Effects of Orally Administered Resveratrol on TNF, IL-1ß, Leukocyte Phagocytic Activity and Oxidative Burst Function in Horses: A Prospective, Randomized, Double-Blinded, Placebo-Controlled Study.

Resveratrol, a phytophenol, is a commonly used equine nutraceutical supplement touted to exert anti-inflammatory effects. The effect of orally administered resveratrol on tumor necrosis factor (TNF), interleukin-1ß (IL-1ß), leukocyte phagocytic activity or oxidative burst function have not been reported in horses. The objective of this study was to determine the effects of a commercially available, orally administered resveratrol product on innate immune functions in healthy adult horses. Whole blood was collected from 12 horses prior to and following 3 weeks of treatment with either the manufacturer's recommended dose of resveratrol or placebo. Phagocytosis, oxidative burst and pathogen associated molecular pattern (PAMP) motif-stimulated leukocyte production of TNF and IL-1ß were compared pre- and post-treatment between treatment groups. Phagocytosis and oxidative burst capacity were evaluated via flow cytometry. Tumor necrosis factor and IL-1ß were measured using cytotoxicity and ELISA assays, respectively. There were no significant differences in phagocytosis, oxidative burst or stimulated TNF or IL-1ß production between resveratrol and placebo treatment groups. Orally administered resveratrol at a routinely recommended dose for a duration of 3 weeks did not significantly affect phagocytic activity, oxidative burst function or PAMP-stimulated leukocyte cytokine production.

Dogs with osteosarcoma have altered pro- and anti-inflammatory cytokine profiles.

BACKGROUND: Current advances in immunotherapy are an exciting area of study in canine osteosarcoma (OSA). The objective of this study was to determine the immune response in dogs with osteosarcoma by measuring stimulated leukocyte production of tumor necrosis factor (TNF), interleukin (IL)-6, IL-10 and TNF and IL-6 to IL-10 ratios. METHODS: Whole blood was collected from dogs with osteosarcoma receiving non-steroidal anti-inflammatory drugs (NSAIDs, n = 11), dogs with osteosarcoma not receiving NSAIDs (n = 14) and healthy dogs (n = 5). RESULTS: No difference in TNF production was found among healthy and OSA dogs regardless of NSAID administration following stimulation with lipopolysaccharide (LPS) (p = .410), lipoteichoic acid (LTA) (p = .693) or PBS (p = .120). Leukocyte IL-6 production was greater in all dogs with OSA after stimulation with LPS (p = .015), LTA (p = .014) and PBS (p = .034) with no difference between OSA dogs receiving NSAIDs and those not. No differences in IL-10 were found among healthy controls and dogs with OSA regardless of NSAID use. There was no difference among groups for LPS-stimulated TNF to IL-10 ratios (p = .407). For LTA-stimulated leukocytes, the TNF to IL-10 ratio was lower in dogs with OSA than in healthy dogs (p = .031) with no difference between OSA NSAID dogs compared to OSA non-NSAID dogs (p = .059). No differences were found in LPS (p = .310)- or LTA (p = .265)-stimulated leukocyte IL-6 to IL-10 production ratios among groups. CONCLUSIONS: Dogs with osteosarcoma have an altered pro- and anti-inflammatory immunologic profile compared to healthy dogs regardless of NSAID use. Further study is indicated to determine the potential prognostic and therapeutic implications of these findings.

Resveratrol administration increases phagocytosis, decreases oxidative burst, and promotes pro-inflammatory cytokine production in healthy dogs.

Resveratrol is a polyphenol that is safe to administer to dogs and has immunomodulating properties. Canine in vitro work indicated that resveratrol spared polymorphonuclear cell (PMN) phagocytosis but reduced the robustness of PMN oxidative burst and resulted in a pro-inflammatory leukocyte cytokine profile. The objective of this study was to determine the short-term effect of resveratrol on the healthy canine innate immune system in vivo. The hypothesis was that resveratrol would spare phagocytosis, depress the vigor of PMN oxidative burst, and result in a proinflammatory stimulated leukocyte cytokine profile in vivo. In an open-label study, whole blood was collected from 12 healthy, adult client-owned dogs on day 0 and 3. Six dogs received resveratrol, 200 mg kg-1, orally once daily for three days and six dogs served as controls with no supplement administered. Phagocytosis, oxidative burst and pathogen associated molecular pathogen stimulated leukocyte production of tumor necrosis factor (TNF), interleukin (IL)-6, and IL-10 were measured. Results between days 0 and 3 were compared using two way repeated measures analysis of variance and Fisher least significant difference method. A P -value of < 0.05 was considered statistically significant. Resveratrol administration resulted in an increased number of Escherichia coli phagocytized by PMNs and decreased robustness of the oxidative burst reaction. Resveratrol also increased stimulated TNF and IL-6 production with no effect on IL-10. Resveratrol had differential effects on peripheral innate immune system function in dogs. Studies of resveratrol including tissue compartments and the adaptive immune system are indicated to determine if these immunologic effects may be beneficial in disease states.

Investigation of the potential immunomodulatory effects of resveratrol on equine whole blood: An in vitro investigation.

Horses affected with gastrointestinal conditions such as colic or colitis are at substantial risk for translocation of bacterial components such as lipopolysaccharide (LPS, endotoxin) from the gastrointestinal tract into circulation resulting in systemic inflammation and subsequent morbidity and mortality. Therefore, there is a need for effective preventive and treatment strategies aimed at minimizing the host's inflammatory reaction to these pathogen-associated molecular patterns (PAMPs) from gastrointestinal disease. Resveratrol (RES, trans-3,5,4'-trihydroxystilbene) is a phytoalexin commonly found in fruits and beverages, including red wine. Health benefits associated with the consumption of red wine have been attributed to RES. Resveratrol has been significantly shown to exert a powerful anti-inflammatory effect in laboratory animals subjected to experimental endotoxemia/sepsis. Therefore, the objective of this study was to determine in vitro whether RES had an inhibitory effect on the production of tumor necrosis factor (TNF) in cultivated whole blood (Cwb) following stimulation by PAMPs. We hypothesized that RES would inhibit TNF production in Cwb following stimulation by LPS or lipoteichoic acid (LTA). Production of TNF bioactivity in Cwb was measured in the presence of phosphate buffered saline (control), ethanol (solvent control), dexamethasone (anti-inflammatory control), LPS, LTA, and three different concentrations of RES. Both LPS and LTA stimulated TNF production, and addition of dexamethasone was inhibitory to this effect. An anti-inflammatory effect for RES was not demonstrated under the current experimental conditions. Further studies are required to characterize the effect of RES on the equine innate immune system during systemic inflammation.

Resveratrol decreases oxidative burst capacity and alters stimulated leukocyte cytokine production in vitro.

INTRODUCTION: Resveratrol, a naturally-occurring phytophenol, has been shown to bolster immune surveillance and reverse immunosenescence in a dose dependent manner in rodents and humans. Although safety and pharmacokinetic studies have been completed in dogs, the immunomodulatory effects of resveratrol in dogs has not yet been investigated. The objective of this study was to determine the effect of resveratrol on canine innate immune system function in vitro. The hypothesis was that similar to other species, low concentrations of resveratrol would stimulate while high concentrations would depress innate immune system function. METHODS: Whole blood was collected from six healthy, adult, client-owned dogs and was incubated with resveratrol at final concentrations of 6000 ng ml(-1), 3000 ng ml(-1), 1000 ng ml(-1), or control solution for 4h. Following incubation, phagocytosis and oxidative burst were evaluated using flow cytometry, and LPS-, lipoteichoic acid (LTA) - and peptidoglycan (PG)-stimulated leukocyte production of TNF, IL-6, and IL-10 were measured using a canine specific multiplex assay. RESULTS: Phagocytosis was not altered by resveratrol at any concentration compared to control. However, while the number of PMNs capable of performing oxidative burst did not change, the robustness of the reaction following stimulation with Escherichia coli and PMA was reduced in a dose dependent manner. In addition, LPS-, LTA-, PG, and PBS-stimulated TNF production was increased following incubation with all concentrations of resveratrol compared to control, and this effect was dose dependent. LTA-stimulated IL-6 was increased with resveratrol compared to control. Furthermore, LTA-stimulated IL-10 was decreased with 6000 ng ml(-1) and 3000 ng ml(-1) concentrations of resveratrol and PG-stimulated IL-10 production was decreased with all concentrations of resveratrol compared to control. The LPS-, LTA-, and PG-stimulated TNF:IL-10 ratio was increased with 6000 ng ml(-1) of resveratrol compared to control and lower resveratrol concentrations. CONCLUSION: While resveratrol was sparing to PMN phagocytosis, it reduced the robustness of PMN oxidative burst. Resveratrol also increased pro-inflammatory and decreased anti-inflammatory leukocyte cytokine production capacity in vitro. These data suggest that resveratrol supplementation may depress oxidative burst reactions while promoting pro-inflammatory leukocyte cytokine production and decreasing anti-inflammatory cytokine production. Based on these findings, further in vivo study regarding the effects of resveratrol on PMN oxidative burst capability and leukocyte cytokine production capacity are indicated prior to routine supplementation.