Actions and Comparative Efficacy of Phosphatidylcholine Formulation and Isolated Sodium Deoxycholate for Different Cell Types

Background  Phosphatidylcholine formulation has been used to dissolve local fat deposits. This study aimed to evaluate and compare the effects of phosphatidylcholine formulation and its vehicle sodium deoxycholate alone on different cell lines to understand better its mechanism of action. Methods  Cells and media including 3T3-L1 preadipocytes, normal foreskin fibroblasts, neonatal human dermal microvascular endothelial cells (CADMEC), and fetal human skeletal muscle cells (HSkMC) were used. After 24 h, cells were exposed in 3-4, 5-dimethylthiazol-2-yl-2, 3-diphenyl tetrazolium bromide reagent (MTT assays) to increasing dosages of phosphatidylcholine formulation (0.0156–0.5 mg/ml) or an equivalent vehicle, sodium deoxycholate solution, pH 9.0 (0.0066–0.210 mg/ml). Viability was assessed after 1, 2, and 3 days of treatment. Fat tissue (4 × 4 cm) obtained ex vivo from the dorsal fat pads of five rabbits was injected with 2 ml of phosphatidylcholine formulation (50 mg/ml), sodium deoxycholate (21 mg/ml), or normal saline and incubated for 24 h. These were examined histologically to identify cell lysis and morphologic changes. Results  At 0.125- and 0.25-mg/ml doses of phosphatidylcholine solution, CADMEC and HSkMC were more sensitive (P < 0.001, one-way ANOVA) than adipocytes at all time points examined. Phosphatidylcholine formulation at a dose of 0.5 mg/ml and the equivalent vehicle, sodium deoxycholate, at a dose of 0.21-mg/ml both induced nearly 100% fat cell lysis after 24 h, and evidence of cell lysis as early as 6 h after exposure. After incubation of fat tissue for 24 h with phosphatidylcholine formulation, loss of intracellular lipid staining with an increase in extracellular lipids was seen. Conclusions  Isolated sodium deoxycholate was almost as effective as the phosphatidylcholine formulation, at clinical concentrations, in reducing the viability of mature adipocytes over time. Similar cytotoxic effects of phosphatidylcholine formulation on normal foreskin fibroblasts, endothelial cells, and human skeletal muscle cells also were observed. The data prove that the formulation acts in a nonspecific manner and that its unintentional administration to other tissues causes cell death.     

Increased plasma homocysteine and S-adenosylhomocysteine and decreased methionine is associated with altered phosphatidylcholine and phosphatidylethanolamine in cystic fibrosis

OBJECTIVE: We used a novel approach based on the intersection of phospholipid and methionine metabolism at the S-adenosylmethionine (SAM)-dependent methylation of phosphatidylethanolamine (PE) to study potential alterations in phospholipid metabolism in children with cystic fibrosis (CF). Methyl groups from methionine via SAM are used for sequential methylation of PE to form phosphatidylcholine (PC) with the generation of S-adenosylhomocysteine (SAH) and homocysteine. STUDY DESIGN: Plasma phospholipids and methionine metabolites and plasma and red blood cell phospholipid fatty acids were determined in 53 children with CF and 18 control children. RESULTS: Plasma methionine and the PC/PE ratio was lower and homocysteine, SAH, and PE were higher in children with CF than in control children (P<.001). Plasma methionine was inversely (P<.05) and SAH and homocysteine were positively (P<.001) correlated with the plasma PE. Docosahexaenoic acid (22:6n-3) was significantly lower in plasma phospholipids and triglycerides and in red blood cell PC and PE of children with CF than in control children (P<.05). CONCLUSIONS: These studies demonstrate that methionine metabolism is altered and associated with alteration of the plasma PC/PE ratio in CF. Altered phospholipid and methionine metabolism may contribute to the clinical complications associated with CF.     

Very Long-Chain Fatty Acids in Erythrocyte Membrane Phospholipids in Adrenoleukodystrophy

Mass fragmentography was used to analyze the very longchain fatty acid (VLCFA) composition of erythrocyte membrane phospholipids. The VLCFA content decreased in the order sphingomyelin (SM), phosphatidylcholine (PC) and phosphatidylethanolamine (PE). The tetracosanoic acid (C24:0) and hexacosanoic acid (C26:0) content of both SM and PC in patients with adrenoleukodystrophy (ALD) were significantly higher than those in controls. The VLCFA content of PE was too small, in comparison with those of SM, to be accurately determined. ( Acta Paediatr Jpn 1989;31: 136–143)     

甘草酸二铵脂质配位体对大鼠酒精性脂肪肝的治疗作用

目的：观察新一代甘草酸制剂甘草酸二铵脂质配位体(DGLL)对酒精性脂肪肝的治疗作用。方法：用连续灌服(IG)酒精的方法建立大鼠酒精性脂肪肝模型，造模成功后给予药物治疗，以多烯磷脂酰胆碱(PPC)为对照，观察一般情况及测定血清肝功能指标和血脂参数，并对大鼠肝脏行病理学检查。结果：连续灌服(IG)酒精5周后大鼠形成酒精性脂肪肝，给药2周后，PPC与DGLL中剂量(500mg／kg)组能显著降低血中门冬氨酸氨基转移酶(AST)活性与肝中甘油三酯(TG)、总胆固醇(TC)含量，改善肝脏炎症活动度与脂肪性变，DGLL中剂量组还能显著降低血中TC、丙二醛(MDA)含量。结论：甘草酸二铵脂质配位体能改善酒精性脂肪肝大鼠体内脂质代谢，对酒精性脂肪肝具有一定的治疗作用。     

Roles of bile acid conjugates and phospholipids in in vitro activation of pancreatic lipase by bear bile and cattle bile

Ethnopharmacological relevance

Bear bile (BB) originally used as a traditional Chinese medicine has also been adopted in Japan as a traditional home remedy mainly for gastrointestinal problems due to impaired digestion. However, recently, efforts have been made to find alternatives to BB for ecological and ethical reasons.

Aims of the study

To find alternatives to BB for facilitating fat digestion, we compared the potency of cattle bile (CB) or synthetic mixtures of major bile components to activate pancreatic lipase with that of BB.

Materials and methods

The compositions of bile acid conjugates and phospholipids in BB and CB were determined by high-performance liquid chromatography and thin layer chromatography, respectively. The effects of BB and CB as well synthetic mixtures of bile acid conjugates and phospholipids on pancreatic lipase activity in vitro were examined.

Results

BB and CB contained markedly different types and quantities of bile acid conjugates and phospholipids, although the potencies of BB and CB to activate pancreatic lipase were not significantly different. The potency of BB to activate pancreatic lipase was reconstituted by the major bile acid conjugates and phospholipids found in BB. In contrast, only bile acid conjugates found in CB could reconstitute its potency to activate pancreatic lipase.

Conclusions

Our observations indicate that CB or the synthetic mixture of bile components can be used as an alternative to BB for facilitating fat digestion.     

The phosphatidylcholine/lysophosphatidylcholine ratio in human plasma is an indicator of the severity of rheumatoid arthritis: investigations by 31P NMR and MALDI-TOF MS

OBJECTIVES: Lipid second messengers, e.g. lysophosphatidylcholines (LPC) are involved in the pathogenesis of inflammatory diseases, for instance, rheumatoid arthritis (RA). Unfortunately, the analysis of LPC in complex mixtures as present in body fluids is still challenging. DESIGN AND METHODS: Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) was applied for phospholipid (PL) analysis of organic extracts of synovial fluids from patients with RA as well as the corresponding plasma. These data were compared with results obtained by high resolution 31P NMR spectroscopy. RESULTS: Synovial fluids may be replaced by plasma since the analysis of both body fluids gives very similar results. Patients undergoing treatment with TNF-alpha inhibitors (ADALIMUMAB (HUMIRA)) were examined in order to investigate whether the clinically-significant attenuation of disease activity is accompanied by changes of the PL composition of plasma. It will be shown that especially the PC/LPC ratios of plasma represent a reliable measure of inflammation and increase upon therapy. CONCLUSIONS: Since plasma samples are readily available, our approach might be useful to draw conclusions before puncture of the affected joints is necessary and the PC/LPC ratio detected in plasma may serve as an indicator of RA in early stages.     

Protective effect of oral phosphatidylcholine on radiation-induced release of intestinal peptidases in rats

Purpose: To investigate whether phosphatidylcholine (PPC) has a protective effect on mucosa-irradiated rats. Methods: The rats were orally fed with 25, 50, and 100 mg PPC/kg body weight (b.w.), respectively, for 3 weeks before irradiation. After administering the medication and 1 day after irradiation, a 20 cm segment of the proximal jejunum was perfused in situ and peptidase activities, as well as the concentrations of the membrane components, were assayed. Results: We have shown that the application of a low dose of 25 mg PPC/kg b.w. daily for 21 days can prevent damage to membranes induced by 2.0 Gy as represented in the peptidase release profiles during the perfusion of the proximal jejunum of rats. Higher dose levels did not increase the protective effect. Conclusions: These findings suggest that a low dosage of exogenous PPC is capable of hindering the impairment of membranes induced by a small dose of radiation. Received: 14 December 2000 / Accepted: 22 January 2001     

维生素K2联合磷脂酰胆碱抑制肝癌细胞的作用

目的 观察维生素K2联合磷脂酰胆碱抑制肝癌的协同作用并探讨其作用机制.方法 采用细胞计数试剂盒(CCK-8)细胞增殖实验评价维生素K2(1.25 ～ 500.00 μmol/L)联合磷脂酰胆碱( 1.25 ～400.00 μmol/L)抑制人肝癌细胞SMMC-7721的浓度依赖性和时间依赖性(24、48、72 h),采用流式细胞仪检测肝癌细胞凋亡率,采用Western blot法检测半胱氨酸-天冬氨酸蛋白酶前体(procaspase)-3、procaspase-8和procaspase-9的活性表达.结果 维生素K2(500.00 μmol/L)联合磷脂酰胆碱( 20.00 μmol/L)共同作用72 h可致使65.1％的肝癌细胞发生凋亡,实验组procaspase-3和procaspase-9表达差异有统计学意义(P＜0.05),procaspase-8表达差异无统计学意义(P＞0.05).结论 维生素K2联合磷脂酰胆碱对抑制人肝癌细胞有协同作用,其机制可能依赖于Caspase-9的活化.     

Changes in plasma phospholipids and sphingomyelins with aging in men and women: A comprehensive systematic review of longitudinal cohort studies

BackgroundAging affects the serum levels of various metabolites which may be involved in the pathogenesis of chronic diseases. The aim of this review article is to summarize the relationship between aging and alterations in the plasma phospholipids and sphingomyelins.MethodsPRISMA guidelines were employed during all steps. MEDLINE (PubMed), Scopus, Embase and Web of Sciences databases and Google Scholar were searched up to October 2020. Cohort studies investigating the relationship between aging and within-person changes in sphingomyelin (SM), phosphatidyl choline (PC), lyso PC (LPC) and phosphatidyl ethanolamine (PE) were included. Newcastle-Ottawa scale was used to assess the quality of included studies.ResultsA total of 1425 studies were identified. After removing 610 duplicates and 723 irrelevant studies, full texts of 92 articles were evaluated. Of these 92, 6 studies (including data from 7 independent cohorts) met the inclusion criteria and are included in this review. All study populations were healthy and included both men and women. Results by sex were reported in 3 cohorts for PC, 5 cohorts for LPC, 3 cohorts for SM, and only 1 cohort for PE. In men, PC, SM, PE and LPC decreased with aging, although results for LPC were inconsistent. In women, LPC, SM, and PE increased age, whereas changes in PC were inconsistent.ConclusionWithin-person serum levels of phospholipids and sphingomyelins, decrease during aging in men and increase in women. Notably, however, there were some inconsistencies across studies of LPC in men and of PC in women.     

Phosphatidylcholine synthesis in isolated type II pneumocytes from ozone-exposed rats

Phosphatidylcholine (PC) synthesis by alveolar type II cells, as an indicator for the production of pulmonary surfactant, was studied after a 4-h exposure of rats to 4 mg ozone/m³ (2 ppm). Lung ravage fluid analysis after exposure revealed significant increases in proteins, which is indicative for pulmonary injury. When type II cells were isolated immediately and thereafter cultured for 20 h, the rate of PC synthesis in cells derived from ozone-exposed rats was not significantly different from that in cells from unexposed controls. Yet, a decreased rate of PC synthesis was observed when these cells were subsequently exposed to ozone in vitro. The activity of the enzyme glycerolphosphate acyltransferase (GPAT) was slightly enhanced in cultured type II cells isolated from ozone-exposed rats, while the lysophosphatidylcholine acyltransferase (LPCAT) activity was unchanged. However, ozone exposure of rats did result in a significant decrease of PC synthesis when measured in freshly prepared type II cell suspensions, although both GPAT and LPCAT activities were not affected. It is concluded that a decrease in pulmonary surfactant related PC synthesis after ozone exposure of rats can be demonstrated in freshly isolated type II pneumocytes. Cultured type II cells from exposed rats lack this effect and are therefore less useful to study changes in phospholipid biosynthesis after in vivo ozone exposure. The data on in vitro ozone exposure of cultured type II cells, however, support the view that ozone may impair pulmonary surfactant production.Abbreviations PC phosphatidylcholines - GPAT glycerolphosphate acyltransferase - LPCAT lysophosphatidylcholine acyltransferase