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At least 127 records · Page 7Linked to original sources
PubMed1985

Improvement of bioavailability of poorly absorbed drugs. II. Effect of medium chain glyceride base on the intestinal absorption of cefmetazole sodium in rats and dogs.

The effect of medium chain glyceride (MCG) on the intestinal absorption of cefmetazole sodium (CMZ) was investigated in rats and dogs. In rats, MCG containing glyceryl mono-, di- and tri-caprylate enhanced the intestinal absorption of CMZ after intraduodenal administration, though the promoting effect of MCG was less than that after rectal administration. The promoting effect of MCG was found to be mainly due to glycerylmonocaprylate and dependent on the dosage of MCG. The plasma CMZ levels after intraduodenal administration as MCG solution tended to be slightly higher than those observed after administration as MCG emulsion, though the differences were found to be statistically insignificant. Moreover, the intestinal absorption of CMZ after intraduodenal administration as MCG emulsion was decreased significantly by increasing the amount of water in the emulsion. The promoting effect of MCG in dogs was more clearly demonstrated in the lower intestine than in the upper intestine. Furthermore, the oral bioavailability of pharmaceutical formulations of CMZ was also investigated in dogs. When enteric coated capsules filled with MCG solution were administered to dogs, the bioavailability of CMZ was enhanced significantly.

Animals↗
PubMed1985

Improvement of bioavailability of poorly absorbed drugs. III. Oral acute toxicity and local irritation of medium chain glyceride.

Oral acute toxicity of medium chain glyceride (MCG) was studied in mice and rats. In mice and rats, clinical signs such as irregular respiration, laxity of movement, staggering gait and loss of righting reflex appeared after single oral administration of MCG at a relatively large dose. The LD50 values determined in male and female mice were 26.9 and 28.5 ml/kg, and in male and female rats were 27.4 and 26.7 ml/kg, respectively. In order to evaluate the biological safety of MCG suppository of cefmetazole sodium (CMZ), its local irritation on the mucous membrane was studied. Primary eye irritation of MCG suppository of CMZ was studied in rabbits. Although mild irritation was seen in conjunctivae, no remarkable changes were observed in cornea and iris. Furthermore, primary effect of MCG suppository of CMZ on the rectal mucous membrane was studied macro- and microscopically. It was observed that remarkable histological changes of rectal mucous membrane by MCG suppository of CMZ were not observed in all animals used.

Animals↗
PubMed1985

Improvement of bioavailability of poorly absorbed drugs. IV. Mechanism of the promoting effect of medium chain glyceride on the rectal absorption of water soluble drugs.

The mechanisms of the promoting effect of medium chain glyceride (MCG) containing glyceryl mono-, di- and tri-caprylate on rectal absorption of water soluble drugs were investigated. It was found that the solubility behavior of the drugs in mucosal fluids on the surface of the membrane are critical factor for the enhanced rectal absorption. Moreover, the drugs to be readily absorbed from MCG base may be ones of low partition coefficients to MCG phase as well as high solubility in water. And it was found that MCG can't be absorbed from the rectum, different from oral administration, suggesting an interaction of MCG with absorption membrane, rather than the carrier effect of MCG itself. Furthermore, from the results in the pretreatment experiments and additional administration of MCG alone, it was suggested that the interactions of MCG with the membrane components, as well as the induction of biological or physiological changes, may be at least partly responsible for the promoting effect of MCG.

Animals↗
PubMed1985

Improvement of bioavailability of poorly absorbed drugs. V. Effect of surfactants on the promoting effect of medium chain glyceride for the rectal absorption of beta-lactam antibiotics in rats and dogs.

The promoting effects of medium chain glyceride (MCG) on the rectal absorption of beta-lactam antibiotics were compared among various experimental animals (such as rats, rabbits and dogs). The plasma levels of cefmetazole (CMZ) after rectal administration, when MCG was used as the vehicle, significantly increased in all animals, but the bioavailability of CMZ was greatly varied among the animal species; the bioavailability of CMZ in dogs was apparently less than those in other animals (rats = rabbits greater than dogs). However, in dogs, the promoting effect of MCG on the rectal absorption of CMZ increased by addition of nonionic surfactants such as ether-type (Brij 30 and Brij 35) and ester type (Nikkol MYL-10). And the promoting effect of surfactants in the MCG vehicle is not always correlated with blood hemolysis, suggesting contribution of other physicochemical or biological factors.

Animals↗
PubMed1986

Effect of medium-chain glycerides (MGK) on the intestinal absorption and the hepatobiliary transport of bromthymol blue.

The effect of medium chain glyceride (MGK) emulsion on the intestinal absorption and the biliary excretion of bromthymol blue (BTB) was investigated in rats. Extensive tissue accumulation of BTB was reduced when BTB was administered with MGK emulsion formulation. HCO-100, an emulsifier, was also important for the decrease in the tissue accumulation of BTB. The ratios of absorption percent to tissue accumulation percent and to free fraction, not contained in the droplet of emulsion, in MGK emulsion were much greater than that of the control. Pretreatment with BTB-free emulsion reduced BTB absorption under the control, although tissue accumulation was not affected. The absorption appeared to decrease with increase in the time of pretreatment. The effect of leaving treatment after pretreatment on the absorption of BTB was also investigated. With the increase in leaving time after pretreatment, reduced absorption tended to resume to the level of control. The change in monocaprylate content from 54 to 60% in MGK made a difference in BTB absorption and it was suggested that monocaprylate content in MGK was one of the significant factors of MGK emulsion on drug absorption. Bile recovery study was simultaneously carried out with an in situ recirculation experiment. The recovery of BTB into bile tended to decrease. The ratio of recovery percent of BTB into bile to the absorption percent of BTB also decreased extensively, which is possibly another effect of MGK on drug disposition.

Animals↗
PubMedDate not supplied

Phospholipids and glycerides composition during spheroplasts formation of Mycobacterium smegmatis ATCC 14468.

The phospholipids and glycerides composition of spheroplasts of Mycobacterium smegmatis ATCC 14468 was examined. The percent total phospholipids in total lipids as well as cardiolipin were found to be higher in spheroplasts as compared to their parent forms. Increase in cardiolipin and free fatty acids content and decrease in triglycerides levels were observed during spheroplasts formation. The results suggest that increase in cardiolipin content in spheroplasts is an adaptational change concomitant with the loss of cell walls.

Carbon Radioisotopes↗
PubMed2000

Improved brain delivery of a nonsteroidal anti-inflammatory drug with a synthetic glyceride ester: a preliminary attempt at a CNS drug delivery system for the therapy of Alzheimer's disease.

1,3-Diacetyl-2-ketoprofen glyceride (DAKG), a prodrug of ketoprofen, was synthesized as a model compound in our attempt to develop a central nervous system (CNS) drug delivery system to treat Alzheimer's disease. The primary purpose of the present study is to test whether DAKG improves the delivery of ketoprofen to the brain and to quantitatively evaluate several factors that influence the brain distribution of this prodrug. ddY mice were injected with either ketoprofen or DAKG at a dose of 40 micromol/kg and then the plasma and brain pharmacokinetics of these agents were assessed. The brain uptake clearance of ketoprofen and DAKG across the BBB was measured by in situ mouse brain perfusion. In addition, the efflux permeability of ketoprofen through the BBB was evaluated using the in vivo mouse brain microdialysis technique. The in vivo metabolism of DAKG in the brain was assessed by a short infusion into the internal carotid artery coupled with the brain metabolism index (BMI) method. Administration of DAKG produced an approximately 3-fold increase in the area under the brain concentration - time curve of ketoprofen, compared with administration of ketoprofen itself. The brain uptake clearance (CL(in) ) of ketoprofen across the BBB was 0.0308 +/- 0.0046 mL/min/g whereas the CL(in) of DAKG was 1.60 +/- 0.16 mL/min/g, suggesting a marked increase in BBB permeability following lipidization of ketoprofen. The BMI method confirmed that DAKG is taken up by the brain to rapidly release ketoprofen in a dose-dependent manner. The in vitro metabolism studies revealed that isolated bovine brain capillaries as well as whole brain homogenate have the hydrolysis activity to DAKG. In addition, the brain concentration of ketoprofen after DAKG administration was maintained for a significant period following co-administration of probenecid. These results suggest that DAKG improves the delivery of ketoprofen to the brain, and this improved delivery is due to avid uptake of DAKG across the BBB followed by rapid hydrolysis to ketoprofen within the brain. The ketoprofen produced in the brain was probably cleared by the active efflux system operating in the BBB. Significant inhibition of this efflux system by co-administration of probenecid could result in a sustained concentration of ketoprofen in the brain following DAKG administration.

Alzheimer Disease↗
PubMed1975

Fatty acid composition of glycerides and stereospecific analysis of triglyceride in pea seeds.

Pea seeds were shown to contain ten kinds of neutral lipids, among which triglyceride, free sterol and sterolester are the main components and diglyceride, monoglyceride, free fatty acid, wax and some pigments are the minor ones. The major component fatty acids in the glycerides and the free fatty acid are C18:2, C18:1 and C16:0. The positional distribution of fatty acids in triglyceride is such that, position 1 and 3, especially the former, abound in saturated fatty acids, and position 2 is filled almost entirely with unsaturated fatty acids.

Chemical Phenomena↗
PubMed2005

[Progress on microbial glyceride biosynthesis and metabolic regulation in oleaginous microorganisms].

Oleaginous microorganisms are small portion of organisms that have ability to accumulate lipids over 20% of their biomass. These species can transform renewable material into microbial oil with similar fatty acid composition to that of plant-based oil. Some organisms may also produce glycerides with high content of poly-unsaturated fatty acids. Therefore, microbial lipids are considered as potential oil resource. Summarized here are some features of oleaginous species and recent developments on their biosynthetic machinery and metabolic regulation mechanism.

Fatty Acids, Unsaturated↗
PubMed1991

Enhanced skin permeation of papaverine by a medium chain glyceride.

The mode and mechanism of action of Sefsol-318, a medium chain glyceride and a potent percutaneous absorption enhancer, on the in vitro permeation of papaverine hydrochloride through hairless rat skin were investigated and compared with those of laurocapram (Azone). The total amount of the drug delivered through excised skin over 28 h from aqueous solutions of the drug in which 5% S-318 or Azone was suspended was about 820 or 420 times higher, respectively, than from the solution alone. Experiments using liposomes as models, indicated that both the enhancers markedly increased the fluidity of lipid membranes. Skin conductance measurements in hairless rats indicated that they both also increased in vivo skin moisturizing and water holding capacity. These results suggest that the mechanism of action of Sefsol-318 and Azone in enhancing skin permeation are similar. But following in vitro pretreatment of the excised skin with 5% Sefsol-318 and aqueous emulsion for 2 h, skin permeation of papaverine hydrochloride through the pretreated skin was much lower than through non-treated skin in the presence of Sefsol-318. In contrast, the enhancing effect of Azone on the pretreated skin was similar to that of Azone on the in vitro non-treated skin. We found that, unlike Azone, Sefsol-318 disappeared from skin completely one day after 24 h-in vivo pretreatment of skin with aqueous gels containing each agent. In agreement, drug permeation through skin excised one day after the in vivo pretreatment with Sefsol-318 was almost the same as in non-pretreated controls without Sefsol-318. This difference in the mode of action of Sefsol-318 and Azone may arise from the difference in the residence times of these enhancers in skin.

Administration, Cutaneous↗
PubMed1989

[Physicochemical and toxicologic aspects of partial glycerides as carrier systems for transdermal systems].

Lipid containing carrier systems are increasingly important for an intercellular transport of drugs. Out of the numerous lipids, triglycerides and partial glycerides of medium chain fatty acids have become of particular interest as absorption promoters. Their chemical and physical properties as well as their analysis are described. Being lipids which are endogenous or very similar to those, they are distinguished by a very low oral and dermal toxicity and a good tolerance. Also at mucous membranes no morphological changes occur.

Administration, Cutaneous↗
PubMed1986

Glyceride synthesis by a cell-bound lipase from Aspergillus niger.

A cell-bound lipase from the mould Aspergillus niger was isolated and purified to homogeneity as judged by disc electrophoresis on a Sephadex G-75 column. Molecular weight determination and electrophoretic mobility (Rf value) indicated that the enzyme differed from that secreted extracellularly. The cell-bound lipase showed a higher capacity than the extracellular enzyme for glyceride synthesis, and reacted in an opposite manner in the synthetic reaction compared with the extracellular enzyme.

Aspergillus niger↗
PubMed1974

Metabolism of sulfoquinovosyl diglyceride in Chlorella pyrenoidosa by sulfoquinovosyl monoglyceride: fatty acyl CoA acyltransferase and sulfoquinovosyl glyceride: fatty acyl ester hydrolase pathways.

Cell-free preparations of Chlorella pyrenoidosa catalyze the transfer of the fatty acyl moiety of fatty acyl CoA derivatives to sulfoquinovosyl monoglyceride to form sulfoquinovosyl diglyceride. This reaction is stimulated by Triton X-100 concentrations of up to 0.6 mg/ml and has a pH optimum of 7.7. Similar Chlorella preparations catalyze the stepwise removal of both fatty acyl groups from sulfoquinovosyl diglyceride to form sulfoquinovosyl monoglyceride and then sulfoquinovosyl glycerol. This reaction is inhibited by both calcium and magnesium. The nonionic surfactant Triton X-100 inhibits the enzymatic deacylation at concentrations of less than 0.5 mg/ml but stimulates it at higher concentrations. The pH optimum for the deacylation of sulfoquinovosyl glycerides is 8.2, with little activity observed below pH 8. The enzymatic activities for both the transacylation and deacylation reactions are associated with a 30,000 g particulate fraction of Chlorella. Sulfoquinovosyl glycerol was found not to be an acceptor of the fatty acyl moiety of fatty acyl CoA derivatives. Methods are described for the preparation of sulfoquinovosyl monoglyceride, sulfoquinovose, and 3-sulfo-1,2-propanediol.

Acyltransferases↗
PubMed1969

Simple liquid-liquid partition system for isolation of labeled oleic acid from mixtures with glycerides.

Oleic acid has a partition coefficient, upper phase/lower phase, of 1.9 (22 degrees C) in the liquid-liquid partition system described herein. Tri-, di-, and monoolein are found almost exclusively in the lower (organic) phase. Oleic acid can be quantitatively removed from mixtures of triglyceride and partial glycerides by means of this partition system under conditions resembling those in a lipase assay.

Animals↗
PubMed1967

Partition of lipids between emulsified oil and micellar phases of glyceride-bile salt dispersions.

The composition of the emulsified oil and of the micellar phases obtained when a glyceride-fatty acid mixture is dispersed in bile salt solution has been defined. The micellar phase in equilibrium with the emulsified oil phase was obtained by filtration through Millipore filters. The behavior of different lipids in such systems was defined as the partition ratio, micellar/emulsified oil phase (m/o). Partition of fatty acids was found to be strongly dependent on the chain length of the fatty acid and the pH of the dispersion. The curve for partition against pH for oleic acid was interpreted to show a pK(a) for oleic acid in bile salt solution of approximately 7. The partition between micellar and oil phases is given for a series of lipids of different polarity. No significant difference in behavior was found for cholesterol and sitosterol. A relationship was found between the partition m/o and filtration rates through a Millipore filter in micellar solution. The lower the partition coefficient the lower was the rate of filtration. The results obtained are discussed in relation to the mechanism of absorption of fat from the small intestine.

Bile Acids and Salts↗
PubMed1980

Accumulation of glyceride-containing precursor of the outer membrane lipoprotein in the cytoplasmic membrane of Escherichia coli treated with globomycin.

The protein accumulated in the cell envelope of Escherichia coli treated with globomycin was identified as the precursor of the outer membrane lipoprotein. The prolipoprotein was almost exclusively localized in the cytoplasmic membrane. The prolipoprotein could be immunoprecipitated with antilipoprotein immunoglobulin and could be chased to the lipoprotein in both in vivo and in vitro. Globomycin inhibited the chase. The prolipoprotein contained glycerol and fatty acid residues, whereas no free sulfhydryl group was detected in it. From these results, it is concluded that the prolipoprotein possesses a glyceride which is covalently bound to the cysteine residue in the peptide as the lipoprotein does and that the removal of signal peptide takes place after the modification. The inhibition of bacterial growth with increasing concentrations of globomycin was accompanied by a gradual increase in the accumulation of the prolipoprotein. Furthermore, growth of the lipoprotein-negative mutant was highly resistant to globomycin. These results strongly indicate that the accumulation of the prolipoprotein in the cytoplasmic membrane causes the death of cells.

Anti-Bacterial Agents↗
PubMed1997

Colonic xanthelasma due to glyceride accumulation associated with an adenoma.

The case is reported of a 66-year-old woman who presented with endoscopic and histological features of multiple lipid deposits in the mucosa of the sigmoid colon associated with an adenoma. Associated clinical features were abdominal pain and diarrhea. Colectomy led to the complete resolution of symptoms. Biochemical analysis disclosed the presence of glycerides in the mucosa. The pathogenesis of lipid deposits and the possible link with the formation of an adenoma is discussed.

Adenomatous Polyps↗
PubMed2003

Analysis of cell cycle regulation by 1-mono-O-acyl-3-O-(alpha-D-sulfoquinovosyl)-glyceride (SQMG), an inhibitor of eukaryotic DNA polymerases.

One of the sulfo-lipids, 1-mono-O-acyl-3-O-(alpha-D-sulfoquinovosyl)-glyceride (SQMG), potently and selectively inhibited the activity of mammalian DNA polymerases. SQMG was also a potent apoptosis inducer and the SQMG effect occurred through the induction of G1 arrest with a reduction in the proportion of cells in the S phase. SQMG clearly increased the levels of p53 and p21 proteins, but did not induce the expression of p27 and p16 proteins. SQMG markedly reduced the pRb protein level and inhibited pRb phosphorylation after 48hr. These results suggested that SQMG activates the G1 checkpoint as a result of the DNA polymerase inhibition, and then promotes a p53-dependent apoptotic response. Since aphidicolin, a well-known replicative DNA polymerase inhibitor, did not promote these protein expressions, the apoptosis-inducing pathway by SQMG differs from that by aphidicolin.

Apoptosis↗