-
Journal of Pharmaceutical Sciences Jan 1984Methods were developed for the determination of octanoic acid and N-acetyl-DL-tryptophan, which are used as stabilizers in the human blood-derived therapeutic products...
Methods were developed for the determination of octanoic acid and N-acetyl-DL-tryptophan, which are used as stabilizers in the human blood-derived therapeutic products normal serum albumin and plasma protein fraction. The method for octanoic acid uses GC; quantitation is achieved using heptanoic acid as the internal standard. The method for N-acetyl-DL-tryptophan is based on UV spectrophotometry of the acid-soluble fraction remaining after precipitation of the protein (epsilon 280 for N-acetyl-DL-tryptophan, 5250). The coefficient of variation for replicate determinations of octanoic acid averaged 3.9% (range 2.1-5.5%); that of N-acetyl-DL-tryptophan averaged 1.9% (range 0.5-4.0%). Use of these methods for the analysis of 138 lots of commercial products for octanoic acid and 159 lots for N-acetyl-DL-tryptophan showed that the stabilizer contents of 132 and 158 of these lots, respectively, were within 20% of the value indicated on the product label.
Topics: Albumins; Caprylates; Chromatography, Gas; Humans; Spectrophotometry, Ultraviolet; Tryptophan
PubMed: 6694090
DOI: 10.1002/jps.2600730122 -
Stem Cells and Development Jun 2022Lowest observable adverse effects level (LOAEL) is a standard point-of-departure dose in toxicology. However, first observable adverse effects level (FOAEL) was recently...
Using Live Imaging and Fluorescence Ubiquitinated Cell Cycle Indicator Embryonic Stem Cells to Distinguish G1 Cell Cycle Delays for General Stressors like Perfluoro-Octanoic Acid and Hyperosmotic Sorbitol or G2 Cell Cycle Delay for Mutagenic Stressors like Benzo(a)pyrene.
Lowest observable adverse effects level (LOAEL) is a standard point-of-departure dose in toxicology. However, first observable adverse effects level (FOAEL) was recently reported and is used, in this study, as one criterion to detect a mutagenic stimulus in a live imager. Fluorescence ubiquitinated cell cycle indicator (FUCCI) embryonic stem cells (ESC) are green in the S-G2-M phase of the cell cycle and not green in G1-phase. Standard media change here is a mild stress that delays G1-phase and media change increases green 2.5- to 5-fold. Since stress is mild, media change rapidly increases green cell number, but higher stresses of environmental toxicants and positive control hyperosmotic stress suppress increased green after media change. Perfluoro-octanoic acid (PFOA) and diethyl phthalate (DEP) previously suppressed progression of nongreen to green cell cycle progression. Here, bisphenol A (BPA), cortisol, and positive control hyperosmotic sorbitol also suppress green fluorescence, but benzo(a)pyrene (BaP) at high doses (10 μM) increases green fluorescence throughout the 74-h exposure. Since any stress can affect many cell cycle phases, messenger RNA (mRNA) markers are best interpreted in ratios as dose-dependent mutagens increase in G2/G1 and nonmutagens increase G1/G2. After 74-h exposure, RNAseq detects G1 and G2 markers and increasing BaP doses increase G2/G1 ratios but increasing hyperosmotic sorbitol and PFOA doses increase G1/G2 marker ratios. BaP causes rapid green increase in FOAEL at 2 h of stimulus, whereas retinoic acid caused significant green fluorescence increases only late in culture. Using a live imager to establish FOAEL and G2 delay with FUCCI ESC is a new method to allow commercial and basic developmental biologists to detect drugs and environmental stimuli that are mutagenic. Furthermore, it can be used to test compounds that prevent mutations. In longitudinal studies, uniquely provided by this viable reporter and live imager protocol, follow-up can be done to test whether the preventative compound itself causes harm.
Topics: Benzo(a)pyrene; Caprylates; Cell Cycle; Cell Division; Embryonic Stem Cells; Fluorescence; Mutagens; Sorbitol
PubMed: 35678645
DOI: 10.1089/scd.2021.0330 -
The Laryngoscope Nov 2021The purpose of this study was to characterize the clinical features, tremor variability, and factors related to octanoic acid (OA) treatment response in essential voice...
OBJECTIVES/HYPOTHESIS
The purpose of this study was to characterize the clinical features, tremor variability, and factors related to octanoic acid (OA) treatment response in essential voice tremor (EVT).
STUDY DESIGN
Prospective, double blind, placebo-controlled, crossover study with secondary analysis.
METHODS
Clinical tremor features in 16 individuals with EVT were comprehensively assessed, and correlations with acoustic tremor severity were determined. Intrasubject and intersubject variability measures were analyzed from 18 repeated measures for each acoustic tremor variable. Clinical correlates of treatment response were evaluated, and cumulative effects over a 2-week period of OA drug dosing were assessed.
RESULTS
Participants with EVT were 90% female with a mean age of 70.31 (±8.68) years at the time of testing. Neurologist-rated body tremor beyond the vocal tract region was present in 69% of participants, and multiple vocal tract regions contributed to the voice tremor. The mean frequency of amplitude tremor was 4.67 Hz (±0.88). Respiratory tremor was evident in 50% of participants. Participants experienced moderate voice-related disability as assessed on the Voice Handicap Index-10 (19.38, ±8.50), and increased speaking effort. Acoustic tremor severity was significantly associated with severity of tremor affecting vocal tract structures. Overall intrasubject consistency was strong (single measures intraclass correlation coefficient = 0.701, P < .01), with high intersubject variability. Acoustic tremor severity was significantly, positively associated with treatment response, and results suggested a cumulative OA benefit for magnitude of amplitude tremor.
CONCLUSIONS
This study identified common clinical correlates of EVT and demonstrated positive associations between acoustic tremor severity, severity of affected vocal tract structures, and response to treatment.
LEVEL OF EVIDENCE
2 Laryngoscope, 131:E2792-E2801, 2021.
Topics: Aged; Caprylates; Case-Control Studies; Cross-Over Studies; Double-Blind Method; Essential Tremor; Female; Humans; Male; Middle Aged; Observer Variation; Phenotype; Placebos; Prospective Studies; Severity of Illness Index; Sound; Treatment Outcome; Tremor; Voice; Voice Disorders
PubMed: 33864634
DOI: 10.1002/lary.29558 -
Environment International Jan 2022Perfluoroalkyl substances (PFASs) are synthetic chemicals widely used in industrial and consumer products. The environmental spreading of PFASs raises concerns for their...
Impairment of human dopaminergic neurons at different developmental stages by perfluoro-octanoic acid (PFOA) and differential human brain areas accumulation of perfluoroalkyl chemicals.
Perfluoroalkyl substances (PFASs) are synthetic chemicals widely used in industrial and consumer products. The environmental spreading of PFASs raises concerns for their impact on human health. In particular, the bioaccumulation in humans due to environmental exposure has been reported also in total brain samples and PFAS exposure has been associated with neurodevelopmental disorders. In this study we aimed to investigate the specific PFAS bioaccumulation in different brain areas. Our data reported major accumulation in the brainstem region, which is richly populated by dopaminergic neurons (DNs), in brain autopsy samples from people resident in a PFAS-polluted area of Italy. Since DNs are the main source of dopamine (DA) in the mammalian central nervous system (CNS), we evaluated the possible functional consequences of perfluoro-octanoic acid (PFOA) exposure in a human model of DNs obtained by differentiation of human induced pluripotent stem cells (hiPSCs). Particularly, we analyzed the specific effect of the exposure to PFOA for 24 h, at the concentration of 10 ng/ml, at 3 different steps of dopaminergic differentiation: the neuronal commitment phase (DP1), the neuronal precursor phase (DP2) and the mature dopaminergic differentiation phase (DP3). Interestingly, compared to untreated cells, exposure to PFOA was associated with a reduced expression of Tyrosine Hydroxylase (TH) and Neurofilament Heavy (NFH), both markers of dopaminergic maturation at DP2 phase. In addition, cells at DP3 phase exposed to PFOA showed a severe reduction in the expression of the Dopamine Transporter (DAT), functionally involved in pre-synaptic dopamine reuptake. In this proof-of-concept study we show a significant impact of PFOA exposure, mainly on the most sensitive stage of neural dopaminergic differentiation, prompting the way for further investigations more directly relevant to risk assessment of these chemicals.
Topics: Alkanesulfonic Acids; Animals; Brain; Caprylates; Dopaminergic Neurons; Fluorocarbons; Humans; Induced Pluripotent Stem Cells
PubMed: 34781208
DOI: 10.1016/j.envint.2021.106982 -
Journal of Oleo Science 2015Ghrelin is a growth hormone-releasing peptide that also displays orexigenic activity. Since serine-3 acylation with octanoylate (octanoylation) is essential for the...
Ghrelin is a growth hormone-releasing peptide that also displays orexigenic activity. Since serine-3 acylation with octanoylate (octanoylation) is essential for the orexigenic activity of ghrelin, suppression of octanoylation could lead to amelioration or prevention of obesity. To enable the exploration of inhibitors of octanoylated ghrelin production, we developed a cell-based assay system using AGS-GHRL8 cells, in which octanoylated ghrelin concentration increases in the presence of octanoic acid. Using this assay system, we investigated whether fatty acids contained in foods or oils, such as acetic acid, stearic acid, oleic acid, linoleic acid, and α-linolenic acid, have inhibitory effects on octanoylated ghrelin production. Acetic acid did not suppress the increase in octanoylated ghrelin production in AGS-GHRL8 cells, which was induced by the addition of octanoic acid. However, stearic acid, oleic acid, linoleic acid, and α-linolenic acid significantly suppressed octanoylated ghrelin production, with the effect of oleic acid being the strongest. Additionally, oleic acid decreased the serum concentration of octanoylated ghrelin in mice. The serum concentration of des-acyl ghrelin (without acyl modification) was also decreased, but the decrease was smaller than that of octanoylated ghrelin. Decreased octanoylated ghrelin production likely resulted from post-translational ghrelin processing, as there were no significant differences in gene expression in the stomach between oleic acid-treated mice and controls. These results suggest that oleic acid is a potential inhibitor of octanoylated ghrelin production and that our assay system is a valuable tool for screening compounds with suppressive effects on octanoylated ghrelin production.
Topics: Animals; Biological Assay; Caprylates; Cells, Cultured; Fatty Acids; Ghrelin; Mice; Oleic Acid; Protein Processing, Post-Translational
PubMed: 26521811
DOI: 10.5650/jos.ess15137 -
Dalton Transactions (Cambridge, England... Apr 2021The Pt(iv) complexes based on (SP-4-2)-dichlorido(cyclohexane-1,4-diamine)platinum(ii) (kiteplatin) and the histone deacetylase inhibitor 2-(2-propynyl)octanoic acid...
Pt(iv) complexes based on cyclohexanediamines and the histone deacetylase inhibitor 2-(2-propynyl)octanoic acid: synthesis, characterization, cell penetration properties and antitumor activity.
The Pt(iv) complexes based on (SP-4-2)-dichlorido(cyclohexane-1,4-diamine)platinum(ii) (kiteplatin) and the histone deacetylase inhibitor 2-(2-propynyl)octanoic acid (POA) were investigated. Since POA contains a chiral carbon, all the possible Pt(iv) isomers were prepared and characterized, and their antiproliferative activity on six cancer cell lines was compared with that of the corresponding Pt(iv) complexes containing the cyclohexane-1R,2R-diamine equatorial ligand. To justify the very good antiproliferative activity (nanomolar IC), the polarity, lipophilicity, permeability, and cell accumulation of the complexes were studied. Overall, the two series of Pt(iv) complexes showed similar cell penetration properties, being significantly better than that of the Pt(ii) reference compounds. Finally, a representative compound of the whole set of complexes (i.e., that based on cyclohexane-1R,2R-diamine and racemic POA) was tested in vivo on mice bearing Lewis lung carcinoma, showing good tumor growth inhibition with negligible body weight loss.
Topics: Animals; Antineoplastic Agents; Caprylates; Cell Line, Tumor; Cell Proliferation; Cyclohexanes; Diamines; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Female; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Ligands; Male; Mice; Mice, Inbred C57BL; Molecular Structure; Neoplasms, Experimental; Organoplatinum Compounds; Structure-Activity Relationship
PubMed: 33725031
DOI: 10.1039/d0dt04135a -
The Biochemical Journal Jan 2002A reaction of 13-hydroperoxide octadecadienoic acid (13-HPODE) with cytochrome c was analysed using ESR, HPLC-ESR and HPLC-ESR-MS by the combined use of the...
A reaction of 13-hydroperoxide octadecadienoic acid (13-HPODE) with cytochrome c was analysed using ESR, HPLC-ESR and HPLC-ESR-MS by the combined use of the spin-trapping technique. The ESR, HPLC-ESR and HPLC-ESR-MS analyses showed that cytochrome c catalyses formation of pentyl and octanoic acid radicals from 13-HPODE. On the other hand, only the alpha-(4-pyridyl-1-oxide)-N-t-butylnitrone/octanoic acid radical adduct was detected in the elution profile of HPLC-ESR for a mixture of 13-HPODE with haematin, indicating that haematin catalyses the formation of octanoic acid radical. In addition, the reaction of 13-HPODE with cytochrome c was inhibited by chlorogenic acid, caffeic acid and ferulic acid via two possible mechanisms, i.e. reducing cytochrome c (chlorogenic acid and caffeic acid) and scavenging the radical intermediates (chlorogenic acid, caffeic acid and ferulic acid).
Topics: Animals; Caffeic Acids; Caprylates; Chlorogenic Acid; Chromatography, High Pressure Liquid; Coumaric Acids; Cyanides; Cytochrome c Group; Electron Spin Resonance Spectroscopy; Flavonoids; Free Radical Scavengers; Free Radicals; Hemin; In Vitro Techniques; Linoleic Acids; Lipid Peroxides; Mass Spectrometry; Models, Biological; Oxidation-Reduction; Pentanes; Phenols; Polymers; Polyphenols; Spectrophotometry
PubMed: 11742529
DOI: 10.1042/0264-6021:3610057 -
Epilepsia Aug 2017The medium-chain triglyceride (MCT) ketogenic diet contains both octanoic (C8) and decanoic (C10) acids. The diet is an effective treatment for pharmacoresistant...
OBJECTIVE
The medium-chain triglyceride (MCT) ketogenic diet contains both octanoic (C8) and decanoic (C10) acids. The diet is an effective treatment for pharmacoresistant epilepsy. Although the exact mechanism for its efficacy is not known, it is emerging that C10, but not C8, interacts with targets that can explain antiseizure effects, for example, peroxisome proliferator-activated receptor-γ (eliciting mitochondrial biogenesis and increased antioxidant status) and the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor. For such effects to occur, significant concentrations of C10 are likely to be required in the brain.
METHODS
To investigate how this might occur, we measured the β-oxidation rate of C-labeled C8 and C10 in neuronal SH-SY5Y cells using isotope-ratio mass spectrometry. The effects of carnitine palmitoyltransferase I (CPT1) inhibition, with the CPT1 inhibitor etomoxir, on C8 and C10 β-oxidation were also investigated.
RESULTS
Both fatty acids were catabolized, as judged by CO release. However, C10 was β-oxidized at a significantly lower rate, 20% that of C8. This difference was explained by a clear dependence of C10 on CPT1 activity, which is low in neurons, whereas 66% of C8 β-oxidation was independent of CPT1. In addition, C10 β-oxidation was decreased further in the presence of C8.
SIGNIFICANCE
It is concluded that, because CPT1 is poorly expressed in the brain, C10 is relatively spared from β-oxidation and can accumulate. This is further facilitated by the presence of C8 in the MCT ketogenic diet, which has a sparing effect upon C10 β-oxidation.
Topics: Caprylates; Carbon Isotopes; Carnitine O-Palmitoyltransferase; Cell Line, Tumor; Cell Survival; Decanoic Acids; Diet, Ketogenic; Glucose; Humans; Neuroblastoma; Oxidation-Reduction
PubMed: 28682459
DOI: 10.1111/epi.13833 -
Metabolic Engineering Sep 2020Medium-chain fatty acids (C6-C10) have attracted much attention recently for their unique properties compared to their long-chain counterparts, including low melting...
Medium-chain fatty acids (C6-C10) have attracted much attention recently for their unique properties compared to their long-chain counterparts, including low melting points and relatively higher carbon conversion yield. Thioesterase enzymes, which can catalyze the hydrolysis of acyl-ACP (acyl carrier protein) to release free fatty acids (FAs), regulate both overall FA yields and acyl chain length distributions in bacterial and yeast fermentation cultures. These enzymes typically prefer longer chain substrates. Herein, seeking to increase bacterial production of MCFAs, we conducted structure-guided mutational screening of multiple residues in the substrate-binding pocket of the E. coli thioesterase enzyme 'TesA. Confirming our hypothesis that enhancing substrate selectivity for medium-chain acyl substrates would promote overall MCFA production, we found that replacement of residues lining the bottom of the pocket with more hydrophobic residues strongly promoted the C8 substrate selectivity of 'TesA. Specifically, two rounds of saturation mutagenesis led to the identification of the 'TesA variant that exhibited a 133-fold increase in selectivity for the C8-ACP substrate as compared to C16-ACP substrate. Moreover, the recombinant expression of this variant in an E. coli strain with a blocked β-oxidation pathway led to a 1030% increase in the in vivo octanoic acid (C8) production titer. When this strain was fermented in a 5-L fed-batch bioreactor, it produced 2.7 g/L of free C8 (45%, molar fraction) and 7.9 g/L of total free FAs, which is the highest-to-date free C8 titer to date reported using the E. coli type II fatty acid synthetic pathway. Thus, reshaping the substrate binding pocket of a bacterial thioesterase enzyme by manipulating the hydrophobicity of multiple residues altered the substrate selectivity and therefore fatty acid product distributions in cells. Our study demonstrates the relevance of this strategy for increasing titers of industrially attractive MCFAs as fermentation products.
Topics: Binding Sites; Caprylates; Escherichia coli; Escherichia coli Proteins; Lysophospholipase; Periplasmic Proteins; Protein Engineering
PubMed: 32339761
DOI: 10.1016/j.ymben.2020.04.010 -
Journal of Agricultural and Food... Oct 2018The effects of octanoic acid/nonanoic acid and acclimation time on the synthesis of short-chain-length and medium-chain-length PHA blends from activated sludge were...
Synthesis of Short-Chain-Length and Medium-Chain-Length Polyhydroxyalkanoate Blends from Activated Sludge by Manipulating Octanoic Acid and Nonanoic Acid as Carbon Sources.
The effects of octanoic acid/nonanoic acid and acclimation time on the synthesis of short-chain-length and medium-chain-length PHA blends from activated sludge were investigated. An increased concentration (847-1366 mg/L) of PHAs resulted from 4-month acclimation compared with the concentration derived from 2-month acclimation (450-1126 mg/L). The content of octanoic acid had a positive linear relationship with the content of even-numbered carbon monomers among the PHAs. The blending products were identified mainly with scl-PHAs during the 2-month acclimation period and were thereafter dominated by mcl-PHAs until 4 months of acclimation. Thermal properties analysis demonstrated that the products derived from 4-month acclimation were a mixture of scl-PHAs and mcl-PHAs rather than a copolymer of scl-PHAs and mcl-PHAs. High-throughput sequencing results indicated that Pseudofulvimonas, Paracoccus, and Blastocatella were the dominant genera that might be responsible for scl-PHAs production during the 2-month acclimation period, whereas Comamonas and Pseudomonas that were responsible for mcl-PHAs production then became the dominant genera after 4-months acclimation.
Topics: Bacteria; Base Sequence; Caprylates; Carbon; Fatty Acids; Gene Expression Regulation, Bacterial; High-Throughput Screening Assays; Polyhydroxyalkanoates; Sewage; Time Factors
PubMed: 30265532
DOI: 10.1021/acs.jafc.8b04001