Preparation, characterization and evaluation of kaempferol phospholipid complex: Improvement of its solubility and biological eff ect

Kaempferol(KA),as one of the flavonoids,has extensive pharmacological properties.However,the poor solubility of KA severely limits its clinical application.In our study,the kaempferol phospholipid complex(KA-PC)has been prepared by solvent evaporation for the enhancement of the bioavailability of KA.KA-PC was verified by scanning electron microscope characterization methods.Drug loading,solubility and long-term stability were measured.The characterization results showed that KA-PC was formed through the intermolecular interaction between KA and phospholipids.The solubility of KA-PC in water was 189 times higher than that of KA,and the solubility in n-octanol was also significantly improved.Besides,pharmacodynamic studies showed that KA-PC can significantly reduce the level of serum uric acid in mice without causing renal injury.This study expanded the clinical application of KA by preparing KA-PC.

Effects of Addition of Amino Acids or Soybean Phospholipid in Diet on Slaughter Performance and Meat Quality of Pigs

[Objectives]The study aims to discuss the effects of addition of arginine and glutamic acid or soybean phospholipid,vitamin E and yeast selenium in diet on the slaughter performance and meat quality of long(white)×large(York)binary hybrid pigs.[Methods]27 long×large castrated hybrid boars with the body weight of(54.4±0.15)kg were randomly divided into 3 groups,with 3 replicates per group and 3 pigs per replicate.Group A was the control group,in which the pigs were fed basal diet;in group B,0.8%arginine and 0.60%glutamate were added to the basal diet;in group C,75 g of soybean phospholipid,20 g of vitamin E and 8 g of yeast selenium were added to every 100 kg of the basal diet.The trial period was 60 d.After the experiment was ended,one test pig with similar body weight was selected from each replicate for slaughter and meat determination.[Results]The average weight gain and eye muscle area of the pigs in group B were significantly higher than those in group C(P<0.05),and also showed an increasing trend compared with group A,but there was no statistically significant difference(P>0.05);there was no significant difference between group B or C and group A in the average weight gain and eye muscle area(P>0.05).There was no significant difference in other slaughter performance between the three groups(P>0.05).Besides,there was also no significant difference in the content of various amino acids,total amino acids and total umami amino acids between the three groups(P>0.05).The inosine content in the longissimus dorsi muscle and muscle cooking loss of binary hybrid pigs in group C were significantly better than those in group B(P<0.05),and also had a tendency to be better than those in group A,but there was no significant difference(P>0.05);there was no significant difference between group B or C and group A in the inosine content and muscle cooking loss of the pigs(P>0.05).In addition,there was no significant difference in other meat traits and chemical composition of the longissimus dorsi muscle between group B or C and group A(P>0.05).[Conclusions]The addition of arginine and glutamic acid or soybean phospholipid,vitamin E and yeast selenium in diet had no significant effect on the growth rate,slaughter performance and meat traits of long×large binary hybrid pigs.

Association Mapping and Marker Development of Genes forStarch Lysophospholipid Synthesis in Rice

Phospholipids are a major kind of lipids in rice grains and have fundamental nutritional andfunctional benefits to the plant. Their lyso forms （lysophospholipids, LPLs） often form inclusion complexeswith amylose or independently influence the physicochemical and functional properties of rice starch.However, the genetic basis for LPL synthesis in rice endosperm is largely unknown. Here, we performeda preliminary association test of 13 LPL compositions among 20 rice accessions, and identified 22putative main-effect quantitative trait loci responsible for all LPLs except for LPC14：0 and LPE14：0. Fivederived cleaved amplified polymorphic sequences and one insertion/deletion marker for threeLPL-synthesis-related candidate genes were developed. Association analysis revealed two markerssignificantly associated with starch LPL traits. These results provide an insight into the genetic basis ofphospholipid biosynthesis in rice and may contribute to the rice quality breeding programs usingfunctional markers.

Mucin and phospholipids determine viscosity of gallbladder bile in patients with gallstones

AIM An increased viscosity of gallbladder bile has been considered an important factor in the pathogenesis of gallstone disease. Besides lipids and proteins, mucin has been suggested to affect the viscosity of bile. To further clarify these issues we compared mucin, protein and the lipid components of hepatic and gallbladder bile and its viscosity in patients with gallstones.METHODS Viscosity of bile ( mpa. s ) wasmeasured using rotation viscosimetry in regard to the non-Newtonian property of bile at law shear rates.RESULTS Biliary viscosity was markedly higher in gallbladder bile of patients with cholesterol (5.00 ± 0.60 mpa. s, mean ± SEM, n --28) and mixed stones (3.50±0.68 mPa. s; n =8) compared to hepatic bile (0.92 ± 0.06 mpa. s,n -6). A positive correlation between mucin and viscosity was found in gallbladder biles (r=0.65; P＜0.001) but not in hepatic biles. The addition of physiologic and supraphysiologic amounts of mucin to gallbladder bile resulted in a dose dependent non linear increase of its viscosity. A positive correlation was determined between phospholipid concentration and viscosity (r = 0.34, P＜0.005) in gallbladder biles. However, no correlation was found between total protein or the other lipid concentrations and viscosity in both gallbladder and hepatic biles.CONCLUSION The viscosity of gallbladder bile is markedly higher than that of hepatic bile in patients with gallstones. The concentration of mucin is the major determinant of biliary viscosity and may contribute by this mechanism to the role of mucin in the pathogenesis of gallstones.

Advances in studies of phospholipids as carriers in skin topical application

Objective： This article provides an overview of characteristics of phospholipids, the characteristics and influential factors of liposome and microemulsion as carriers for skin delivery of drugs, and the latest advances of the phospholipids carriers in transdermal delivery systems. The perspective is that phospholipids carriers may be capable of a wide range of applications in the transdermal delivery system.

A review on phospholipids and their main applications in drug delivery systems

Phospholipids have the characteristics of excellent biocompatibility and a especial amphiphilicity.These unique properties make phospholipids most appropriate to be employed as important pharmaceutical excipients and they have a very wide range of applications in drug delivery systems.The aim of this review is to summarize phospholipids and some of their related applications in drug delivery systems,and highlight the relationship between the properties and applications,and the effect of the species of phospholipids on the efficiency of drug delivery.We refer to some relevant literatures,starting from the structures,main sources and properties of phospholipids to introduce their applications in drug delivery systems.The present article focuses on introducing five types of carriers based on phospholipids,including liposomes,intravenous lipid emulsions,micelles,drug-phospholipids complexes and cochleates.

Changes of Tumor Necrosis Factor, Surfactant Protein A, and Phospholipids in Bronchoalveolar Lavage Fluid in the Development and Progression of Coal Workers’ Pneumoconiosis

Objective To evaluate the alterations of biomarkers in the development and progression of coal workers＇ pneumoconiosis （CWP）. Methods The type and number of cells, and the levels of tumor necrosis factor-alpha （TNF-α）, pulmonary surfactant protein, phospholipids and fibronectin in bronchoalveolar lavage fluid were assayed in 14 health active coal miners, 21 coal miners without CWP and 13 miners with CWP of 0/1 to 1/1. Results Compared to active coal miners without CWP （8,23μg/mL）, TNF-α concentration was gradually decreased when dust exposure was stopped （5.90 μg/mL）. Elevated surfactant protein A （SP-A） level and phosphatidylglycerol （PG） to phosphatidylinositol （PI） ratio were found in miners actively exposed to coal dust （6528 μg/mL for SP-A and 10. for PG/P1）, and both parameters decreased when CWP progressed from CWP （0/1） （3419μg/mL for SP-A and 5.9 for PG/PI） to CWP （1/1） （1654 μg/mL for SP-A and 5.5 for PG/PI）. Conclusion Biomarkers in bronchoalveolar lavage fluid can be used to screen coal miners at high risk of developing coal workers＇ pneumoconiosis.

Effect of copper on phospholipid fatty acid composition of microbial communities in two red soils

The phospholipid fatty acid （PLFA） composition was analyzed in two red soils experimentally contaminated with copper at different concentrations. The total amounts ofphospholipid fatty acids （PLFAs） in both red soils were significantly correlated with soil microbial biomass C and N, which decreased consistently with increasing levels of copper. The relative quantities of the PLFAs 17：0 （10 Me）, i16：0, il 5：0 and 16：1w5c, decreased with increasing heavy metal concentration, while those of cyl7：0, which is an indicator of gram-negative bacteria, increased. The Shannon index calculated from the PLFA data indicated that Cu addition in the red soils decreased the population diversity of soil microbial communities. Multivariate analysis of PLFA data demonstrated that high levels of Cu application had a significant impact on microbial community structure and there is a threshold metal concentration for PLFA composition. Comparatively higher toxic effect on microbial biomass and community structure were found in the red sandy soil than those in the red clayey soil. The differential effect of Cu addition on microbial communities in the two soils may be due to differences in soil texture and cation exchange capacity.

Effects of cell membrane phospholipid level and protein kinase C isoenzyme expression on hepatic metastasis of colorectal carcinoma

BACKGROUND: The molecular mechanism of hepaticmetastasis of colorectal cancer is not well understood. Theaim of this study was to assess the relations between phos-pholipid contents of cellular membrane and isoenzyme ex-pression of protein kinase C (PKC) and their effects on he-patic metastasis of colorectal cancer.METHODS: High performance liquid chromatography wasused to detect contents of cell membrane phospholipids:phosphatidylinosital (PI), phosphatidylserine (PS), phos-phatidylethanolamine (PE) and phosphatidylcholine (PC)in primary foci, paratumor mucosa and hepatic metastaticfoci in patients with colorectal carcinoma. The mRNA ex-pression levels of PKC-α, -δ, -ε, -λ, -ξ isoenzymeswere detected with the QRT-PCR technique.RESULTS: The levels of PI, PC and PE in primary foci andhepatic metastatic foci were higher than those in paratumormucosa. The level of PE in hepatic metastatic foci wasmuch higher than that in primary foci (t =98.88, P <0.01);but the levels of PI and PC were not significantly differentbetween primary foci and hepatic metastatic foci (t =1.73 ,1.36, P>0.05). The expression levels of -δ, -ε,-λ, -ξ were enhanced in primary foci and hepatic metasta-tic foci, but the level of PKC-α in primary foci was de-creased as compared with that in paratumor mucosa. Thelevels of PKC-δ, -ε, -λ, -ξ in hepatic metastatic foci werehigher than those in primary foci. A positive correlationwas observed between the expression levels of PI, PC andand also between those of PE and PKC-δ, -ε, -λ,-ξ. However, there was a close negative correlation be-tween PE and PKC-α.CONCLUSION: Increased levels of PI and PC and de-creased ratio of PKC-α to are related to colorectalcancer genesis. Increased levels of PE, increased expressionof PKC-δ, -ε, -λ, -ξ isoenzymes and decreased level ofPKC-α are related to hepatic metastasis in colorectal carci-noma.

Silencing phospholipid scramblase 1 expression by RNA interference in colorectal cancer and metastatic liver cancer

BACKGROUND:Phospholipid scramblase 1(PLSCR1) not only participates in the transbilayer movement of phospholipids,but also plays a role in the pathogenesis and progression of cancers.The present study aimed to evaluate the effect of silencing PLSCR1 expression by RNA interference in colorectal cancer(CRC) and metastatic liver cancer.METHODS:The expression of PLSCR1 in CRC and metastatic liver cancer samples was assessed by immunohistochemistry.The cultured cells with the highest expression were selected for subsequent experiments.We designed three siRNA oligonucleotide segments targeted at PLSCR1.Successful transfection was confirmed.The biological behavior of the cells in proliferation,adhesion,migration and invasion was determined.RESULTS:PLSCR1 protein expression increased significantly in the majority of CRC and metastatic liver cancer samples compared with normal samples.Lovo cells had the highest expression of PLSCR1.The siRNA-390 oligonucleotide segment had the best silencing effect.After transfection,Lovo cell proliferation was significantly inhibited compared with the controls in the MTT assay.Laminin and fibronectin adhesion assays showed Lovo cell adhesion was also significantly inhibited.In the migration assay,the number of migrating cells in the PLSCR1 siRNA-390 group was 50±12,significantly lower than the number in the siRNA-N group(115±28) and in the control group(118±31).In an invasion test,the number of invading cells in the PLSCR1 siRNA-390 group was 60±18,significantly lower than that in the siRNA-N group(97±26) and the control group(103±24).CONCLUSIONS:PLSCR1 is overexpressed in CRC and metastatic liver cancer.Silencing of PLSCR1 by siRNA inhibits the proliferation,adhesion,migration and invasion of Lovo cells,which suggests that PLSCR1 contributes to the tumorigenesis and tumor progression of CRC.PLSCR1 may be a potential gene therapy target for CRC and associated metastatic liver cancer.

Using Phospholipid FattyAcid Technique toAnalysis the Rhizosphere Specific Microbial Community of Seven Hybrid Rice Cultivars

To analyze the intrinsic relationship between rhizosphere microbial community structure and variety of rice, the microbial community structures in rhizosphere of different hybrid rice cultivars were determined with phospholipid fatty acids （PLFA） analysis. Three series of new-breeding hybrid rice cultivars in China were tested in the experiment, Ilyouming 86 （II-32A/Minghui 86）, Ilyouhang 1 （II-32A/Hang 1）, and Ilyouhang 2 （II-32A/Hang 2） with H-32A as female parent, XinyouHK02 （XinA/HK02） and YiyouHK02 （YXA/HK02） with HK02 as male parent, Chuanyou 167 （ChuanxiangA/MR167） and 44you167 （Hunan44A/MR167） with MR167 as male parent. The results showed that the microbial community in rhizosphere of the hybrid rice comprised bacteria, fungi, actinomycetes, and protozoa, according to the 40 PLFA biomarkers detected. Bacteria were more abundant than fungi and actinomycetes in rhizosphere of the hybrid rice tested. Both sulfate-reducing and methane-oxidizing bacteria were found to exist in the hybrid rice rhizosphere. It was also found that the characteristics of PLFA biomarkers had correlation with the biological traits of rice. The cluster analysis suggested that microbial community structure and activity in rhizosphere were associated with genetic background of the rice cultivar.

Preparation and characterization of solidified oleanolic acid–phospholipid complex aiming to improve the dissolution of oleanolic acid

The purpose of this study was to prepare the oleanolic acid–phospholipid complex (OAPC) and then solidify it employing fumed silica by simple solvent evaporation technique to improve dissolution rate of oleanolic acid and oleanolic acid–phospholipid complex. The process of OA-PC was optimized and the type and proportion of fumed silica were studied by dissolution text. The structures of the phospholipid complex and solidified powder were also characterized by differential scanning calorimetry, X-ray diffraction, and scanning electron microscope. In the dissolution tests, OA from solidified powder was further released compared with that from pure OA and OA-PC in different kinds of dissolution media. These results suggest that the method of preparing solidified powder of oleanolic acid–phospholipid complex is suitable for enhancing the dissolution rate of OA and OA-PC.

Anticancer effects of saponin and saponin–phospholipid complex of Panax notoginseng grown in Vietnam

Objective:To evaluate the antitumor activity both in vitro and in vivo of saponin–phospholipid complex of Panax notoginseng.Methods:The in vitro cytotoxic effect of saponins extract and saponin–phospholipid complex against human lung cancer NCI-H460 and breast cancer cell lines BT474 was examined using MTS assay.For in vivo evaluation of antitumor potential,saponin and saponin–phospholipid complex were administered orally in rats induced mammary carcinogenesis by 7,12-dimethylbenz(a)anthracene,for 30 days.Results:Our data showed that saponin–phospholipid complex had stronger anticancer effect compared to saponin extract.The IC50 values of saponin–phospholipid complex and saponin extract for NCI-H460 cell lines were 28.47 mg/m L and 47.97 mg/mL,respectively and these values for BT474 cells were 53.18 mg/mL and 86.24 mg/mL,respectively.In vivo experiments,administration of saponin,saponin–phospholipid complex and paclitaxel(positive control) effectively suppressed 7,12-dimethylbenz(a) anthracene-induced breast cancer evidenced by a decrease in tumor volume,the reduction of lipid peroxidation level and increase in the body weight,and elevated the enzymatic antioxidant activities of superoxide dismutase,catalase,glutathione peroxidase in rat breast tissue.Conclusions:Our study suggests that saponin extract from Panax notoginseng and saponin–phospholipid complex have potential to prevent cancer,especially breast cancer.

Long-Term Effects of Docosahexaenoic Acid-Bound Phospholipids and the Combination of Docosahexaenoic Acid-Bound Triglyceride and Egg Yolk Phospholipid on Lipid Metabolism in Mice

The bioavailability of docosahexaenoic acid(DHA) and eicosapentaenoic acid(EPA) depends on their chemical forms. This study investigated the long-term effects of DHA-bound triglyceride(TG-DHA), DHA-bound phospholipid(PL-DHA), and the combination of TG-DHA and egg yolk phospholipid(Egg-PL) on lipid metabolism in mice fed with a high-fat diet(fat levels of 22.5%). Male C57BL/6J mice were fed with different formulations containing 0.5% DHA, including TG-DHA, PL-DHA, and the combination of TG-DHA and Egg-PL, for 6 weeks. Serum, hepatic, and cerebral lipid concentrations and the fatty acid compositions of the liver and brain were determined. The concentrations of serum total triglyceride(TG), total cholesterol(TC), high-density lipoprotein cholesterol(HDL-c), and hepatic TG in the PL-DHA group and the combination group were significantly lower than those in the high-fat(HF) group(P < 0.05). Atherogenic index(AI) of the PL-DHA group was significantly lower than that of the combination group(P < 0.05). Hepatic TC level in the combination group was significantly lower than that in the HF group(P < 0.05), but no significant difference was observed between the combination group and the PL-DHA group. Both the PL-DHA and the combination groups showed significantly increased DHA levels in the liver compared with the HF group(P < 0.05). However, there were no obvious increases in the cerebral DHA levels in all DHA diet groups. These results suggest that PL-DHA was superior to the combination of TG-DHA and Egg-PL in decreasing the AI. Long-term dietary supplementation with low amount of DHA(0.5%) may improve hepatic DHA levels, although cerebral DHA levels may not be enhanced.

Knockout of butyrophilin subfamily 1 member A1(BTN1A1) alters lipid droplet formation and phospholipid composition in bovine mammary epithelial cells

Background: Milk lipids originate from cytoplasmic lipid droplets(LD) that are synthesized and secreted from mammary epithelial cells by a unique membrane-envelopment process. Butyrophilin 1 A1(BTN1 A1) is one of the membrane proteins that surrounds LD, but its role in bovine mammary lipid droplet synthesis and secretion is not well known.Methods: The objective was to knockout BTN1 A1 in bovine mammary epithelial cells(BMEC) via the CRISPR/Cas9 system and evaluate LD formation, abundance of lipogenic enzymes, and content of cell membrane phospholipid(PL) species. Average LD diameter was determined via Oil Red O staining, and profiling of cell membrane phospholipid species via liquid chromatography-tandem mass spectrometry(LC-MS/MS).Results: Lentivirus-mediated infection of the Cas9/sg RNA expression vector into BMEC resulted in production of a homozygous clone BTN1 A1^((-/-)). The LD size and content decreased following BTN1 A1 gene knockout. The m RNA abundance of fatty acid synthase(FASN) and peroxisome proliferator-activated receptor-gamma(PPARG) was downregulated in the BTN1 A1^((-/-))clone. Subcellular analyses indicated that BTN1 A1 and LD were co-localized in the cytoplasm. BTN1 A1 gene knockout increased the percentage of phosphatidylethanolamine(PE) and decreased phosphatidylcholine(PC), which resulted in a lower PC/PE ratio.Conclusions: Results suggest that BTN1 A1 plays an important role in regulating LD synthesis via a mechanism involving membrane phospholipid composition.

PNPLA3 rs139051 is associated with phospholipid metabolite profile and hepatic inflammation in nonalcoholic fatty liver disease

AIM To investigate the effect of PNPLA3 polymorphisms on serum lipidomics and pathological characteristics in nonalcoholic fatty liver disease(NAFLD).METHODS Thirty-four biopsy-proven NAFLD patients from Northern, Central, and Southern China were subjected to stratification by genotyping their single nucleotide polymorphisms(SNPs) in PNPLA3. Ultra performance liquid chromatography-tandem mass spectrometry was then employed to characterize the effects of PNPLA3 SNPs on serum lipidomics. In succession, correlation analysis revealed the association of PNPLA3-related lipid profile and hepatic pathological characteristics on a basis of steatosis, activity, and fibrosis assessment. The variant-based scoring of hepatocyte steatosis, ballooning, lobular inflammation, and liver fibrosis was finally performed so as to uncover the actions of lipidomics-affecting PNPLA3 SNPs in NAFLD-specific pathological alterations. RESULTS PNPLA3 SNPs(rs139051, rs738408, rs738409, rs 2072906, rs2294918, rs2294919, and rs4823173) demonstrated extensive association with the serum lipidomics, especially phospholipid metabolites [lysophosphatidylcholine(LPC), lysophosphatidylcholine plasmalogen(LPCO), lysophosphatdylethanolamine(LPE), phosphatidylcholine(PC), choline plasmalogen(PCO), phosphatidylethanolamine(PE), ethanolamine plasmalogen(PEO)], of NAFLD patients. PNPLA3 rs139051(A/A genotype) and rs2294918(G/G genotype) dominated the up-regulatory effect on phospholipids of LPCs(LPC 17:0, LPC 18:0, LPC 20:0, LPC 20:1, LPC 20:2) and LPCOs(LPC O-16:1, LPC O-18:1). Moreover, subjects with high-level LPCs/LPCOs were predisposed to low-grade lobular inflammation of NAFLD(rho:-0.407 to-0.585, P < 0.05-0.001). The significant correlation of PNPLA3 rs139051 and inflammation grading [A/A vs A/G + G/G: 0.50(0.00, 1.75) vs 1.50(1.00, 2.00), P < 0.05] further demonstrated its pathological role based on the modulation of phospholipid metabolite profile.CONCLUSION The A/A genotype at PNPLA3 rs139051 exerts an upregulatory effect on serum phospholipids of LPCs and LPCOs, which are associated with low-grade lobular inflammation of NAFLD.

An Effective Extract Method of Phospholipids from Antarctic Krill <em>Euphausea superba</em>

Phospholipids are one of the major bioactive ingredients of Antarctic krill Euphausea superba. A feasible and effective extraction method of Antarctic krill oil was investigated and modified by orthogonal test which the ratio of solid to liquid was 1:2.5, extraction time was 5 min, ratio of ethyl acetate (EA) and n-butanol (BuOH) was 1:1. With this method, the extract of krill oil has a higher phospholipids content of 27.7% - 42.3%, together with total oil yields of 4.15% - 6.18%.

Phyto-phospholipid complexes(phytosomes): A novel strategy to improve the bioavailability of active constituents

Although active constituents extracted from plants show robust in vitro pharmacological effects, low in vivo absorption greatly limits the widespread application of these compounds. A strategy of using phyto-phospholipid complexes represents a promising approach to increase the oral bioavailability of active constituents, which is consist of ‘‘label-friendly'phospholipids and active constituents. Hydrogen bond interactions between active constituents and phospholipids enable phospholipid complexes as an integral part. This review provides an update on four important issues related to phyto-phospholipid complexes: active constituents, phospholipids, solvents, and stoichiometric ratios. We also discuss recent progress in research on the preparation, characterization, structural verification, and increased bioavailability of phyto-phospholipid complexes.

The absorption kinetics of Antarctic krill oil phospholipid liposome in blood and the digestive tract of healthy mice by single gavage

Antarctic krill(Euphausia superba)oil has been gaining increasing attention due to its nutritional and functional potentials.Krill oil usually contains a high concentration(about 50%)of phospholipids(AKOP)rich in DHA and EPA accompanied with 30%–40%triacylglycerols.Phospholipids can be made into liposomes without emulsifiers due to its amphiphilic characteristics.However,the absorption kinetics of AKOP liposome in vivo is not clear,which restrict the molecular mechanism analysis related to its distinct bioactivities.The lipid analysis in serum,small intestinal content and wall was carried out after oral administration of AKOP liposome to illustrate its absorption kinetics in blood and the digestive tract of healthy mice by single gavage.The major type of the obtained AKOP was phosphatidylcholine,and the total contents of the DHA and EPA were 29.31%.AKOP liposome was almost completely digested in the small intestine in 1 h and the hydrolysis products could be quickly absorbed by intestinal enterocytes.The DHA in serum peaked at 2 h after administration of AKOP liposome.AKOP liposome could be quickly digested and absorbed in vivo.The obtained results might provide a scientific basis for the molecular mechanism analysis related to distinct bioactivities of Antarctic krill oil phospholipid.

Temperature-Dependent Fatty Acid Composition Change of Phospholipid in Steelhead Trout (Oncorhynchus mykiss) Tissues

In this study, the changes of the fatty acid composition of phospholipid in different tissues(muscle, heart, brain and spleen) of steelhead trout(Oncorhynchus mykiss) were analyzed when the water temperature decreased gradually from 16 to 12℃℃, 8℃, 6℃, 4℃, 2 and 1℃℃. Three fish individuals each tank(average weight 70.32 g ± 9.12 g) were collected and used to analysis at each designed temperatures. At normal temperature(16℃), the fatty acid composition of phospholipid of muscle and heart was similar each other. The highest concentration of saturate fatty acids(SFA) was found in the phospholipid of spleen. The brain phospholipid contained higher oleic acid(18:1 n9) than the phospholipid of other tissues at 16℃. When the environmental temperature decreased, the concentration of unsaturated fatty acids of phospholipids in all tissues increased, and accordingly the ratio pf the unsaturated to saturated fatty acids(U/S) and unsaturation index(UI) increased, indicating that steelhead trout can compensate temperature-dependent changes in membrane fluidity by remodeling the fatty acid composition of phospholipids. The changes in the fatty acid composition of phospholipid were tissue-specific. At the early stages of the experiment(16 to 8℃℃), the fatty acid composition of phospholipid changed remarkably in muscle, heart, and spleen. When temperature decreased to less than 8℃, an obvious response of phospholipid fatty acid was observed in all tissues. The change of phospholipid composition of steelhead trout tissues may be affected by both cold stress and starvation when the temperature decreased to 2℃, and the change of phospholipid composition of muscle was very obvious.