To find out specific antigens to M. tuberculosis, the researchers searched for sensitivity, specificity and cross reactions of 6 glycolipid antigens which were extracted and purified from M. tuberculosis with 168 sera by ELISA. The 168 samples were divided into 3 groups: Group I: 62 lung tuberculosis patients with AFB-smear positive; group II: 53 healthy persons and group III: 53 infectious other than tuberculosis patients. There were 6 glycolipid antigens were used in this study, they were Phosphoinositomannoside (P2), 6, 6’-dimycolyltrehalose (cord factor) (DT), Trehalose monomycolate (MT), Phenol glycolipid (PA), Glycolipid (MI) and Glycopeptide (Co). The sensitivity and specificity of DT. MT and PA antigens were 74.2; 66.1; 69, 4% and 83.0; 69.8%; 73.6%, respectively; cross reaction ranging from 22.6% to 39.6%. The sensitivity and specificity of other antigens were lower and its cross reactions were higher than DT, MT and PA antigens. ELISA with specific glycolipid antigens can be used to diagnose extra-lung tuberculosis and lung tuberculosis with AFB(-).
Tuberculosis ; Antigens ; Glycolipids

Aims: Rhamnolipids are seeking utmost attention as a new class of biosurfactants having promising potential in diverse fields as they offer a wide range of advantages over chemically synthesised surfactants. However, the high extraction costs make large scale production face difficulty. In present study, hydrocarbon degrading bacteria Pseudomonas aeruginosa UKMP14T was exploited for its biosurfactant producing ability including a comparative study between different extraction procedures for its recovery. In addition to this, the recovered biosurfactant was explored for its potential application as an antimicrobial agent. Methodology and results: The production of rhamnolipid biosurfactant was confirmed through various detection methods which are drop-collapse test, oil spreading assay, emulsification index, cetyltrimethylammonium bromide (CTAB) assay and hemolytic assay. The test strain P. aeruginosa UKMP14T showed positive results for all the detection assays. Following this, shake flask cultivation was carried out for several time intervals (1, 3, 5, 7 and 9 days) to discover the optimum time for rhamnolipid biosurfactant production. The results were evaluated by quantifying the rhamnolipid yield using Anthrone method and maximum yield was obtained on day 7. Then, three commonly employed rhamnolipid biosurfactant extraction methods (acid precipitation, solvent extraction and zinc sulphate precipitation) were incorporated for the extraction of rhamnolipid biosurfactant. Among these methods, organic solvent extraction (using methanol, chloroform and acetone in 1:1:1 ratio) gave the highest yield (7.37 ± 0.81 g/L) of biosurfactant, followed by zinc sulphate precipitation (5.83 ± 0.02 g/L), whereas acid precipitation gave the lowest yield (2.8 ± 0.12 g/L) and required longer time (30 days). Finally, the antimicrobial activity of several concentrations of rhamnolipid was tested using modified microdilution method and highest antibacterial activity (in the form of percent reduction in growth) of 95.05% and 91.89% was recorded for Escherichia coli ATCC 10536 and Staphylococcus aureus ATCC 11632, respectively, at 100 µg/mL concentration of rhamnolipid biosurfactant. Conclusion, significance and impact of study The ability of P. aeruginosa UKMP14T in producing rhamnolipid biosurfactant was confirmed. Despite the higher yield obtained by organic solvent extraction method, the recovery technique (involving the separation of solvent system) caused some loss in product. In addition, the transfer and storage of rhamnolipid was challenging using solvent extraction in comparison to acid precipitation and zinc sulphate precipitation. On the other hand, recovery using acid precipitation suffered from lowest yield of rhamnolipid. Therefore, zinc sulphate precipitation is prioritised over the other two methods. Furthermore, the antimicrobial potential of rhamnolipid biosurfactant was tested successfully for as low as 10 µg/mL concentration against E. coli ATCC 10536 and S. aureus ATCC 11632. Therefore, the recovery cost of a high value product like rhamnolipid can be reduced by incorporating the results of this study in the downstream processing and promote rhamnolipid biosurfactant as a potential antimicrobial agent.
Glycolipids--biosynthesis ; Surface-Active Agents ; Pseudomonas aeruginosa

The bitter taste is one of the important properties among five flavors of Chinese materia medica (CMM), characterized by downbearing and discharging, drying dampness, and consolidating Yin. In common CMM, bitter-taste CMM accounts for a large proportion, indicating the importance of it. Through the efficacy of clearing away heat and dampness, reducing fire and removing toxin, bitter-taste CMM has achieved good results in treating diabetes in clinical application, proving their definite therapeutic effect on regulating glucose and lipid metabolism (main features of diabetes). At present, there are many reports about the chemical constituents and pharmacological effects of CMM on diabetes, but there are few reviews on the chemistry and biology of bitter-taste CMM. This study summarized the properties and compatibility characteristics of bitter-taste CMM for treating diabetes, and mainly analyzed the chemistry and biology basis of bitter-taste CMM with function of regulating glycolipid metabolism, laying foundation for further researches on properties theory of CMM.
Glycolipids ; metabolism ; Materia Medica ; chemistry ; Medicine, Chinese Traditional ; Research ; Taste

The fatty acid desaturase 2 (FADS2) gene encodes delta-6 desaturase (D6D) and is a member of the fatty acid desaturase gene family.D6D is the key enzyme catalyzing the transformation of linoleic acid and α-linolenic acid to long-chain polyunsaturated fatty acid (LC-PUFA).LC-PUFA play a crucial role in regulating the glycolipid metabolism of living organisms.In recent years,the activity of D6D and the single nucleotide polymorphism (SNP) of FADS2 gene have become a hot topic in the research on glycolipid metabolism.This article reviews the role of FADS2 gene in glycolipid metabolism.
Fatty Acid Desaturases/metabolism* ; Glycolipids/metabolism* ; Humans ; Polymorphism, Single Nucleotide

Serum specimens from leprosy patients, their contacts and controls were examined for the presence of phenolic glycolipid I (PGL-I), a Mycobacterium leprae specific antigen, and antibodies to the antigen using enzyme-linked immunosorbent assays. Of 12 lepromatous patients with less than 2 years of therapy, 11(91.7%) were seropositive to PGL-l, thus indicating that new lepromatous cases can be identified by detecting anti-PGL-l antibodies. In contrast 88(56.4%) of 156 lepromatous patiens treated more than 2 years were positve. Moreover, only 69(40.8%) were seropositve among 169 lepromatous patients in the leprosy resettlement villages. The mean antibody level also declined significantly in proportion to the duration of chemotherapy. This may suggest the possibility of monitoring chemotherapy by detecting anti-PGL-l antibodies. The prevalence of anti-PGL-l antibodies among 200 controls from a high endemic area for leprosy was 5.5% and was significantly higher than that(1.5%) among 200 controls from a low endemic area. Of 103 household contacts in the resettlement villages, 10(9.7%) were seropositive, reflecting the frequent chance of exposure to M. leprae. However, PGL-l was not detected many in any of the sera from controls, contacts, and inactive lepromatous patients having the anti-PGL-l antibodies; on the other hand, 6(50%) of 12 lepromatous patients treated less than 2 years had detectable PGL-l in their sera. The results thus indicate that PGL-l detection may be more suitable for monitoring the effectiveness of chemotherapy and that it may be necessary to examine for the presence of PGL-l in sera from contacts and normal populations for confirming M. leprae infection.
Antibodies, Bacterial/*analysis ; Glycolipids/*blood ; Human ; Leprosy/*blood/diagnosis ; Serologic Tests ; Support, Non-U.S. Gov't

The CD1 system is a novel antigen-presenting system for T cell recognition of lipid and glycolipids in antimicrobial immunity. Lepromatous leprosy is characterized by lack of cell-mediated immunity against M.leprae. The lack of cell-mediated immunity in lepromatous leprosy has been suggested to be correlated with weak CD1 expression on antigen presenting cells. In order to define how CD1 is down-regulated on M. leprae-infected antigen-presenting cells, we examined effects of interferon-gamma(IFN-gamma) on interleukin-10 (IL-10) secretion and CD1 expression of M.leprae-infected macrophages from granuloma of lepromatous leprosy. Our results showed that a significant trend of increased CD1 expression in response to decresed IL-10 secretion from M.leprae-infected macrophages by IFN-gamma. These results suggest that the local cytokine milieu, especially the balance between IFN-gamma and IL-10, is an important determinant in the regulation of CD1 in lepromatous lesions.
Antigen-Presenting Cells ; Glycolipids ; Granuloma ; Immunity, Cellular ; Interferon-gamma* ; Interleukin-10* ; Leprosy ; Leprosy, Lepromatous* ; Macrophages*

Adenosine 5'-monophosphate-activated protein activated protein kinase (AMPK), a heterotrimeric complex, is an important kinase to regulate glycolipid metabolism and energy balance involved in a variety physiological processes in human body. Many research indicated that the function and activity of AMPK were closely related to inflammation, diabetes and cancers. Recent reports show that inhibition of metformin (a first-line drug) on hepatic glucose in patients with hyperglycemia is associated with AMPK pathway, suggesting that targeting AMPK may be one of the effective strategies for the prevention and treatment of a variety of chronic diseases. Here, we review research progress on the structure, activation and regulation of AMPK in glycolipid metabolism to provide an insight into the basic and clinical research of diabetes therapy.
AMP-Activated Protein Kinases ; Adenosine ; Adenosine Monophosphate ; Energy Metabolism ; Enzyme Activation ; Glycolipids ; Humans

Visfatin, also named nicotinamide phosphoribosyl transferase (NAMPT), is a cytokine secreted from adipose tissue. Visfatin can regulate immune action and is involved in the NAD+ salvage pathway. In addition, recent researches have shown that visfatin helps the regulation of glucose and lipid metabolism, especially in exercise-induced weight reduction for obesity. The aim of this review is to provide an overview of the contribution of visfatin gene polymorphisms to glucose and lipid metabolism and exercise-induced weight reduction in obesity.
Exercise ; physiology ; Glycolipids ; metabolism ; Humans ; Nicotinamide Phosphoribosyltransferase ; genetics ; physiology ; Obesity ; genetics ; metabolism ; Polymorphism, Genetic ; Weight Loss ; genetics

Mannosylerythritol lipids (MELs), mainly produced by Ustilago and Pseudozyma, are surface active compounds that belong to the glycolipid class of biosurfactants. MELs have potential application in food, pharmaceutical and cosmetics industries due to their excellent surface activities and other peculiar bioactivities. In recent years, the research field of MELs has regained much attention abroad. However, MELs are rarely studied in China. In this review, the producing microorganisms and production conditions, diverse structures, biochemical properties, structure-function relationship and biosynthetic pathways of MELs are described. Some research problems and prospects are summarized and discussed as well.
Glycolipids ; biosynthesis ; genetics ; Metabolic Networks and Pathways ; genetics ; Surface-Active Agents ; metabolism ; Ustilaginales ; classification ; genetics ; metabolism ; Ustilago ; genetics ; metabolism

PURPOSE: Cytolethal distending toxin (CDT) is a family of heat-labile cytotoxins produced by several gram-negative mucosa-associated pathogens, including Aggregatibacter actinomycetemcomitans. CDT is well known to be capable of inducing growth arrest, morphological alterations, and eventually death in various cells. CDT belongs to a tripartite AB2 toxin (CdtB: the enzymatic A subunit ; CdtA and CdtC: the heterodimeric B subunit). Previous studies proposed that CdtA and CdtC together bind to a cell surface receptor and glycolipids act as a receptor for A. actinomycetemcomitans CDT (AaCDT). In this study, recombinant CdtA and CdtC proteins of AaCDT were co-expressed in a bacterial expression system and tested for their affinity for GM1 ganglioside. METHODS: The genes for CdtA and CdtC from A. actinomycetemcomitans Y4 were utilized to construct the expression vectors, pRSET-cdtA and pET28a-cdtC. Both CdtA and CdtC proteins were expressed in Escherichia coli BL21(DE3) and then purified using hexahistidine (His6) tag. The identity of purified protein was confirmed by anti-His6 antibody and monoclonal anti-CdtA antibody. Furthermore, the affinity of recombinant protein to GM1 ganglioside was checked through ELISA. RESULTS: Recombinant CdtA and CdtC proteins were expressed as soluble proteins and reacted to anti-His6 and monoclonal anti-CdtA antibodies. ELISA revealed that purified soluble CdtA-CdtC protein bound to GM1 ganglioside, while CdtA alone did not. CONCLUSIONS: Co-expression of CdtA and CdtC proteins enhanced the solubility of the proteins in E. coli, leading to convenient preparation of active CdtA-CdtC, a critical material for the study of AaCDT pathogenesis.
Antibodies ; Bacterial Toxins ; Cytotoxins ; Edetic Acid ; Enzyme-Linked Immunosorbent Assay ; Escherichia coli ; Glycolipids ; Histidine ; Humans ; Oligopeptides ; Proteins ; Solubility