Dietary fish oil supplementation affects serum fatty acid concentrations in horses

Obesity during Pregnancy in the Horse: Effect on Term Placental Structure and Gene Expression, as Well as Colostrum and Milk Fatty Acid Concentration

In horses, the prevalence of obesity is high and associated with serious metabolic pathologies. Being a broodmare has been identified as a risk factor for obesity. In other species, maternal obesity is known to affect the development of the offspring. This article is a follow-up study of previous work showing that Obese mares (O, n = 10, body condition score > 4.25 at insemination) were more insulin resistant and presented increased systemic inflammation during pregnancy compared to Normal mares (N, n = 14, body condition score < 4 at insemination). Foals born to O mares were more insulin-resistant, presented increased systemic inflammation, and were more affected by osteoarticular lesions. The objective of the present study was to investigate the effect of maternal obesity on placental structure and function, as well as the fatty acid profile in the plasma of mares and foals, colostrum, and milk until 90 days of lactation, which, to our knowledge, has been poorly studied in the horse. Mares from both groups were fed the same diet during pregnancy and lactation. During lactation, mares were housed in pasture. A strong heat wave, followed by a drought, occurred during their 2nd and 3rd months of lactation (summer of 2016 in the Limousin region, France). In the present article, term placental morphometry, structure (stereology), and gene expression (RT-qPCR, genes involved in nutrient transport, growth, and development, as well as vascularization) were studied. Plasma of mares and their foals, as well as colostrum and milk, were sampled at birth, 30 days, and 90 days of lactation. The fatty acid composition of these samples was measured using gas chromatography. No differences between the N and O groups were observed for term placental morphometry, structure, or gene expression. No difference in plasma fatty acid composition was observed between groups in mares. The plasma fatty acid profile of O foals was more pro-inflammatory and indicated an altered placental lipid metabolism between birth and 90 days of age. These results are in line with the increased systemic inflammation and altered glucose metabolism observed until 18 months of age in this group. The colostrum fatty acid profile of O mares was more pro-inflammatory and indicated an increased transfer and/or desaturation of long-chain fatty acids. Moreover, O foals received a colostrum poorer in medium-chain saturated fatty acid, a source of immediate energy for the newborn that can also play a role in immunity and gut microbiota development. Differences in milk fatty acid composition indicated a decreased ability to adapt to heat stress in O mares, which could have further affected the metabolic development of their foals. In conclusion, maternal obesity affected the fatty acid composition of milk, thus also influencing the foal's plasma fatty acid composition and likely participating in the developmental programming observed in growing foals.

Effect of dietary krill oil supplementation on horse red blood cell membrane fatty acid composition and blood parameters

Supplementation with marine-derived n-3 long-chain polyunsaturated fatty acids (LC PUFAs), eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3) is linked to beneficial health effects in both humans and horses. Krill oil (KO), which is extracted from the Antarctic krill (Euphausia superba), is well documented as a safe and biologically available dietary supplement in humans and several animal species, but there is a lack of documentation regarding its effect as a dietary ingredient for horses. The objective of this study was to test whether KO as a dietary supplement had the ability to raise horse red blood cell (RBC) membrane EPA and DHA, expressed as the n-3 index. Five nonworking Norwegian cold-blooded trotter horse geldings (body weight [BW]: 567 ± 38 kg) were supplemented with KO (10 mL/100 kg BW) for 35 days in a longitudinal study. Blood samples were analysed for RBC membrane fatty acid (FA) profile, haematology and serum biochemistry every 7th day. KO was well accepted by all horses, and no adverse health effects were observed during the 35-day trial period. KO supplementation affected the RBC membrane FA profile by increasing the n-3 index from Day 0 to 35 (Day 0: 0.53% vs. Day 35: 4.05% of total RBC FAs). The observed increase in the sum of EPA and DHA (p < 0.001), total n-3 FAs (p < 0.001) and the reduction of n-6 FAs (p < 0.044) resulted in a lower n-6:n-3 ratio (p < 0.001) by Day 35 of KO supplementation. In conclusion, the RBC n-3 index was increased and the general n-6:n-3 ratio was decreased in horses receiving 35-day dietary KO supplementation.

Dose-Dependent Increase in Whole Blood Omega-3 Fatty Acid Concentration in Horses Receiving a Marine-Based Fatty-Acid Supplement

The objective of this study was to determine the effects of an oral, commercially available, marine based omega-3 fatty acid (n3-FA) supplement on fatty acid characteristics in horse whole blood. Fifty healthy, adult horses of various light breeds were assigned to one of two treatment groups: Group 1 receiving 7.5g/day of the test supplement, and Group 2 receiving 15g/day of the test supplement. The supplement contained 0.092g docosahexaenoic acid (DHA) and 0.148g eicosapentaenoic acid (EPA) per gram. Therefore, Group 1 received 1.11g of EPA and 0.69g of DHA daily, while Group 2 received 2.22g of EPA and 1.38g DHA daily. Blood was taken at time of enrollment and after 6 and 12 weeks of supplementation. Blood was subjected to gas chromatography to quantify the fatty acid characteristics of whole blood. At both 6 and 12 weeks following supplementation, there was a significant increase in all n3-FAs evaluated, including DHA and EPA, compared to baseline values, with Group 2 significantly increased compared to Group 1 at both time points. There was also a significant decrease in omega-6 fatty acids (n6-FAs) between baseline and 6 weeks of supplementation in both groups, with a larger decrease seen in Group 2. The dose-dependent increases in concentration of all n3-FAs evaluated at all-time points validates the use of this product as a n3-FA targeted supplement in horses. These findings also suggest that dose of supplement has a greater effect on increasing whole blood n3-FAs compared to duration of treatment.

Effects of dietary fish oil and alpha-tocopherol supplementation on selected blood parameters and fatty acid profiles in mares and their foals

The effects of fish oil (40 ml/day) supplementation, with or without synthetic all-rac-alpha-tocopherol-acetate (2,500 IU/day), during the last 65 days before expected parturition were investigated in 15 adult mares (553 ± 24 kg BW) and their foals. Mares were assigned to one of three diets: control (n = 5), control plus fish oil and alpha-tocopherol (n = 4; FO + AT) or control with just fish oil (n = 6; FO). Blood samples were obtained from the mares before a 15-day dietary adaptation period (T1) and from mares and foals the first (T2) and fifth (T3) days post-partum. Colostrum was collected at T2 and milk at T3. Routine haematological, biochemical and alpha-tocopherol analyses were undertaken on all blood samples. Fatty acid concentrations were determined in the foal serum and alpha-tocopherol concentrations measured in the milk and colostrum. Diet had no effect on haematology or biochemistry in the mares. Alpha-tocopherol concentrations were significantly higher at T2 & T3 in the FO + AT mares. Foal WBCs were higher in FO (11.33 ± 2.59 × 10⁹ /l), comparing to FO + AT and control groups (9.18 ± 1.24 × 10⁹ /l and 7.26 ± 1.03 × 10⁹ /l, respectively), at T3 (p < .05). There was no significant effect of the fish oil supplementation on the foal's serum fatty acid profile. In the FO + AT group, both colostrum and milk alpha-tocopherol concentrations (2.56 ± 0.36 and 1.36 ± 0.22 µg/ml, respectively) were higher compared than those of the FO group (1.33 ± 0.39 and 0.72 ± 0.31 µg/ml, respectively; p < .05). Additional 2,500 IU/day of synthetic alpha-tocopherol in the last 65 days of pregnancy increased alpha-tocopherol concentrations in colostrum and milk and the foal's serum. 40 ml/day fish oil, however, did not significantly increase serum eicosapentaenoic acid and docosahexaenoic acid concentrations in the foals.

Digestibility of diets containing calcium salts of fatty acids or soybean oil in horses

Calcium salts of fatty acids (CSFAs) frequently are fed to ruminants, but their fate in the equine digestive system is unknown. The purpose of this study was to compare Enertia s/f, a proprietary CSFAs, and soybean (SB) oil with respect to impact on apparent total tract nutrient digestion and cecal fermentation parameters in horses. Eight cecally cannulated Quarter Horses were used in a crossover design in which horses consumed a diet for 32 d consisting of 1.5% body weight (BW) (as-fed) smooth bromegrass hay and 0.5% BW (as-fed) pelleted concentrate containing 4.9% CSFAs or 4.1% SB oil. Fecal samples were collected every 4 h from day 30 to 32 of each period and analyzed for apparent total tract digestibilities of dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), crude protein (CP), crude fat (CF), and gross energy (GE) using acid detergent insoluble ash as an internal marker. Cecal digesta was obtained at 0, 2, 4, 6, 8, 10, and 12 h following the morning meal on day 29 of each period and analyzed for pH and concentrations of volatile fatty acid (VFA) and long-chain fatty acids (LCFAs). Serum was collected on day 33 of each period following a 16-h fast and analyzed for triglycerides and cholesterol. Apparent total tract digestibilities of DM, NDF, ADF, CP, CF, and GE were unaffected by lipid source (P > 0.10). Serum triglycerides tended to be greater in horses consuming CSFAs compared to SB (P = 0.10); however, serum cholesterol was not different (P = 0.45). In horses consuming SB, cecal pH decreased below baseline (hour 0) at hours 2, 4, and 6 (P < 0.01), whereas cecal pH in horses consuming CSFAs was below baseline at hours 4 and 6 (P < 0.01). There were no treatment or time effects on cecal pH (P > 0.10). Cecal concentrations of total VFAs were greater in horses consuming SB compared to CSFAs at hour 2 (P = 0.01). Cecal concentrations of acetate, propionate, acetate:propionate (A:P), and butyrate were affected by time (P < 0.01). Propionate was less at hour 2 in horses fed CSFAs compared to horses fed SB (P = 0.04). A treatment × time interaction was detected for total cecal LCFAs concentration (P < 0.01); LCFAs concentration was greater at hour 2 for horses consuming CSFAs compared to horses fed SB (P = 0.02). SB oil and CSFAs have similar effects on the digestion of DM, NDF, ADF, GE, CF, and CP.

Effects of supplementation with combination of polyunsaturated oils in diet of horses in maintenance and during marcha training

Abstract This study aimed to evaluate the effects of supplementation with polyunsaturated oil on lipid and mineral blood biomarkers in two different groups of horses. Was used 6 healthy horses in maintenance (MT-g) and 10 healthy horses in marcha gait training (GT-g). The MT-g and the GT-g received 100mL and 300mL/day/animal of combination of polyunsaturated oils, respectively, during 8 weeks. Blood was collected in pre-test and after 4 and 8 weeks, after overnight fasting and it was measured: total cholesterol, HDL cholesterol, LDL cholesterol, triglyceride, NEFA, LPS, glycerol, Ca, P, Mg, and Cl. The supplementation produced significant increase in NEFA and reduction in lipase in both groups. In addition, the LPS content in both groups had a large decrease (~35%) from the pre-test to the 8th week of supplementation. In the MT-g, the LDL cholesterol and glycerol increased significantly after 4 weeks but returned to the pre-test levels after 8 weeks, and the triglyceride content decreased (~62%) after 4 weeks. The total cholesterol concentration in the GT-g increased after 4 weeks (~70%), but after 8 weeks it decreased to levels similar to those observed in the pre-test. The mineral biomarkers increased in the MT-g and GT-g, after 8 weeks. In the MT-g and in the GT-g, Ca decreased. In conclusion, supplementation with a combination of polyunsaturated oils increased NEFA concentration and reduced LPS activity in both groups, unlike the concentrations of the other biomarkers that showed different variations between groups, indicating that both NEFA and LPS the changes in their concentrations during supplementation may be more sensitive and more indicated for these types of evaluation. In addition, some blood mineral concentrations reduced significantly in both groups of horses, and thus, they need to be evaluated in horses under chronic oil supplementation

Effects of Docosahexaenoic Acid-Rich Microalgae Supplementation on Metabolic and Inflammatory Parameters in Horses With Equine Metabolic Syndrome

Much of the equine population is obese and therefore predisposed to the development of additional health concerns such as equine metabolic syndrome (EMS). However, pharmacologic treatments for EMS are limited. Omega-3 fatty acid supplementation is a therapeutic strategy in humans with metabolic dysfunction that improves insulin sensitivity and reduces inflammation, but the effects of omega-3 fatty acid supplementation in horses with EMS are unclear. Therefore, in this pilot study, 10 mixed-sex and mixed-breed horses with EMS were fed a docosahexaenoic acid (DHA)-rich microalgae containing 16 g DHA/horse/d or served as controls for 46 days. Inflammatory status was measured using serologic enzyme-linked immunosorbent assay and in peripheral blood mononuclear cells (PBMCs) using flow cytometry and reverse transcription polymerase chain reaction. Circulating fatty acids, triglyceride, leptin, and adiponectin concentrations were also determined. Insulin and glucose dynamics were assessed with oral sugar test (OST) and frequently sampled intravenous glucose tolerance testing. Postsupplementation, treated horses had an increase in many circulating fatty acids, including DHA (P < .001). Treated horses also had lower serum triglycerides postsupplementation (P = .02) and a trend (P = .07) for reduced PBMC tumor necrosis factor α. Interestingly, after 46 days, control horses had an increase in insulin responses to the OST (P = .01), whereas treated horses did not (P = .69). These pilot data indicate that DHA-rich microalgae supplementation alters circulating fatty acids, modulates metabolic parameters, and may reduce inflammation in horses with EMS.

Use of oil-rich diet for gaited horses during physical training

In Brazil, gaited horses are selected based on field tests, during which they move at speeds of 3 to 4 m/s for 30 to 60 min. To cover their nutrient requirements, feed manufacturers have developed oil-rich dietary supplements and concentrates. The aim of this research was to evaluate the effects of increasing the density of dietary fats in the feed of 16 Campolina horses undergoing intense gaited training. The training schedule consisted of training 4 × a week: 3 days riding for 60 min (10' warm-up, 40' doing marcha gait, and 10' cool down, and 1 day walking for 90'). The horses were divided in two groups: control and supplemented. The dietary supplementation was isocaloric, with the control group receiving an ordinary concentrate (3.5% fat) and the supplemented group fed 1.0 kg of the supplement (18% fat) plus the ordinary concentrate. Both groups had free access to fresh grass, salt and water. Blood samples were collected prior to and after 4 and 8 weeks of supplementation to calculate the complete blood count, glucose, total protein, triglycerides, total cholesterol, HDL, LDL and non-esterified fatty acids (NEFA). The results were evaluated by ANOVA and Tukey's test (P < 0.05). The supplemented group showed elevated levels of NEFA, red blood cells and haematocrit (P < 0.05), while the control group showed high triglyceride concentrations; both groups showed reduced plasma protein concentrations (P < 0.05). The other indices did not change (P > 0.05). The increase in dietary fat intake increased the blood lipid biomarkers and antioxidant capacity of gaited horses during intense training, possibly contributing to improve their metabolic performance.

Phospholipid analysis in sera of horses with allergic dermatitis and in matched healthy controls

Background

Lipids have become an important target for searching new biomarkers typical of different autoimmune and allergic diseases. The most common allergic dermatitis of the horse is related to stings of insects and is known as insect bite hypersensitivity (IBH) or summer eczema, referring to its recurrence during the summer months. This intense pruritus has certain similarities with atopic dermatitis of humans. The treatment of IBH is difficult and therefore new strategies for therapy are needed. Autoserum therapy based on the use of serum phospholipids has recently been introduced for horses. So far, serum lipids relating to these allergic disorders have been poorly determined. The main aim of this study was to analyse phospholipid profiles in the sera of horses with allergic dermatitis and in their healthy controls and to further assess whether these lipid profiles change according to the clinical status after therapy.

Methods

Sera were collected from 10 horses with allergic dermatitis and from 10 matched healthy controls both before and 4 weeks after the therapy of the affected horses. Eczema horses were treated with an autogenous preparation made from a horse’s own serum and used for oral medication. Samples were analysed for their phospholipid content by liquid chromatography coupled to a triple-quadrupole mass spectrometer (LC-MS). Data of phospholipid concentrations between the groups and over the time were analysed by using the Friedman test. Correlations between the change of concentrations and the clinical status were assessed by Spearman’s rank correlation test.

Results

The major phospholipid classes detected were phosphatidylcholine (PC), sphingomyelin (SM), phosphatidylinositol (PI) and phosphatidylethanolamine (PE). Eczema horses had significantly lower total concentrations of PC (p < 0.0001) and SM (p = 0.0115) than their healthy controls. After a 4-week therapy, no significant differences were found between the groups. Changes in SM concentrations correlated significantly with alterations in clinical signs (p = 0.0047).

Conclusions

Horses with allergic dermatitis have an altered phospholipid profile in their sera as compared with healthy horses and these profiles seem to change according to their clinical status. Sphingomyelin seems to have an active role in the course of equine insect bite hypersensitivity.

Capacidade funcional em cavalos de salto suplementados com linhaça

Objetivou-se avaliar a suplementação com linhaça, como fonte do ácido graxo ômega-3, sobre a capacidade funcional de cavalos de salto. Foram utilizados seis equinos distribuídos em dois quadrados latinos 3x3 balanceados. Os grupos experimentais consistiram em níveis crescentes de linhaça (na forma de farinha e óleo de linhaça na proporção de 75:25, respectivamente), resultando nos tratamentos de 0 (controle), 60 e 120g/cavalo/dia de linhaça. Os cavalos foram suplementados por período de 30 dias. A atividade física consistiu em trabalho para salto no nível de equitação fundamental. As variáveis funcionais mensuradas foram índice de claudicação (IC), comprimento da passada e biometria da articulação metacarpofalangeana - MCF (circunferência e ângulo de flexão). Observou-se efeito significativo da suplementação com linhaça, independentemente da dosagem, sobre o IC. Ainda, o fornecimento de 120g de linhaça/cavalo/dia aumentou o comprimento da passada dos cavalos ao trote (P<0,05) e promoveu redução de 0,5cm na circunferência da articulação MCF (P<0,05) em comparação ao grupo controle. A suplementação de cavalos de salto com 120g/dia de linhaça promoveu maior comprimento da passada ao trote e redução de edema na articulação metacarpofalangeana, melhorando suas capacidades funcionais.

Phospholipids in sera of horses with summer eczema: lipid analysis of the autoserum preparation used in therapy

REASONS FOR PERFORMING STUDY

Equine summer eczema, also known as insect bite hypersensitivity, affects horses recurrently during summer months. The treatment of this allergic pruritus is difficult and therefore there is a need for efficacious treatments. Autoserum therapy, based on the use of autogenous serum that is specifically prepared for oral administration and given when the animal shows clinical signs has been introduced recently. Lipids are thought to be responsible for the effect of this therapy.

OBJECTIVES

The main aim of this study was to analyse the phospholipid content of autogenous serum preparations and to further assess whether these preparations have different lipid profiles depending on the clinical status of the horse. The hypothesis is that the major serum phospholipids typical of the horse are present in the autoserum preparation.

STUDY DESIGN

Descriptive controlled clinical study.

METHODS

Sera were collected from 10 affected and 6 healthy horses, prepared in a similar fashion and the lipids contained in the resulting autoserum preparations were analysed by electrospray ionisation mass spectrometry.

RESULTS

The major phospholipid classes detected were phosphatidylcholine, sphingomyelin, phosphatidic acid and traces of lysophosphatidylcholine. Horses with summer eczema had significantly abundant concentrations of phosphatidylcholine (P = 0.042) and sphingomyelin (P = 0.0017) in comparison with healthy horses, while the concentration of phosphatidic acid was significantly higher in healthy horses (P = 0.0075).

CONCLUSIONS

The autoserum preparation contains minute amounts of the main serum phospholipids in differing concentrations in healthy horses and horses with an allergic skin disease.

The deficit of lipid in cultured cells contrasted with clinical lipidomics

Cells grown in culture are frequently employed to model lipid metabolism in vivo. There are reasons of convenience for this but examination of the lipidome of cultured cells and their metabolic responses to lipid supplementation give cause to indicate disparity with their counterparts in living animals. The reason is mainly that homeostatic regulation is exercised in animals supplied with an adequate diet in which the adipose tissue and liver represent plentiful sources of lipid integrated via inter-organ collaboration and able to buffer transient fluctuations in dietary lipid and essential fatty acids (EFAs). Moreover, conventional culture media are generally deficient in total lipids as well as essential EFAs. Cultured cells exposed to high glucose concentrations and lipid deficit typically manifest accelerated rates of lipogenesis evidenced by high rates of de novo FA biosynthesis. A more realistic model may be obtained by increasing supplements of lipid especially enriched in essential EFAs in the growth medium. Increasing concentrations of ω3 FAs, in particular, attenuate the rate of de novo lipogenesis. The improvement of cell culture models for pharmacological screening of drug-candidates targeting lipid or glucose metabolism is highlighted.

Dietary supplementation of conjugated linoleic acid in horses increases plasma conjugated linoleic acid and decreases plasma arachidonic acid but does not alter body fat

Studies using dietary supplementation of eicosapentaenoic and docosahexaenoic fatty acids (FA) in horses report inconsistent anti-inflammatory results but consistently report an increase in plasma arachidonic acid (C20:4), the major substrate of cyclooxygenase (COX) II inflammatory pathway. Conjugated linoleic acid has shown anti-inflammatory effects in laboratory and food animal species, but effects of CLA supplementation in horses have not been reported. Our objective was to determine the effects of CLA supplementation on plasma CLA and C20:4 and body fat in healthy horses at maintenance. In a crossover study, 12 mature mares were blocked by breed, age, and BCS and separated into 2 treatment groups (n = 6/group). Groups were fed CLA and corn oil (CO; isocaloric control) for two 6-wk feeding periods, separated by a 4-wk period during which treatment was withheld. Corn oil or CLA supplement (55% mixed CLA isomers) was incorporated into diets at 0.01% BW/d. Mares were fed individually and restricted to dry lots to control forage intake. Rump fat thickness (RFT), BW, and BCS were measured before (d 0) and after (d 42) each feeding period. Blood was collected on d 0, 14, 28, and 42 of each 6-wk period for GLC analysis of plasma CLA isomers (cis-9, trans-11; trans-10, cis-12; and trans-9, trans-11) and C20:4. An ANOVA was conducted to compare the response of RFT, BW, and BCS of CLA-treated and control mares. A mixed methods analysis with repeated measures was used to detect differences in plasma FA concentrations. There were no differences in BW, RFT, or BCS between treatment groups. All CLA isomers present in the CLA supplement were greater in plasma of horses fed CLA compared with controls (P < 0.01). Additionally, plasma concentrations of C20:4 were decreased in horses fed CLA (P < 0.05). This decline in C20:4 may impact the COX II pathway and warrants further investigation. These results suggest that in an equine model, dietary CLA increases circulating concentrations of supplemented CLA isomers and decreases circulating C20:4. Examining physiological effects of CLA supplementation in horses at varying levels of growth, exercise, and progression of joint disease may offer insight to potential benefits of CLA in the horse.

Effect of dietary omega-3 fatty acid source on plasma and red blood cell membrane composition and immune function in yearling horses

To determine the effect of different sources of dietary n-3 fatty acids (FA) on plasma and red blood cell (RBC) FA composition and immune response, 18 Quarter Horse yearlings were randomly and equally assigned to 1 of 3 treatments: encapsulated fish oil (n = 6), milled flaxseed (n = 6), or no supplementation (control, n = 6). Fish oil contained 15 g of eicosapentaenoic acid (C20:5n-3) and 12.5 g of docosahexaenoic acid (C22:6n-3), and flaxseed contained 61 g of alpha-linolenic acid (C18:3n-3) per 100 g of FA. Horses had free access to bahiagrass pasture during the active growing season and were individually fed a grain mix concentrate at 1.5% BW/d. Fish oil and flaxseed were mixed into the concentrate in amounts to provide 6 g of total n-3/100 kg of BW. Horses were fed their respective treatments for 70 d. Blood samples were obtained to determine plasma and RBC FA composition and for isolation of peripheral blood mononuclear cells. Peripheral blood mononuclear cells were stimulated with concanavalin A and phytohemagglutinin (PHA) to determine lymphocyte proliferation and were challenged with lipopolysaccharide to determine PGE(2) production. In vivo inflammatory response was assessed on d 70 by measuring skin thickness and area of swelling in response to intradermal injection of PHA. Treatment did not affect BW gain, which averaged 0.6 +/- 0.03 kg/d. Horses fed fish oil had greater (P < 0.05) proportions of eicosapentaenoic acid, docosahexaenoic acid, and sum of n-3 in plasma and RBC compared with those in the flaxseed and control treatments. In addition, plasma arachidonic acid was greater (P < 0.05) and plasma linoleic and alpha-linolenic acids were less (P < 0.05) in the fish oil treatment compared with the flaxseed and control treatments. Dietary treatment did not affect lymphocyte proliferation or PGE(2) production. Across treatments, the peak increase in skin thickness was observed 4 to 8 h after PHA injection. At 4 h postinjection, horses fed fish oil and those fed flaxseed had a greater increase in skin thickness than those in the control treatment (P < 0.05) and horses fed fish oil had a larger area of swelling than those in the control treatment (P < 0.05). Skin thickness remained greater (P < 0.05) in horses fed flaxseed than in control horses 6 h after injection. Although fed to supply a similar amount of n-3 FA, fish oil had a greater impact on plasma and RBC n-3 FA content than did flaxseed. However, supplementing horses with both fish oil and flaxseed resulted in a more pronounced early inflammatory response to PHA injection as compared with nonsupplemented horses.

The hypolipidemic effect of an ethyl ester of algal-docosahexaenoic acid in rats fed a high-fructose diet

Preclinical and clinical studies demonstrate that the omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) as a triacylglycerol (TAG) or an ethyl ester are protective against cardiovascular disease. Both have significant TAG-lowering effects. We developed a concentrated ethyl ester of DHA (MATK-90, 900 mg/g) using microalgae as its source. This study evaluated the effects that different doses of MATK-90 had on lipid levels and clinical parameters in male Wistar rats fed a high-fructose diet used to induce hypertriglyceridemia (TAG > or = 300 mg/dL). Effects of MATK-90 were compared to those produced by a pharmaceutical product (Lovaza, formerly Omacor, P-OM3; 465 mg EPA + 375 mg DHA), a TAG oil used in food (DHASCO, algal-DHA, 40% DHA by weight), and a control (corn oil). Doses of MATK-90 (0.6, 1.3, 2.5, 5.0 g kg(-1) day(-1)), algal-DHA (2 g DHA kg(-1) day(-1)), and P-OM3 (5.0 g kg(-1) day(-1)) were administered by oral gavage for 28 days. A significant dose-related decrease was observed in TAG and cholesterol levels in all but the lowest dose of MATK-90 treatment group vs. control. The high-dose group of MATK-90 and the P-OM3 group produced similar reductions in TAG levels.