Wendy Pearson

Protection against LPS-induced cartilage inflammation and degradation provided by a biological extract of Mentha spicata

BackgroundA variety of mint [Mentha spicata] has been bred which over-expresses Rosmarinic acid (RA) by approximately 20-fold. RA has demonstrated significant anti-inflammatory activity in vitro and in small rodents; thus it was hypothesized that this plant would demonstrate significant anti-inflammatory activity in vitro. The objectives of this study were: a) to develop an in vitro extraction procedure which mimics digestion and hepatic metabolism, b) to compare anti-inflammatory properties of High-Rosmarinic-Acid Mentha spicata (HRAM) with wild-type control M. spicata (CM), and c) to quantify the relative contributions of RA and three of its hepatic metabolites [ferulic acid (FA), caffeic acid (CA), coumaric acid (CO)] to anti-inflammatory activity of HRAM.MethodsHRAM and CM were incubated in simulated gastric and intestinal fluid, liver microsomes (from male rat) and NADPH. Concentrations of RA, CA, CO, and FA in simulated digest of HRAM (HRAMsim) and CM (CMsim) were determined (HPLC) and compared with concentrations in aqueous extracts of HRAM and CM. Cartilage explants (porcine) were cultured with LPS (0 or 3 μg/mL) and test article [HRAMsim (0, 8, 40, 80, 240, or 400 μg/mL), or CMsim (0, 1, 5 or 10 mg/mL), or RA (0.640 μg/mL), or CA (0.384 μg/mL), or CO (0.057 μg/mL) or FA (0.038 μg/mL)] for 96 h. Media samples were analyzed for prostaglandin E2 (PGE2), interleukin 1β (IL-1), glycosaminoglycan (GAG), nitric oxide (NO) and cell viability (differential live-dead cell staining).ResultsRA concentration of HRAMsim and CMsim was 49.3 and 0.4 μg/mL, respectively. CA, FA and CO were identified in HRAMsim but not in aqueous extract of HRAM. HRAMsim (≥ 8 μg/mL) inhibited LPS-induced PGE2 and NO; HRAMsim (≥ 80 μg/mL) inhibited LPS-induced GAG release. RA inhibited LPS-induced GAG release. No anti-inflammatory or chondroprotective effects of RA metabolites on cartilage explants were identified.ConclusionsOur biological extraction procedure produces a substance which is similar in composition to post-hepatic products. HRAMsim is an effective inhibitor of LPS-induced inflammation in cartilage explants, and effects are primarily independent of RA. Further research is needed to identify bioactive phytochemical(s) in HRAMsim.

Evaluation of inflammatory responses induced via intra-articular injection of interleukin-1 in horses receiving a dietary nutraceutical and assessment of the clinical effects of long-term nutraceutical administration.

OBJECTIVE To evaluate inflammatory responses induced via intra-articular recombinant human interleukin (IL)-1beta treatment in horses receiving a dietary nutraceutical (DN; composed of mussel, shark cartilage, abalone, and Biota orientalis lipid extract) and assess the clinical effects of long-term DN administration. ANIMALS 22 healthy horses. PROCEDURES 12 horses were fed 0, 15, 45, or 75 mg of DN (3 horses/treatment) daily for 84 days. General health and clinicopathologic variables were monitored at intervals. Ten other horses received 0 or 15 g of DN/d (5 horses/treatment) for 29 days (beginning day -14). One intercarpal joint in each horse was injected twice with IL-1beta (10 and 100 ng on days 0 and 1, respectively), and the contralateral joint was similarly injected with saline (0.9% NaCl) solution. Synovial fluid prostaglandin E(2) (PGE(2)), sulfated glycosaminoglycan (GAG), nitric oxide (NO), and protein concentrations and leukocyte counts were analyzed before and at intervals after injections. RESULTS Administration of the DN (up to 75 g/d) to horses for 84 days did not induce any adverse effects. In the other experiment, synovial fluid PGE(2), GAG, and protein concentrations and leukocyte count increased after intra-articular injections of IL-1beta (compared with effects of saline solution injections) in horses that received no DN; NO concentration was not affected. In horses that were fed the DN, intra-articular IL-1beta injections did not induce significant increases in synovial fluid PGE(2) and GAG concentrations. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that administration of the DN may be useful in preventing inflammation associated with arthritis and degenerative joint disease in horses.

Oral rosmarinic acid-enhanced Mentha spicata modulates synovial fluid biomarkers of inflammation in horses challenged with intra-articular LPS

A biological extract of high-rosmarinic acid mint (HRAM) has previously demonstrated inhibitory effects on lipopolysaccharide (LPS)-induced prostaglandin E(2) (PGE(2)), nitric oxide (NO) and glycosaminoglycan (GAG) release in vitro. This study was undertaken to determine whether HRAM added to feed produces similar effects in horses challenged with intra-articular LPS. Eight horses received HRAM (0 or 28.1 ± 1.3 g/day; n = 4 per group) in their feed for 24 days in a blinded manner. On day 21, all horses received an intra-articular injection of LPS (0.3 ng) into their left or right intercarpal joint. Synovial fluid (SF) samples were taken on postinjection day (PID)-21 (i.e. prior to commencement of supplementation), PID0, PID0.25, PID0.5, PID1 and PID3 and analysed for PGE(2), GAG, NO, protein and total nucleated cells counts. Blood biochemistry and haematology screens were conducted at PID-21, PID0, PID1 and PID3. There was a significant reduction in LPS-induced PGE(2) and GAG in SF in horses supplemented with HRAM compared with controls and a tendency to increase complement recognition protein accumulation in synovial fluid of HRAM horses. Plasma from HRAM horses had reduced total white blood cells, segmented neutrophils (compared with baseline concentrations) and lymphocytes (compared with controls), and increased SF nucleated cell count (compared with baseline concentrations and controls). It is concluded that HRAM offered as part of the feed alter biomarkers of inflammation in SF of LPS-challenged horses. Larger studies that seek to clarify effects of HRAM on synovial fluid cell counts and possible role of HRAM-induced interference with complement signalling are warranted.

Effects of simulated digests of Biota orientalis and a dietary nutraceutical on interleukin-1– induced inflammatory responses in cartilage explants

OBJECTIVE To test the hypothesis that simulated digests of Biota orientalis (BO) and a dietary nutraceutical (DN; composed of mussel, shark cartilage, abalone, and BO seed lipid extract) inhibit prostaglandin E2 (PGE2), nitric oxide (NO), and glycosaminoglycan (GAG) production in interleukin (IL)-1-stimulated cartilage explants. SAMPLE POPULATION Cartilage tissue from 12 pigs. PROCEDURES Articular cartilage explants were conditioned with a simulated digest of BO (BOsim) or DN (DNsim) at concentrations of 0, 0.06, or 0.18 mg/mL or indomethacin (INDOsim; 0 or 0.02 mg/mL) for 72 hours. Control explants received digest vehicle only. Explants were or were not stimulated with recombinant human-IL-1beta (10 or 0 ng/mL) during the final 48 hours of culture. Concentrations of PGE2, GAG, and NO in media samples (mPGE2,mGAG, and mNO concentrations, respectively) were analyzed, and explant tissue was stained fluorochromatically to determine chondrocyte viability. Treatment effects during the final 48-hour culture period were analyzed. RESULTS IL-1 increased mPGE2, mGAG, and mNO concentrations in control explants without adversely affecting cell viability. Treatment with INDOsim blocked PGE2 production and increased mNO concentration in IL-1-stimulated and unstimulated explants and increased mGAG concentration in unstimulated explants. Treatment with DNsim (0.06 and 0.18 mg/mL) reduced mPGE2 concentration in IL-1-stimulated and unstimulated explants, reduced mNO concentration in IL-1-stimulated explants, and increased mNO concentration in unstimulated explants. Treatment with 0.18 mg of DNsim/mL increased cell viability in the presence of IL-1. In IL-1-stimulated explants, BOsim (0.06 and 0.18 mg/mL) reduced mPGE2 concentration, but 0.18 mg of BOsim/mL increased cell viability. CONCLUSIONS AND CLINICAL RELEVANCE Effects of IL-1 on cartilage explants in vitro were modulated by DNsim and BOsim.

Pyrrolizidine alkaloids in higher plants : Hepatic veno-occlusive disease associated with chronic consumption

ABSTRACT Pyrrolizidine alkaloids (PAs) are a class of phytochemi-cals found in more than 350 plant species, with the main suspect species being Heliotroprium, Senecio, Crotalaria, and Symphytum. Many of these types of alkaloids have been shown to have important pharmacological properties, but many others have demonstrated severe toxicity. Consumption of plants containing these alkaloids has been associated with potentially fatal hepatic veno-occlusive disease (Budd-Chiari Syndrome), carcinogenesis, and fibrotic lung disease. This article reviews literature published on comfrey (Symphytum officinale), as a case-study of a potentially toxic plant commonly consumed in North America as an herbal remedy. The pharmacology of the plant is discussed together with the phytochemical features lending the plant to toxicity problems. Finally, there is an attempt to estimate the human intake of potentially toxic pyrrolizidine alkaloids in high-risk areas, and a discussion of reported case-studies of PA poisoning.

Effect of a Proprietary Herbal Product on Equine Joint Disease

ABSTRACT Osteoarthritis is a degenerative disease of the joints that affects a great number of horses, and accounts for a considerable economic burden on the industry. The condition is typically treated with NSAIDs and steroids, but these treatments may elicit negative side-effects when used over the long-term. Herbal remedies have increased in popularity over the past 3 years, but little scientific documentation exists to further the knowledge of these products for horses. This study investigated the effects of an herbal mixture “Mobility” on equine osteoarthritis. It was found that Mobility significantly suppressed production of prostaglandin E2 in the arthritic joints. This observation provides a unique objective, scientific insight which may explain the anecdotal testimonials relating to the success of this product.

Effects of a Novel Dietary Supplement on Indices of Muscle Injury and Articular GAG Release in Horses

&NA; This study determined the ability of an oral nutraceutical supplement to attenuate the oxidative stress and inflammation that occurs in muscles and joints with repeated bouts of high‐intensity exercise in horses. The supplement, fed daily, was comprised of whole dried mushrooms, golden flaxseed, omega‐3 fatty acids, plant‐based enzymes, a melon‐concentrate powder, and Saccharomyces cerevisiae boulardii. Ten horses participated in a partial cross‐over design, with 7 horses completing the Control trial and 7 horses completing the supplement trial. Blood and synovial fluid samples (from the intercarpal joint) were taken before, and at 1 and 24 hours after a standardized, repeated high‐intensity exercise test that was performed before supplementation and on the 22nd day of supplementation. At the end of the supplement trial exercise resulted in reduced concentrations of plasma markers of oxidative stress (decreased thiobarbituric acid reactive substances, with increased total antioxidant status and increased superoxide dismutase activity); there was no effect on plasma markers of muscle injury (creatine, creatine kinase, and aspartate aminotransferase) or inflammation (PGE2, nitric oxide). Within synovial fluid, there was a tendency for increased superoxide dismutase activity, and decreased concentration of glycosaminoglycans. It is concluded that the supplement, when fed to horses as part of the normal diet for 23 days, was associated with reduced concentrations of markers of oxidative stress and inflammation in muscle and synovial fluid. HighlightsWe measured plasma and synovial fluid (from the intercarpal joint) markers of oxidative stress, inflammation and muscle damage before and after exercise, and before and after providing a supplement for 23 days.The supplement contained plant, mushroom and yeast products that have been shown to combat tissue oxidative stress and inflammation, and enhance immune function in animals.High‐intensity exercise resulted in muscle injury and release of glycosaminoglycans (GAGs) from articular cartilage in the intercarpal joint.The supplement reduced the appearance of muscle enzymes in plasma and abolished the increase in synovial fluid GAGs after high‐intensity exercise.

A Time Course Evaluation of Inflammatory and Oxidative Markers Following High Intensity Exercise in Horses: a Pilot Study

Exercise is a physiological stress resulting in reactive oxygen species and inflammatory mediators, the accumulation of which are thought to contribute to degenerative articular diseases. The horse is of particular interest in this regard as equine athletes are frequently exposed to repetitive bouts of high-intensity exercise. The purpose of this study was to provide a detailed description of the response of articular and systemic oxidative and inflammatory biomarkers following high-intensity, exhaustive exercise in horses. A group of horses (Ex) underwent repeated bouts of high-intensity exercise, at a target heart rate of 180 beats/min, until voluntary exhaustion. Baseline plasma and synovial fluid (SF) samples were taken 24 h before exercise and then at 0.5, 1, 2, 4, 8, and 24 h following exercise cessation. This time course was repeated in a group of nonexercised control horses (Co). Plasma and SF samples were analyzed for prostaglandin E2 (PGE2), nitric oxide (NO), total antioxidant status (TAS), and glycosaminoglycans (GAG). The Ex group had significantly higher plasma NO at 0.5, 1, and 2 h; and higher plasma PGE2 at 0.5 and 1 h compared with Co. SF PGE2 and GAG were also higher in Ex horses at 8 h compared with Co. It is concluded that high-intensity exercise in horses results in a rapid increase in systemic oxidative and inflammatory markers from 0.5 to 2 h after exercise, which is followed by local articular inflammation and cartilage turnover at 8 h postexercise. NEW & NOTEWORTHY In horses, the influence of exercise systemically and within the articular space remains unclear and requires further detailed characterization. In this study, we identify that an acute bout of high-intensity exercise in horses induces systemic inflammation and oxidative stress within 30 min of exercise cessation, which lasts for ~2 h. Articular inflammation and cartilage turnover were also be observed within the equine carpal joint 8 h following exercise completion.

Acute Effects of a Single-Dose Nutritional Product on Stress Response and Task Completion in Horses

ABSTRACT There is a growing number of nutraceutical products for promoting tractability and reducing anxiety in horses, despite a virtual absence of scientific assessment of these products. The objective of this study was to compare the effects of acepromazine (ACE) and a magnesium‐based antianxiety formulation in horses participating in tasks typical of normal equine management. Six horses were randomly allocated to one of the three treatment groups in a 2 × 3 randomized block design. Each horse was fitted with a heart‐rate (HR) monitor, and received a single dose of ACE (0.5 cc/horse), the nutritional formulation (NUT), or a placebo paste exactly 30 minutes before commencement of tasks. Tasks included loading onto an equine weighbridge, loading onto a two‐horse trailer, unaccompanied transport in a two‐horse trailer, jugular venous blood sampling, and 10 minutes in a stall with an unfamiliar object. Stress response with respect to peak and average HR, time to completion of tasks, and plasma cortisol were measured. This study demonstrated that tasks inherent to modern equine management are sufficient to induce a stress response, as demonstrated by increased peak and average HRs, and increased plasma cortisol. The average HR of the earliest task (30 minutes after ACE and NUT administration) was effectively blunted by administration of ACE or NUT 30 minutes before onset of stress. It is concluded that oral ACE and NUT reduce HRavg during a stressful task with which they were challenged 30 minutes after administration. Effects of these treatments on plasma cortisol require further research. HIGHLIGHTSTasks typical of equine management induce elevated heart rate and plasma cortisol in horses.Administration of acepromazine or magnesium‐based nutraceutical reduced average heart rate.Effectiveness of acepromazine and magnesium‐based nutraceutical were comparable.