Phosphatidylserine (PS)

This study aimed to evaluate the effects of phytosterols (PSs) alone and in combination with phospholipids (PLs) on blood lipid levels, erythrocyte membrane fluidity (EMF) and lipid profiles in subjects with borderline hyperlipidemia in a randomized, double-blind, placebo-controlled clinical trial. Among 144 initially screened participants, 87 were enrolled and randomly assigned to three groups receiving PSs (2 g of PSs), PSs and PLs (2 g of PSs plus 0.825 g of PLs), or placebo for 60 days, respectively. A total of 83 subjects completed the entire trial. After 60 days of intervention, the levels of total cholesterol (TC) and apolipoprotein B (ApoB) in the combined PSs and PLs group decreased by 7.8% and 6.4% (P < 0.001), respectively, relative to the baseline. In the PSs-only group, the level of total cholesterol (TC) was significantly reduced by 6.2% (P < 0.001). Nevertheless, in the PSs and PLs group, low-density lipoprotein cholesterol (LDL-C) was significantly reduced by 7.7% compared with the baseline only at 30 days of intervention (P = 0.017). After 60 days of intervention, ExGP in the PSs and PLs group decreased by 0.66% compared with the baseline, but this change was not statistically significant. Results from the erythrocyte membrane lipidomic analysis indicated that TC and LDL-C were significantly negatively correlated with phosphatidylserine (PS), phosphatidylcholine (PC), and bis(monoacylglycerol)phosphate (BMP). Additionally, the excitation generalized polarization (ExGP) value was significantly negatively correlated with PC. In the future, supplementation with phytosterols and phospholipids may be considered for improving blood lipid profiles in individuals with borderline hyperlipidemia, thereby preventing or delaying the progression to overt hyperlipidemia and cardiovascular diseases.

BACKGROUND: Supplementation of the diet with phosphatidylserine (PS) is associated with cognitive and neuropsychological benefits in healthy and neuro-compromised adults. It has also been shown to mitigate symptoms of inattention in children with attention-deficit hyperactivity disorder. However, there is little data on the effects of PS in healthy children. OBJECTIVE: The aim of this randomized, placebo-controlled clinical trial was to examine the effects of sunflower-derived PS on cognitive performance in healthy, neurotypical children aged 8-12 years. METHODS: Participants received 100 mg of sunflower-derived PS daily in gummy form or a matching placebo for 12 weeks and completed an assessment battery at baseline and after 6 and 12 weeks to monitor changes in cognitive performance, mood, and sleep. Retrospectively registered at Clinicaltrials.gov; NCT05177978 RESULTS: There were no differences in the primary or secondary outcomes in the total cohort. However, in a pre-defined subgroup analysis of children who were selected based on their constant below median performance across the cognitive tasks at baseline, PS-supplementation showed benefit on a visuospatial memory task. The supplementation with 100 mg of Sharp PS green was shown to be safe and well tolerated. CONCLUSION: Although there were no differences in the primary and secondary outcomes, the findings suggest that future research should focus on children with below median performance, who are more prone to benefit from PS supplementation. © 2025. The Author(s).

BACKGROUND: Phosphatidylserine (PS) and α-Linolenic acid (ALA), are positively associated with cognitive function, but their combination effects and possible mechanisms remain unclear. We aimed to explore the effects on cognition and potential mechanism of the supplements. METHODS: This randomized, double-blind, placebo-controlled trial recruited 190 MCI patients in Tianjin, China, and randomly assigned in intervention group and placebo group. Each group consumed two capsules every day for 12 months. Each capsule for intervention group contains 144 mg ALA, 31.5 mg PS and 3.6 mg Ginkgo total flavonoids as main functional components, with 0.48 mg Vitamin B1 (as thiamine hydrochloride), 0.48 mg Vitamin B6 (as pyridoxine hydrochloride) and 90 μg folic acid as supplement. Capsules for placebo group were identical but contain no active ingredients. Cognitive function, serum n-3 polyunsaturated fatty acids (PUFAs) and neurotransmitters were assessed at baseline and 12 months. Linear mixed effects model and causal mediation analysis were conducted to explore the effects and potential mechanism of the intervention. RESULTS: A total of 190 participants (mean [SD] age, 67.95 [5.62] years; 70 (36.8 %) male and 120 (63.2 %) female) were randomized to the placebo group (n = 95) and intervention group (n = 95). Compared with placebo group, the intervention group had statistically significant improvements in arithmetic testing (β, 0.688; 95 % CI, 0.103-1.274), the similarity test (β, 1.070; 95 % CI, 0.472-1.667) and short-term memory (β, 0.600; 95 % CI, 0.399-0.800). Besides, the intervention group had statistically significant increases in serum ALA (β, 1.620; 95 % CI, 0.967-2.265), DHA (β, 2.797; 95 % CI, 1.075-4.532), EPA (β, 1.472; 95 % CI, 0.296-2.643), acetylcholine (β, 0.441; 95 % CI, 0.415-0.468), GABA (β, 0.009; 95 % CI, 0.001-0.016) and 5-HT (β, 0.160; 95 % CI, 0.081-0.238) compared to the placebo group. And the intervention may improve short-term memory by increasing serum ALA levels (average causal mediation effect = 0.132, 95 % CI, 0.053-0.225) with 19.7 % mediation proportion. CONCLUSIONS: This food supplement containing phosphatidylserine could improve different

PURPOSE: Adrenergic stimulation affects lymphocyte autophagy and apoptosis by activating β1-adrenergic receptor (β1-AR) and G protein-coupled receptor kinase 2 (GRK-2) downstream signaling. This study investigated how combined aerobic and resistance exercise training on the interval or continuous pattern influences aerobic/muscular fitness and β1-AR/GRK-2 signaling, and corresponding apoptosis/autophagy of lymphocytes in sedentary males. METHODS: Thirty-four sedentary males were randomized into interval training (IT, age = 22.5 ± 0.6 years, fitness level = 47.5 ± 0.9 mL/min/kg, body mass index (BMI) = 22.4 ± 0.4 kg/m2, n = 17) and continuous training (CT, age = 21.6 ± 0.4 years, fitness level = 45.2 ± 1.0 mL/min/kg, BMI = 22.2 ± 0.3 kg/m2, n = 17) groups. These subjects performed IT (bicycle exercise at alternating 40% and 80%VO2 reserve (VO2R) and isokinetic exercise at alternating 60°/s and 180°/s) or CT (bicycle exercise at continuously 60%VO2R and isokinetic exercise at continuously 120°/s) for 30 min/day, 5 days/week for 6 weeks. Aerobic capacity and muscular strength/endurance were determined by the graded exercise test (GXT) and isokinetic strength test, respectively. Blood lymphocyte autophagy/apoptosis and β1-AR/GRK-2 signaling were analyzed using flow cytometry. RESULTS: Both IT and CT groups increased isokinetic strengths at various angular velocities, whereas only IT significantly enhanced muscle endurance, indicated by lowered fatigue index from 47.0 ± 1.3% to 41.8 ± 1.6% (P < 0.05). Moreover, the IT group (143 ± 7%) revealed a higher improvement in VO2peak than CT group (132 ± 6%) (P < 0.05). Acute GXT augmented (i) GRK-2 and protein kinase A expressions, (ii) LAMP-2 upregulation and acridine orange staining, (iii) mitochondrial transmembrane potential diminishing, caspase-3 activation, and phosphatidylserine (PS) exposure caused by epinephrine in blood lymphocytes. However, the degree of epinephrine-induced lymphocyte PS exposure potentiated by GXT was suppressed from 65.2 ± 5.2% to 47.4 ± 6.5% following 6 weeks of the IT (P < 0.05). CONCLUSION: The IT may be considered more beneficial than CT in terms of improving aerobic/muscular fitness and sim

PURPOSE: The intracellular fraction of unbound compound (fu,cell) is an important parameter for accurate prediction of drug binding to intracellular targets. fu,cell is the result of a passive distribution process of drug molecules partitioning into cellular structures. Initial observations in our laboratory showed an up to 10-fold difference in the fu,cell of a given drug for different cell types. We hypothesized that these differences could be explained by the phospholipid (PL) composition of the cells, since the PL cell membrane is the major sink of unspecific drug binding. Therefore, we determined the fu,cell of 19 drugs in cell types of different origin. METHOD: The cells were characterized for their total PL content and we used mass spectrometric PL profiling to delineate the impact of each of the four major cellular PL subspecies: phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS) and phosphatidylinositol (PI). The cell-based experiments were compared to cell-free experiments that used beads covered by PL bilayers consisting of the most abundant PL subspecies. RESULTS: PC was found to give the largest contribution to the drug binding. Improved correlations between the cell-based and cell-free assays were obtained when affinities to all four major PL subspecies were considered. Together, our data indicate that fu,cell is influenced by PL composition of cells. CONCLUSION: We conclude that cellular PL composition varies between cell types and that cell-specific mixtures of PLs can replace cellular assays for determination of fu,cell as a rapid, small-scale assay covering a broad dynamic range. Graphical Abstract.

Dihydroartemisinin (DHA) and artesunate (ARS), two artemisinin derivatives, have efficacious anticancer activities against human hepatocarcinoma (HCC) cells. This study aims to study the anticancer action of the combination treatment of DHA/ARS and farnesylthiosalicylic acid (FTS), a Ras inhibitor, in HCC cells (Huh-7 and HepG2 cell lines). FTS pretreatment significantly enhanced DHA/ARS-induced phosphatidylserine (PS) externalization, Bak/Bax activation, mitochondrial membrane depolarization, cytochrome c release, and caspase-8 and -9 activations, characteristics of the extrinsic and intrinsic apoptosis. Pretreatment with Z-IETD-FMK (caspase-8 inhibitor) potently prevented the cytotoxicity of the combination treatment of DHA/ARS and FTS, and pretreatment with Z-VAD-FMK (pan-caspase inhibitor) significantly inhibited the loss of ΔΨm induced by DHA/ARS treatment or the combination treatment of DHA/ARS and FTS in HCC cells. Furthermore, silencing Bak/Bax modestly but significantly inhibited the cytotoxicity of the combination treatment of DHA/ARS and FTS. Interestingly, pretreatment with an antioxidant N-Acetyle-Cysteine (NAC) significantly prevented the cytotoxicity of the combination treatment of DHA and FTS instead of the combination treatment of ARS and FTS, suggesting that reactive oxygen species (ROS) played a key role in the anticancer action of the combination treatment of DHA and FTS. Similar to FTS, DHA/ARS also significantly prevented Ras activation. Collectively, our data demonstrate that FTS potently sensitizes Huh-7 and HepG2 cells to artemisinin derivatives via accelerating the extrinsic and intrinsic apoptotic pathways.

Obesity is associated with chronic inflammation and is known as a major risk factor for several diseases including chronic kidney disease, diabetes, and cardiovascular diseases. Macrophages play a critical role in the development of obesity-induced inflammation. Efficient delivery of therapeutic anti-inflammatory molecules, such as interleukin (IL)-10, to macrophages can dramatically improve therapeutic efficacy of obesity treatments. We used liposomes containing the 'eat-me' signal phosphatidylserine (PS) (PS-containing liposomes; PSL), which have macrophage targeting ability and anti-inflammatory functions, as a biomaterial carrier for the delivery of IL-10 to macrophages. The IL-10-conjugated PSL (PSL-IL10) showed high affinity for macrophages. In obese mice, PSL-IL10 treatment exhibited significant anti-obesity and anti-inflammatory effects, such as reduced serum total cholesterol, adipocyte size, crown-like structures, proinflammatory cytokine secretion (IL-6 and tumor necrosis factor α) in adipose tissue, liver injury, hepatic steatosis, and inflammation foci, while treatment with IL-10 or PSL alone did not. These findings suggest that the PSL-IL10 has macrophage targeting ability and enhanced anti-inflammatory effect due to the synergistic anti-inflammatory effects of IL-10 and PSL, and can be used as a macrophage-targeted therapeutic material for inflammation-related diseases, including obesity.

In order to expand the repertoire of antifungal compounds a novel, high-throughput phenotypic drug screen targeting fungal phosphatidylserine (PS) synthase (Cho1p) was developed based on antagonism of the toxin papuamide A (Pap-A). Pap-A is a cyclic depsipeptide that binds to PS in the membrane of wild-type Candida albicans, and permeabilizes its plasma membrane, ultimately causing cell death. Organisms with a homozygous deletion of the CHO1 gene (cho1ΔΔ) do not produce PS and are able to survive in the presence of Pap-A. Using this phenotype (i.e. resistance to Pap-A) as an indicator of Cho1p inhibition, we screened over 5,600 small molecules for Pap-A resistance and identified SB-224289 as a positive hit. SB-224289, previously reported as a selective human 5-HT1B receptor antagonist, also confers resistance to the similar toxin theopapuamide (TPap-A), but not to other cytotoxic depsipeptides tested. Structurally similar molecules and truncated variants of SB-224289 do not confer resistance to Pap-A, suggesting that the toxin-blocking ability of SB-224289 is very specific. Further biochemical characterization revealed that SB-224289 does not inhibit Cho1p, indicating that Pap-A resistance is conferred by another undetermined mechanism. Although the mode of resistance is unclear, interaction between SB-224289 and Pap-A or TPap-A suggests this screening assay could be adapted for discovering other compounds which could antagonize the effects of other environmentally- or medically-relevant depsipeptide toxins.

Microglia, the brain's resident macrophages, contribute to immune surveillance and the response to disease and injury. These immune cells play a dual role in the nervous system, having both neurotoxic and neuroprotective effects. Activation of microglia results in the production of inflammatory molecules and neurotoxic factors that often cause or contribute to neurodegenerative diseases. Inhibition of neurotoxic microglia activation and consequent inflammatory processes may represent an important therapeutic target. Phosphatidylserine (PS), an aminophospholipid of plasma membranes, and curcumin, the yellow pigment isolated from the rhizome of the turmeric plant, have both been reported to suppress microglial activation by reducing pro-inflammatory mediator production and release. In this study we analyzed the effects of PS, curcumin, and their association on microglial activation induced by the bacterial toxin lipopolysaccharide. Primary rat cortical microglial cells were treated with increasing concentrations of PS-liposomes and curcumin, alone or in combination, and their effects on pro-inflammatory cytokine release from unstimulated and lipopolysaccharide-stimulated microglia were evaluated by enzyme-linked immunosorbent assay. Isobolographic analysis was performed to investigate the effect of PS-liposomes and curcumin combination. PS and curcumin inhibited the release of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α induced by lipopolysaccharide. Furthermore, PS and curcumin in combination exerted a synergistic effect in down-regulating IL-1β release. These results suggest that the association of PS with curcumin could be of potential therapeutic utility against diseases associated with microglial activation.

Inspired from the apoptotic cascade, we developed phosphatidylserine (PS)-based proapoptotic lipid nanovesicles, capable of bypassing drug resistance and exhibiting synergistic anticancer activity with encapsulated paclitaxel in chemoresistant human colon adenocarcinoma (HCT-15). MATERIALS & METHODS: Nanovesicles were developed and evaluated both in vitro and in vivo for their proapoptotic activity, synergism with encapsulated paclitaxel and ability to bypass drug resistance. RESULTS: 110 ± 7 nm sized nanovesicles were found to be proapoptotic and synergistic with paclitaxel, and bypassed drug resistance. The formulation, with synergistic inputs from PS and paclitaxel, downregulated Ki-67 and inhibited angiogenesis leading to apoptosis by activating caspase-3 and downregulating Bcl-2, resulting in DNA fragmentation. The nanovesicles, while increasing the systemic circulation time of paclitaxel by 6.9-fold reduced systemic toxic effects of paclitaxel and were found to be nonimmunogenic. CONCLUSION: These results suggest the therapeutic potential of PS-based proapoptotic nanovesicles encapsulating paclitaxel in chemoresistant human colon carcinoma.

OBJECTIVE: Thrombus formation is the key event of vascular manifestations in antiphospholipid syndrome (APS). Phosphatidylserine (PS) is normally sequestered in the inner leaflet of cell membranes. Externalization of PS occurs during cell activation and is essential for promoting blood coagulation and for the binding of antiphospholipid antibodies (aPL) to cells. One of the molecules involved in PS externalization is phospholipid scramblase 1 (PLSCR1). We evaluated PLSCR1 expression on monocytes from APS patients and analyzed the in vitro effect of monoclonal aPL on PLSCR1 expression. PATIENTS AND METHODS: Forty patients with APS were investigated. In vitro experiments were performed in monocyte cell lines incubated with monoclonal aPL. PLSCR1 expression was determined by quantitative real-time polymerase chain reactions. PS exposure on CD14(+) cell surface was analyzed by flow cytometry. RESULTS: Levels of full-length PLSCR1 messenger RNA (mRNA) were significantly increased in APS patients compared with healthy controls (2.4 ± 1.2 vs. 1.3 ± 0.4, respectively, p < 0.001). In cultured monocytes, interferon alpha enhanced tissue-factor expression mediated by β2-glycoprotein-I-dependent monoclonal anticardiolipin antibody. CONCLUSIONS: Monocytes in APS patients had increased PLSCR1 mRNA expression.

N,N-Diethyl-2-[4-(phenylmethyl)phenoxy]ethanamine (DPPE, tesmilifene), a potent chemopotentiating drug currently in Phase III clinical trials of metastatic breast cancer, increases cytotoxicity of anthracyclines and taxanes in a variety of multi-drug resistance expressing (MDR+) tumor cell lines in vitro; inhibits binding of histamine to CYP3A4, a lipid/prostanoid-regulatory P450; and modulates serum levels of HDL/LDL cholesterol and phospholipids in vivo. Since increased exposure of phosphatidylserine (PS) on the outer cell membrane leaflet is associated with apoptosis, increased clearance of dead cells by phagocytes and inhibition of the P-glycoprotein pump, the effect of DPPE on PS synthesis was assessed in vitro in a human breast cancer cell line. MCF-7 cells were incubated with 5 microM DPPE for 24 hr or 5 days, followed by addition of [1-(14)C]arachidonic acid for 4 hr; or [3H]serine for 8 hr. Compared to untreated cells, a 27-42% (p < 0.05) increase in [1-(14)C]arachidonic acid incorporated into all phospholipids, including a 1.9-fold increase (p < 0.05) in PS was observed in DPPE-treated cells. [3H]Serine incorporation into PS was elevated 37%, while the pool size of PS was elevated 23% (p < 0.05) in DPPE-treated cells, indicating elevated de novo PS biosynthesis. Annexin-5 binding studies indicated an elevation in exposure of PS on the surface of the plasma membrane in DPPE-treated cells. DPPE-treatment also resulted in N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine accumulation indicative of phospholipidosis-inducing potential. Thus, the chemopotentiating effect of DPPE may be due to its phospholipidosis-inducing potential and stimulation of PS synthesis leading to an increased exposure of PS on the cell surface which could potentially enhance cancer cell clearance by phagocytes.

The purpose of these studies was to design an intravenous drug formulation consisting of two active agents having synergistic in vitro activity. Specifically, we describe a novel drug combination consisting of a cytotoxic agent (vinorelbine) with an apoptosis-inducing lipid (phosphatidylserine, PS). In vitro cytotoxicity screening of PS and vinorelbine, alone and in combination, against human MDA435/LCC6 breast cancer and H460 lung cancer cells was used to identify the molar ratio of these two agents required for synergistic activity. PS and vinorelbine were co-formulated in a lipid-based system at the synergistic molar ratio and the pharmacokinetic and antitumor characteristics of the combination assessed in mice bearing H460 tumors. The cytotoxicity of the lipid, and the synergy between the lipid and vinorelbine, were specific to PS; these effects were not observed using control lipids. A novel formulation of PS, incorporated as a membrane component in liposomes, and encapsulating vinorelbine using a pH gradient based loading method was developed. The PS to vinorelbine ratio in this formulation was 1/1, a ratio that produced synergistic in vitro cytotoxicity over a broad concentration range. The vinorelbine and PS dual-agent treatment significantly delayed the growth of subcutaneous human H460 xenograft tumors in Rag2M mice compared to the same dose of free vinorelbine given alone or given as a cocktail of the free vinorelbine simultaneously with empty PS-containing liposomes. These studies demonstrate the potential to develop clinically relevant drug combinations identified using in vitro drug-drug interactions combined with lipid-based delivery systems to co-formulate drugs at their synergistic ratios.

Prenatal and postnatal ethanol exposure induces abnormal cell death in the nervous system. We have previously reported that docosahexaenoic acid (DHA; 22:6n-3) prevents neuronal apoptosis through promoting phosphatidylserine (PS) accumulation. Previously, we have shown in C6 glioma cells that ethanol inhibits the accumulation of PS caused by DHA supplementation. In this report, we demonstrate that in vitro or in vivo exposure to ethanol inhibits DHA-dependent PS accumulation and neuronal survival. We found that Neuro 2A cells exposed to ethanol accumulated considerably less PS in response to the DHA enrichment and were less effective at phosphorylating Akt and suppressing caspase-3 activity under serum-starved or staurosporine-treated conditions. The in vivo paradigm correlated well with the in vitro findings. We found that the total PS and DHA contents in the fetal hippocampus were slightly but significantly lowered by the prenatal ethanol exposure. Fetal hippocampal cultures obtained at embryonic day 18 from ethanol-treated pregnant rats contained significantly higher apoptotic cells after 7 days in vitro under basal conditions and exhibited particular susceptibility to cell death induced by trophic factor removal in comparison with the pair-fed control group. The reduction of PS and the resulting neuronal cell death inappropriately enhanced during development may contribute to the defects in brain function often observed in fetal alcohol syndrome.