Phosphatidylserine Supplementation Research Articles

Phosphatidylserine supplementation as a potential strategy to improve endothelial function in type 2 diabetes

Endothelial dysfunction represents a causal factor in the pathogenesis of cardiovascular disease associated with type 2 diabetes (T2D), including hypertension. Previous work has revealed that endothelial mechanosensing structures are degraded in T2D, resulting in impaired shear stress mechanotransduction and decreased flow-mediated dilation (FMD). One well-known mechanosensor that is susceptible to cleavage is glypican-1, a prominent proteoglycan member of the endothelial glycocalyx. In this regard, recent evidence from a proteomic analysis suggests that glypican-1 is a substrate of the proinflammatory enzyme ADAM17 (a disintegrin and metalloproteinase-17), which is elevated in the vasculature of T2D. Recent work has revealed that exogenous phosphatidylserine (PS) inhibits in vitro ADAM17 sheddase activity, which may aid in retaining the membrane-bound glypican-1. Therefore, we hypothesized that oral administration of PS in diabetic mice (db/db) would enhance shear stress mechanotransduction, as assessed by FMD, and that this would be accompanied by greater presence of glypican-1 on the endothelial surface. We further hypothesized that PS would reduce blood pressure. We tested this hypothesis in ~10-week-old db/db male mice that were randomized to receive a daily peanut butter pellet as vehicle control or the pellet mixed with soy-derived PS (200 mg/kg/day) for 28 days. A third group of untreated age-matched wild-type C57BL/6J male mice served as healthy controls. Excised mesenteric arteries were used for assessment of FMD using pressure myography, while femoral arteries were used for determining presence of glypican-1 content on the endothelial surface using confocal microscopy. Blood pressure was assessed using the tail-cuff method. All reported differences are significant at p<0.05. Compared with wild-types, untreated db/db mice had impaired FMD, reduced presence of endothelial glypican-1, and increased blood pressure. Notably, these effects were not observed in db/db mice treated with PS. These findings suggest that oral PS may be effective at improving indices of endothelial dysfunction in T2D, an effect likely mediated by the retention of endothelial mechanosensor glypican-1 via reduced ADAM17 sheddase activity. No support to disclose. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The effect of phosphatidylserine supplementation on athletic performance: A systematic review of randomized clinical trials

The effect of phosphatidylserine supplementation on athletic performance: A systematic review of randomized clinical trials

Ergogenic effects of phosphatidylserine alone and combined with branched-chain amino acids in trained rats

Acute phosphatidylserine (PS) or branched-chain amino acids (BCAA) supplements alone may have an adrenocorticotropic hormone, cortisol suppressive effect and increase the testosterone/cortisol ratio, but the associated effect of these supplements during a period of high-intensity physical stress is not yet known. The study investigated the effects of chronic PS supplementation alone and combined with BCAA during high-intensity interval training (HIIT) on training volume tolerance, anabolic-catabolic balance and stress biomarkers in rats. Thirty-three rats were separated into: placebo (PLA, n=11), PS alone (n=11) and combined with BCAA (PSBCAA, n=11). Groups performed swimming sessions of HIIT (5 series × 1 min × 1 min recovery; external load equivalent to 13% of body mass) and nine recovery sessions of moderate-intensity training (30 min at 5% of body mass) alternately. One-way ANOVA was used to compare biochemical variables and two-way ANOVA was calculated to compare training volume. Training volume performed (TVP) was higher in first, fourth, fifth, sixth, and eighth HIIT sessions in the PS group in comparison to PLA (P<0.05). TVP was higher in the fourth session in PSBCAA compared to PLA. There were no differences in TVP during the sessions between PS and BCAA groups. Creatine kinase (CK) was lower in PSBCAA in comparison to PS alone (P=0.03) and PLA (P=0.04) after the experimental period. Testosterone concentration was enhanced in PSBCAA group compared to PLA (P=0.01); testosterone/corticosterone ratio was higher in PSBCAA compared to PS (P=0.05) and PLA (P=0.004) after protocol. PS combined with BCAA increases testosterone concentration and testosterone/corticosterone ratio, demonstrating an enhancement of anabolic state in trained rats.

The effect of phosphatidylserine administration on cognition and symptoms of reactive attachment disorder ‐ a randomized, double‐blind, placebo‐controlled clinical trial in adolescents

BACKGROUND Reactive Attachment Disorder (RAD) occurs in 1% of the general population and is caused by a disregard for a child's emotional or physical needs, or a repeated change in caregivers. Children with RAD display persistent social and emotional disturbances resulting in underperforming at school. Phosphatidylserine (PS) is a naturally occurring phospholipid that is most concentrated in the brain and has unique regulatory and structural functions. Supplementation with PS beneficially influences numerous neurotransmitter systems such as acetylcholine, dopamine, serotonin and norepinephrine. PS improves the cognitive response to physical or mental stress, and has been shown to improve memory and cognition in healthy individuals. In addition, PS has previously been shown to improve symptoms of attention-deficit hyperactivity disorder (ADHD) and short-term auditory memory in children with ADHD. HYPOTHESIS We hypothesized that PS supplementation results in favorable changes in cognition and RAD symptoms in adolescents. METHODS Thirty male and female adolescents (PS: n=14 (11 male, 3 female), 17.7±3.3 years; PLA n=16 (13 male, 3 female), 19.4±2.4 years) from Showa Gakuen school (Tokyo, Japan) ingested 200mg of PS (LIPAMINE-PS, Healthy Navi Co., Ltd., Japan) in form of a cocoa flavored chewable tablet or a matching placebo for two months in a randomized, double-blind, parallel design in accordance with the Basic Principles of the Declaration of Helsinki. Main outcome measures included: (i) RAD symptoms based on DSM-IV-TR; (ii) cognitive tests to evaluate memory, attention and concentration: short-term auditory memory (Digit Spin Forward), working memory (Digit Span Backward), attention and working memory (Serial Subtraction Test: Serial Sevens), visual-motor integration skills (Beery-Buktenica Developmental Test), processing speed, mental flexibility and language skills. Subjects were randomized into groups based on their baseline working memory scores. Statistical analysis was performed using STATCEL 2 (Oms-Publishing, Saitama, Japan). A p-value of <0.05 was considered statistically significant. RESULTS PS administration resulted in a statistically significant decrease in RAD symptoms (-65%) and an increases in sort-term auditory memory (+26%), working memory (+30%), calculus performance (+48%), Visual-Motor Integration (+32%), and processing speed (+32%), p<0.01, as well as language skills (+28%, p<0.05), compared to baseline, while the placebo group showed an improvement in processing speed (+24%, p<0.05). CONCLUSIONS PS supplementation can be an important nutritional strategy to improve RAD symptoms and cognition in adolescents.

Phosphatidylserine Supplementation as a Novel Strategy for Reducing Myocardial Infarct Size and Preventing Adverse Left Ventricular Remodeling.

Phosphatidylserines are known to sustain skeletal muscle activity during intense activity or hypoxic conditions, as well as preserve neurocognitive function in older patients. Our previous studies pointed out a potential cardioprotective role of phosphatidylserine in heart ischemia. Therefore, we investigated the effects of phosphatidylserine oral supplementation in a mouse model of acute myocardial infarction (AMI). We found out that phosphatidylserine increases, significantly, the cardiomyocyte survival by 50% in an acute model of myocardial ischemia-reperfusion. Similar, phosphatidylserine reduced significantly the infarcted size by 30% and improved heart function by 25% in a chronic model of AMI. The main responsible mechanism seems to be up-regulation of protein kinase C epsilon (PKC-ε), the main player of cardio-protection during pre-conditioning. Interestingly, if the phosphatidylserine supplementation is started before induction of AMI, but not after, it selectively inhibits neutrophil’s activation, such as Interleukin 1 beta (IL-1β) expression, without affecting the healing and fibrosis. Thus, phosphatidylserine supplementation may represent a simple way to activate a pre-conditioning mechanism and may be a promising novel strategy to reduce infarct size following AMI and to prevent myocardial injury during myocardial infarction or cardiac surgery. Due to the minimal adverse effects, further investigation in large animals or in human are soon possible to establish the exact role of phosphatidylserine in cardiac diseases.

Phosphatidylserine for the Treatment of Pediatric Attention-Deficit/Hyperactivity Disorder: A Systematic Review and Meta-Analysis.

Objective: To examine the evidence for efficacy of phosphatidylserine for symptoms of attention-deficit/hyperactivity disorder (ADHD) in children. Methods: Medline, Cochrane Library, and ClinicalTrials.gov were searched from inception through August 2020. Studies of any design that assessed phosphatidylserine supplementation for children aged ≤18 years with a diagnosis of ADHD were included in the systematic review; only randomized clinical trials were included in the meta-analysis. Standardized mean differences and 95% confidence intervals (CIs) were calculated, and the heterogeneity of the studies was estimated using I2. The overall quality of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation tool. Results: Four studies met the inclusion criteria for the narrative review (n = 344) and three for the meta-analysis (n = 216). Results of the meta-analysis showed a statistically significant effect of 200-300 mg/day of phosphatidylserine on symptoms of inattention relative to placebo (effect size [ES] 0.36; 95% CI: 0.07 to 0.64; p = 0.01). The effects of phosphatidylserine on overall symptoms of ADHD (ES 0.76; 95% CI: -0.07 to 1.60; p = 0.07) and hyperactivity-impulsivity (ES 0.24; 95% CI: -0.04 to 0.53; p = 0.09) were not statistically significant. Conclusions: Preliminary evidence suggests that phosphatidylserine may be effective for reducing symptoms of inattention in children with ADHD, although the quality of the evidence is low and additional research in this area is warranted.

Abstract 3003: Inhibiting the mitochondrial enzyme phosphatidylserine decarboxylase (PISD) reduces stemness and increases differentiation in acute myeloid leukemia (AML)

Abstract Acute myeloid leukemia (AML) is a hematopoietic malignancy characterized by the accumulation of malignant myeloid cells that have arrested maturation. Most therapeutic regimens approved or under development are cytotoxics. An alternate, but less explored therapeutic approach, is to induce terminal differentiation of AML cells. Upon differentiation, AML cells cease to proliferate or die. Phosphatidylserine decarboxylase (PISD) is a mitochondrial enzyme that converts phosphatidylserine (PS) to phosphatidylethanolamine (PE). Here, we explored the effects of inhibiting PISD on AML growth, stemness and differentiation. Knockout of PISD by CRISPR reduced the growth and clonogenic growth of OCI-AML2 cells. The reported chemical PISD inhibitor, 7-chloro-N-(4-ethoxyphenyl)-4-quinolinamine (aka: MMV007285), reduced growth and viability of OCI-AML2 cells (IC50 = 4.741 μM) and TEX cells (IC50 = 4.868 μM). Using the 8227 primary AML cell culture model, we showed that inhibiting PISD induced cell death in the functionally defined stem cell fraction (CD34+CD38-). MMV007285 also preferentially inhibited the clonogenic growth of primary AML cells (n = 7) over normal hematopoietic cells (n= 3). Moreover, MMV007285 induced AML cell differentiation as evidenced by increased CD11b expression and staining for non-specific esterase. Using high-performance thin layer chromatography (HPTLC), we found that inhibition of PISD with MMV007285 increased intracellular PS. To determine whether increased PS was functionally important, OCI-AML2 cells were treated with PS, resulting in reduced growth and clonogenic growth. Furthermore, PS supplementation targeted AML progenitor cells as it decreased engraftment of TEX cells in mice. Mechanistically, inhibiting PISD induced differentiation and decreased stemness in AML by activating Toll-like receptor (TLR) signaling. Specifically, inhibiting PISD upregulated TLR4 and 8 expression and increased expression of cytokines downstream of TLR activation. We also showed that TLR activation was functionally important to induce AML differentiation. Finally, we evaluated the effects of PISD inhibition in AML mouse models. MMV007285 (300 mg/kg/5 of 7 days orally for 10 days) decreased the growth of OCI-AML2 cells in SCID mice. Moreover, MMV007285 (150 mg/kg/5 of 7 days orally for 5 weeks) impeded the leukemic engraftment of primary AML cell in NOD/SCID mice without toxicity. Using secondary transplants, we showed that MMV007285 also targeted the leukemic stem cells. Taken together, inhibition of PISD altered phospholipid metabolism, inhibited growth and stemness, and increased differentiation in AML cells. Our findings reveal a previously undescribed link between mitochondrial phospholipid metabolism and AML stemness and differentiation, highlighting a potential new therapeutic strategy for AML. Citation Format: Mingjing Xu, Ayesh Seneviratne, Val A. Fajardo, Geethu E. Thomas, G. Wei Xu, Rose Hurren, S. Kim, Neil MacLean, Xiaoming Wang, Marcela Gronda, Danny Jeyaraju, Yulia Jitkova, David Sharon, Ahmed Aman, Rima Al-awar, Steven Chan, Mark D. Minden, Paul LeBlanc, Aaron D. Schimmer. Inhibiting the mitochondrial enzyme phosphatidylserine decarboxylase (PISD) reduces stemness and increases differentiation in acute myeloid leukemia (AML) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3003.

Revisiting: “A food supplement is associated with changes in Subjective Memory Complaints and Geriatric Depression Scale in adults and older persons in Portugal”

This study aims to evaluate the effect of phosphatidylserine supplementation on Scale Memory Complaints (SMC) and Geriatric Depression Scale (GDS). A group of healthy adults and elderly people (n= 915) aged 65,65 ± 11,10 years with an education level of 7,56 ± 4,56 years participated in the study. Participants were submitted to the Mini-Mental State Examination (MMSE), SMC and GDS. Four individuals presented cognitive impairment, 874 presented memory complaints and 436 were above cut-off point for GDS. Subsequently, one group of women (n=48) used phosphatidylserine supplementation for 4 weeks. The consumption of phosphatidylserine over the course of 4 weeks significantly decreased SMC ( p=0,000) and GDS (p=0.009) values in this group.

Effect of soy phosphatidylserine supplemented diet on skin wrinkle and moisture in Vivo and clinical trial

Effect of supplementation of phosphatidylserine (PS), enzymatically synthesized from soy lecithin, on skin moisture and wrinkle in animal and human was investigated. Skin moisture content of hairless mice was significantly decreased and skin thickness and wrinkle were significantly increased by UV irradiation, whereas PS-supplemented groups showed reduced wrinkle depth and much less wrinkle area unlike UV control (UV/Con) group. The collagen content in PS-supplemented groups increased compared with that in UV/Con group. A placebo-controlled double-blind intake study of soft capsules containing PS (300 mg/day) was performed on 63 subjects who had normal healthy skin for 12 weeks. Dermatologist’s visual assessment and image analysis of replicas showed that wrinkle near eye was improved by PSsupplementation. Upon measurement of moisture content in the skin, PS supplementation increased the moisture content in the skin. These findings showed that PS supplementation was effective in moisturizing and improving wrinkle of the skin in both animal and human; thus, PS could be used as an effective skin food ingredient.

The effect of phosphatidylserine administration on memory and symptoms of attention‐deficit hyperactivity disorder: a randomised, double‐blind, placebo‐controlled clinical trial

Attention-deficit hyperactivity disorder (ADHD) is the most commonly diagnosed behavioural disorder of childhood, affecting 3-5% of school-age children. The present study investigated whether the supplementation of soy-derived phosphatidylserine (PS), a naturally occurring phospholipid, improves ADHD symptoms in children. Thirty six children, aged 4-14years, who had not previously received any drug treatment related to ADHD, received placebo (n=17) or 200mgday(-1) PS (n=19) for 2months in a randomised, double-blind manner. Main outcome measures included: (i) ADHD symptoms based on DSM-IV-TR; (ii) short-term auditory memory and working memory using the Digit Span Test of the Wechsler Intelligence Scale for Children; and (iii) mental performance to visual stimuli (GO/NO GO task). PS supplementation resulted in significant improvements in: (i) ADHD (P<0.01), AD (P<0.01) and HD (P<0.01); (ii) short-term auditory memory (P<0.05); and (iii) inattention (differentiation and reverse differentiation, P<0.05) and inattention and impulsivity (P<0.05). No significant differences were observed in other measurements and in the placebo group. PS was well-tolerated and showed no adverse effects. PS significantly improved ADHD symptoms and short-term auditory memory in children. PS supplementation might be a safe and natural nutritional strategy for improving mental performance in young children suffering from ADHD.

Docosahexaenoic acid and phosphatidylserine improves the antioxidant activities in vitro and in vivo and cognitive functions of the developing brain

Fish oil during early postnatal period may modulate the impact of oxidative stress in the developing brain and thus improve memory and cognitive behaviour. This study investigated the impacts of docosahexaenoic acid (DHA, C22:6, n-3) and/or phosphatidylserine (PS) on antioxidant activities in vitro, and the beneficial effects of feeding with DHA and/or PS on antioxidant activities in brain and liver tissues and on the cognitive functions of the developing brain. Results indicated that DHA and/or PS significantly enhanced antioxidant activities and increased cell viabilities in vitro. Feeding with DHA and/or PS supplementation not only significantly improved escape latency of animals, but it also improved the oxidative parameters in the brain, enhanced glutathione peroxidase activity as well as reduced nitric mono-oxide levels in the liver. DHA and PS may serve to protect cells from oxidative stress and further improve learning and memory ability in vivo.

Omega-3 fatty acids administered in phosphatidylserine improved certain aspects of high chronic stress in men

Nutrients such as omega-3 oils and phosphatidylserine have been considered to exert stress-buffering effects. In this randomized, double-blind, placebo-controlled trial, we investigated effects of omega-3 phosphatidylserine (PS) on perceived chronic stress, assessed by the Trier Inventory for Chronic Stress (Schulz P, Schlotz W, Becker P. TICS: Trierer Inventar zum chronischen Stress. Göttingen, Germany: Hogrefe, 2004.), and on psychobiological stress responses to an acute laboratory stress protocol, the Trier Social Stress Test (Neuropsychobiology.1993;28:76-81), at baseline and after the treatment period. We hypothesized that omega-3 PS supplementation lowers chronic and acute stress. Sixty healthy nonsmoking men aged 30 to 60 years either received omega-3 PS or a matching placebo for 12 weeks. Results revealed no significant main effect of omega-3 PS supplementation on stress measures. However, by accounting for chronic stress level of study participants, stress-reducing effects of omega-3 PS were found exclusively for high chronically stressed subjects. As expected, these individuals also showed a blunted cortisol response to the Trier Social Stress Test. Treatment with omega-3 PS seemed to restore the cortisol response in this particular subgroup of low responders. These results are in line with previous findings. We conclude that subgroups characterized by high chronic stress and/or a dysfunctional response of the hypothalamus-pituitary-adrenal axis may profit from omega-3 PS supplementation.

The effects of phosphatidylserine supplementation on cognitive functioning prior and following an acute bout of resistance training in young males

Background Making quick decisions and reducing the amount of errors at the beginning of a competition are crucial to the success in team sports and individual events. Phosphatidylserine (PS) has been shown to reduce stress and increase performance in runners, cyclists and golfers. A randomized, double-blind, placebo-controlled, cross-over pilot study was performed to evaluate the effect of PS supplementation on cognitive function prior to and following an acute bout of resistance training in 18 males aged 18-30.

Phosphatidylserine (PS) as a potential nutraceutical for canine brain aging: A review

Abstract Neurodegenerative processes are one of the main age-related features of dogs. Senile neurodegeneration can be clinically asymptomatic, borderline (i.e., a condition that is intermediate between normal and disease state) or progress toward overt clinical abnormalities, known as age-related cognitive disorders, cognitive dysfunction syndrome (CDS), or senile dementia. The aim of the present article is to review the rationale for the use of phosphatidylserine (PS), a natural phospholipid, in the management of neurodegenerative processes in senior dogs. The preliminary clinical data on PS supplementation in senior dogs will also be reviewed. There is evidence that PS is absorbed rapidly, reaches high concentrations in the brain, and is well tolerated. Phosphatidylserine has emerged to exert several in vitro and in vivo neuroprotective activities. It has been shown to positively affect neurotransmitter release and neurotransmitter receptor density in several regions from laboratory animals with memory impairments. Phosphatidylserine also was found to revert experimentally-induced amnesia in rats and improve memory deficits both in old animals and in elderly humans with various degrees of cognitive impairment and Alzheimer's dementia. On the basis of the data reported in the scientific literature, PS stands out as an essential brain nutrient. In view of these features, some supplements containing PS have been licensed recently as adjuvant treatment for canine and feline aging. The results of the studies on its use in the preventative and combined treatment of dogs with clinical features consistent with the diagnosis of CDS are reported. Although PS-based neuroprotection in dogs and cats is still at its infancy, the preliminary collected data look promising and thus merit further investigation.

The effects of phosphatidylserine on endocrine response to moderate intensity exercise

BackgroundPrevious research has indicated that phosphatidylserine (PS) supplementation has the potential to attenuate the serum cortisol response to acute exercise stress. Equivocal findings suggest that this effect might be dose dependent. This study aimed to examine the influence of short-term supplementation with a moderate dose of PS (600 mg per day) on plasma concentrations of cortisol, lactate, growth hormone and testosterone before, during, and following moderate intensity exercise in healthy males.Methods10 healthy male subjects participated in the study. Each subject was assigned to ingest 600 mg PS or placebo per day for 10 days using a double-blind, placebo-controlled, crossover design. Serial venous blood samples were taken at rest, after a 15 minute moderate intensity exercise protocol on a cycle ergometer that consisted of five 3-minute incremental stages beginning at 65% and ending at 85% VO2 max, and during a 65 minute passive recovery. Plasma samples were assessed for cortisol, growth hormone, testosterone, lactate and testosterone to cortisol ratio for treatment (PS or placebo).ResultsMean peak cortisol concentrations and area under the curve (AUC) were lower following PS (39 ± 1% and 35 ± 0%, respectively) when compared to placebo (p < 0.05). PS increased AUC for testosterone to cortisol ratio (184 ± 5%) when compared to placebo (p < 0.05). PS and placebo supplementation had no effect on lactate or growth hormone levels.ConclusionThe findings suggest that PS is an effective supplement for combating exercise-induced stress and preventing the physiological deterioration that can accompany too much exercise. PS supplementation promotes a desired hormonal status for athletes by blunting increases in cortisol levels.

The effect of phosphatidylserine on golf performance

BackgroundA randomized, double-blind, placebo-controlled study was performed to evaluate the effect of oral phosphatidylserine (PS) supplementation on golf performance in healthy young golfers with handicaps of 15–40.MethodsPerceived stress, heart rate and the quality of the ball flight was evaluated before (pre-test) and after (post-test) 42 days of 200 mg per day PS (n = 10) or placebo (n = 10) intake in the form of a nutritional bar. Subjects teed-off 20 times aiming at a green 135 meters from the tee area.ResultsPS supplementation significantly increased (p < 0.05) the number of good ball flights (mean: pre-test 8.3 ± 3.5, post-test 10.1 ± 3.0), whereas placebo intake (mean: pre-test 7.8 ± 2.4, post-test 7.9 ± 3.6) had no effect. PS supplementation showed a trend towards improving perceived stress levels during teeing-off (mean: pre-test 5.8 ± 2.0, post-test 4.0 ± 2.0, p = 0.07), whereas stress levels remained unchanged in the placebo group (mean: pre-test: 5.1 ± 2.0, post-test: 5.1 ± 3.1). Supplementation did not influence mean heart rate in either group.ConclusionIt is concluded that six weeks of PS supplementation shows a statistically not significant tendency (p = 0.07) to improve perceived stress levels in golfers and significantly improves (p < 0.05) the number of good ball flights during tee-off which might result in improved golf scores.

Phosphatidylserine Supplementation and Recovery following Downhill Running

Phosphatidylserine Supplementation and Recovery following Downhill Running

Phosphatidylserine Supplementation and Recovery following Downhill Running

This study investigated the effects of 750 mg of soybean-derived phosphatidylserine (S-PtdSer), administered daily for 7 d prior to a bout of eccentric exercise and for 2d following exercise, on delayed onset of muscle soreness and markers of muscle damage, inflammation, and oxidative stress that followed prolonged downhill running. Following preliminary testing and a familiarization session, eight recreationally active males repeated an individualized downhill run at -16.5% for 51.0 +/- 1.5 min at 8.7 +/- 0.3 km x h(-1) on four occasions (trials 1-4). Trials 1 and 37 were presupplementation control trials. After trials 1 and 3 the subjects received, in a double-blind and crossover fashion, either S-PtdSer or a glucose polymer placebo. Trials 2 and 3 were separated by a 4-wk washout period. Venous blood, perceived soreness ratings, and feeling states were assessed prior to exercise, after exercise, and at 24 and 48 h after exercise during each trial. Downhill running led to elevations in perceived soreness (P < 0.05), creatine kinase activities (P < 0.001), myoglobin concentrations (P < 0.001), interleukin-6 (IL-6) concentrations (P < 0.001), and lipid hydroperoxide concentrations (P < 0.01). However, supplementation did not significantly attenuate these responses. These results suggest that supplementation with 750 mg x d(-1) S-PtdSer for 10 d does not afford additional protection against delayed onset of muscle soreness and markers of muscle damage, inflammation, and oxidative stress that follow prolonged downhill running.

Effects of Phosphatidylserine on Exercise Capacity during Cycling in Active Males

The purpose of the study was to investigate the effects of 750 mg of soybean-derived phosphatidylserine, administered daily for 10 d, on exercise capacity, oxygen uptake kinetic response, neuroendocrine function, and feeling states during exhaustive intermittent exercise. Following preliminary testing, fourteen active males completed a staged intermittent exercise protocol on two further occasions (T1 and T2) separated by 16 +/- 1 d. The protocol consisted of three 10-min stages of cycling at 45, 55, and 65% VO2max, followed by a final bout at 85% VO2max that was continued until exhaustion. Approximately 5 d after T1 the subjects were assigned, in a double-blind manner, to either phosphatidylserine (PS) or placebo (P). Breath-by-breath respiratory data and heart rate were continually recorded throughout the exercise protocol, and blood samples were obtained at rest, during the rest periods within the protocol (Post-55, Post-65), at the end of exercise (Post-85), 20 min after the completion of exercise (postexercise), and the day following exercise (Post-24 h). The main finding of this study was that supplementation had a significant effect on exercise time to exhaustion at 85% VO2max (P = 0.005). The exercise time to exhaustion in PS increased following supplementation (7:51 +/- 1:36 to 9:51 +/- 1:42 min:s, P = 0.001), whereas P remained unchanged (8:09 +/- 0:54 to 8:02 +/- 0:54 min:s, P = 0.670). Supplementation did not significantly affect oxygen kinetic mean response times (MRT(on) and MRT(off)), serum cortisol concentrations, substrate oxidation, and feeling states during the trial. This is the first study to report improved exercise capacity following phosphatidylserine supplementation. These findings suggest that phosphatidylserine might possess potential ergogenic properties.

Effects of Phosphatidylserine Supplementation on Exercising Humans

Phosphatidylserine (PtdSer) is a ubiquitous phospholipid species that is normally located within the inner leaflet of the cell membrane. PtdSer has been implicated in a myriad of membrane-related functions. As a cofactor for a variety of enzymes, PtdSer is thought to be important in cell excitability and communication. PtdSer has also been shown to regulate a variety of neuroendocrine responses that include the release of acetylcholine, dopamine and noradrenaline. Additionally, PtdSer has been extensively demonstrated to influence tissue responses to inflammation. Finally, PtdSer has the potential to act as an effective antioxidant, especially in response to iron-mediated oxidation. The majority of the available research that has investigated the effects of PtdSer supplementation on humans has concentrated on memory and cognitive function; patients experiencing some degree of cognitive decline have traditionally been the main focus of investigation. Although investigators have administered PtdSer through intravenous and oral routes, oral supplementation has wider appeal. Indeed, PtdSer is commercially available as an oral supplement intended to improve cognitive function, with recommended doses usually ranging from 100 to 500 mg/day. The main sources that have been used to derive PtdSer for supplements are bovine-cortex (BC-PtdSer) and soy (S-PtdSer); however, due to the possibility of transferring infection through the consumption of prion contaminated brain, S-PtdSer is the preferred supplement for use in humans. Although the pharmacokinetics of PtdSer have not been fully elucidated, it is likely that oral supplementation leads to small but quantifiable increases in the PtdSer content within the cell membrane.A small number of peer-reviewed full articles exist that investigate the effects of PtdSer supplementation in the exercising human. Early research indicated that oral supplementation with BC-PtdSer 800 mg/day moderated exercise-induced changes to the hypothalamo-pituitary-adrenal axis in untrained participants. Subsequently, this finding was extended to suggest that S-PtdSer 800 mg/day reduced the cortisol response to overtraining during weight training while improving feeling of well-being and decreasing perceived muscle soreness. However, equivocal findings from our laboratory might suggest that the dose required to undertake this neuroendocrine action may vary between participants.Interestingly, recent findings demonstrating that short-term supplementation with S-PtdSer 750 mg/day improved exercise capacity during high-intensity cycling and tended to increase performance during intermittent running might suggest an innovative application for this supplement. With the findings from the existing body of literature in mind, this article focuses on the potential effects of PtdSer supplementation in humans during and following exercise.