Identification of food-derived elastin peptide, prolyl-glycine (Pro-Gly), in human blood after ingestion of elastin hydrolysate

Elastin hydrolysate has apparent beneficial effects, and the food-derived peptide prolyl-glycine (Pro-Gly) is present in human blood after oral ingestion. Following ingestion of elastin hydrolysate (10 g/60 kg body weight) by healthy human volunteers, peripheral blood was used to prepare plasma samples from which peptides were extracted by solid phase extraction and fractionated by size-exclusion chromatography (SEC). Peptides in the SEC fractions were derivatized with phenyl isothiocyanate (PITC) and resolved by reversed phase (RP)-HPLC. Pro-Gly was the major food-derived elastin peptide, reaching a maximum (18 μM) at 30 min after ingestion, and decreasing to approximately 20% at 4 h after ingestion. Finally, in cell culture, levels of Pro-Gly in the medium above 0.1 μg/mL significantly enhanced elastin synthesis of normal human dermal fibroblasts (NHDF) without affecting the rate of cell proliferation.     

Angiotensin I-converting enzyme-inhibitory peptides obtained from chicken collagen hydrolysate

In this study, collagen extracted from chicken legs (which are the yellow keratin parts containing a nail) was hydrolyzed with various enzymes, and the angiotensin I-converting enzyme (ACE)-inhibitory activity of each hydrolysate was determined. The hydrolysate by treatment with an Aspergillus species-derived enzyme had the highest activity (IC 50 = 260 microg/mL). The fraction of this hydrolysate obtained by ultrafiltration with a molecular-weight cutoff of 3000 Da (low fraction) had a stronger activity (IC 50 = 130 microg/mL) than the fractionated one. This fraction was further fractionated by HPLC, and the peptides in the fraction with high ACE-inhibitory activity were identified. The amino acid sequences of the four peptides were identified using a protein sequencer. These peptides were synthesized to confirm their ACE-inhibitory activities; this showed that peptides with a Gly-Ala-Hyp-Gly-Leu-Hyp-Gly-Pro sequence had the highest activity (IC 50 = 29 microM). When the low fraction was administered to spontaneous hypertensive rats, a decrease in their blood pressure was observed after 2 h of administration, and a significant decrease in blood pressure (-50 mmHg) was observed after 6 h. Moreover, long-term administration studies indicated that the low fraction showed a significant suppression of increased blood pressure.     

Blood pressure lowering effect of a pea protein hydrolysate in hypertensive rats and humans

The blood pressure lowering effect of a pea protein hydrolysate (PPH) that contained <3 kDa peptides, isolated by membrane ultrafiltration from the thermolysin digest of pea protein isolate (PPI), was examined using different rat models of hypertension as well as hypertensive human subjects. The PPH showed weak in vitro activities against renin and angiotensin converting enzyme (ACE) with inhibitory activities of 17 and 19%, respectively, at 1 mg/mL test concentration. Oral administration of the PPH to spontaneously hypertensive rats (SHR) at doses of 100 and 200 mg/kg body weight led to a lowering of hourly systolic blood pressure (SBP), with a maximum reduction of 19 mmHg at 4 h. In contrast, orally administered unhydrolyzed PPI had no blood pressure reducing effect in SHR, suggesting that thermolysin hydrolysis may have been responsible for releasing bioactive peptides from the native protein. Oral administration of the PPH to the Han:SPRD-cy rat (a model of chronic kidney disease) over an 8-week period led to 29 and 25 mmHg reductions in SBP and diastolic blood pressure, respectively. The PPH-fed rats had lower plasma levels of angiotensin II, the major vasopressor involved in development of hypertension, but there was no effect on plasma activity or renal mRNA levels of ACE. However, renal expression of renin mRNA levels was reduced by approximately 50% in the PPH-fed rats, suggesting that reduced renin may be responsible for the reduced levels of angiotensin II. In a 3-week randomized double blind placebo-controlled crossover human intervention trial (7 volunteers), significant (p<0.05) reductions (over placebo) in SBP of 5 and 6 mmHg were obtained in the second and third weeks, respectively, for the PPH group. Therefore, thermolysin derived bioactive peptides from PPH reduced blood pressure in hypertensive rats and human subjects, likely via effects on the renal angiotensin system.     

Rice bran fractions improve blood pressure, lipid profile, and glucose metabolism in stroke-prone spontaneously hypertensive rats

Effect of dietary supplementation of two types of rice bran fraction on blood pressure (BP), lipid profile, and glucose metabolism in stroke-prone spontaneously hypertensive rats was studied. Male 4-week-old rats were divided into one group fed the AIN-93M-based control (C) diet and two groups fed diet supplemented with 60 g/kg of Driselase and ethanol fractions (DF and EF, respectively) of rice bran. After 8 weeks feeding, the BP decreased in the DF and EF groups in comparison with the C group (p < 0.01). Plasma ACE inhibitory activity, BUN, BUN/creatinine ratio, albumin, triglyceride, and glucose levels were lower in the DF and EF groups than in the C group (p < 0.01). Plasma nitric oxide and urinary 8-hydroxy-2'-deoxyguanosine levels were lower in the DF and EF groups than in the C group (p < 0.01). Rice bran fractions appear to have a beneficial dietary component that improves hypertension, hyperlipidemia, and hyperglycemia.     

Gravinol ameliorates high-fructose-induced metabolic syndrome through regulation of lipid metabolism and proinflammatory state in rats

Using a rat model with fructose-induced metabolic syndrome, the effect of gravinol was investigated. Male Wistar rats were fed a 65% fructose diet and administered 10 or 20 mg of gravinol/kg of body weight/day for 2 weeks. High-level fructose feeding led to hyperglycemia, hyperlipidemia, hypertri-glyceridemia, and hypertension. On the other hand, the administration of gravinol significantly lowered serum glucose and total cholesterol levels. The tail arterial blood pressure was significantly elevated with the high-fructose diet. However, rats given gravinol showed a lower blood pressure as compared with fructose-fed control rats. In addition, the triglyceride (TG) levels in serum and lipoprotein fraction were dose-dependently reduced in rats fed gravinol. The decreases of hepatic TG and total cholesterol by gravinol were responsible for the down-regulation of hepatic sterol regulatory element binding protein (SREBP)-1. However, gravinol did not affect the protein levels of hepatic peroxisome proliferator-activated receptor-alpha and SREBP-2. Moreover, gravinol administration in the fructose-fed rats markedly reduced the glycosylated protein and thiobarbituric acid-reactive substance levels in the serum and hepatic mitochondria, and it inhibited the increase of the cyclooxygenase-2 protein level as a result of the down-regulation of nuclear factor kappa B (NF-kappaB). Furthermore, the decrease of anti-apoptotic bcl-2 protein levels and the increase of pro-apoptotic bax protein levels by the high-fructose diet were reversed by gravinol. These findings suggest that fructose-induced metabolic syndrome is attenuated by gravinol administration, which is associated with the reduction of serum lipids and protection against the proinflammatory state induced by oxidative stress.     

Protective effect of Mesona procumbens against tert-butyl hydroperoxide-induced acute hepatic damage in rats

The protective effect of Hsian-tsao (Mesona procumbens Hemsl.) and its active compounds on liver damage was evaluated using the model of tert-butyl hydroperoxide (t-BHP)-induced acute hepatic damage in rats. Male Sprague-Dawley rats (200 +/- 10 g) were orally pretreated with a water extract of Hsian-tsao (WEHT) (0.1, 0.5, and 1.0 g/kg) or caffeic acid (0.1 g/kg of body weight) for 13 days before a single dose of t-BHP (0.2 mmol/kg, intraperitoneally) to each animal, and the rats were sacrificed 18 h later by decapitation; blood samples were collected for the assays of serum biochemical values. The livers were excised from the animals and assayed for oxidative injury, antioxidant enzyme, and pathological histology. The result showed that the oral pretreatment of WEHT (0.1, 0.5, and 1.0 g/kg) or caffeic acid (0.10 g/kg) before t-BHP (0.2 mmol/kg) treatment significantly lowered the serum levels of the hepatic enzyme markers (alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase) and reduced oxidative stress of the liver by evaluation of malondialdehyde, glutathione, 8-hydroxy-2'-deoxyguanosine, glutathione peroxidase, and glutathione reductase. The histopathological evaluation of the rat livers showed that WEHT and caffeic acid reduced the incidence of liver lesions including cloudy swelling, pyknosis, and cytolysis induced by t-BHP in rats. On the basis of the results of this study, it can be speculated that M. procumbens protects liver against t-BHP-induced hepatic damage in rats.     

Components and activity of polysaccharides from coarse tea

Coarse tea contained a high content of polysaccharide complex. Composed of polysaccharide and protein, the polysaccharide complex from tea (TPS) belonged to glycoprotein with the molecular weight () of (10.7-11.0) x 10(4). When mice (7 weeks old, C57BL/8) were injected with TPS, the levels of blood glucose (BG) in normal mice and model mice with high BG were decreased significantly by averages of 13.54 and 22.18%, respectively. The antibody concentration (OD(413 nm)) in the mice injected with 2.4 mg/mL TPS was increased evidently by 44.93% (p < 0.01). TPS treatment was beneficial not only for the subsequent production of interleukin (IL) 2 in spleen cells of adjuvant arthritis (AA) rats but also because it prohibited the body from producing too much IL-1 in AA rats. Treatment of diabetes with coarse tea in both China and Japan may be related to TPS and the content of TPS in coarse tea.     

The hypocholesterolemic activity of transgenic rice seed accumulating lactostatin, a bioactive peptide derived from bovine milk β-lactoglobulin

Lactostatin is a novel pentapeptide (IIAEK) derived from bovine milk β-lactoglobulin with greater hypocholesterolemic activity than β-sitosterol, the drug commonly used to treat hypercholesterolemia. We developed transgenic rice expressing lactostatin as a fusion protein with seed storage protein (SSP) glutelins under the control of three different endosperm-specific promoters. Lactostatin accumulated in transgenic rice seed at approximately 1.6 mg/g seeds (dry seeds) without any apparent influence on seed traits such as endogenous SSP expression levels or alterations in the intracellular structures of endosperm cells. Short-term (three day) oral administration of the glutelin fraction containing lactostatin (namely three times of 300 mg/kg body weight/day) extracted from transgenic rice seeds resulted in hypocholesterolemic activity in rats; namely, the serum low-density-lipoprotein (LDL) cholesterol level was significantly reduced accompanied by a significant increase in beneficial serum high-density-lipoprotein (HDL) cholesterol.     

Accelerated aerobic degradation of γ-hexachlorocyclohexane in suspensions of flooded and non-flooded soils pretreated with hexachlorocyclohexane

Summary A commercial wettable-powder formulation (50% a. i.) of hexachlorocyclohexane (HCH) was applied to unplanted and planted (to rice) soils under flooded and non-flooded conditions at 1 kg a. i. ha^–1 at 15-day intervals. A mineral salts medium supplemented with -HCH as a sole source of C was inoculated with suspensions from HCH-treated and untreated soils (unplanted or planted to rice) and incubated under aerobic conditions. -HCH disappeared completely within 10 days from the aerobically incubated medium inoculated with the suspension from the treated soil compared to less than 30% loss from the uninoculated medium or from the medium inoculated with the suspension from the untreated soil, during the corresponding period. Soil samples from HCH-treated flooded pots lost their capacity for accelerated degradation of -HCH after autoclaving. The addition of HCH clearly stimulated aerobic degradation of -HCH, even in predominantly anaerobic flooded soil. The factor responsible for the accelerated degradation of -HCH in pretreated soil was not detected in the deeper layers (>10 cm) of flooded soil and in fields that had dried following the rice harvest.     

Peptide with angiotensin I-converting enzyme inhibitory activity from hydrolyzed corn gluten meal

Corn gluten meal (CGM) was hydrolyzed by Alcalase after starch removal of CGM was applied as a pretreatment. A new inhibitory peptide for angiotensin I-converting enzyme (ACE) was isolated from the hydrolysate of CGM with the use of Bio-Rad P-2 gel filtration and followed by reverse-phase high-performance liquid chromatography (RP-HPLC). The sequence of the active peptide was determined to be Ala-Tyr after the application of amino acid analysis and HPLC/MS. The IC50 of the peptide was 14.2 microM, and it was not affected by preincubation with 30 mU of ACE at 37 degrees C for 3 h. Ala-Tyr also exerted antihypertensive effects after oral administration to spontaneously hypertensive rats. A maximal reduction of systolic blood pressure of 9.5 mmHg was observed 2 h after oral administration of Ala-Tyr at doses of 50 mg/kg.     

Quantification of soy isoflavones, genistein and daidzein, and conjugates in rat blood using LC/ES-MS.

Genistein is the principal soy isoflavone to which the putative beneficial effects of soy consumption have been attributed; however, the possibility of adverse biological effects (e.g., estrogenic, antithyroid) has also been raised. This paper describes development and validation of a simple and sensitive analytical method for the determination of genistein in the blood of rats receiving dietary genistein (<0.5-1250 microg of genistein aglycone/g of chow). The method uses serum/plasma deproteination, liquid-liquid extraction, deuterated genistein and daidzein internal standards, isocratic LC separation, and electrospray mass spectrometric quantification using selected ion monitoring. Extraction efficiency is approximately 85%, the detection limits for genistein and daidzein from 50 microL of rat blood are approximately 5 nM, and the limit of quantification is approximately 15 nM. Interassay precision (relative standard deviation 4.5-4.6%) and intraassay precision (3.3-6.7%) were determined from replicate analysis of a spiked control and an incurred serum sample. The distribution of conjugated and unconjugated forms of genistein in the blood of rats was determined using selective enzyme hydrolysis. The glucuronide was the predominant metabolite (>90%), and only small amounts of the sulfate conjugate and the aglycone were observed at all dose levels. No evidence for additional metabolites was obtained. The 7- and 4'-glucuronide conjugates of genistein were identified using electrospray mass spectrometry and (1)H NMR. Total blood genistein ranged from <15 nM in animals fed soy-free control diet to as high as 8.9 microM in male rats fed 1250 microg of genistein/g of chow and encompasses blood isoflavone levels observed in humans consuming a typical Asian diet and nutritional supplements (0.1-1 microM) and infants consuming soy formulas (2-7 microM).     

Purification of a novel angiotensin I-converting enzyme (ACE) inhibitory peptide with an antihypertensive effect from loach (Misgurnus anguillicaudatus)

To isolate and characterize novel angiotensin I-converting enzyme (ACE) inhibitory peptide from loach (Misgurnus anguillicaudatus), six proteases, pepsin, α-chymotrypsin, bromelain, papain, alcalase, and Neutrase, were used to hydrolyze loach protein. The hydrolysate (LPH) generated by bromelain [ratio of enzyme to substrate, 3:1000 (w/w)] was found to have the highest ACE inhibitory activity (IC(50), 613.2 ± 8.3 μg/mL). Therefore, it was treated by ultrafiltration to afford fraction of LPH-IV (MW < 2.5 kDa) with an IC(50) of 231.2 ± 3.8 μg/mL, having higher activity than the other fractions. Then, LPH-IV was isolated and purified by consecutive purification steps of gel filtration chromatography and reverse-phase high-performance liquid chromatography to afford a purified peptide with an IC(50) of 18.2 ± 0.9 μg/mL, an increase of 33.7-fold in ACE inhibitory activity as compared with that of LPH. The purified peptide was identified as Ala-His-Leu-Leu (452 Da) by Q-TOF mass spectrometry and amino acid analyzer. An antihypertensive effect in spontaneously hypertensive rats revealed that oral administration of LPH-IV could decrease systolic blood pressure significantly.     

Biofortification of rice with zinc: assessment of the relative bioavailability of zinc in a Caco-2 cell model and suckling rat pups

Staple foods, such as rice, can now be enriched in micronutrients through conventional breeding (i.e., biofortification) to enhance dietary intake of vulnerable populations. The objectives of this study were (1) to establish a rapid, high capacity Caco-2 cell model to determine the relative bioavailability of zinc (Zn) from samples of staple food breeding lines for potential use as a guideline for selection/breeding and (2) to determine the relative bioavailability of Zn from conventional rice varieties and one Zn-biofortified type. Polished or undermilled, parboiled rice samples were digested in vitro with pepsin and pH adjustment, and by pancreatic enzymes. Zn uptake from digested samples was measured in Caco-2 cells in culture. A previously validated rat pup model was also used to assess Zn absorption in vivo, using gastric intubation and (65)Zn labeling. Pups were killed after 6 h, and radioactivity in tissues and in small intestine perfusate and cecum-colon contents was used to measure Zn bioavailability. A biofortified rice variety contained substantially more Zn than conventional varieties, with no change in phytate content. Absorbed Zn (μg/g rice) was significantly higher from the new variety in both the in vitro Caco-2 cell model (2.1-fold) and the rat pup model (2.0-fold). Results from the two models were highly correlated, particularly for the polished samples. Biofortification of rice with Zn results in significantly increased Zn uptake in both models. Since results from the Caco-2 cell model correlated well with those from rat pups, this cell model is likely to predict results in human populations and can be used for screening purposes.     

鹅肝酶解物对酒精性脂肪肝的改善作用

为探索鹅肝酶解物对酒精性脂肪肝的防治效果,以6周龄SD大鼠为研究对象,将其随机分为对照组、模型组,以及鹅肝酶解物高(GLH-H)、低剂量处理组(GLH-L),其中对照组以Lieber-DeCarli液体对照饲料喂养,其他各组以Lieber-DeCarli乙醇液体饲料喂养;GLH-H、GLH-L处理组分别给药600、200 mg·kg^-1 BW(体质量)GLH进行干预,对照组和模型组分别给予相同体积的生理盐水灌胃,试验共持续5周。试验结束后测定各试验组大鼠的体质量、肝脏指数、血清中尿素氮、总胆固醇、甘油三酯及炎症因子,分析大鼠肠道微生物的组成,并对各试验组大鼠肝脏病理切片进行观察。结果表明,GLH处理明显降低了酒精性脂肪肝大鼠的肝脏指数(P<0.05),改善了酒精性脂肪肝大鼠肝脏脂肪变性程度,显著降低了大鼠血清中的尿素氮、总胆固醇、甘油三酯及炎症水平(P<0.05)。高通量测序发现,GLH可改善大鼠肠道微生物紊乱的现象。综上,GLH对酒精性脂肪肝的发生具有一定的预防作用。本研究结果为酒精性脂肪肝治疗药物的研究提供了新思路。     

Effects of Chinese and North American Wild Rice on Blood Lipids,Oxidative Stress,and Inflammation Factors in Hyperlipidemic Rats

The aim of the present study was to compare the effects of replacing processed rice and wheat starch with Chinese and North American wild rice as the chief source of dietary carbohydrates in rats fed high levels of saturated fat and cholesterol. The study consisted of five groups: low‐fat diet, high fat/cholesterol diet, city diet, North American wild rice diet, and Chinese wild rice diet. At the end of eight weeks of the diet regimen, the North American and Chinese wild rice diets suppressed the increase in serum triglyceride and total cholesterol but also decreased the high‐density lipoprotein cholesterol level. In addition, rats fed either the North American or Chinese wild rice diet suppressed the build‐up of oxidative stress by improving total antioxidant capacity, increasing superoxide dismutase activity, and reducing malondialdehyde concentration. In contrast, rats fed with the high fat/cholesterol diet and city diet had increased concentrations of high‐sensitivity C‐reactive protein (hs‐CRP) and tumor necrosis factor α (TNF‐α) compared with the low‐fat diet; rats fed with the Chinese wild rice diet had a significantly decreased serum hs‐CRP protein and TNF‐α concentration. Higher serum hs‐CRP levels were verified in the city diet group compared with North American wild rice diet group. These findings illustrate that both North American wild rice and Chinese wild rice are effective in suppressing hyperlipidemia, oxidative stress, and inflammation in rats even when the diet consumed is high in fat and cholesterol.     

棉秆脱毒水解液发酵生产2,3-丁二醇的工艺优化

2,3-丁二醇是一种重要的化工产品,利用棉秆水解液替代淀粉原料制备2,3-丁二醇可保证粮食安全并降低成本。该文以棉秆稀酸水解液为基础,研究了其中糠醛和苯酚微波辅助加热-活性炭吸附的脱毒条件,优化结果为：活性炭用量1%、微波功率330 W、作用时间10 min。在此工艺条件下,糠醛的去除率为81.2%,苯酚的脱除率为92.3%,总糖的损失为10.6%。脱毒棉秆水解液为底物发酵生产2,3-丁二醇研究表明,水解液浓度为40 g/L时Klebsiella pneumoniae XJ-Li菌体浓度和2,3-丁二醇的产率最高,补料批式发酵可以缓解高浓度棉秆水解液对微生物生长与代谢的抑制作用。通过采用添加60 mg/L维生素C和维持发酵液pH值于5.5的复合调控方法,2,3-丁二醇的质量浓度达到了45.1 g/L,产率为0.45 g/g。发酵试验表明脱毒的棉杆水解液作为碳源发酵制备2,3-丁二醇具有可行性。     

Effect of temperature on the rate limiting step in the methanogenic degradation pathway in rice field soil

Temperature is an important factor controlling CH₄ production in rice field soils. However, it is unknown which step in the methanogenic degradation of organic matter is the limiting one that is controlled by temperature. Soil slurries prepared from Italian rice field soil were anaerobically incubated in the dark at six different temperatures between 10 and 37 °C until quasi-steady state was reached. Then, the potential and actual rates of polysaccharide hydrolysis and of CH₄ production from different immediate (acetate, H₂) and distal (glucose, propionate) methanogenic substrates were determined. Potential activities of exo-glucanase and glucosidase were always higher than the actual rates of polysaccharide hydrolysis indicating that the availability of the polysaccharide substrate was limiting at all temperatures. The actual rates of CH₄ production were always lower than those predicted from glucose release during polysaccharide hydrolysis indicating that a substantial amount of the released glucose was assimilated into microbial biomass. Addition of the different methanogenic substrates stimulated CH₄ production at all temperatures >10 °C, but only at >20 °C to values higher than rates of polysaccharide hydrolysis. Under steady state conditions, however, hydrolysis of organic polymers was the rate-limiting step at all temperatures >10 °C.     

酶法复合脱毒提高玉米秸秆水解液丁醇发酵效率

利用玉米秸秆发酵产丁醇在生物质转化领域具有明显优势。为解除玉米秸秆水解液中多种有毒物质对微生物生长的抑制及对发酵产量的影响,该研究摒除常用的理化脱毒法,选择高效环保的酶法脱毒以实现溶剂高产。研究结果表明:通过优化漆酶和甲酸脱氢酶添加量以去除水解液中酚类和甲酸,单独添加漆酶5 U/m L、甲酸脱氢酶1 U/m L,水解液发酵的丙酮-丁醇-乙醇(acetone-butanol-ethanol,ABE,总溶剂)产量分别为1.03和1.11 g/L。再在活性炭的辅助下形成高效酶法复合脱毒体系,经复合脱毒处理的水解液发酵后丁醇产量达2.90 g/L,总溶剂ABE产量达到4.4 g/L,比未作处理的对照组发酵产量高出约5倍,实现了生物质的高效转化。可为玉米秸秆水解液发酵生产燃料丁醇提供参考。     

不同地力水平和施氮量下水稻优质高产的氮肥有机替代比例

【目的】氮肥有机替代可减少化肥投入同时消纳有机废弃物,是促进水稻绿色生产的关键技术之一。然而,适宜的氮肥有机替代比例还有待进一步明确。【方法】本研究综合已发表有关水稻氮肥有机替代的71篇文章,分别获取水稻产量和籽粒含氮量田间试验相关数据412组和133组,通过整合分析(meta-analysis)量化不同氮肥有机替代比例对水稻产量和籽粒含氮量的影响,并探究不同土壤条件和施氮水平下适宜的有机替代比例。【结果】适宜的氮肥有机替代比例有利于水稻产量和籽粒含氮量的提升,土壤有机质含量高(>25 g/kg)、中(15～25 g/kg)、低(≤15 g/kg)水平下,获取最高水稻产量的适宜有机替代比例分别是60%、70%、30%;无论土壤全氮含量高(>1.5 g/kg)、中(1～1.5 g/kg)或者低(≤1 g/kg),适宜的有机替代比例均不超过60%。土壤速效氮含量高(>150 mg/kg)和低(≤90 mg/kg)水平下,适宜的有机替代比例均是10%～30%,速效氮中等水平下(90～150 mg/kg)有机替代处理产量增加不显著。高水平施氮量(>250 kg/hm     

Analysis of polar lipids in the serum from rats fed shiitake by liquid chromatography-mass spectrometry/mass spectrometry

Consumption of a shiitake mushroom diet has been reported to have effects on serum phospholipids. However, much less is known about the effect on serum polar lipids including lysophospholipids and free fatty acids. In the present study, the effects of a shiitake diet were evaluated on the basis of identification and quantification of individual polar lipid components in rat serum using liquid chromatography-mass spectrometry/mass spectrometry. By comparison with standards and published data, 50 lysophospholipids and 32 free fatty acids were identified, and the concentrations of 27 polar lipids in rat serum were determined. Shiitake diets decreased the levels of all individual polar lipid components in the serum of male rat. The total level of serum polar lipids in males fed 4% shiitake diets (1365.71 mol/L) was significantly lower than that of the control (2270.26 mol/L). However, shiitake diets did not significantly affect the levels of serum polar lipids in female rats.