Serum fatty acid profiles using GC-MS and multivariate statistical analysis: potential biomarkers of Alzheimer's disease

Previous studies showed the relationship between fatty acids and the risk of developing Alzheimer's disease (AD). However, they did not address potential differences in free fatty acid (FFA) profiles that could be used to distinguish between AD patients and healthy controls. In the present study we used gas chromatography-mass spectrometry (GC-MS) technology coupled with multivariate statistical analysis to study profiles of FFA in AD. The results indicated 2 saturated fatty acids (C14:0 and C16:0; p < 0.001 and p < 0.05, respectively), 3 unsaturated fatty acids (C18:1, C18:3, and C22:6; p < 0.05, p < 0.05, and p < 0.001, respectively), where mean levels in serum from AD patients were significantly lower than controls. Partial least squares discriminant analysis (PLS-DA) models with unit variance (UV) scaling and orthogonal signal correction (OSC) data preprocessing methods were employed to refine intergroup differences between FFA profiles. The results of the analysis have highlighted docosahexaenoic acid (DHA) as the FFA with the greatest potential as a biomarker of AD, and this study has demonstrated that FFA biomarkers have considerable potential in diagnosing and monitoring AD.     

基于60种植物药多糖HPLC图谱的寒热药性分析及统计模式识别研究

目的:探讨中药寒热药性与多糖成分的相关性,寻找适合解释此相关性的统计模式识别方法。方法:选取寒、热性植物药各30种,提取和精制多糖并彻底水解成单糖,进行衍生化反应,测定多糖的单糖组成HPLC指纹图谱并构建数据库,经数据预处理后,比较6种统计模式识别方法在识别中药药性特征标记方面的优劣。结果:与其他模型相比,偏最小二乘判别分析识别率最高,对测试集植物药的组内判别正确率为91.7%,且对96个模拟药性特征标记整体识别率也明显优于其他模型。结论:中药寒热药性与多糖成分有明显相关性,用偏最小二乘判别分析建立的中药药性识别模型最适合发现与解释中药多糖成分与药性之间的相关性。     

原发性肝癌阳虚证患者血清代谢组特征初步研究

目的:探讨原发性肝癌阳虚证患者血清代谢组模式改变特征,为实现肝癌阳虚证诊断的客观化、规范化提供依据。方法:应用肝癌基本证候定性诊断标准和量化分析模型判定原发性肝癌基本证候类别,将42例原发性肝癌患者分成阳虚证组21例,非阳虚证组21例作为对照病例。应用基于核磁共振波谱(NMR)技术的代谢组学研究方法获得血清1H NMR谱,用偏最小二乘法-判别分析(PLS-DA)等模式识别、多元统计分析方法,发掘不同基本证候样本代谢组变化模式,并对主要差异代谢物进行鉴定,分析其生物学意义。结果:利用1H NMR谱信息,用PLS-DA分析可以把阳虚证组和非阳虚证组代谢谱变化区分开,代谢物鉴定发现,肝癌阳虚证组和非阳虚证组有显著统计学意义(P0.05)的差异代谢物有6类,分别是极低密度脂蛋白/低密度脂蛋白(VLDL/LDL)、异亮氨酸、乳酸、脂类、胆碱、葡萄糖/糖类。这些差异代谢物浓度肝癌阳虚证组较非阳虚证组明显下降。结论:肝癌阳虚证与非阳虚证代谢谱的差异提示阳虚证特征性代谢网络的失调,主要表现为脂类代谢、氨基酸代谢、糖代谢、能量代谢等多种代谢的紊乱或衰减,VLDL/LDL、异亮氨酸、乳酸、脂类、胆碱、葡萄糖/糖类等代谢物浓度的下降可能是肝癌阳虚证特征性的代谢物改变,是潜在的肝癌阳虚证生物标志物。     

不同产地麦冬1H-NMR模式识别研究

目的 建立一种基于氢核磁共振-模式识别的不同产地麦冬鉴别新方法。方法 以¹H-NMR技术测定样品的全成分信息,并转化成数据矩阵,采用模式识别法中的主成分分析(PCA)、偏最小二乘法-判别分析(PLS-DA)以及聚类分析(HCA)进行识别分析。结果 氢核磁共振-模式识别法能有效地鉴别不同产地的麦冬样本。结论 氢核磁共振-模式识别法是一种有效的药材分类鉴别方法,可作为药材质量控制的手段之一。     

PLS-DA结合熵权TOPSIS法综合评价不同产地苍耳子

目的 综合评价不同产地苍耳子的质量。方法 采用HPLC法测定不同产地苍耳子中羧基苍术苷、苍术苷、新绿原酸、绿原酸、隐绿原酸、噻嗪双酮苷、1,5-二咖啡酰奎宁酸、3,4-二咖啡酰奎宁酸、3,5-二咖啡酰奎宁酸和4,5-二咖啡酰奎宁酸,采用偏最小二乘判别分析（PLS-DA）和熵权优劣解距离法（EW-TOPSIS）法综合分析测定结果,寻找引起苍耳子产品质量的主要差异性物质,评价不同产地苍耳子质量的优劣。结果 10种成分在各自范围内线性关系良好;绿原酸、1,5-二咖啡酰奎宁酸、3,5-二咖啡酰奎宁酸、羧基苍术苷和新绿原酸是影响苍耳子产品质量的主要潜在标志物;EW-TOPSIS法分析结果显示江苏和山东产的苍耳子质量优。结论 建立的HPLC法操作便捷、结果准确,结合PLS-DA、EW-TOPSIS法可综合评价不同产地苍耳子的质量。     

Metabolic profiling reveals therapeutic biomarkers of processed Aconitum Carmichaeli Debx in treating hydrocortisone induced Kidney-Yang deficiency syndrome rats

Ethnopharmacological relevance

Kidney-Yang Deficiency syndrome (KYDS) is a diagnostic pattern in traditional Chinese medicine (TCM) and clinical data showed that the unbalance in adrenal cortical hormone is the key issue in KYDS patients. The processed Ranunculaceae Aconitum carmichaeli debx (Bai-Fu-Pian in Chinese, BFP) is one of the most commonly used Chinese herbs for treating KYDS. The present study was conducted to explore the therapeutic biomarkers of the BFP in treating hydrocortisone administration induced KYDS rats.

Materials and methods

Thirty male Sprague-Dawley rats were randomly divided into five groups with six in each group. KYDS in rats was induced by i.p. injection of hydrocortisone at the dose of 10 mg/kg per day for 15 days as described previously. The rats with KYDS were administered orally, starting from the day of hydrocortisone administration stopped, with BFP extract at the dose of 0.32 g/kg, 0.64 g/kg and 1.28 g/kg per day respectively for 15 days. The blood samples were collected for the liquid chromatography quadruple time-of-flight mass spectrometry (LC-Q-TOF-MS) test, as well as radioimmunoassay to determine the concentrations of cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP) and adrenocorticotrophic hormone (ACTH). The metabolic responses to BFP administration were investigated by using the principal components analysis (PCA) and orthogonal partial least squares analysis (OPLS). Bioinformatics analyses were performed by using the Ingenuity Pathway Analysis (IPA). Variance analysis and linear regression analysis were used in this study.

Results

The signs and concentrations of cAMP, cGMP and ACTH in the model rats were similar to those previously described about KYDS rats and BFP treatment can reverse the changes. Seventeen significantly changed metabolites among different groups were identified. Thirteen metabolites were identified in the KYDS rats comparing to healthy rats with nine up-regulated and four down-regulated. After BFP treatment at three dosages, five up-regulated metabolites including phosphate, betaine, (4-hydroxyphenyl) acetaldehyde, 5-hydroxyindol-3-acetic acid and 5'-phosphoribosyl-N-formylglycinamide were dose-dependently reversed. The network analysis with IPA showed that four canonical pathways including superpathway of methionine degradation, purine nucleotides De Novo biosynthesis II, tyrosine synthesis and serotonin receptor signaling involved the therapeutic mechanism of BFP in treating the KYDS rats.

Conclusions

Five therapeutic biomarkers (phosphate, betaine, (4-hydroxyphenyl) acetaldehyde, 5-hydroxyindol-3-acetic acid and 5'-phosphoribosyl-N-formylglycinamide) and two corresponding canonical pathways (amino acid metabolism and purine nucleotide metabolism) were identified to be involved in the therapeutic mechanism of BFP treating the KYDS.     

Age related changes in brain metabolites observed by 1H MRS in APP/PS1 mice

Translational biomarkers in Alzheimer's disease based on non-invasive in vivo methods are highly warranted. ¹H magnetic resonance spectroscopy (MRS) is non-invasive and applicable in vivo in both humans and experimental animals. In vivo ¹H MRS and 3D MRI were performed on brains of double transgenic (tg) mice expressing a double mutant human β-amyloid precursor protein APP(K670N,M671L) and human mutated presenilin gene PS1M146L, and wild-type (wt) littermates at 2.5, 6.5 and 9 months of age using a 9.4 T magnet. For quantification, LCModel™ was used, and the data were analyzed using multivariate data analysis (MVDA). MVDA evidenced a significant separation, which became more pronounced with age, between tg and wt mice at all time points. While myo-inositol and guanidoacetate were important for group separation in young mice, N-acetylaspartate, glutamate and macrolipids were important for separation of aged tg and wt mice. Volume segmentation revealed that brain and hippocampus were readily smaller in tg as compared to wt mice at the age of 2.5 months. Amyloid plaques were seen in 6.5 and 9 months, but not in 2.5 months old animals.In conclusion, differences in brain metabolites could be accurately depicted in tg and wt mice in vivo by combining MRS with MVDA. First differences in metabolite content were readily seen at 2.5 months, when volume defects in tg mice were present, but no amyloid plaques.     

Metabolic profiling studies on the toxicological effects of realgar in rats by H NMR spectroscopy

The toxicological effects of realgar after intragastrical administration (1 g/kg body weight) were investigated over a 21 day period in male Wistar rats using metabonomic analysis of ¹H NMR spectra of urine, serum and liver tissue aqueous extracts. Liver and kidney histopathology examination and serum clinical chemistry analyses were also performed. ¹H NMR spectra and pattern recognition analyses from realgar treated animals showed increased excretion of urinary Kreb's cycle intermediates, increased levels of ketone bodies in urine and serum, and decreased levels of hepatic glucose and glycogen, as well as hypoglycemia and hyperlipoidemia, suggesting the perturbation of energy metabolism. Elevated levels of choline containing metabolites and betaine in serum and liver tissue aqueous extracts and increased serum creatine indicated altered transmethylation. Decreased urinary levels of trimethylamine-N-oxide, phenylacetylglycine and hippurate suggested the effects on the gut microflora environment by realgar. Signs of impairment of amino acid metabolism were supported by increased hepatic glutamate levels, increased methionine and decreased alanine levels in serum, and hypertaurinuria. The observed increase in glutathione in liver tissue aqueous extracts could be a biomarker of realgar induced oxidative injury. Serum clinical chemistry analyses showed increased levels of lactate dehydrogenase, aspartate aminotransferase, and alkaline phosphatase as well as increased levels of blood urea nitrogen and creatinine, indicating slight liver and kidney injury. The time-dependent biochemical variations induced by realgar were achieved using pattern recognition methods. This work illustrated the high reliability of NMR-based metabonomic approach on the study of the biochemical effects induced by traditional Chinese medicine.     

A review of near infrared spectroscopy and chemometrics in pharmaceutical technologies

Near-infrared spectroscopy (NIRS) is a fast and non-destructive analytical method. Associated with chemometrics, it becomes a powerful tool for the pharmaceutical industry. Indeed, NIRS is suitable for analysis of solid, liquid and biotechnological pharmaceutical forms. Moreover, NIRS can be implemented during pharmaceutical development, in production for process monitoring or in quality control laboratories.This review focuses on chemometric techniques and pharmaceutical NIRS applications. The following topics are covered: qualitative analyses, quantitative methods and on-line applications. Theoretical and practical aspects are described with pharmaceutical examples of NIRS applications.