA, might enable an improvement in host defence mechanisms or a reduction in adverse immunological reactions.

Effect of chronic supplementation with shark liver oil on immune responses of exercise-trained rats

Previous studies have reported that chronic supplementation with shark liver oil (SLO) improves immune response of lymphocyte, macrophage and neutrophil in animal models and humans. In a similar manner, exercise training also stimulates the immune system. However, we are not aware of any study about the association of exercise and SLO supplementation on immune response. Thus, our main goal was to investigate the effect of chronic supplementation with SLO on immune responses of exercise-trained rats. Male Wistar rats were divided into four groups: sedentary with no supplementation (SED, n = 20), sedentary with SLO supplementation (SEDslo, n = 20), exercised (EX, n = 17) and exercised supplemented with SLO (EXslo, n = 19). Rats swam for 6 weeks, 1.5 h/day, in water at 32 +/- 1 degrees C, with a load of 6.0% body weight attached to the thorax of rat. Animals were killed 48 h after the last exercise session. SLO supplementation did not change phagocytosis, lysosomal volume, superoxide anion and hydrogen peroxide production by peritoneal macrophages and blood neutrophils. Thymus and spleen lymphocyte proliferation were significantly higher in SEDslo, EX, and EXslo groups compared with SED group (P < 0.05). Gut-associated lymphocyte proliferation, on the other hand, was similar between the four experimental groups. Our findings show that SLO and EX indeed are able to increase lymphocyte proliferation, but their association did not induce further stimulation in the adaptive immune response and also did not modify innate immunity.

Glucose metabolism by lymphocytes, macrophages, and tumor cells from Walker 256 tumor-bearing rats supplemented with fish oil for one generation

Here we investigated the effect of lifelong supplementation of the diet with coconut fat (CO, rich in saturated fatty acids) or fish oil (FO, rich in n-3 polyunsaturated fatty acids) on tumor growth and lactate production from glucose in Walker 256 tumor cells, peritoneal macrophages, spleen, and gut-associated lymphocytes. Female Wistar rats were supplemented with CO or FO prior to mating and then throughout pregnancy and gestation and then the male offspring were supplemented from weaning until 90 days of age. Then they were inoculated subcutaneously with Walker 256 tumor cells. Tumor weight at 14 days in control rats (those fed standard chow) and CO supplemented was approximately 30 g. Supplementation of the diet with FO significantly reduced tumor growth by 76%. Lactate production (nmol h(-1) mg(-1) protein) from glucose by Walker 256 cells in the group fed regular chow (W) was 381.8 +/- 14.9. Supplementation with coconut fat (WCO) caused a significant reduction in lactate production by 1.6-fold and with fish oil (WFO) by 3.8-fold. Spleen lymphocytes obtained from W and WCO groups had markedly increased lactate production (553 +/- 70 and 635 +/- 150) when compared to non-tumor-bearing rats ( approximately 260 +/- 30). FO supplementation reduced significantly the lactate production (297 +/- 50). Gut-associated lymphocytes obtained from W and WCO groups increased lactate production markedly (280 +/- 31 and 276 +/- 25) when compared to non-tumor-bearing rats ( approximately 90 +/- 18). FO supplementation reduced significantly the lactate production (168 +/- 14). Lactate production by peritoneal macrophages was increased by tumor burden but there was no difference between the groups fed the various diets. Lifelong consumption of FO protects against tumor growth and modifies glucose metabolism in Walker tumor cells and lymphocytes but not in macrophages.

Neutrophil response of anaerobic jump trained diabetic rats

This paper investigated the effect of jump training on blood biochemical parameters and neutrophil responses of diabetic rats. Male Wistar rats were divided into control, trained, diabetic and trained-diabetic groups. Diabetes was induced by i.v. injection of streptozotocin. Jump training consisted of six sets of ten jumps in water with overload of 50% of body mass with 1-min of resting, four times per week during 6 weeks. Plasma glucose, lactate, triacylglycerol and total cholesterol concentrations, differential leukocyte count, phagocytosis and anion superoxide production by neutrophils were evaluated. Diabetes caused hyperglycemia, hypertriacylglycerolemia, and body weight loss. Physical training reversed hypertriacylglycerolemia. Jump training increased phagocytosis and anion superoxide production by blood neutrophils from trained and trained-diabetic rats. Neutrophilia and lymphocytopenia occur in diabetic and trained-diabetic rats. Anaerobic jump training in diabetic rats reduced hypertriacylglycerolemia and increased neutrophil anion superoxide production. Phagocytosis was not altered in trained-diabetic rats.

The effect of dietary supplementation with 9-cis:12-trans and 10-trans:12-cis conjugated linoleic acid (CLA) for nine months on serum cholesterol, lymphocyte proliferation and polymorphonuclear cells function in Beagle dogs

Conjugated linoleic acids (CLA), 9-cis:11-trans and 10-trans:12-cis, have been shown to be able to modify some immune cells parameters and plasma lipids in a variety of experiment models. Since lymphocytes and polymorphonuclear cells (PMNC) have a large spectrum functions in the immune response, the knowledge in this field has to be expanded. Beagle dogs were fed a control diet or a CLA supplemented diet for nine months. Blood was collected for biochemical analysis and lymphocyte and PMNC isolation. PMNC were assayed for lysosome content, phagocytic activity and superoxide anion production. A lymphocyte proliferation capacity assay was done. The CLA fed dogs had a 34% reduction in total cholesterol (P < 0.05), 28% in LDL (P < 0.05) and 28% non-HDL-cholesterol (P < 0.05). Neither of the PMNC parameters evaluated demonstrated significant alteration. Lymphocytes from CLA group increased by 45% their mitotic capacity (P < 0.05). Our study demonstrates that CLA can successfully modify the lipid profile of dogs (monogastrics) when fed at reasonable levels, but did not significantly alter inflammatory function as would generally predicted. Further, we had some indication that CLA modulated T cell responsiveness.

The effects of omega-3 polyunsaturated fatty acids on TNF-alpha and IL-10 secretion by murine peritoneal cells in vitro

Omega-3 polyunsaturated fatty acids (PUFA) affect immune response, partly by affecting cytokine secretion. Omega-3 PUFA decrease tumor necrosis factor (TNF)-alpha secretion by RAW 264.7 macrophages but increase TNF-alpha secretion by primary elicited peritoneal macrophages in vitro. In this study, the effects of omega-3 and omega-6 PUFA on lipopolysaccharide induced TNF-alpha and interleukin (IL)-10 secretion by murine primary resident and elicited peritoneal macrophages and by RAW 264.7 macrophages, were examined in vitro using an enzyme-linked immunosorbent assay. In addition, the effects of dietary omega-3 PUFA on the number of cells secreting these cytokines were examined with enzyme-linked immunospot assay. All cell types secreted more TNF-alpha but similar amounts of IL-10 when incubated with the omega-3 PUFA, eicosapentaenoic acid or docosahexaenoic acid, compared with that when incubated with the omega-6 PUFA, linoleic acid or arachidonic acid. Dietary fish oil did not affect the number of TNF-alpha secreting resident peritoneal macrophages but decreased the number of macrophages secreting IL-10 ex vivo. These results show that dietary omega-3 PUFA and omega-3 PUFA added to cells in vitro increase TNF-alpha secretion by resident peritoneal macrophages, probably by a direct effect on the cells. In contrast, omega-3 PUFA did not affect IL-10 secretion by the cells but decreased the number of cells secreting IL-10 ex vivo, possibly by affecting cell recruitment, maturation or proliferation.