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Hypocholesterolaemic effect of yoghurt containing Bifidobacterium pseudocatenulatum G4 or Bifidobacterium longum BB536

Al-Sheraji SH, Ismail A, Manap MY, Mustafa S, Yusof RM, Hassan FA

Food Chem, 2012 Nov 15;135(2):356-61.
PMID: 22868099 DOI: 10.1016/j.foodchem.2012.04.120

The effect of a yoghurt supplement containing Bifidobacterium pseudocatenulatum G4 or Bifidobacterium longum BB536 on plasma lipids, lipid peroxidation and the faecal excretion of bile acids was examined in rats fed a cholesterol-enriched diet. After 8 weeks, the rats in the positive control (PC) group who were fed the cholesterol-enriched diet showed significant increases in plasma total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and malondialdehyde (MDA). However, groups fed a cholesterol-enriched diet supplemented with yoghurt containing B. pseudocatenulatum G4 or B. longum BB536 had significantly lower plasma TC, LDL-C, very-low-density lipoprotein (VLDL) cholesterol, and MDA than had the PC group after 8 weeks of treatment. In addition, faecal excretion of bile acids was markedly increased in the rats fed the yoghurt containing B. pseudocatenulatum G4 or B. longum BB536 as compared to the PC and NC groups.

Matched MeSH terms: Cholesterol/metabolism
Growth properties and cholesterol removal ability of electroporated Lactobacillus acidophilus BT 1088

Lye HS, Khoo BY, Karim AA, Rusul G, Liong MT

J Microbiol Biotechnol, 2012 Jul;22(7):981-9.
PMID: 22580318

This study aimed to evaluate the effects of electroporation on the cell growth, cholesterol removal, and adherence abilities of L. acidophilus BT 1088 and their subsequent passages. The growth of electroporated parent cells increased (P<0.05) by 4.49-21.25% compared with that of the control. This may be attributed to the alteration of cellular membrane. However, growth of first, second, and third passages of treated cells was comparable with that of the control, which may be attributed to the resealing of transient pores on the cellular membrane. Electroporation also increased (P<0.05) assimilation of cholesterol by treated parent cells (>185.40%) and first passage (>21.72%) compared with that of the control. Meanwhile, incorporation of cholesterol into the cellular membrane was also increased (P<0.05) in the treated parent cells (>108.33%) and first passage (>26.67%), accompanied by increased ratio of cholesterol:phospholipids (C:P) in these passages. Such increased ratio was also supported by increased enrichment of cholesterol in the hydrophilic heads, hydrophobic tails, and the interface regions of the membrane phospholipids of both parent and first passage cells compared with that of the control. However, such traits were not inherited by the subsequent second and third passages. Parent cells also showed decreased intestinal adherence ability (P<0.05; decreased by 1.45%) compared with that of the control, without inheritance by subsequent passages of treated cells. Our data suggest that electoporation could be a potential physical treatment to enhance the cholesterol removal ability of lactobacilli that was inherited by the first passage of treated cells without affecting their intestinal adherence ability.

Matched MeSH terms: Cholesterol/metabolism*
Electroporation enhances the ability of lactobacilli to remove cholesterol

Lye HS, Karim AA, Rusul G, Liong MT

J Dairy Sci, 2011 Oct;94(10):4820-30.
PMID: 21943733 DOI: 10.3168/jds.2011-4426

The objective of the present study was to evaluate the effect of electroporation on the membrane properties of lactobacilli and their ability to remove cholesterol in vitro. The growth of lactobacilli cells treated at 7.5 kV/cm for 4 ms was increased by 0.89 to 1.96 log(10) cfu/mL upon fermentation at 37 °C for 20 h, the increase being attributed to the reversible and transient formation of pores and defragmentation of clumped cells. In addition, an increase of cholesterol assimilation as high as 127.2% was observed for most cells electroporated at a field strength of 7.5 kV/cm for 3.5 ms compared with a lower field strength of 2.5 kV/cm. Electroporation also increased the incorporation of cholesterol into the cellular membrane, as shown by an increased cholesterol:phospholipids ratio (50.0-59.6%) upon treatment at 7.5 kV/cm compared with treatment at 2.5 kV/cm. Saturation of cholesterol was observed in different regions of the membrane bilayer such as upper phospholipids, apolar tail, and polar heads, as indicated by fluorescence anisotropy using 3 fluorescent probes. Electroporation could be a useful technique to increase the ability of lactobacilli to remove cholesterol for possible use as cholesterol-lowering adjuncts in the future.

Matched MeSH terms: Cholesterol/metabolism
Ultrasound treatment enhances cholesterol removal ability of lactobacilli

Lye HS, Alias KA, Rusul G, Liong MT

Ultrason Sonochem, 2012 May;19(3):632-41.
PMID: 21907608 DOI: 10.1016/j.ultsonch.2011.08.004

This study aimed to evaluate the effect of ultrasound treatment on the cholesterol removing ability of lactobacilli. Viability of lactobacilli cells was significantly increased (P < 0.05) immediately after treatment, but higher intensity of 100 W and longer duration of 3 min was detrimental on cellular viability (P < 0.05). This was attributed to the disruption of membrane lipid bilayer, cell lysis and membrane lipid peroxidation upon ultrasound treatment at higher intensity and duration. Nevertheless, the effect of ultrasound on membrane properties was reversible, as the viability of ultrasound-treated lactobacilli was increased (P < 0.05) after fermentation at 37 °C for 20 h. The removal of cholesterol by ultrasound-treated lactobacilli via assimilation and incorporation of cholesterol into the cellular membrane also increased significantly (P < 0.05) upon treatment, as observed from the increased ratio of membrane C:P. Results from fluorescence anisotropies showed that most of the incorporated cholesterol was saturated in the regions of phospholipids tails, upper phospholipids, and polar heads of the membrane bilayer.

Matched MeSH terms: Cholesterol/metabolism*
In vitro assessment of pediococci- and lactobacilli-induced cholesterol-lowering effect using digitally enhanced high-performance thin-layer chromatography and confocal microscopy

Syakila RN, Lim SM, Agatonovic-Kustrin S, Lim FT, Ramasamy K

Anal Bioanal Chem, 2019 Feb;411(6):1181-1192.
PMID: 30680424 DOI: 10.1007/s00216-018-1544-2

The cholesterol-lowering properties of 12 lactic acid bacteria (LAB) in the absence or presence of 0.3% bile salts were assessed and compared quantitatively and qualitatively in vitro. A new, more sensitive and cost-effective high-performance thin-layer chromatography method combined with digital image evaluation of derivatised chromatographic plates was developed and validated to quantify cholesterol in LAB culture media. The performance of the method was compared with that of the o-phthalaldehyde method. For qualitative assessment, assimilated fluorescently tagged cholesterol was visualised by confocal microscopy. All LAB strains exhibited a cholesterol-lowering effect of various degrees (19-59% in the absence and 14-69% in the presence of bile salts). Lactobacillus plantarum LAB12 and Pentosaceus pentosaceus LAB6 were the two best strains of lactobacilli and pediococci. They lowered cholesterol levels by 59% and 54%, respectively, in the absence and by 69% and 58%, respectively, in the presence of bile salts. Confocal microscopy showed that cholesterol was localised at the outermost cell membranes of LAB12 and LAB6. The present findings warrant in-depth in vivo study. Graphical abstract (A) 3D plots based on scan at 525 nm of (B) derivatized HPTLC plate of separated cholesterol and (C) confocal microscopic image showing the localisation of NBD-cholesterol assimilated by LAB.

Matched MeSH terms: Cholesterol/metabolism*
Hylocereus polyrhizus peel's high-methoxyl pectin: A potential source of hypolipidemic agent

Zaid RM, Mishra P, Wahid ZA, Sakinah AMM

Int J Biol Macromol, 2019 Aug 01;134:361-367.
PMID: 31059740 DOI: 10.1016/j.ijbiomac.2019.03.143

In the present study, high-methoxyl pectin (HMP) was extracted from Hylocereus polyrhizus peel's using physico-chemical process. In addition, the hypolipidemic activity of HMP was investigated at different concentration and time corresponding to its adsorption ability. FTIR and contact angle analysis were used to determine the sorbent characterization. A high degree of esterification (63.8%) and the contact angle (95.5°) confirmed hydrophobic nature and resulting bad wetting of the HMP extract, respectively. The methoxyl content in the pectin acted as an affinity-precursor of the pectin towards cholesterol due to its increased hydrophobicity. The maximum equilibrium uptake capacity of cholesterol of 370.5mg/g (0.96mmol/g) was observed by HMP. The experimental data showed good fitting for Freundlich isotherm equation and followed pseudo-first-order kinetic model with a correlation coefficient (R2) of 0.89-0.97 due to physisorption mechanism. Intra-particle model confirmed that the cholesterol sorption rate by HMP was significantly influenced by external mass transfer (surface diffusion) and intra-particle diffusion (diffusion control). It was also revealed that the HMP extracted from Hylocereus polyrhizus peels possess a high affinity towards cholesterol, making it an ideal hypolipidemic agent.

Matched MeSH terms: Cholesterol/metabolism
Effects of feeding fermented fish on egg cholesterol content in hens

Loh TC, Law FL, Goh YM, Foo HL, Zulkifli I

Anim Sci J, 2009 Feb;80(1):27-33.
PMID: 20163464 DOI: 10.1111/j.1740-0929.2008.00591.x

This study was conducted to investigate the effects of feeding fermented fish (FF) to layers on laying performance, and polyunsaturated fatty acid and cholesterol levels in eggs and plasma. A total of 96, 13-week-old Babcock B380 pullets were used in this study. They were randomly assigned to four numerically equal groups with eight replicates per treatment, three birds per replicate. All the birds were housed in individual cages. The dietary treatments were: Control diet, without FF; FF3 diet containing 3% (w/w) FF, FF6 diet containing 6% (w/w) FF and FF9 diet containing 9% (w/w) FF. The study was carried out for 16 weeks inclusive of two weeks of adjustment. Weekly feed intake and egg production were recorded. Blood plasma cholesterol and fatty acid profiles were assayed at the end of the experiment. FF did not enhance (P > 0.05) egg mass but (P < 0.05) decreased egg weight slightly. However, egg yolk cholesterol and plasma cholesterol concentrations were reduced (P < 0.05) by FF. The n-6:n-3 fatty acids ratio in the egg yolk (Control = 7.9, FF9 = 6.2) and plasma (Control = 10.6, FF9 = 6.2) were decreased by feeding FF. Moreover, FF was able to increase (P < 0.05) the docosahexaenoic acid (DHA) concentrations in egg yolk and plasma. In conclusion, this study demonstrated that FF increased DHA and reduced egg yolk cholesterol in poultry eggs.

Matched MeSH terms: Cholesterol/metabolism
Fulltext Metabolite Profiling of the Microalgal Diatom Chaetoceros Calcitrans and Correlation with Antioxidant and Nitric Oxide Inhibitory Activities via ¹H NMR-Based Metabolomics

Azizan A, Ahamad Bustamam MS, Maulidiani M, Shaari K, Ismail IS, Nagao N, et al.

Mar Drugs, 2018 May 07;16(5).
PMID: 29735927 DOI: 10.3390/md16050154

Microalgae are promising candidate resources from marine ecology for health-improving effects. Metabolite profiling of the microalgal diatom, Chaetoceros calcitrans was conducted by using robust metabolomics tools, namely ¹H nuclear magnetic resonance (NMR) spectroscopy coupled with multivariate data analysis (MVDA). The unsupervised data analysis, using principal component analysis (PCA), resolved the five types of extracts made by solvents ranging from polar to non-polar into five different clusters. Collectively, with various extraction solvents, 11 amino acids, cholesterol, 6 fatty acids, 2 sugars, 1 osmolyte, 6 carotenoids and 2 chlorophyll pigments were identified. The fatty acids and both carotenoid pigments as well as chlorophyll, were observed in the extracts made from medium polar (acetone, chloroform) and non-polar (hexane) solvents. It is suggested that the compounds were the characteristic markers that influenced the separation between the clusters. Based on partial least square (PLS) analysis, fucoxanthin, astaxanthin, violaxanthin, zeaxanthin, canthaxanthin, and lutein displayed strong correlation to 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and nitric oxide (NO) inhibitory activity. This metabolomics study showed that solvent extractions are one of the main bottlenecks for the maximum recovery of bioactive microalgal compounds and could be a better source of natural antioxidants due to a high value of metabolites.

Matched MeSH terms: Cholesterol/metabolism
In Vitro Assessment of Bioactivities of Lactobacillus Strains as Potential Probiotics for Humans and Chickens

Shokryazdan P, Jahromi MF, Liang JB, Sieo CC, Kalavathy R, Idrus Z, et al.

J Food Sci, 2017 Nov;82(11):2734-2745.
PMID: 29023714 DOI: 10.1111/1750-3841.13921

Twelve previously isolated Lactobacillus strains were investigated for their in vitro bioactivities, including bile salt hydrolase (BSH), cholesterol-reducing and antioxidant activities, cytotoxic effects against cancer cells, enzyme activity, and biogenic amine production. Among them, only 4 strains showed relatively high BSH activity, whereas the rest exhibited low BSH activity. All 12 strains showed cholesterol-reducing and antioxidant activities, especially in their intact cells, which in most of the cases, the isolated strains were stronger in these activities than the tested commercial reference strains. None of the tested strains produced harmful enzymes (β-glucosidase and β-glucuronidase) or biogenic amines. Among the 12 strains, 3 strains were tested for their cytotoxic effects against 3 cancer cell lines, which exhibited strong cytotoxic effects, and they also showed selectivity in killing cancer cells when compared to normal cells. Hence, all 12 Lactobacillus strains could be considered good potential probiotic candidates because of their beneficial functional bioactivities.
PRACTICAL APPLICATION: The Lactobacillus strains tested in this study could be considered good potential probiotic candidates for food/feed industry because of their beneficial functional bioactivities such as good cholesterol-reducing ability, high antioxidant activity, and good and selective cytotoxic effect against cancer cells.

Matched MeSH terms: Cholesterol/metabolism
Fulltext Cholesterol-lowering effects of probiotics and prebiotics: a review of in vivo and in vitro findings

Ooi LG, Liong MT

Int J Mol Sci, 2010 Jun 17;11(6):2499-522.
PMID: 20640165 DOI: 10.3390/ijms11062499

Probiotics are live microorganisms that promote health benefits upon consumption, while prebiotics are nondigestible food ingredients that selectively stimulate the growth of beneficial microorganisms in the gastrointestinal tract. Probiotics and/or prebiotics could be used as alternative supplements to exert health benefits, including cholesterol-lowering effects on humans. Past in vivo studies showed that the administration of probiotics and/or prebiotics are effective in improving lipid profiles, including the reduction of serum/plasma total cholesterol, LDL-cholesterol and triglycerides or increment of HDL-cholesterol. However, other past studies have also shown that probiotics and prebiotics had insignificant effects on lipid profiles, disputing the hypocholesterolemic claim. Additionally, little information is available on the effective dosage of probiotics and prebiotics needed to exert hypocholesterolemic effects. Probiotics and prebiotics have been suggested to reduce cholesterol via various mechanisms. However, more clinical evidence is needed to strengthen these proposals. Safety issues regarding probiotics and/or prebiotics have also been raised despite their long history of safe use. Although probiotic-mediated infections are rare, several cases of systemic infections caused by probiotics have been reported and the issue of antibiotic resistance has sparked much debate. Prebiotics, classified as food ingredients, are generally considered safe, but overconsumption could cause intestinal discomfort. Conscientious prescription of probiotics and/or prebiotics is crucial, especially when administering to specific high risk groups such as infants, the elderly and the immuno-compromised.

Matched MeSH terms: Cholesterol/metabolism*
Cloning and functional expression of novel cholesterol transporters ABCG1 and ABCG4 in gonadotropin-releasing hormone neurons of the tilapia

Phang YL, Soga T, Kitahashi T, Parhar IS

Neuroscience, 2012 Feb 17;203:39-49.
PMID: 22198513 DOI: 10.1016/j.neuroscience.2011.12.016

In addition to reproduction, gonadotropin-releasing hormone (GnRH) has been postulated to control cholesterol metabolism via cholesterol transport, which is carried out partly by the members of ATP-binding cassette (ABC) transporters G1 (ABCG1) and G4 (ABCG4). However, there is yet to be evidence demonstrating the relationship between these transporters with reference to GnRH neurons. In the present study, we cloned two ABCG1 messenger RNA (mRNA) variants and one ABCG4 mRNA and examined their expression in the brain including GnRH neurons (GnRH1, GnRH2, and GnRH3) in the cichlid tilapia (Oreochromis niloticus). Comparison of nucleotide sequences of the tilapia ABCG1 and ABCG4 with that of other fish species showed that both of these genes are evolutionarily conserved among fishes. ABCG1 and ABCG4 were shown to have high mRNA expressions in the CNS, pituitary, and gonads. In the brain, real-time polymerase chain reaction (PCR) showed that ABCG4 mRNA was higher than ABCG1a in all brain regions including the olfactory bulb (ABCG1=13.34, ABCG4=6796.35; P<0.001), dorsal telencephalon (ABCG1=8.64, ABCG4=10149.13; P=0.001), optic tectum (ABCG1=22.12, ABCG4=13931.04; P<0.01), cerebellum (ABCG1=8.68, ABCG4=12382.90; P<0.01), and preoptic area-midbrain-hypothalamus (ABCG1=21.36, ABCG4=13255.41; P=0.001). Similarly, although ABCG1 mRNA level is much higher in the pituitary compared with the brain, it was still significantly lower compared with ABCG4 (ABCG1=337.73, ABCG4=1157.87; P=0.01). The differential pattern of expression of ABCG1 and ABCG4 in the brain versus pituitary suggests that the two transporters are regulated by different mechanisms. Furthermore, ABCG1 and ABCG4 mRNA expressions were found in all three types of laser-captured GnRH neurons with highly similar percentage of expressions, suggesting that cholesterol efflux from GnRH neurons may require heterodimerization of both ABCG1 and ABCG4.

Matched MeSH terms: Cholesterol/metabolism*
Removal of cholesterol by lactobacilli via incorporation and conversion to coprostanol

Lye HS, Rusul G, Liong MT

J Dairy Sci, 2010 Apr;93(4):1383-92.
PMID: 20338415 DOI: 10.3168/jds.2009-2574

Fifteen strains of Lactobacillus and Bifidobacterium were screened based on their ability to adhere to hydrocarbons via the determination of cellular hydrophobicity. Lactobacillus acidophilus ATCC 314, L. acidophilus FTCC 0291, Lactobacillus bulgaricus FTCC 0411, L. bulgaricus FTDC 1311, and L. casei ATCC 393 showed greater hydrophobicity and, thus, were selected for examination of cholesterol-removal properties. All selected strains showed changes in cellular fatty acid compositions, especially total fatty acids and saturated and unsaturated fatty acids in the presence of cholesterol compared with those grown in the absence of cholesterol. In addition, we found that cells grown in media containing cholesterol were more resistant to sonication and enzymatic lysis compared with those grown without cholesterol. We further evaluated the location of the incorporated cholesterol via the insertion of fluorescence probes into the cellular membrane. In general, enrichment of cholesterol was found in the regions of the phospholipid tails, upper phospholipids, and polar heads of the cellular membrane phospholipid bilayer. Our results also showed that lactobacilli were able to reduce cholesterol via conversion of cholesterol to coprostanol, aided by the ability of strains to produce cholesterol reductase. Our results provided experimental evidence to strengthen the hypothesis that probiotics could remove cholesterol via the incorporation of cholesterol into the cellular membrane and conversion of cholesterol to coprostanol. The strains studied may be potential health adjunct cultures in fermented dairy products with possible in vivo hypocholesterolemic effects.

Matched MeSH terms: Cholesterol/metabolism*
In Vitro Permeation and Skin Retention of α-Mangostin Proniosome

Chin GS, Todo H, Kadhum WR, Hamid MA, Sugibayashi K

Chem Pharm Bull (Tokyo), 2016;64(12):1666-1673.
PMID: 27904075

The current investigation evaluated the potential of proniosome as a carrier to enhance skin permeation and skin retention of a highly lipophilic compound, α-mangostin. α-Mangostin proniosomes were prepared using the coacervation phase seperation method. Upon hydration, α-mangostin loaded niosomes were characterized for size, polydispersity index (PDI), entrapment efficiency (EE) and ζ-potential. The in vitro permeation experiments with dermis-split Yucatan Micropig (YMP) skin revealed that proniosomes composed of Spans, soya lecithin and cholesterol were able to enhance the skin permeation of α-mangostin with a factor range from 1.8- to 8.0-fold as compared to the control suspension. Furthermore, incorporation of soya lecithin in the proniosomal formulation significantly enhanced the viable epidermis/dermis (VED) concentration of α-mangostin. All the proniosomal formulations (except for S20L) had significantly (p<0.05) enhanced deposition of α-mangostin in the VED layer with a factor range from 2.5- to 2.9-fold as compared to the control suspension. Since addition of Spans and soya lecithin in water improved the solubility of α-mangostin, this would be related to the enhancement of skin permeation and skin concentration of α-mangostin. The choice of non-ionic surfactant in proniosomes is an important factor governing the skin permeation and skin retention of α-mangostin. These results suggested that proniosomes can be utilized as a carrier for highly lipophilic compound like α-mangostin for topical application.

Matched MeSH terms: Cholesterol/metabolism
Pediococcus acidilactici LAB4 and Lactobacillus plantarum LAB12 assimilate cholesterol and modulate ABCA1, CD36, NPC1L1 and SCARB1 in vitro

Lim FT, Lim SM, Ramasamy K

Benef Microbes, 2017 Feb 07;8(1):97-109.
PMID: 27903090 DOI: 10.3920/BM2016.0048

There is growing interest in the use of probiotic lactic acid bacteria (LAB) for prevention of hypercholesterolaemia. This study assessed the cholesterol lowering ability of Pediococcus acidilactici LAB4 and Lactobacillus plantarum LAB12 in growth media. Both LAB yielded >98% (39.2 μg/ml) cholesterol lowering in growth media. Nile Red staining indicated direct assimilation of cholesterol by the LAB. The LAB were then explored for their prophylactic (pre-treatment of HT29 cells with LAB prior to cholesterol exposure) and biotherapeutic (treatment of HT29 cells with LAB after exposure to cholesterol) use against short and prolonged exposure of HT29 cells to cholesterol, respectively. For HT29 cells pre-treated with LAB, cholesterol lowering was accompanied by down-regulation of ATP-binding cassette family transporter-type A1 (ABCA1), cluster of differentiation 36 (CD36) and scavenger receptor class B member 1 (SCARB1). HT29 cells treated with LAB after prolonged exposure to cholesterol source, on the other hand, was associated with up-regulation of ABCA1, restoration of CD36 to basal level and down-regulation of Neimann-Pick C1-Like 1 (NPC1L1). The present findings implied the potential use of LAB4 and LAB12 as part of the strategies in prevention and management of hypercholesterolaemia.

Matched MeSH terms: Cholesterol/metabolism*
Fulltext The major allergen Der p 2 is a cholesterol binding protein

Reginald K, Chew FT

Sci Rep, 2019 02 07;9(1):1556.
PMID: 30733527 DOI: 10.1038/s41598-018-38313-9

Der p 2 is a major dust mite allergen and >80% of mite allergic individuals have specific IgE to this allergen. Although it is well characterized in terms of allergenicity, there is still some ambiguity in terms of its biological function. Three-dimensional structural analysis of Der p 2 and its close homologues indicate the presence of a hydrophobic cavity which can potentially bind to lipid molecules. In this study, we aimed to identify the potential ligand of Der p 2. Using a liposome pulldown assay, we show that recombinant Der p 2 binds to liposomes prepared with exogenous cholesterol in a dose dependent fashion. Next, an ELISA based assay using immobilized lipids was used to study binding specificities of other lipid molecules. Cholesterol was the preferred ligand of Der p 2 among 11 different lipids tested. Two homologues of Der p 2, Der f 2 and Der f 22 also bound to cholesterol. Further, using liquid chromatography-mass spectrometry (LC-MS), we confirmed that cholesterol is the natural ligand of Der p 2. Three amino acid residues of Der p 2, V104, V106 and V110 are possible cholesterol binding sites, as alanine mutations of these residues showed a significant decrease in binding (p cholesterol.

Matched MeSH terms: Cholesterol/metabolism
Fulltext Escherichia coli K1 utilizes host macropinocytic pathways for invasion of brain microvascular endothelial cells

Loh LN, McCarthy EMC, Narang P, Khan NA, Ward TH

Traffic, 2017 11;18(11):733-746.
PMID: 28799243 DOI: 10.1111/tra.12508

Eukaryotic cells utilize multiple endocytic pathways for specific uptake of ligands or molecules, and these pathways are commonly hijacked by pathogens to enable host cell invasion. Escherichia coli K1, a pathogenic bacterium that causes neonatal meningitis, invades the endothelium of the blood-brain barrier, but the entry route remains unclear. Here, we demonstrate that the bacteria trigger an actin-mediated uptake route, stimulating fluid phase uptake, membrane ruffling and macropinocytosis. The route of uptake requires intact lipid rafts as shown by cholesterol depletion. Using a variety of perturbants we demonstrate that small Rho GTPases and their downstream effectors have a significant effect on bacterial invasion. Furthermore, clathrin-mediated endocytosis appears to play an indirect role in E. coli K1 uptake. The data suggest that the bacteria effect a complex interplay between the Rho GTPases to increase their chances of uptake by macropinocytosis into human brain microvascular endothelial cells.

Matched MeSH terms: Cholesterol/metabolism
Fulltext Anti-Obesity Effects of Melastoma malabathricum var Alba Linn in Rats Fed with a High-Fat Diet

Karupiah S, Ismail Z

AAPS PharmSciTech, 2015 Jun;16(3):548-53.
PMID: 25374344 DOI: 10.1208/s12249-014-0245-1

Obesity is one of the major public health problems worldwide and it is generally associated with many diseases. Although synthetic drugs are available for the treatment of obesity, herbal remedies may provide safe, natural, and cost-effective alternative to synthetic drugs. One example of such drugs is Melastoma malabathricum var Alba Linn (MM). Although several studies have been reported for the pharmacological activities of MM, there is no report on the anti-obesity effect of MM. The aim of the present study is to evaluate the anti-obesity potential of methanolic extract of MM. The anti-obesity effect of MM on rats fed with a high-fat diet was investigated through determination of the changes in body weight, fat weight, organ weights, and blood biochemicals. The animals in this study were divided into three groups: a normal group with a standard diet (N), a control group fed with high-fat diet (C), and a MM treatment group fed with high-fat (HFD + MM) diet for 8 weeks. There was no significant difference in the amount of food intake between control and HFD + MM treatments. These results also suggest that MM does not induce a dislike for the diet due to its smell or taste. The study shows that MM significantly prevented increases in body weight, cholesterol, LDL, HDL, and total lipids that resulted from the high-fat diet. MM also decreased the epididymal fat (E-fat) and retroperitoneal fat (R-fat) weights and phospholipid concentrations induced by the high-fat diet. On the basis of these findings, it was concluded that MM had anti-obesity effects by suppressing body weight gain and abdominal fat formation.

Matched MeSH terms: Cholesterol/metabolism
The effects of anti-obesity intervention with orlistat and sibutramine on microvascular endothelial function

Al-Tahami BA, Ismail AA, Bee YT, Awang SA, Salha Wan Abdul Rani WR, Sanip Z, et al.

Clin. Hemorheol. Microcirc., 2015;59(4):323-34.
PMID: 24002121 DOI: 10.3233/CH-131765

INTRODUCTION: Obesity is associated with impaired microvascular endothelial function. We aimed to determine the effects of orlistat and sibutramine treatment on microvascular endothelial function, anthropometric and lipid profile, blood pressure (BP), and heart rate (HR).
METHODS: 76 subjects were recruited and randomized to receive orlistat 120 mg three times daily or sibutramine 10 mg daily for 9 months. Baseline weight, BMI, BP, HR and lipid profile were taken. Microvascular endothelial function was assessed using laser Doppler fluximetry and iontophoresis process. Maximum change (max), percent change (% change) and peak flux (peak) in perfusion to acetylcholine (ACh) and sodium nitroprusside (SNP) iontophoresis were used to quantify endothelium dependent and independent vasodilatations.
RESULTS: 24 subjects in both groups completed the trial. After treatment, weight and BMI were decreased for both groups. AChmax, ACh % change and ACh peak were increased in orlistat-treated group but no difference was observed for sibutramine-treated group. BP and total cholesterol (TC) were reduced for orlistat-treated group. HR was reduced for orlistat-treated group but was increased in sibutramine-treated group.
CONCLUSION: 9 months treatment with orlistat significantly improved microvascular endothelial function. This was associated with reductions in weight, BMI, BP, HR, TC and low density lipoprotein cholesterol. No effect was seen in microvascular endothelial function with sibutramine.
KEYWORDS: Microvascular endothelial function; obesity; orlistat; sibutramine

Matched MeSH terms: Cholesterol/metabolism
Fulltext Hypolipidemic activities of xanthorrhizol purified from centrifugal TLC

Oon SF, Nallappan M, Kassim NK, Shohaimi S, Sa'ariwijaya MS, Tee TT, et al.

Biochem Biophys Res Commun, 2016 09 23;478(3):1403-8.
PMID: 27576204 DOI: 10.1016/j.bbrc.2016.08.136

Hyperlipidemia is defined as the presence of either hypertriglyceridemia or hypercholesterolemia, which could cause atherosclerosis. Although hyperlipidemia can be treated by hypolipidemic drugs, they are limited due to lack of effectiveness and safety. Previous studies demonstrated that xanthorrhizol (XNT) isolated from Curcuma xanthorrhizza Roxb. reduced the levels of free fatty acid and triglyceride in vivo. However, its ability to inhibit cholesterol uptake in HT29 colon cells and adipogenesis in 3T3-L1 cells are yet to be reported. In this study, XNT purified from centrifugal TLC demonstrated 98.3% purity, indicating it could be an alternative purification method. The IC50 values of XNT were 30.81 ± 0.78 μg/mL in HT29 cells and 35.07 ± 0.24 μg/mL in 3T3-L1 adipocytes, respectively. Cholesterol uptake inhibition study using HT29 colon cells showed that XNT (15 μg/mL) significantly inhibited the fluorescent cholesterol analogue NBD uptake by up to 27 ± 3.1% relative to control. On the other hand, higher concentration of XNT (50 μg/mL) significantly suppressed the growth of 3T3-L1 adipocytes (5.9 ± 0.58%) compared to 3T3-L1 preadipocytes (81.31 ± 0.55%). XNT was found to impede adipogenesis of 3T3-L1 adipocytes in a dose-dependent manner from 3.125 to 12.5 μg/mL, where 12.5 μg/mL significantly suppressed 36.13 ± 2.1% of lipid accumulation. We postulate that inhibition of cholesterol uptake, adipogenesis, preadipocyte and adipocyte number may be utilized as treatment modalities to reduce the prevalence of lipidemia. To conclude, XNT could be a potential hypolipidemic agent to improve cardiovascular health in the future.

Matched MeSH terms: Cholesterol/metabolism
Cholesterol lowering by Pediococcus acidilactici LAB4 and Lactobacillus plantarum LAB12 in adult zebrafish is associated with improved memory and involves an interplay between npc1l1 and abca1

Lim FT, Lim SM, Ramasamy K

Food Funct, 2017 Aug 01;8(8):2817-2828.
PMID: 28725889 DOI: 10.1039/c7fo00764g

This study assessed the cholesterol lowering effect of Pediococcus acidilactici LAB4 and Lactobacillus plantarum LAB12 using adult zebrafish. Animals were fed with a high cholesterol diet (HCD) with/without LAB for seven weeks. Serum and liver cholesterol was quantified using colorimetric and dye staining methods. Expressions of npc1l1 and abca1 in the liver and intestine and appa in the brain were quantified using RT-PCR. Serum and liver cholesterol was significantly lowered in LAB4- and LAB12-fed zebrafish (≤64% and ≤71%, respectively), with reduced liver cholesterol deposition. The cholesterol lowering effect was accompanied by down-regulation of npc1l1 in intestines (≤28.7%), up-regulation of abca1 in the liver (≥30.5%) and down-regulation of appa in the brain (≤24.5%). A moderately strong positive Pearson correlation (r = 0.617, p < 0.01) was found between appa and serum cholesterol. LAB-fed zebrafish exhibited improved spatial learning and memory. LAB4 and LAB12 can be potentially used in preventing hypercholesterolaemia and Alzheimer's diseases.

Matched MeSH terms: Cholesterol/metabolism*

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