BACKGROUND: Constipation is prevalent after bariatric surgery and glucagon-like-peptide 1 (GLP-1) analogues. Increasing fat content in the distal small intestine and colon can enhance colonic peristalsis, potentially alleviating symptoms of constipation.
OBJECTIVE: We investigated whether oleic acid can ameliorate constipation in patients undergoing bariatric surgery or receiving GLP-1 analogues.
METHODS: Fourteen adults with chronic constipation according to Rome IV criteria following bariatric surgery or GLP-1 analogues were on stable treatment for constipation for more than 4 weeks. This randomized double-blind crossover trial compared microcapsules containing 21.25 g of oleic acid delivered in the distal small intestine or the stomach. The primary outcome was changed in the number of bowel motions over 24 h. Exploratory endpoints included alterations in straining, diarrhoea, faecal leakage over 24 h and hunger, fullness, nausea and calorie intake for the 3 h after ingesting the microcapsules.
RESULTS: Receiving oleic acid into the distal small intestine increased number of bowel movements per day (2.5 vs 1.1, p = 0.009) and caused softer stool consistency (p = 0.03). 9/14 of the control group passed motions and 13/14 of the intervention group passed motions in 24 h (p = 0.059). No significant differences were observed in straining (p = 0.65), rapid bowel movements (p = 0.08), accidental leakage (p = 0.32), hunger, fullness, nausea or food intake between the groups (all p > 0.05). There were no disparities in safety profile between groups.
CONCLUSIONS: Microcapsules containing oleic acid delivered to the distal small intestine appear to be a safe and effective relief from chronic constipation in patients undergoing bariatric surgery and/or receiving GLP-1 analogues.

In this study, the potential mechanism of aroma loss in non-smoked bacon due to excessive hot air drying (beyond 24 h) was investigated, focusing on protein conformational changes and the inhibition of heme protein-mediated lipid oxidation by oleic acid. The results showed that prolonged hot-air drying caused a stretching of the myofibrillar protein (MP) conformation in bacon before 36 h, leading to an increase in reactive sulfhydryl groups, surface hydrophobicity, and the exposure of additional hydrophobic sites. Consequently, the binding ability of MP to the eight key aroma compounds (hexanal, 1-octen-3-ol, (E)-2-nonenal, 3-methyl-butanoic acid, 2-undecenal, (E, E)-2,4-decadienal, 2,3-octanedione, and dihydro-5-pentyl-2(3H)-furanone) was enhanced, resulting in their retention. On the other hand, a sustained increase in oleic acid levels has been demonstrated to effectively inhibit heme protein-mediated lipid oxidation and the formation of these key aroma compounds. Using lipidomic techniques, 30 lipid molecules were identified as potential precursors of oleic acid during the bacon drying process. Among these precursors, triglycerides (16:0/18:0/18:1) may be the most significant.

Hydroxy fatty acids (HFAs) are fatty acids with hydroxyl functional groups attached to the main chain. HFAs are used in widely diverse industrial applications, healthy functional foods, artificial food flavorings, and alcoholic beverages. A lactic acid bacterium (LAB), Lactobacillus sakei, hydroxylates oleic acid. Furthermore, the hydroxyl fatty acid was identified by GC-MS as 10-hydroxystearic acid. The Lactobacillus sakei hydroxylated more than 90% of the oleic acid in the medium at 15 °C after 30-48 h. The hydroxyl enzyme needs a coenzyme for an electron donor as NADPH. The enzyme is useful for assay with monitoring NADPH concentration used an A340 device. The hydroxylate fatty acids are converted by LAB lactonize aroma lactone from commercial yeast strains, which can be detected directly by scent. Commercial beer brewing yeast T-58 produced the highest concentration of aroma lactone from hydroxyl fatty acids. Furthermore, the aroma lactone is identified by GC-MS as gamma-dodecalactone. The ratio of conversion is 87%. These results suggest that the lactonization conversion system is useful to hydroxylate fatty acids for alcoholic beverages.

The Trichilia emetica plant is traditionally used for medicinal and food purposes. However, there are limited studies on the bioactivity and cytotoxicity of its seed butter and aril oil. This study aimed to assess the antidiabetic activity and cytotoxicity of seed butter and aril oil, obtained via two different extraction methods, and compare their lipid profiles. The plant samples were collected from the Faifa mountains and extracted using a Soxhlet apparatus for hot extraction and a magnetic stirrer for cold maceration. The antidiabetic activity and cytotoxicity were evaluated using the α-amylase and MTT assays, respectively. The fatty acids were quantified utilizing gas chromatography-mass spectrometry. This study proves the impact of the extraction method on the yield, cytotoxicity, antidiabetic activity and lipid profile. The highest cytotoxicity was observed with the seed butter obtained via Soxhlet extraction. The α-amylase inhibition was observed at the highest levels with the seed butter and aril oil obtained via cold maceration. The palmitic acid (PA) and oleic acid (OA) were detected at their maximal concentrations in the seed butter obtained via Soxhlet extraction and aril oil obtained via cold maceration, respectively. This study represents an essential basis for understanding the importance of T. emetica as a valuable tree for food, cosmetic and medicinal purposes. Further experiments can lead to the development of green extraction techniques and isolation of the cytotoxic and antidiabetic molecules that can be developed into new pharmaceutical products or serve as lead molecules for new drugs.

Delivering nucleic acid therapeutics across cell membranes is a significant challenge. Cell-penetrating peptides (CPPs) containing arginine (R), tryptophan (W), and histidine (H) show promise for siRNA delivery. To improve siRNA delivery and silence a model STAT3 gene, we hypothesized that oleyl acylation to CPPs, specifically (WRH)n, would enhance STAT3 silencing efficiency in breast and ovarian cancer cells. Using Fmoc/tBu solid-phase peptide chemistry, we synthesized, purified, and characterized the oleyl-conjugated (WRH)n (n = 1-4) peptides. The peptide/siRNA complexes were non-cytotoxic at N/P 40 (~20 μM) against MDA-MB-231, MCF-7, SK-OV-3, and HEK-293 cells after 72 h incubation. All peptide/siRNA complexes showed serum stability at N/P ≥ 40. The synthesized conjugates, with a diameter of <100 nm, formed nano-complexes with siRNA and exhibited a stable range of zeta potential values (13-18 mV at N/P = 40). Confocal microscopy and flow cytometry analysis provided qualitative and quantitative evidence of a successful cellular internalization of siRNA. The peptides oleyl-(WRH)3 and oleyl-(WRH)4 showed ~60% and ~75% cellular uptake of siRNA, respectively, in both MDA-MB-231 and SK-OV-3 cells. Western blot analysis of oleyl-(WRH)4 demonstrated effective silencing of the STAT-3 gene, with ~75% silencing in MDA-MB-231 cells and ~45% in SK-OV-3 cells.

The research compared the combined effect of ultrasound (160 W, 2 min), oleic acid (15%, 11 h), and moist-heat treatment (HMT, 25% moisture content, 110 °C, 2 h) with their individual treatment on rice grains. The results showed that ultrasound treatment created pores and cracks in the rice grains, facilitating an easier penetration for oleic acid to develop amylose-oleic acid complex during HMT. Compared to native raw rice (NR), both single and combined treatments significantly altered the morphology, reduced swelling power and solubility, enhanced hydrophilicity, thus changing the moisture distribution, thermal and pasting characteristics. Notably, the combined treatment of three techniques significantly increased the relative crystallinity, accompanied by the highest digestive resistance, and the content of resistant starch was increased from 20.53% in NR to 31.75%, much higher than the other treatments. These findings provide potential for the manufacturers to rationally and flexibly employ this low digestible rice in health food products.

This research aims to assess the effect of amino acids as lipid antioxidants in reducing the formation of volatile aldehydes in frying oil. Methionine, histidine, and glycine at concentrations of 2.5, 5, and 10 mM were added to high oleic sunflower oil (HOSO) to investigate their effects on the distribution and formation of saturated, monounsaturated, and polyunsaturated volatile aldehydes. The results showed that the proportion of saturated volatile aldehydes was greater than that of unsaturated ones; Methionine exhibited the best inhibitory effect, after 12 h of frying, 10 mM methionine reduced the content of saturated volatile aldehydes by 24.21 %, monounsaturated by 52.4 %, and polyunsaturated by 54.73 % compared to the control. Methionine\'s sulfur-containing side chain was also proven to have strong antioxidant activity. Combined with the results of this study, this can also provide insights for using amino acids as lipid antioxidants.

In the present study, we investigated the genotoxicity of the active products formed from N-nitrosoproline (NPRO) dissolved in oleic acid following ultraviolet A (UVA) irradiation, bypassing the need for metabolic activation. We previously demonstrated the photomutagenicity of NPRO dissolved in a phosphate-buffered solution. It has been suggested that the association of the nitrosamine group with acid ions facilitates rapid photodissociation and photoactivation. We hypothesized that NPRO\'s inherent carboxyl group may mimic an acid, inducing photodissociation and photomutagenicity, even in a non-aqueous solvent lacking acidic ions. Following UVA irradiation, NPRO dissolved in oleic acid exhibited a dose-dependent mutagenic activity. Similar results were obtained when NPRO was dissolved in linoleic acid and triolein. Nitric oxide formation, which is dependent on NPRO concentration, is accompanied by mutagenic activity. The mutagenicity spectrum obtained in response to NPRO irradiation followed the absorption curve of NPRO dissolved in oleic acid. Irradiated NPRO in oleic acid displayed relative stability, retaining approximately 18, 36, and 63 % of initial mutagenicity after 10 days of storage at 25, 4, and -20 °C, respectively. Thus NPRO stored in a fatty environment undergoes photoactivation upon irradiation, leading to genotoxicity.

TiO2is one of the most studied semiconductor materials for the photoelectrochemical water splitting to hydrogen production, but it only responds to ultraviolet light. The introduction of organic compound is one of the common means to expand the visible light response of TiO2. In this work, rutile TiO2nanowire arrays (NWs) were grown on conductive glass by a modified solvothermal method using oleic acid as the key additive. The obtained TiO2NWs are characterized using x-ray diffraction, x-ray photoelectron spectroscopy, infrared spectroscopy and electrochemical characterization. The results show that the carboxyl groups arising from oleic acid are chemically bonded with the TiO2NWs in the form of chelating bidentate, which increases the visible light absorption range and active sites of TiO2, and reduces the transfer resistance between the photoelectrode and the electrolyte. The photocurrent density is doubled to 0.17 mA cm-2at 1.23 V vs. RHE. This work provides a novel idea for the design of metal oxide semiconductor photoanodes by adsorbing organic compounds.

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) has surged due to changes in economic and lifestyle patterns, leading to significant health challenges. Previous reports have studied the establishment of animal and cellular models for MASLD, highlighting differences between them. In this study, a cellular model was created by inducing fat accumulation in MASLD. HepG2 cells were stimulated with the unsaturated fatty acid oleic acid at various concentrations (0.125 mM, 0.25 mM, 0.5 mM, 1 mM) to emulate MASLD. The model\'s efficacy was assessed using cell counting kit-8 assays, Oil Red O staining, and lipid content analysis. This study aimed to create a simple-to-operate cellular model for MASLD cells. Results from the cell counting kit-8 assays showed that the survival of HepG2 cells was dependent on the concentration of oleic acid, with a GI50 of 1.875 mM. Cell viability in the 0.5 mM and 1 mM groups were significantly lower than those in the control group (P < 0.05). Furthermore, Oil Red O staining and lipid content analysis examined fat deposition at varying oleic acid concentrations (0.125 mM, 0.25 mM, 0.5 mM, 1 mM) on HepG2 cells. The lipid content of the 0.25 mM, 0.5 mM, and 1 mM groups was significantly higher than that of the control group (P < 0.05). Additionally, triglyceride levels in the OA groups were significantly higher than those in the control group (P < 0.05).