Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 17 de 17
Filter
1.
Front Pharmacol ; 14: 1106961, 2023.
Article in English | MEDLINE | ID: mdl-37153768

ABSTRACT

Background: Evidence of efficacy and safety of programmed cell death 1 (PD-1) and programmed death ligand-1 (PD-L1) checkpoint inhibitors in oesophageal cancer (EC), gastric cancer (GC) and colorectal cancer (CRC) was inconsistent, obscuring their clinical application and decision-making. The aim of this study was to comprehensively evaluate the value of PD-1/PD-L1 inhibitors in EC, GC and CRC to select valuable PD-1/PD-L1 inhibitors, and to assess the association between the value and cost of PD-1/PD-L1 inhibitors. Methods: A comprehensive search of trials of PD-1/PD-L1 inhibitors in EC, GC and CRC was performed in Chinese and English medical databases with a cut-off date of 1 July 2022. Two authors independently applied the ASCO-VF and ESMO-MCBS to assess the value of PD-1/PD-L1 inhibitors. A receiver operating characteristic (ROC) curve was generated to establish the predictive value of the ASCO-VF score to meet the threshold of the ESMO-MCBS grade. Spearman's correlation was used to calculate the relationship between the cost and value of drugs. Results: Twenty-three randomized controlled trials were identified: ten (43.48%) in EC, five (21.74%) in CRC, and eight (34.78%) in GC or gastroesophageal junction cancer (GEJC). For advanced diseases, ASCO-VF scores ranged from -12.5 to 69, with a mean score of 26.5 (95% CI 18.4-34.6). Six (42.9%) therapeutic regimens met the ESMO-MCBS benefit threshold grade. The area under the ROC curve was 1.0 (p = 0.002). ASCO-VF scores and incremental monthly cost were negatively correlated (Spearman's ρ = -0.465, p = 0.034). ESMO-MCBS grades and incremental monthly cost were negatively correlated (Spearman's ρ = -0.211, p = 0.489). Conclusion: PD-1/PD-L1 inhibitors did not meet valuable threshold in GC/GEJC. Pembrolizumab met valuable threshold in advanced microsatellite instability-high CRC. The value of camrelizumab and toripalimab may be more worth paying in EC.

2.
Front Immunol ; 13: 953761, 2022.
Article in English | MEDLINE | ID: mdl-35911744

ABSTRACT

Background: An influx of systematic reviews (SRs) of programmed cell death 1 (PD-1) and programmed death ligand-1 (PD-L1) checkpoint inhibitors in cancer treatment with or without meta-analysis and with different methodological quality and inconsistent results have been published, confusing clinical decision making. The aim of this study was to comprehensively evaluate and summarize the current evidence of PD-(L)1 inhibitors in the treatment of cancer. Methods: A comprehensive search of SRs, which included meta-analyses of PD-(L)1 inhibitors on cancer, was performed on eight databases with a cutoff date of 1 January 2022. Two authors independently identified SRs, extracted data, assessed the report quality according to the guidance of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement, evaluated the methodological quality by the Assessment of Multiple Systematic Reviews 2 (AMSTAR 2), and appraised the quality of evidence by the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE). Results: A total of 172 SRs with meta-analysis met the inclusion criteria. The report quality of included SRs was quite good, with 128 (74.42%) SRs of high quality and 44 (25.58%) of moderate quality. The methodological quality was alarming, as only one (0.58%) SR had high quality, five (2.91%) SRs had low quality, and the other 166 (96.51%) SRs had critically low quality. For GRADE, 38 (3.77%) outcomes had high-quality evidence, 288 (28.57%) moderate, 545 (54.07%) low, and 137 (13.59%) critically low-quality evidence. Current evidence indicated that treatment with PD-(L)1 inhibitors were significantly effective in non-small cell lung cancer, small cell lung cancer, hepatocellular carcinoma, malignant melanoma, renal cell carcinoma, and urothelial carcinoma, breast cancer, and head and neck squamous cell carcinoma with PD-L1 expression level≥1%, whereas the evidence in gastroesophageal and colorectal tumors is still controversial. Monotherapy with PD-(L)1 inhibitors was associated with a lower frequency of any grade and high-grade adverse events (AEs). The incidence of any grade and high-grade AEs caused by PD-(L)1 inhibitors in combination with other therapies was no lower than the controls. However, PD-(L)1 inhibitors were associated with a higher frequency of any grade and high-grade immune-related AEs. Conclusions: PD-(L)1 inhibitors appeared to be effective and safe for cancer treatment, except for gastrointestinal tumors; however, the quality of the evidence is not convincing. Future studies should improve methodological quality and focus on the sequential trial analysis of subgroups and safety. Systematic Review Registration: http://www.crd.york.ac.uk/prospero, identifier CRD42020194260.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Carcinoma, Transitional Cell , Lung Neoplasms , Urinary Bladder Neoplasms , Apoptosis , B7-H1 Antigen , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Transitional Cell/drug therapy , Humans , Immune Checkpoint Inhibitors/adverse effects , Lung Neoplasms/drug therapy , Programmed Cell Death 1 Receptor , Urinary Bladder Neoplasms/drug therapy
4.
Reproduction ; 161(6): 623-632, 2021 05 05.
Article in English | MEDLINE | ID: mdl-33784242

ABSTRACT

Preeclampsia is a gestational hypertensive disease; however, preeclampsia remains poorly understood. Bioinformatics analysis was applied to find novel genes involved in the pathogenesis of preeclampsia and identified CLDN1 as one of the most differentially expressed genes when comparing patients with preeclampsia and healthy controls. The results of the qRT-PCR, Western blotting and immunohistochemistry experiments demonstrated that CLDN1 was significantly downregulated in the chorionic villi in samples from patients with preeclampsia. Furthermore, knockdown of CLDN1 in HTR-8/SVneo cells resulted in the inhibition of proliferation and induction of apoptosis, and overexpression of CLDN1 reversed these effects. In addition, RNA-seq assays demonstrated that the gene BIRC3 is potentially downstream of CLDN1 and is involved in the regulation of apoptosis. Knockdown of CLDN1 confirmed that the expression level of BIRC3 was obviously decreased and was associated with a significant increase in cleaved PARP. Interestingly, the apoptotic effect in CLDN1 knockdown cells was rescued after BIRC3 overexpression. Overall, these results indicate that a decrease in CLDN1 inhibits BIRC3 expression and increases cleaved PARP levels thus participating in the pathogenesis of preeclampsia.


Subject(s)
Apoptosis , Cell Proliferation , Claudin-1/metabolism , Gene Expression Regulation, Developmental , Pre-Eclampsia/pathology , Trophoblasts/pathology , Adult , Baculoviral IAP Repeat-Containing 3 Protein/genetics , Baculoviral IAP Repeat-Containing 3 Protein/metabolism , Case-Control Studies , Cell Movement , Claudin-1/genetics , Female , Humans , Poly (ADP-Ribose) Polymerase-1/genetics , Poly (ADP-Ribose) Polymerase-1/metabolism , Pre-Eclampsia/genetics , Pre-Eclampsia/metabolism , Pregnancy , Trophoblasts/metabolism
5.
Strahlenther Onkol ; 196(3): 270-279, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31748837

ABSTRACT

PURPOSE: The efficacy and tolerability of adding chemotherapy to radiotherapy in the era of intensity-modulated radiation therapy (IMRT) remain controversial among older patients with nasopharyngeal carcinoma (NPC). The present study compared IMRT alone with IMRT in combination with chemotherapy in elderly NPC patients. METHODS: Between January 2011 and December 2014, 102 patients aged >65 years with NPC who received IMRT alone (IMRT group) or IMRT in combination with chemotherapy (IMRT/CT group) were enrolled. Patients from both treatment arms were pair-matched (1:1 ratio) based on six clinical factors. Differences in overall survival (OS), disease-free survival (DFS), locoregional relapse-free survival (LRRFS), and distant metastasis-free survival (DMFS) were assessed using the Kaplan-Meier method and Cox proportional hazards models, whereas the toxicity profile was assessed using Common Terminology Criteria for Adverse Events (CTCAE) version 4. RESULTS: No significant differences were noted in OS (72.1% vs. 72.5%, p = 0.799), DFS (65.9% vs. 70.1%, p = 0.733), LRRFS (76.4% vs. 71.6%, p = 0.184), and DMFS (90.8% vs. 98.0%, p = 0.610) between the IMRT and IMRT/CT groups. Multivariate analyses showed that chemotherapy was not an independent factor for OS, DFS, LRRFS, and DMFS. However, the incidences of grade 3 vomiting/nausea (p = 0.000), leukopenia/neutropenia (p = 0.000), thrombocytopenia (p = 0.041), and anemia (p = 0.040) were significantly higher in the IMRT/CT group compared with the IMRT group. No grade 4 toxicities were observed. CONCLUSION: IMRT alone was similar to IMRT/CT in treating elderly NPC patients (age >65 years), with comparable survival outcomes and less grade 3 toxicities.


Subject(s)
Chemoradiotherapy , Nasopharyngeal Carcinoma/therapy , Nasopharyngeal Neoplasms/therapy , Radiotherapy, Intensity-Modulated , Aged , Chemoradiotherapy/methods , Disease-Free Survival , Female , Humans , Kaplan-Meier Estimate , Male , Nasopharyngeal Carcinoma/pathology , Nasopharyngeal Neoplasms/pathology , Neoplasm Recurrence, Local/pathology , Neoplasm Recurrence, Local/prevention & control , Proportional Hazards Models , Radiotherapy, Intensity-Modulated/methods , Retrospective Studies
6.
Cancer Chemother Pharmacol ; 84(1): 155-161, 2019 07.
Article in English | MEDLINE | ID: mdl-31087135

ABSTRACT

BACKGROUND: The objective of this study was to evaluate the efficacy and safety of gemcitabine plus cisplatin concurrent chemoradiotherapy (CCRT) in patients with nasopharyngeal carcinoma. METHOD: Patients with NPC were randomly assigned to the gemcitabine plus cisplatin (GP) group or fluorouracil plus cisplatin (PF) group. Primary end-point was disease-free survival (DFS); secondary endpoints: overall survival, distant metastasis-free survival (DMFS), locoregional relapse-free survival, and treatment-related adverse events. RESULTS: Seventy-six patients were prospectively enrolled and the median follow-up time was 41 months (9-61 months). Three-year DFS were similar between the GP and PF groups (73.7% vs. 60.5%, HR 0.66, 95% CI 0.30-1.44; P = 0.30). Distant metastasis was the most common failure form in PF compared with GP (P = 0.034). Three-year DMFS was significantly better in the GP group than PF group (89.5% vs. 71.1%, P = 0.045). Grade 3-4 gastrointestinal toxicities (vomiting and diarrhea) were significantly more common in the PF group; grade 3-4 neutropenia and thrombocytopenia were more common in the GP group. CONCLUSION: Gemcitabine plus cisplatin could be used as an alternative regimen in CCRT for nasopharyngeal carcinoma.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Nasopharyngeal Carcinoma/drug therapy , Nasopharyngeal Neoplasms/drug therapy , Adult , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Chemoradiotherapy , Cisplatin/administration & dosage , Deoxycytidine/administration & dosage , Deoxycytidine/analogs & derivatives , Disease-Free Survival , Female , Fluorouracil/administration & dosage , Follow-Up Studies , Humans , Male , Middle Aged , Prospective Studies , Young Adult , Gemcitabine
7.
Mol Ther Nucleic Acids ; 12: 600-609, 2018 Sep 07.
Article in English | MEDLINE | ID: mdl-30195796

ABSTRACT

Tristetraprolin (TTP) regulates the stability of multiple targets that have important biological roles. However, the role of TTP in trophoblasts at the maternal-fetal interface remains poorly understood. We demonstrated that TTP was upregulated in placental trophoblasts from patients with recurrent miscarriages (RMs). Immunofluorescence and immunoblotting analyses indicated that TTP was redistributed from the nucleus to the cytoplasm in trophoblasts from patients with RMs. Trophoblast invasion and proliferation was repressed by TTP overexpression and was enhanced by TTP knockdown. Interestingly, TTP knockdown promoted trophoblast invasion in an ex vivo explant culture model. Furthermore, TTP overexpression in trophoblasts significantly inhibited the expression of the long non-coding RNA (lncRNA) HOTAIR. TTP was found to regulate HOTAIR expression by a posttranscriptional mechanism. To RNA immunoprecipitation (RIP) and RNA-protein, pull-down identified TTP as a specific binding partner that decreased the half-life of HOTAIR and lowered steady-state HOTAIR expression levels, indicating a novel posttranscriptional regulatory mechanism. Our findings identify a novel function for TTP in lncRNA regulation and provide important insights into the regulation of lncRNA expression. This study reveals a new pathway governing the regulation of TTP/HOTAIR in trophoblast cell invasion during early pregnancy.

8.
Int J Mol Sci ; 19(8)2018 Aug 02.
Article in English | MEDLINE | ID: mdl-30072674

ABSTRACT

Spinal cord injury (SCI) is a severe traumatic lesion of central nervous system (CNS) with only a limited number of restorative therapeutic options. Diosgenin glucoside (DG), a major bioactive ingredient of Trillium tschonoskii Max., possesses neuroprotective effects through its antioxidant and anti-apoptotic functions. In this study, we investigated the therapeutic benefit and underlying mechanisms of DG treatment in SCI. We found that in Sprague-Dawley rats with traumatic SCI, the expressions of autophagy marker Light Chain 3 (LC3) and Beclin1 were decreased with concomitant accumulation of autophagy substrate protein p62 and ubiquitinated proteins, indicating an impaired autophagic activity. DG treatment, however, significantly attenuated p62 expression and upregulated the Rheb/mTOR signaling pathway (evidenced as Ras homolog enriched in brain) due to the downregulation of miR-155-3p. We also observed significantly less tissue injury and edema in the DG-treated group, leading to appreciable functional recovery compared to that of the control group. Overall, the observed neuroprotection afforded by DG treatment warrants further investigation on its therapeutic potential in SCI.


Subject(s)
Apoptosis/drug effects , Autophagy/drug effects , Diosgenin/analogs & derivatives , Glucosides/therapeutic use , Neuroprotective Agents/therapeutic use , Spinal Cord Injuries/prevention & control , Animals , Diosgenin/chemistry , Diosgenin/therapeutic use , Glucosides/chemistry , MicroRNAs/genetics , Neuroprotective Agents/chemistry , Rats, Sprague-Dawley , Signal Transduction/drug effects , Spinal Cord/drug effects , Spinal Cord/metabolism , Spinal Cord/pathology , Spinal Cord Injuries/genetics , Spinal Cord Injuries/metabolism , Spinal Cord Injuries/pathology , Trillium/chemistry
9.
Oral Oncol ; 74: 34-39, 2017 11.
Article in English | MEDLINE | ID: mdl-29103749

ABSTRACT

OBJECTIVES: The efficacy of various chemotherapy regimens in nasopharyngeal carcinoma (NPC) remains under debate. We compared the efficacy and toxicity of a taxane-based regimen and regimen including fluorouracil in NPC. MATERIALS AND METHODS: Eight-hundred and six patients with stage II-IVB NPC from four institutions in China were pair-matched (1:1 ratio) to the cisplatin plus fluorouracil (PF) group or cisplatin plus taxanes (TP) group using eight clinical factors. Overall survival (OS), disease-free survival (DFS), locoregional relapse-free survival (LRRFS) and distant metastasis-free survival (DMFS) were assessed using the Kaplan-Meier method and Cox regression model. Toxicities were assessed in all patients. RESULTS: Three-year DFS was significantly better in the TP group than PF group (82.5% vs. 72.7%, P=0.002), with no significant difference in OS, LRRFS or DMFS. TP led to significantly better DFS compared to PF in the subgroups advanced stage NPC, patients aged ≤45-years-old and female patients. In multivariate analysis, chemotherapy regimen was an independent prognostic factor for DFS [hazard ratio, 0.591, 95% CI 0.444-0.786, P=0.000]. Grade 3-4 leukopenia, neutropenia and anemia were significantly more common in the TP group; grade 3-4 mucositis, vomiting, vasculitis and diarrhea were more common in the PF group. CONCLUSION: Taxane-based regimens have a higher efficacy in NPC than regimens including fluorouracil, especially in patients with advanced stage, patients aged≤45-years-old and female patients.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma/drug therapy , Fluorouracil/administration & dosage , Nasopharyngeal Neoplasms/drug therapy , Taxoids/administration & dosage , Adult , Aged , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Carcinoma/pathology , Female , Humans , Male , Middle Aged , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms/pathology , Retrospective Studies , Survival Analysis , Treatment Outcome
10.
Zhongguo Zhong Yao Za Zhi ; 42(2): 357-362, 2017 Jan.
Article in Chinese | MEDLINE | ID: mdl-28948744

ABSTRACT

To investigate the metabolism of quercitrin in rat intestinal flora and possible biological pathways, laying the foundation for the metabolic mechanism of traditional Chinese medicine glycosides ingredients. UPLC-Q-TOF-MS/MS method was established to detect the quercitrin and its metabolites with 0.1% formic acid solution(A)-0.1% formic acid acetonitrile(B) as the mobile phase for gradient elution at a flow rate of 0.3 mL•min⁻¹. Electrospray negative ion mode was applied to analyze the metabolites of quercitrin in rat intestinal flora. Metabolite ToolsTM, mass defect filter(MDF) and other technologies were used to screen, analyze the metabolites and infer the chemical formula of the metabolites. The results showed that quercitrin would have degalactoside, deoxygenation and acetylation reactions, and the aglycone quercetin resulted from degalactoside would have further reactions such as hydroxylation, deoxygenation, reduction, and ring opening to achieve deoxygenation metabolite kaempferol, C2-C3 double bonds hydrogenation and reduction product taxifolin, and degalactoside product quercetin. The research results showed that quercitrin can be metabolized by rat intestinal flora, which could increase their hydrophobicity and chemical diversity.


Subject(s)
Gastrointestinal Microbiome , Quercetin/analogs & derivatives , Animals , Chromatography, High Pressure Liquid , Quercetin/metabolism , Rats , Tandem Mass Spectrometry
11.
Molecules ; 22(3)2017 Feb 25.
Article in English | MEDLINE | ID: mdl-28245598

ABSTRACT

The principal active constituents of Polygonum capitatum are phenolic acids and flavonoids, such as gallic acid, quercitrin, and quercetin. The aim of this study was to develop and validate a method to determine the three constituents and the corresponding conjugated metabolites of Polygonum capitatum in vivo and to conduct pharmacokinetic studies on the herb, a well-known Miao medicinal plant in China. Gallic acid, quercitrin, and quercetin were analysed by ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS). Protein precipitation in plasma samples was performed using methanol. For the determination of total forms of analytes, an additional process of hydrolysis was conducted using ß-glucuronidase and sulphatase. The analytes were separated on a BEH C18 column (50 mm × 2.1 mm; i.d., 1.7 µm) and quantified by multiple reaction monitoring (MRM) mode. The linear regression showed high linearity over a 729-fold dynamic range for the three analytes. The relative standard deviations of intra- and inter-day measurements were less than 9.5%, and the method was accurate to within -11.1% to 12.5%. The extraction recoveries for gallic acid, quercitrin, and quercetin were 94.3%-98.8%, 88.9%-98.8%, and 95.7%-98.5%, respectively. All samples were stable under short- and long-term storage conditions. The validated method was successfully applied to a comparative pharmacokinetic study of gallic acid, quercitrin, and quercetin in their free and total forms in rat plasma. The study revealed significantly higher exposure of the constituents in total forms for gallic acid and quercetin, while quercitrin was detected mainly in its corresponding free form in vivo. The established method was rapid and sensitive for the simultaneous quantification of free and total forms of multiple constituents of Polygonum capitatum extract in plasma.


Subject(s)
Gallic Acid/blood , Polygonum/chemistry , Quercetin/analogs & derivatives , Quercetin/blood , Animals , Chromatography, High Pressure Liquid , Gallic Acid/chemistry , Gallic Acid/pharmacokinetics , Male , Plant Extracts/chemistry , Plants, Medicinal/chemistry , Plasma/chemistry , Quercetin/chemistry , Quercetin/pharmacokinetics , Rats , Rats, Sprague-Dawley , Tandem Mass Spectrometry
12.
Int J Mol Sci ; 17(8)2016 Aug 05.
Article in English | MEDLINE | ID: mdl-27527166

ABSTRACT

Intrauterine infection is one of the most frequent causes of miscarriage. CpG oligodeoxynucleotide (CpG ODN) can mimic intrauterine infection. CpG ODN-induced embryo-resorption was observed consistently in the NK-cell deficient non-obese diabetic (NOD) mice but not in the wild-type (WT) mice. To elucidate the molecular mechanisms of differential pregnancy outcomes, differentially expressed genes (DEGs) in the placenta and decidua basalis was revealed by RNA-Seq with CpG ODN or control ODN treatment. Common DEGs in the WT and NOD mice were enriched in antimicrobial/antibacterial humoral responses that may be activated as a primary response to bacterial infection. The susceptibility to CpG ODN-induced embryo-resorption in the NOD mice might mainly be attributed to M1 macrophage polarization and the immunodeficient status, such as the down-regulation in antigen processing and presentation, allograft rejection, and natural killer cell mediated cytotoxicity. In contrast, the WT mice with normal immune systems could activate multiple immune responses and be resistant to CpG ODN-induced embryo-resorption, such as M2 macrophage differentiation and activation regulated by complement component C1q and peroxisome proliferation-activated receptor (PPAR) signaling pathways. Collectively, this study suggests that the immunodeficient status of NOD mice and the macrophage polarization regulated by C1q and PPAR signaling might be the basis for differential pregnancy outcomes between the NOD and WT mice.


Subject(s)
Decidua/metabolism , Oligodeoxyribonucleotides/pharmacology , Transcriptome/genetics , Animals , Cell Polarity/drug effects , Complement C1q/metabolism , Decidua/drug effects , Embryo Loss/genetics , Embryo Loss/pathology , Female , Gene Expression Profiling , Gene Expression Regulation/drug effects , Gene Ontology , Immune System/drug effects , Immune System/metabolism , Macrophages/cytology , Macrophages/drug effects , Mice, Inbred NOD , Pregnancy , Pregnancy Outcome , Real-Time Polymerase Chain Reaction , Reproducibility of Results , Sequence Analysis, RNA , Signal Transduction/drug effects
13.
J Environ Biol ; 37(1): 163-8, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26930875

ABSTRACT

In the present study, calcium carbonate (CaCO3) was applied to Cd-contaminated soil at rates of 0, 0.5 and 1.0 g kg(-1). The effect of CaCO3 on soil pH, organic matter, available Cd, exchangeable Cd and level of major nutrients in a tobacco field and on accumulation of various elements in tobacco plants was determined. The results showed that CaCO3 application significantly increased the pH level, available P and exchangeable Ca but decreased organic matter, available Cd, exchangeable Cd, available heavy metals (Fe, Mn, Zn and Cu) and available K in soil. Additionally, CaCO3 application substantially reduced Cd accumulation in tobacco roots, stems, upper leaves, middle leaves and lower leaves, with maximum decrease of 22.3%, 32.1%, 24.5%, 22.0% and 18.2%, respectively. There were large increase in total Ca and slight increases in total N and K but decrease to varying degrees in total Fe, Cu and Zn due to CaCO3 application. CaCO3 had little effect on total P and Mn levels in tobacco leaves.


Subject(s)
Biodegradation, Environmental , Cadmium/metabolism , Calcium Carbonate/pharmacology , Nicotiana/metabolism , Soil Pollutants/metabolism , Soil/chemistry , Calcium/chemistry , Calcium/metabolism , Magnesium/chemistry , Magnesium/metabolism , Phosphorus/chemistry , Phosphorus/metabolism , Potassium/chemistry , Potassium/metabolism , Nicotiana/drug effects
14.
J Sci Food Agric ; 94(8): 1614-21, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24338705

ABSTRACT

BACKGROUND: T1 lipase has received considerable attention due to its thermostability. Fatty acid specificity of T1 lipase (crude and purified) was investigated, and its potential in the synthesis of acylglycerols was also evaluated. RESULTS: Fatty acid specificity of T1 lipase (crude and purified) was investigated in the esterification of fatty acids (C6:0 to C18:3), suggesting that crude and purified T1 lipase had the lowest preference for C18:0 [specificity constant (1/α) = 0.08] followed by C18:1 (1/α = 0.12) and showed the highest preference for C8:0 (1/α = 1). A structural model was constructed to briefly explore interactions between the lipase and its substrate. Furthermore, crude T1 lipase-catalysed synthesis of diacylglycerols (DAGs) and monoacylglycerols (MAGs) by esterification of glycerol with C18:1 was studied for evaluating its potential in acylglycerols synthesis. The optimal conditions were glycerol/oleic acid molar ratio 5:1, the lipase concentration 9.7 U g(-1) of substrates, water content 50 g kg(-1) of substrates and temperature 50 °C, which yielded 42.25% DAGs, 26.34% MAGs and 9.18% triacylglycerols at 2 h. CONCLUSION: DAGs and MAGs were synthesised in good yields although C18:1 (a much poorer substrate) was used. Our work demonstrates that T1 lipase, which was discovered to show 1,3-regio-selectivity, is a promising biocatalyst for lipids modification.


Subject(s)
Fatty Acids/metabolism , Glycerides/biosynthesis , Lipase/metabolism , Binding Sites , Caprylates/metabolism , Diglycerides/biosynthesis , Enzyme Stability , Esterification , Geobacillus/enzymology , Hot Temperature , Kinetics , Models, Molecular , Monoglycerides/biosynthesis , Substrate Specificity
15.
J Agric Food Chem ; 60(9): 2377-84, 2012 Mar 07.
Article in English | MEDLINE | ID: mdl-22360498

ABSTRACT

Tripalmitin-enriched triacylglycerols were concentrated from palm stearin by acetone fractionation and as the substrate reacted with a mixture of equimolar quantities of fatty acids (C8:0-C18:3). The incorporation degree and acyl migration level of the fatty acids and acylglycerols composition were investigated, providing helpful information for the production of human milk fat substitutes. Higher incorporation degrees of the fatty acids were obtained with lipase PS IM, Lipozyme TL IM, and Lipozyme RM IM followed by porcine pancreatic lipase and Novozym 435-catalyzed acidolysis. During reactions catalyzed by Lipozyme TL IM, Lipozyme RM IM, and lipase PS IM, incorporation degrees of C12:0, C14:0, C18:1, and C18:2 were higher than those of other fatty acids at operated variables (molar ratio, temperature, and time), and the triacylglycerols content reached the highest (82.09%) via Lipozyme RM IM-catalyzed acidolysis. On the basis of significantly different levels of acyl migration to the sn-2 position, lipases were in the order of lipase PS IM < Lipozyme TL IM < Lipozyme RM IM.


Subject(s)
Fatty Acids/metabolism , Lipase/metabolism , Triglycerides/metabolism , Fats , Fatty Acids/chemistry , Glycerides/analysis , Humans , Milk Substitutes/chemistry , Milk, Human/chemistry , Triglycerides/chemistry
16.
J Agric Food Chem ; 59(10): 5714-9, 2011 May 25.
Article in English | MEDLINE | ID: mdl-21510711

ABSTRACT

1,3-Dioleoyl-2-palmitoylglycerol, an important triacylglycerol in infant formulas, was effectively enriched by a two-step process: (a) dry fractionation of leaf lard and (b) enzymatic acidolysis of the fractionated leaf lard. In step a, the 1,3-dioleoyl-2-palmitoylglycerol content was increased from 16.77 to 30.73% after programmed temperature treatment of the leaf lard at 60 °C for 20 min followed by 34 °C for 10 h. In step b, 43.72% of the 1,3-dioleoyl-2-palmitoylglycerol content was obtained at the optimal conditions of enzymatic acidolysis: a substrate molar ratio of 1:4 (the fractionated leaf lard/camellia oil fatty acids), 6% (w/w) of enzyme loading, and 6 h of reaction time at 45 °C. On the basis of gas chromatography determination and "deducting score" principle, a model was properly established for characterizing the quality of triacylglycerols enriched with 1,3-dioleoyl-2-palmitoylglycerol. This approach would be a valuable contribution in structured lipids industries because only gas chromatography determination was involved.


Subject(s)
Triglycerides/biosynthesis , Animals , Camellia/chemistry , Chemical Fractionation , Dietary Fats/metabolism , Fatty Acids/metabolism , Humans , Infant , Infant Formula/chemistry , Lipase/metabolism , Swine , Triglycerides/chemistry
17.
J Agric Food Chem ; 58(1): 642-9, 2010 Jan 13.
Article in English | MEDLINE | ID: mdl-20000702

ABSTRACT

Fatty acid composition and distribution of human milk fat (HMF), from mothers over different lactating periods in Guangzhou, China, were analyzed. The universal characteristics were consistent with previously reported results although the fatty acid content was within a different range and dependent on the local population (low saturated fatty acid and high oleic acid for Guangdong mothers' milk fat). Based on the composition of the total and sn-2 fatty acids of mature milk fat, an efficient evaluation model was innovatively established by adopting the "deducting score" principle. The model showed good agreement between the scores and the degree of similarity by assessing 15 samples from different sources including four samples of HMF, eight samples of human milk fat substitutes (HMFSs) and infant formulas, and three samples of fats and oils. This study would allow for the devolvement of individual human milk fat substitutes with different and specific fatty acid compositions for local infants.


Subject(s)
Fat Substitutes/analysis , Milk, Human/chemistry , China , Fatty Acids/analysis , Female , Humans , Models, Statistical
SELECTION OF CITATIONS
SEARCH DETAIL
...