Ionotropic receptors in the turnip moth Agrotis segetum respond to repellent medium-chain fatty acids

In insects, airborne chemical signals are mainly detected by two receptor families, odorant receptors (ORs) and ionotropic receptors (IRs). Functions of ORs have been intensively investigated in Diptera and Lepidoptera, while the functions and evolution of the more ancient IR family remain largely unexplored beyond Diptera. Here, we identified a repertoire of 26 IRs from transcriptomes of female and male antennae, and ovipositors in the moth Agrotis segetum. We observed that a large clade formed by IR75p and IR75q expansions is closely related to the acid-sensing IRs identified in Diptera. We functionally assayed each of the five AsegIRs from this clade using Xenopus oocytes and found that two receptors responded to the tested ligands. AsegIR75p.1 responded to several compounds but hexanoic acid was revealed to be the primary ligand, and AsegIR75q.2 responded primarily to octanoic acid, and less so to nonanoic acid. It has been reported that the C6-C10 medium-chain fatty acids repel various insects including many drosophilids and mosquitos. Our GC-EAD recordings showed that C6-C10 medium-chain fatty acids elicited antennal responses of both sexes of A. segetum, while only octanoic acid had repellent effect to the moths in a behavioural assay. In addition, using fluorescence in situ hybridization, we demonstrated that AsegIR75q.2 and its co-receptor AsegIR8a are not located in coeloconic sensilla as found in Drosophila, but in basiconic or trichoid sensilla. These functional data in combination with our phylogenetic analysis suggest that subfunctionalization of the acid-sensing IRs after gene duplication plays an important role in the evolution of ligand specificities of the acid-sensing IRs in Lepidoptera.

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The combined use of triacylglycerols containing medium-chain fatty acids and exogenous lipolytic enzymes as an alternative to in-feed antibiotics in piglets: concept, possibilities and limitations. An overview

Nutrition Research Reviews ◽

10.1079/nrr200369 ◽

2003 ◽

Vol 16 (2) ◽

pp. 193-210 ◽

Cited By ~ 56

Author(s):

J. A. Decuypere ◽

N. A. Dierick

Keyword(s):

Fatty Acids ◽

Lipase Activity ◽

Antimicrobial Agents ◽

Antibacterial Properties ◽

Carcass Composition ◽

Cross Resistance ◽

Medium Chain ◽

Medium Chain Fatty Acids ◽

Chain Fatty Acids

In the search for alternatives to banned in-feed antibiotics, a concept was developed based on studies with medium-chain fatty acid-containing triacylglycerols (MCTAG) and selected lipases forin situgeneration of diacylglycerols, monoacylglycerols and medium-chain fatty acids (MCFA) in the stomach and proximal gut of piglets. MCFA are known to have strong antibacterial properties but can hardly be used as such because of their repellent odour and taste. Those problems could be overcome by the generation of MCFAin situ. The concept was testedin vitroand validatedin vivowith gastric-cannulated piglets and under field conditions, including effects on zootechnical performance, with classical antibacterial growth promoters or organic acids acting as positive controls. Furthermore, the metabolic and dietary constraints on the nutritional and nutritive use of MCTAG and/or MCFA (for example, the effects on digestive physiology, gut flora, feed intake, performance, carcass composition) are reviewed. The role of natural preduodenal lipase activity, the presence of endogenous plant lipase activity in raw materials and the feasibility for exogenous lipase addition to the feed are discussed, in order to optimize the concept. The present review illustrates the similarity of the action of MCFA and commonly used antimicrobials on the flora (total flora, Gram-positive flora, Gram-negative flora, potential pathogens) and epithelial morphology and histology in the foregut. These observations are believed to be the basis for obtaining optimal growth performances. In addition, these naturally occurring antimicrobial agents have little or no human or animal toxicity and induce no problems of residues and cross-resistance induction. They are proposed as a valuable alternative to in-feed antibiotics, used for growth promotion, and even for the preventive and curative treatment of gastrointestinal diseases.

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Medium-Chain Fatty Acids Affect Citrinin Production in the Filamentous Fungus Monascus ruber

Applied and Environmental Microbiology ◽

10.1128/aem.66.3.1120-1125.2000 ◽

2000 ◽

Vol 66 (3) ◽

pp. 1120-1125 ◽

Cited By ~ 79

Author(s):

Hassan Hajjaj ◽

Alain Klaébé ◽

Gérard Goma ◽

Philippe J. Blanc ◽

Estelle Barbier ◽

...

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Filamentous Fungus ◽

Octanoic Acid ◽

Pigment Production ◽

Monascus Ruber ◽

Red Pigments ◽

Medium Chain ◽

Medium Chain Fatty Acids ◽

Chain Fatty Acids

ABSTRACT During submerged culture in the presence of glucose and glutamate, the filamentous fungus Monascus ruber produces water-soluble red pigments together with citrinin, a mycotoxin with nephrotoxic and hepatoxic effects on animals. Analysis of the13C-pigment molecules from mycelia cultivated with [1-13C]-, [2-13C]-, or [1,2-13C]acetate by 13C nuclear magnetic resonance indicated that the biosynthesis of the red pigments used both the polyketide pathway, to generate the chromophore structure, and the fatty acid synthesis pathway, to produce a medium-chain fatty acid (octanoic acid) which was then bound to the chromophore by atrans-esterification reaction. Hence, to enhance pigment production, we tried to short-circuit the de novo synthesis of medium-chain fatty acids by adding them to the culture broth. Of fatty acids with carbon chains ranging from 6 to 18 carbon atoms, only octanoic acid showed a 30 to 50% stimulation of red pigment production, by a mechanism which, in contrast to expectation, did not involve its direct trans-esterification on the chromophore backbone. However, the medium- and long-chain fatty acids tested were readily assimilated by the fungus, and in the case of fatty acids ranging from 8 to 12 carbon atoms, 30 to 40% of their initial amount transiently accumulated in the growth medium in the form of the corresponding methylketone 1 carbon unit shorter. Very interestingly, these fatty acids or their corresponding methylketones caused a strong reduction in, or even a complete inhibition of, citrinin production byM. ruber when they were added to the medium. Several data indicated that this effect could be due to the degradation of the newly synthesized citrinin (or an intermediate in the citrinin pathway) by hydrogen peroxide resulting from peroxisome proliferation induced by medium-chain fatty acids or methylketones.

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310 Using synergistic antibacterial combinations based on vegetable essential oils to replace feeding antibiotics

Journal of Animal Science ◽

10.1093/jas/skz258.018 ◽

2019 ◽

Vol 97 (Supplement_3) ◽

pp. 10-10

Author(s):

yanping Hu ◽

Jie Huang ◽

Zhongxin Zhou

Keyword(s):

Fatty Acids ◽

Citric Acid ◽

Organic Acids ◽

Essential Oils ◽

Octanoic Acid ◽

Water Solubility ◽

Enterotoxigenic Escherichia Coli ◽

Medium Chain ◽

Medium Chain Fatty Acids ◽

Chain Fatty Acids

Abstract Vegetable essential oils, medium-chain fatty acids and organic acids have great potential in the development of alternatives to feeding antibiotics, but many problems in practice limit their application, such as irritating odor, poor water solubility, easy oxidation and volatility. In this study, we found that vegetable essential oils (carcilol, cinnamaldehyde, terptol-4) and medium chain fatty acids (octanoic acid and nonanoic acid) or organic acids (citric acid) had significantly synergistic bactericidal effects on enterotoxigenic Escherichia coli and Salmonella enteribacilli, which are both common pathogens causing piglets diarrhea. Furthermore, we also compared the tolerances of the enterotoxigenic Escherichia coli against plant essential oils (cinnamaldehyde, carcocol, 4- terptol), medium chain fatty acids (octanoic acid and nonylic acid), organic acids (citric acid), and commonly used antibiotic growth promoter (gentamycin sulfate). They were in vitro cultured with ETEC strain for 30 consecutive generations and the minimum inhibitory concentration (MIC) value was detected. The results showed that the MIC values of carvonol, cinnamaldehyde, terpineol-4, octanoic acid, nonylic acid, and citric acid against the ETEC bacteria increased by 5, 3, 1, 0.3, 0.4 and 0 times. But the MIC value of gentamicin against ETEC bacteria increased, in the 20th generation, by more than 64 times. In conclusions, the synergistic bactericidal combination based on the plant essential oil and middle chain fatty acid or organic acid may be a better strategy to replace feeding antibiotics because their synergistic bactericidal combination can greatly reduce the effective concentration of plant essential oil, medium chain fatty acid and organic acid, thus alleviating to a certain extent the shortcomings of unstable effects caused by the irritating odor, the poor water solubility, easy oxidation and volatility. The synergistic bactericidal combination based on plant essential oils are also relatively difficult to cause bacterial tolerance and alleviate bacterial resistance to a certain extent.

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Enhanced Bioavailability of Curcumin Nanoemulsions Stabilized with Phosphatidylcholine Modified with Medium Chain Fatty Acids

Current Drug Delivery ◽

10.2174/1567201813666160919142811 ◽

2017 ◽

Vol 14 (3) ◽

pp. 377-385 ◽

Cited By ~ 8

Author(s):

Angelica A. Ochoa-Flores ◽

Josafat A. Hernández-Becerra ◽

Adriana Cavazos-Garduño ◽

Ida Soto-Rodríguez ◽

Maria Guadalupe Sanchez-Otero ◽

...

Keyword(s):

Fatty Acids ◽

Medium Chain ◽

Medium Chain Fatty Acids ◽

Chain Fatty Acids

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Effects of ketogenic diet containing medium-chain fatty acids on serum inflammatory factor and mTOR signaling pathway in rats

Chemical and Biological Technologies in Agriculture ◽

10.1186/s40538-020-00194-4 ◽

2020 ◽

Vol 7 (1) ◽

Author(s):

Huan Liu ◽

Jingwei Huang ◽

Hui Liu ◽

Feng Li ◽

Quansheng Peng ◽

...

Keyword(s):

Fatty Acids ◽

Caloric Restriction ◽

Ketogenic Diet ◽

Mtor Pathway ◽

Inflammatory Factor ◽

Medium Chain ◽

Medium Chain Fatty Acids ◽

Sd Rats ◽

Anti Inflammatory ◽

Chain Fatty Acids

Abstract Background The ketogenic diet (KD) can promote the anti-inflammatory metabolic state and increase ketone body level in rats. This study was to explore the effects and differences of KD with or without medium-chain fatty acids (MCFAs) on serum inflammatory factors and mTOR pathway in Sprague–Dawley (SD) rats. Results Male SD rats were assigned to five groups: control diet (C), 20% caloric restriction diet (LC), 20% caloric restriction ketogenic diet (containing MCFAs) (LCKD1), 20% caloric restriction ketogenic diet (LCKD2) and 20% caloric restriction foreign ketogenic diet (LCKD3), and fed for 30 d. LC and KD could significantly reduce the body weight of rats; LC and KD containing MCFAs showed anti-inflammatory effects; KD without MCFAs decreased the concentration of mTOR1, while KD containing MCFAs decreased the expression of AMPK, mtor1 and P70sk. Conclusions KD containing MCFAs showed better effects on the mTOR pathway and anti-inflammation than that without MCFAs.

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