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

Pleiotropic Effects of Resveratrol on Aging-Related Cardiovascular Diseases-What Can We Learn from Research in Dogs?

Resveratrol (RES) is a polyphenol with natural anti-inflammatory and antioxidant properties. It is found in abundance in plants, i.e., grapes and mulberry fruit. In addition, synthetic forms of RES exist. Since the discovery of its specific biological properties, RES has emerged as a candidate substance not only with modeling effects on the immune response but also as an important factor in preventing the onset and progression of cardiovascular disease (CVD). Previous research provided strong evidence of the effects of RES on platelets, mitochondria, cardiomyocytes, and vascular endothelial function. In addition, RES positively affects the coagulation system and vasodilatory function and improves blood flow. Not only in humans but also in veterinary medicine, cardiovascular diseases have one of the highest incidence rates. Canine and human species co-evolved and share recent evolutionary selection processes, and interestingly, numerous pathologies of companion dogs have a human counterpart. Knowledge of the impact of RES on the cardiovascular system of dogs is becoming clearer in the literature. Dogs have long been recognized as valuable animal models for the study of various human diseases as they share many physiological and genetic similarities with humans. In this review, we aim to shed light on the pleiotropic effects of resveratrol on cardiovascular health in dogs as a translational model for human cardiovascular diseases.

The Role of Plant Extracts in Enhancing Nutrition and Health for Dogs and Cats: Safety, Benefits, and Applications

Plant extracts, derived from various natural sources, encompass primary and secondary metabolites, which include plant polysaccharides, polyphenols, alkaloids, flavonoids, glycosides, terpenes, and volatile oils. These compounds exhibit a range of biological activities such as antioxidant, anti-inflammatory, and antimicrobial functions. Currently, polyphenols and other bioactive compounds are being incorporated into the diets of farm animals, fish, and pets to promote health benefits. Despite this, the application and potential of plant extracts in canine and feline nutrition have not been comprehensively explored. Many aspects of the mechanisms underlying the action of these plant metabolites remain to be analyzed and elucidated. Furthermore, leveraging natural plant extracts for the treatment of clinical conditions in dogs and cats is a crucial component of clinical nutrition. Consequently, this review aims to highlight the impact of plant extracts on overall health, gastrointestinal health, immune health, cardiovascular health, redox balance, and pathology in dogs and cats.

Transportation and Routine Veterinary Interventions Alter Immune Function in the Dog

Rapid activation of the hypothalamic pituitary adrenal axis and the sympathetic nervous system are hallmarks of the acute stress response and these systems interact with the immune system by signaling though glucocorticoid and adrenergic receptors on immune cells. There is limited information about the effect of these physiologic responses on immunologic parameters of pet dogs enrolled in clinical studies. The objective of this study was to evaluate how travel, instrumentation, and hospitalization alter immunologic parameters in pet dogs. Blood was collected from healthy dogs in a home environment and from healthy dogs at the time of presentation to the hospital and after instrumentation and 24 hours of hospitalization. We found that lipopolysaccharide (LPS)-induced downregulation of toll like receptor 4 (TLR4) was blunted in dogs exposed to stress. Neutrophil and monocyte major histocompatibility complex class II (MHCII) expression increased after transportation to the veterinary hospital but then became similar to that of the control dogs at the end of hospitalization. Peripheral blood mononuclear cell cytotoxicity function was blunted in dogs exposed to the stress of transportation as well as hospitalization. Neutrophil apoptosis was greater in dogs exposed to stress compared to controls although this effect significantly decreased after hospitalization stress. Conversely, stress did not alter induced or spontaneous cytokine production from leukocytes, neutrophil or monocyte expression of TLR4, LPS-induced downregulation of monocyte TLR4, LPS-induced neutrophil and monocyte expression of MHCII or peripheral blood lymphocyte phenotype. Transportation and instrumentation/hospitalization stress should be considered when interpreting immunologic studies in pet dogs.

Resveratrol inhibited LPS induced transcription of immune genes and secretion of eicosanoids in Atlantic salmon (Salmo salar), comparing mono-, co- and a novel triple cell culture model of head kidney leukocytes, liver cells and visceral adipocyte tissue

The aim was to study the effect of resveratrol on the interplay of inflammatory signals using three different cell models; a metabolic organ (liver), an endocrine organ (visceral adipose tissue, VAT) and an immune organ (head kidney leukocytes, HKL) following lipopolysaccharide challenge (LPS). Atlantic salmon HKL, liver cells and VAT were isolated from the same fish (n = 5). Each cell type was cultured either as mono-cultures, as co-cultures between HKL-liver cells, liver cells-VAT and HKL-VAT. Triple -cultures included all three tissues. In all cultures of HKL, LPS induced transcription of IL-1β, cox2, tnfα, IL-12, ccattβ and Ahr were significantly inhibited by resveratrol (100, 200 μM). Likewise, in all cultures of liver cells, the LPS induced expression of IL-1β was inhibited by resveratrol (100 and 200 μM). HKL, both mono-cultures and triple-cultures and VAT cocultured with liver cells, showed LPS induced cox2 transcription that was inhibited by resveratrol (100 and 200 μM). In contrast, VAT cultured as triple cultures, resveratrol 200 μM particularly, in the presence of LPS, seemed to increase the expression of IL-1β and ccattβ. Resveratrol did not significantly affect lox5 expression in any culture. HKL and VAT are the main producers of PGE2 in response to inflammatory stimuli. VAT showed high endogenous production of eicosanoids, particularly LTB4 and LTB5. Resveratrol inhibited bot LPS induced and endogenous eicosanoid production. Possible targets of resveratrol, Sirt1 and pAMPK were affected differently in the different cells and tissue studied.

Resveratrol Mitigates High-Fat Diet-Induced Vascular Dysfunction by Activating the Akt/eNOS/NO and Sirt1/ER Pathway

We investigated whether resveratrol (RSV) can attenuate obesity and diabetes progression and improve diabetes-induced vascular dysfunction, and we attempted to delineate its underlying mechanisms. Male C57Bl/6 mice were administered a high-fat diet (HFD) for 17 weeks. Mice developed type 2 diabetes with increased body weight, hyperglycemia, hyperinsulinemia, and hyperlipidemia. Oral gavage with RSV significantly reversed the symptoms induced by the HFD. Insulin sensitivity likewise improved after the RSV intervention in these mice. Phenylephrine-induced cremaster arteriolar constriction was impaired, whereas RSV treatment significantly mitigated the vessel responsiveness to phenylephrine. The obese diabetic mice exhibited increased leukocyte rolling, adhesion, and transmigration in the postcapillary venules of the cremaster muscle. By contrast, RSV treatment significantly attenuated HFD-induced extravasation. RSV significantly recovered phosphorylated Akt and eNOS expression in the thoracic aorta. In addition, activated adenosine monophosphate-activated protein kinase in the thoracic aorta was involved in the improvement of epithelial function after RSV intervention. RSV considerably upregulated the plasma NO level in HFD mice. Moreover, RSV-enhanced human umbilical vein endothelial cells healing through Sirt1/ER pathway may be involved in the prevention of leukocyte extravasation. Collectively, RSV attenuates diabetes-induced vascular dysfunction by activating Akt/eNOS/NO and Sirt1/ER pathway. Our mechanistic study provides a potential RSV-based therapeutic strategy against cardiovascular disease.

Effects of trans-stilbene and terphenyl compounds on different strains of Leishmania and on cytokines production from infected macrophages

Most of the antileishmanial modern therapies are not satisfactory due to high toxicity or emergence of resistance and high cost of treatment. Previously, we observed that two compounds of a small library of trans-stilbene and terphenyl derivatives, ST18 and TR4, presented the best activity and safety profiles against Leishmania infantum promastigotes and amastigotes. In the present study we evaluated the effects of ST18 and the TR4 in 6 different species of Leishmania and the modifications induced by these two compounds in the production of 8 different cytokines from infected macrophages. We observed that TR4 was potently active in all Leishmania species tested in the study showing a leishmanicidal activity higher than that of ST18 and meglumine antimoniate in the most of the species. Moreover, TR4 was able to decrease the levels of IL-10, a cytokine able to render the host macrophage inactive allowing the persistence of parasites inside its phagolysosome, and increase the levels of IL-1β, a cytokine important for host resistance to Leishmania infection by inducible iNOS-mediated production of NO, and IL-18, a cytokine implicated in the development of Th1-type immune response.

Nutrigenomic activity of plant derived compounds in health and disease: Results of a dietary intervention study in dog

The study was conducted to investigate the effects of dietary administrations of four nutraceuticals in dogs. Seventy four dogs were enrolled in the trials, 24 healthy dogs were fed with a control diet (CT) and the experimental groups received for 60days the same diet supplemented with nutraceuticals, namely Echinacea angustifolia (EA, 0.10mg/kg live weight as echinacoside; 14 dogs), Vaccinium myrtillus (VM, 0.20mg/kg live weight as anthocyanidin, 13 dogs), Curcuma longa (CL, 6.60mg/kg live weight as curcumin, 18 dogs with arthrosis), and Sylibum marianum (SM, 1.5mg/kg live weight as sylibin, 8 dogs with hepatopathy). Dogs were weighted at the beginning of study and blood samples were collected at the beginning (T0) and at the end (T60) of the study. VM significantly down regulated TNF, CXCL8, NFKB1 and PTGS2 and decreased plasma ceruloplasmin (CuCp). The activity of EA was evidenced by the significant decrease of TNF and NFKB1 expression and CuCp levels and by the increase of plasma Zn. Administration of CL caused a significant decrease of CuCp and increase of Zn and a down regulation of TNF, CXCL8, NFKB1 and PTGS2, corroborating the anti-inflammatory action of curcuminoids. After 60days of treatment with SM, plasma ALT/GPT activity was reduced and paraoxonase was increased, supporting the antioxidant activity of silymarin, also confirmed by the significant up regulation of SOD2. Results indicated that nutraceutical administrations in dogs can be an interesting approach to modulate immune response in order to improve health condition of animals.

Resveratrol: How Much Wine Do You Have to Drink to Stay Healthy?

Resveratrol is a naturally occurring stilbene endowed with multiple health-promoting effects. It is produced by certain plants including several dietary sources such as grapes, apples, raspberries, blueberries, plums, peanuts, and products derived therefrom (e.g., wine). Resveratrol can be isolated and purified from these biological sources or synthesized in a few steps with an overall high yield. This compound and its glucoside, the trans-polydatin piceid, have received worldwide attention for their beneficial effects on cardiovascular, inflammatory, neurodegenerative, metabolic, and age-related diseases. These health-promoting effects are particularly attractive given the prevalence of resveratrol-based nutraceuticals and the paradoxical epidemiologic observation that wine consumption is inversely correlated to the incidence of coronary heart disease. However, the notion of resveratrol as a "magic bullet" was recently challenged by clinical trials showing that this polyphenol does not have a substantial influence on health status and mortality risk. In the present review, we discuss the proposed therapeutic attributes and the mode of molecular actions of resveratrol. We also cover recent pharmacologic efforts to improve the poor bioavailability of resveratrol and influence the transition between body systems in humans. We conclude with some thoughts about future research directions that might be meaningful for resolving controversies surrounding resveratrol.

Multiplex cytokine analyses in dogs with pyometra suggest involvement of KC-like chemokine in canine bacterial sepsis

Clinical diagnostic criteria for sepsis (systemic inflammatory response syndrome caused by infection) are unspecific and, therefore, biomarkers for sepsis diagnosis are needed for appropriate treatment and patient survival. Pyometra, a common disease caused by bacterial infection of the uterus, results in sepsis in nearly 60% of cases in dogs. We used dogs with pyometra as a natural model for sepsis and collected serum samples from 39 dogs, of which 22 with pyometra and 17 healthy controls. Dogs with pyometra were further grouped into dogs with sepsis (n=18) and without sepsis (n=4). Serum concentrations of a panel of cytokines, including keratinocyte-derived chemokine (KC)-like, granulocyte-macrophages colony stimulating factor (GM-CSF), interleukin (IL)-2, IL-4, IL-6, IL-7, IL-8, IL-10, IL-15, IL-18, chemokine C-X-C motif ligand (CXCL)10 and tumor necrosis factor (TNF)-α, were measured using multiplex analyses. Serum C-reactive protein (CRP) levels were determined using an automated immunoturbidimetric assay. In addition to physical examination hematological and serum biochemical analyses were performed to evaluate the overall status of the dogs. Significantly higher concentrations of KC-like (757 vs 304 pg/ml) were detected in dogs with pyometra as compared to healthy dogs. Within the pyometra group, dogs with sepsis compared to dogs without sepsis had a higher KC-like concentration (873 vs 300 pg/ml). Hemoglobin levels were significantly lower in dogs with pyometra compared to healthy dogs, regardless of the presence or absence of sepsis, and correlated negatively with KC-like. KC-like concentrations correlated positively with CRP, number of hospitalization days, number of monocytes, concentrations of IL-8, and percentage band neutrophils. Our data suggest that bacterial infection triggers the expression of KC-like and further studies are warranted of KC-like as a possible biomarker for diagnosing sepsis and uterine bacterial infection in dogs.