Investigation of the influence of minor components and fatty acid profile of oil on properties of beeswax and stearic acid-based oleogels

Understanding the impact of minor components and the fatty acid profile of oil on oleogel properties is essential for optimizing their characteristics. Considering the scarcity of literature addressing this aspect, this study aimed to explore the correlation between these factors and the properties of beeswax and stearic acid-based oleogels derived from rice bran oil and sesame oil. Minor oil components were modified by stripping the oil, heating the oil with water, and adding β-sitosterol. Oleogels were then prepared using a mixture of beeswax and stearic acid (3:1, w/w) at a concentration of 11.74 % (w/w). The properties of oils and oleogels were evaluated. The findings indicated that minor components and fatty acid composition of the oils substantially influence the oleogel properties. Removing minor components by stripping resulted in smaller and less uniformly distributed crystals and less oil binding capacity compared to the oleogels prepared from untreated oils. A moderate amount of minor components exhibited a significant influence on oleogel properties. The addition of β-sitosterol did not show any influence on oleogel properties except for the oleogel made from untreated oil blend added with β-sitosterol which had more uniform crystals in the microstructure and demonstrated better rheological stability when stored at 5 °C for two months. The oil composition did not show any influence on the thermal and molecular properties of oleogels. Consequently, the oleogel formulation derived from the untreated oil blend enriched with β-sitosterol was identified as the optimal formula for subsequent development. The findings of this study suggest that the physical and mechanical properties as well as the oxidative stability of beeswax and stearic acid-based oleogels are significantly affected by the minor constituents and fatty acid composition of the oil. Moreover, it demonstrates that the properties of oleogels can be tailored by modifying oil composition by blending different oils.

A UPLC-MS/MS method for simultaneous determination of arachidonic acid, stearic acid, and related endocannabinoids in human plasma

Endocannabinoids (eCBs) exert considerable influence over energy metabolism, lipid metabolism, and glucose metabolism within the human body. Among the most biologically active cannabinoids identified thus far are 2-arachidonoylglycerol (2-AG), arachidonoyl ethanolamide (AEA), 1-stearoylglycerol (1-SRG), and stearoyl ethanolamide (SEA), which are derived from arachidonic acid (AA) and stearic acid (SA). However, despite the unique in bioactivities exhibited by eCBs, their determination in plasma has been hindered by the lack of sensitive analytical methods. The aim of this study was to develop and validate a highly sensitive and rapid method using ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for accurate measurement of AEA, SEA, 2-AG, 1-SRG, AA, and SA levels in human plasma samples. Sample preparation involved a protein precipitation method and a methyl tert-butyl ether liquid-liquid extraction method. Chromatographic separation was accomplished by utilizing an ACQUITY UPLC BEH C8 column with a mobile phase of acetonitrile containing 0.1% formic acid and water containing 0.1% formic acid, flowing at a rate of 0.35 mL/min. AA-d8, 2-AG-d5, and AEA-d8 were selected as deuterated internal standards. The analytes were determined with MRM in both positive and negative ion mode. The lower limit of quantification ranged from 0.1 to 400 ng/mL, and the correlation coefficient (R2) was >0.99. Inter-day and intra-day precision exhibited values of 0.55-13.29% and 0.62%-13.90%, respectively. Recovery and matrix effect were within the range of 77.7%-109.7%, and 90.0%-113.5%, respectively. Stability tests confirmed the acceptability of all analytes. To demonstrate the effectiveness of the approach, it was implemented to assess and compare plasma samples from healthy volunteers (n = 49) and individuals with non-alcoholic fatty liver disease (NAFLD) (n = 62). The study revealed significant differences in AEA, SEA, AA, and SA levels between the two groups.

Exploring temperature-responsive drug delivery with biocompatible fatty acids as phase change materials in ethyl cellulose nanofibers

This study introduces a novel temperature-responsive drug delivery system using ethyl cellulose (EC) nanofibers encapsulating a eutectic mixture of lauric acid/stearic acid (LA/SA) as phase change materials (PCMs) and Rhodamine B (RhB) as a model drug. Employing blend electrospinning, the nanofibers achieved controlled drug release responsive to temperature changes. The peak shift of the carbonyl group in FTIR analysis confirmed drug-polymer compatibility, while the absence of RhB peaks in the XRD and DSC assessments revealed RhB's amorphous distribution within the fibers. Our findings demonstrate that RhB release is dependent on its loading, with a slow initial release (<2 %) for 1 % and 5 % RhB loadings and a burst release (~12 %) for 10 % loading. Notably, the release rate was tunable at 37 °C by adjusting LA/SA concentration. The optimal LA/SA loading for temperature-responsive release is identified as 10 %. Over 240 h, there is a 32 % increase in RhB release at 37 °C, and an additional 8 % increase at 40 °C, compared to 25 °C. This research illustrates the potential of PCM-integrated nanofibers in smart drug delivery, particularly for chemotherapy, antibiotics, and anti-inflammatory drugs, showcasing an innovative approach to improving therapeutic efficiency while reducing side effects.

Relationship Between the Lipidome Profile and Disease Activity in Patients with Rheumatoid Arthritis

Lipid mediators have been suggested to play important roles in the pathogenesis of rheumatoid arthritis (RA). Lipidomics has recently allowed for the comprehensive analysis of lipids and has revealed the potential of lipids as biomarkers for the early diagnosis of RA and prediction of therapeutic responses. However, the relationship between disease activity and the lipid profile in RA remains unclear. In the present study, we performed a plasma lipidomic analysis of 278 patients with RA during treatment and examined relationships with disease activity using the Disease Activity Score in 28 joints (DAS28)-erythrocyte sedimentation rate (ESR). In all patients, five lipids positively correlated and seven lipids negatively correlated with DAS28-ESR. Stearic acid [FA(18:0)] (r = -0.45) and palmitic acid [FA(16:0)] (r = -0.38) showed strong negative correlations. After adjustments for age, body mass index (BMI), and medications, stearic acid, palmitic acid, bilirubin, and lysophosphatidylcholines negatively correlated with disease activity. Stearic acid inhibited osteoclast differentiation from peripheral blood monocytes in in vitro experiments, suggesting its contribution to RA disease activity by affecting bone metabolism. These results indicate that the lipid profile correlates with the disease activity of RA and also that some lipids may be involved in the pathogenesis of RA.

Stearic acid-modified hollow hydroxyapatite particles with enhanced hydrophobicity for oil adsorption from oil spills

Oil spills lead to a substantial depletion of aquatic biodiversity. The mitigation of an oil spill can entail considerable financial outlays, give rise to consequential environmental impacts, and present formidable operational complexities. In this research, hollow hydroxyapatite particles with enhanced oil adsorption characteristics were prepared by surface modification with stearic acid. Peanut and vacuum pump oils were used to imitate oil spills and conduct adsorption tests. The 50% stearic acid-modified hydroxyapatite (Sa/HAP) adsorbent showed superior hydrophobic properties with respect to water contact angle data. Adsorption isotherm analysis revealed that the adsorption processes of peanut and vacuum pump oils matched well with the Sips isotherm model, with regression coefficients of 0.992 and 0.996, respectively. The oil adsorption by the modified hydroxyapatite (HAP) adsorbent was found to be 9.85 g·g-1 for peanut oil and 12.13 g·g-1 for vacuum pump oil. Furthermore, the adsorption kinetics performance was determined by chemical interaction, whereas the adsorption equilibrium capacities were 8.97 g·g-1 and 11.41 g·g-1, respectively. Recycling of the spent adsorbent was performed with toluene stripping. The synthesized oil-adsorbents were analyzed by SEM, FTIR, XRD, contact angle, and TGA analyses. Hence, the efficacy of the Sa/HAP material as a potential adsorbent for the purification of oil-contaminated water was established, attributed to its commendable oil adsorption capability.

Stearic acid promotes lipid synthesis through CD36/Fyn/FAK/mTORC1 axis in bovine mammary epithelial cells

Stearic acid (C18:0, SA) is a saturated long-chain fatty acid (LCFA) that has a prominent function in lactating dairy cows. It is obtained primarily from the diet and is stored in the form of triacylglycerol (TAG) molecules. The transmembrane glycoprotein cluster of differentiation 36 (CD36) is also known as fatty acid translocase, but whether SA promotes lipid synthesis through CD36 and FAK/mTORC1 signaling is unknown. In this study, we examined the function and mechanism of CD36-mediated SA-induced lipid synthesis in bovine mammary epithelial cells (BMECs). SA-enriched supplements enhanced lipid synthesis and the FAK/mTORC1 pathway in BMECs. SA-induced lipid synthesis, FAK/mTORC1 signaling, and the expression of lipogenic genes were impaired by anti-CD36 and the CD36-specific inhibitor SSO, whereas overexpression of CD36 effected the opposite results. Inhibition of FAK/mTORC1 by TAE226/Rapamycin attenuated SA-induced TAG synthesis, inactivated FAK/mTORC1 signaling, and downregulated the lipogenic genes PPARG, CD36, ACSL1, SCD, GPAT4, LIPIN1, and DGAT1 at the mRNA and protein levels in BMECs. By coimmunoprecipitation and yeast two-hybrid screen, CD36 interacted directly with Fyn but not Lyn, and Fyn bound directly to FAK; FAK also interacted directly with TSC2. CD36 linked FAK through Fyn, and FAK coupled mTORC1 through TSC2 to form the CD36/Fyn/FAK/mTORC1 signaling axis. Thus, stearic acid promotes lipogenesis through CD36 and Fyn/FAK/mTORC1 signaling in BMECs. Our findings provide novel insights into the underlying molecular mechanisms by which LCFA supplements promote lipid synthesis in BMECs.

Effect of fatty acids on intracellular pneumocandin B0 storage in the fermentation of Glarea lozoyensis

The natural product pneumocandin B0 is the precursor of the antifungal drug caspofungin. To explore the relationship between pneumocandin B0 and oil. We found that the addition of 1 g/L of oil to the fermentation medium is more conducive to the production of pneumocandin B0. The metabolic reaction mechanism was explored using different fatty acids and the results showed that stearic acid and acetic acid increased the total production of pneumocandin B0 by 22.98% and 9.08%, respectively, as well as increasing the content of intracellular lipid droplets. We also analyzed gene expression and pathway differences between the two different fatty acids using transcriptome analyses. The addition of both acetic acid and stearic acid promoted an active pentose phosphate pathway, providing cells with higher intracellular reducing power. We found that the addition of fatty acids can lead to lipid accumulation, and lipid droplets can sequester lipophilic secondary metabolites such as pneumocandin B0 to reduce cell damage. These results provide novel insights into the relationship between pneumocandin B0 biosynthesis and fatty acids in G. lozoyensis. In addition, this study provides important genetic information for improving the yield of pneumocandin B0 through a strategy of metabolic engineering in the future.

The imperative of arachidonic acid in early human development

This review is about the role of arachidonic acid (ArA) in foetal and early growth and development. In 1975 and '76, we reported the preferential incorporation of ArA into the developing brain of rat pups, its conservation as a principal component in the brains of 32 mammalian species and the high proportion delivered by the human placenta for foetal nutrition, compared to its parent linoleic acid (LA). ArA is quantitatively the principal acyl component of membrane lipids from foetal red cells, mononuclear cells, astrocytes, endothelium, and placenta. Functionally, we present evidence that ArA, but not DHA, relaxes the foetal mesenteric arteries. The placenta biomagnifies ArA, doubling the proportion of the maternal level in cord blood. The proportions of ArA and its allies (di-homo-gamma-linolenic acid (DGLA), adrenic acid and ω6 docosapentaenoic acid) are similar or higher than the total of ω3 fatty acids in human milk, maintaining the abundant supply to the developing infant. Despite the evidence of the importance of ArA, the European Food Standard Agency, in 2014 rejected the joint FAO and WHO recommendation on the inclusion of ArA in infant formula, although they recommended DHA. The almost universal dominance of ArA in the membrane phosphoglycerides during human organogenesis and prenatal growth suggests that the importance of ArA and its allies in reproductive biology needs to be re-evaluated urgently.

Solidified saturated fats coating subunit vaccines greatly extended vaccine booster release and contributed to a Th1/Th2 mixed immune response in mice

Delayed release of vaccine coupled with a soluble vaccine acts as a primer and a booster with only a single administration, which would be very beneficial to livestock producers. We developed a subdermal pellet consisting of solid-phase pure stearic acid (SA) or palmitic acid (PA) that was used to encapsulate a small volume liquid vaccine consisting of fluorescently labeled *Ovalbumin (Cy5-*OVA) formulated with Emulsigen-D +/- Poly I:C (EMP) adjuvants. Mice were also immunized via the subcutaneous route with Cy5-*OVA-EMP (soluble liquid). The vaccine leached out of the pellet with very little dissolution of the fat itself resulting in the sustained subdermal delivery of antigens and adjuvants. Cy5-*OVA was still visible 60 days post administration in mice immunized with stearic acid-coated or palmitic acid-coated pellets. In these mice, persistently high IgG1 and IgG2a antibody titres were detected as well as significant IFNγ production at least 60 days post-injection. These responses were significantly higher than those observed after a single subcutaneous injection of the vaccine. A repeat trial with the pellets alone +/- the soluble vaccine showed comparable immune responses after surgical implantation of the pellet, suggesting that pellet alone may be sufficient. The PA-coated vaccines led to dermal inflammation in the mice that would limit usefulness of this vehicle, but this was largely absent when SA was used to coat the pellets. These data suggest that the SA-coated adjuvanted vaccine prolonged the release of the vaccine and triggered a comparable immune response to the mice that received the two liquid injections, and a single pellet vaccine should be tested as a novel immunization method for livestock.

Design, development, and in-vitro/in-vivo evaluation of Docetaxel-loaded PEGylated Solid Lipid Nanoparticles in Prostate Cancer Therapy

Docetaxel (DOC) is a potent anticancer molecule widely used to treat various cancers. However, its therapeutic efficacy as a potential anticancer agent has been limited owing to poor aqueous solubility, short circulation time, rapid reticuloendothelial system uptake, and high renal clearance, which consecutively showed poor bioavailability. In the present investigation, we developed polyethylene glycol (PEG) decorated solid lipid nanoparticles (SLN) using the solvent diffusion method to increase the biopharmaceutical properties of DOC. PEG monostearate (SA-PEG₂₀₀₀) was initially synthesized and characterized using various analytical techniques. Afterwards, DOC-loaded SLN was synthesized with and without SA-PEG₂₀₀₀and systematically characterized for in-vitro and in-vivo properties. Spherical-shaped SA-PEG₂₀₀₀-DOC SLN showed hydrodynamic diameter and zeta potential of 177 nm and -13 mV, respectively. During the in-vitro release study DOC-loaded SLN showed a controlledrelease of approximately 54.35 % ±5.46 within 12 h with Higuchi release kinetics in the tumor microenvironment (pH 5.5).In an in-vitro cytotoxicity study,SA-PEG₂₀₀₀-DOC SLN showedsignificantlylower IC₅₀values(p < 0.001)compared to DOC-SLN and DOC aloneagainst prostate cancer cell lines (PC-3). Similarly, an in-vitro cellular uptake study showed a significant increase in intracellular DOC concentration for SA-PEG₂₀₀₀-DOC SLN. Additionally, inin-vivostudies,PEGylated SLN of DOC showed around 2- and 15-fold increase in the maximum concentration of drug (Cmax) and area under the curve (AUC), respectively, as compared to plain DOC solution due to the uniquehydrophilicity and hydrophobicity balance and electrical neutrality of specially designed PEG architect. The biological half-life (t_1/2) and mean residence time (MRT) was found to increase from 8.55 and 11.43 to 34.96 and 47.68 h, respectively, with SA-PEG₂₀₀₀-DOC SLN. Moreover, the bio-distribution study indicates high DOC concentration in the plasma which signifies the more pronounced blood residence time of SA-PEG₂₀₀₀-DOC SLN. In a nutshell, SA-PEG₂₀₀₀-DOC SLNwasfound to bea promising and efficient drug delivery platform for the management of Metastatic Prostate cancer.

Influence of stearic acid and alumina nanofluid on CO2 wettability of calcite substrates: Implications for CO2 geological storage in carbonate reservoirs

HYPOTHESIS

Atmospheric CO₂ emissions trigger global warming and climate change challenges. Thus, geological CO₂ storage appears to be the most viable choice to mitigate CO₂ emissions in the atmosphere. However, the adsorption capacity of reservoir rock in the presence of diverse geological conditions, including organic acids, temperature, and pressure, can cause reduced certainty for CO₂ storage and injection problems. Wettability is critical in measuring the adsorption behavior of rock in various reservoir fluids and conditions.

EXPERIMENT

We systematically evaluated the CO₂-wettability of calcite substrates at geological conditions (323 K and 0.1, 10, and 25 MPa) in the presence of stearic acid (a replicate realistic reservoir organic material contamination). Similarly, to reverse the effects of organics on wettability, we treated calcite substrates with various alumina nanofluid concentrations (0.05, 0.1, 0.25, and 0.75 wt%) and evaluated the CO₂-wettability of calcite substrates at similar geological conditions.

FINDINGS

Stearic acid profoundly affects the contact angle of calcite substrates where wettability shifts from intermediate to CO₂-wet conditions, reducing the CO₂ geological storage potential. The treatment of organic acid-aged calcite substrates with alumina nanofluid reversed the wettability to a more hydrophilic state, increasing CO₂ storage certainty. Further, the optimum concentration displaying the optimum potential for changing the wettability in organic acid-aged calcite substrates was 0.25 wt%. The effect of organics and nanofluids should be augmented to improve the feasibility of CO₂ geological projects at the industrial scale for reduced containment security.

scd knockout activates β-oxidation of fatty acids via accumulating stearic acid (18:0) and induces anorexia in zebrafish

Stearoyl-CoA desaturase (scd) is the rate-limiting enzyme for the biosynthesis of monounsaturated fatty acids (MUFA), and it plays a critical role in regulating hepatic lipogenesis and lipid oxidation. However, its role in teleosts remains unclear. In this study, we generated scd knockout zebrafish (scd^-/-) to explore the role of Scd in regulating growth and metabolism in teleosts. The results showed that scd knockout reduces hepatic lipid deposition by down-regulating the expression of lipogenesis-related genes and up-regulating the expression of lipolysis-related genes. In addition, the knockout of scd suppressed food intake and reduced body weight. Further analysis confirmed that scd knockout suppressed the feeding behavior by decreasing expression of orexigenic peptide genes and increasing expression of anorexigenic peptide genes. The high-level stearic acid (18:0) feeding experiment results showed that the accumulation of 18:0 inhibited feeding behavior, reduced food intake, decreased body weight, and increased lipid β-oxidation, which was essentially consistent with the phenotypes of scd deficiency. Taken together, our results indicate that the knockout of scd inhibited the food intake through the accumulation of 18:0. This study preliminarily reveals the role of Scd in regulating food intake of teleosts, which provides theoretical basis for the functional study of Scd.

Identification and Functional Characterization of Metabolites for Skeletal Muscle Mass in Early Postmenopausal Chinese Women

Low skeletal muscle mass (SMM) is a crucial component of the sarcopenia phenotypes. In the present study, we aim to identify the specific metabolites associated with SMM variation and their functional mechanisms of decreased SMM in early postmenopausal women. We performed an untargeted metabolomics analysis in 430 early postmenopausal women to identify specific metabolite associated with skeletal muscle mass indexes (SMIes). Then, the potential causal effect of specific metabolite on SMM variation was accessed by one-sample Mendelian randomization (MR) analysis. Finally, in vitro experiments and transcriptomics bioinformatics analysis were conducted to explore the impact and potential functional mechanisms of specific metabolite on SMM variation. We detected 65 metabolites significantly associated with at least one SMI (variable importance in projection > 1.5 by partial least squares regression and p < .05 in multiple linear regression analysis). Remarkably, stearic acid (SA) was negatively associated with all SMIes, and subsequent MR analyses showed that increased serum SA level had a causal effect on decreased SMM (p < .05). Further in vitro experiments showed that SA could repress myoblast's differentiation at mRNA, protein, and phenotype levels. By combining transcriptome bioinformatics analysis, our study supports that SA may inhibit myoblast differentiation and myotube development by regulating the migration, adhesion, and fusion of myoblasts. This metabolomics study revealed specific metabolic profiles associated with decreased SMM in postmenopausal women, first highlighted the importance of SA in regulating SMM variation, and illustrated its potential mechanism on decreased SMM.

Inhibition of miR-146a-5p and miR-8114 in Insulin-Secreting Cells Contributes to the Protection of Melatonin against Stearic Acid-Induced Cellular Senescence by Targeting Mafa

BACKGRUOUND

Chronic exposure to elevated levels of saturated fatty acids results in pancreatic β-cell senescence. However, targets and effective agents for preventing stearic acid-induced β-cell senescence are still lacking. Although melatonin administration can protect β-cells against lipotoxicity through anti-senescence processes, the precise underlying mechanisms still need to be explored. Therefore, we investigated the anti-senescence effect of melatonin on stearic acid-treated mouse β-cells and elucidated the possible role of microRNAs in this process.

METHODS

β-Cell senescence was identified by measuring the expression of senescence-related genes and senescence-associated β-galactosidase staining. Gain- and loss-of-function approaches were used to investigate the involvement of microRNAs in stearic acid-evoked β-cell senescence and dysfunction. Bioinformatics analyses and luciferase reporter activity assays were applied to predict the direct targets of microRNAs.

RESULTS

Long-term exposure to a high concentration of stearic acid-induced senescence and upregulated miR-146a-5p and miR- 8114 expression in both mouse islets and β-TC6 cell lines. Melatonin effectively suppressed this process and reduced the levels of these two miRNAs. A remarkable reversibility of stearic acid-induced β-cell senescence and dysfunction was observed after silencing miR-146a-5p and miR-8114. Moreover, V-maf musculoaponeurotic fibrosarcoma oncogene homolog A (Mafa) was verified as a direct target of miR-146a-5p and miR-8114. Melatonin also significantly ameliorated senescence and dysfunction in miR-146a-5pand miR-8114-transfected β-cells.

CONCLUSION

These data demonstrate that melatonin protects against stearic acid-induced β-cell senescence by inhibiting miR-146a- 5p and miR-8114 and upregulating Mafa expression. This not only provides novel targets for preventing stearic acid-induced β-cell dysfunction, but also points to melatonin as a promising drug to combat type 2 diabetes progression.

Kinetics of stearic acid destruction on TiO2 'self-cleaning' films revisited

The photocatalytic oxidation of stearic acid, SA, by O2 is a common test method used to assess the activity of new materials and underpins a standard test for self-cleaning activity. The kinetics of this process have been well-studied and are often interpreted using one of two simple models, which are revisited here in this overview. The first model is based on the common scenario of a SA layer on top of an all-photocatalyst layer which yields zero order kinetics, for which it is suggested that all the reaction sites are occupied by SA during the bulk of the photocatalytic process. An important, but rarely noted feature of this system is that the rate of SA removal depends directly upon the fraction of absorbed ultra-bandgap radiation, which suggests that the photocatalyst particles are extensively networked, thereby allowing the photogenerated electrons and holes to move rapidly and efficiently to the surface to effect the destruction of SA. The second kinetic model has been used to describe the first order kinetics of SA removal observed for mesoporous photocatalytic films comprised of isolated photocatalyst particles, in which the SA is inside (rather than on top) of the photocatalytic film, and is developed further here. It is shown that, contrary to previous reports, this model is not appropriate for porous photocatalytic films in which the particles are extensively networked, such as ones based on powders or sol-gel films, even though they too may exhibit decay kinetics where the order is > 0. The reason for the latter kinetics appears to be a distribution of reactivities through such films, i.e. high and low activity sites.

Nutrient intake, digestibility, and serum metabolites in dairy cows fed diets differing in starch concentration with palmitic acid or stearic acid supplementation postpartum

The present study determined the effect of supplementing palmitic acid (PA) and stearic acid (SA) on the nutrient intake, digestibility, and serum metabolites of dairy cows fed two different starch levels during the postpartum period. Forty-four multiparous Holstein cows were used in a completed randomized block based on their parity and previous milk yield. Dietary treatments were arranged in a 2 × 2 arrangement with two dietary starch levels (HS: 260 g/kg of diet dry matter (DM) vs LS: 210 g/kg of diet DM) and two fat supplements rich in PA or SA at 15 g/kg of diet DM. Increasing the starch concentration of the postpartum diet improved organic matter (OM), ether extract (EE), crude protein (CP), and starch intake. Moreover, HS diets resulted in higher apparent digestibility of OM and CP but lower starch digestibility than LS diets. Feeding HS diets increased fecal starch output compared with LS diets. There was starch levels and FA supplements interaction for serum albumin and total antioxidant capacity (TAC), with higher concentrations in HSSA and LSPA compared to HSPA and LSSA. Significant correlations between performance and blood metabolites were observed in weeks 3 and 4. In week 3, a negative correlation was observed between serum TAC with milk protein (r =  - 0.51) and lactose percentage (r =  - 0.49) in the HS diet. However, non-esterified FA was correlated with the fat to protein ratio in the LS diet (r = 0.54). Moreover, in week 4, serum TAC was negatively related to the body condition score of the cows fed LS diet (r = 0.50), while there was no relationship for cows fed HS diets. In conclusion, feeding HS diets to postpartum cows increased nutrient intake and the digestibility of OM and CP compared with LS diets. The addition of SA to the HS diet may be more beneficial than PA in improving the oxidative status of dairy cows in the postpartum period.

Facile fabrication of thermostable and colorimetric starch-based waterproof coating with edible organic materials

With the attention to pollution and human health, nontoxic food grade superhydrophobic coating as a strategy to reduce food waste has aroused wide interest. Herein, a food grade colorimetric starch-based waterproof coating was achieved using starch nanoparticle (SNP), stearic acid (STA) and anthocyanin. The as-prepared coating exhibited considerable thermostability and remarkable water repellency due to the low-surface-energy pomegranate pulp-like micro/nanostructure assembled by STA and SNP. The certain mechanical and chemical durability, prominent self-cleaning property and liquid food repellency in the coating had been thoroughly verified. Additionally, anthocyanin was creatively introduced to the coating via SNP loading, which endowed the coating with color response to different pH solutions. Thus, the coating is applicable to freshness monitoring without being disabled by water. This thermostable and colorimetric starch-based waterproof coating shows promising application prospects in advanced bio-based food-contact material field.

Fatty acids and their lipid mediators in the induction of cellular apoptosis in cancer cells

The oxygenation of polyunsaturated fatty acids such as arachidonic and linoleic acid through enzymes like lipoxygenases (LOXs) are common and often leads to the production of various bioactive lipids that are important both in acute inflammation and its resolution and thus in disease progression. Amongst the several isoforms of LOX that are expressed in mammals, 15-lipoxygenase (15-LOX) has shown to be crucial in the context of inflammation. Moreover, being expressed in cells of the immune system, as well as in epithelial cells; the enzyme has been shown to crosstalk with a number of important signalling pathways. Mounting evidences from recent reports suggest that 15-LOX has anti-cancer activities which are dependent or independent of its metabolites, and is executed through several downstream pathways like cGMP, PPAR, p53, p21 and NAG-1. However, it is still unclear whether the up-regulation of 15-LOX is associated with cancer cell apoptosis. Monoamine oxidase A (MAO-A), on the other hand, is a mitochondrial flavoenzyme which is believed to be involved in the pathogenesis of atherosclerosis and inflammation and in many other neurological disorders. MAO-A has also been reported as a potential therapeutic target in different types of cancers like prostate cancer, lung cancer etc. In this review, we discussed about the role of fatty acids and their lipid mediators in cancer cell apoptosis. Here we particularly focused on the contribution of oxidative enzymes like 15-LOX and MAO-A in mediating apoptosis in lung cancer cell after fatty acid induction.

Empagliflozin does not reverse lipotoxicity-induced impairment in human myeloid angiogenic cell bioenergetics

Background

Empagliflozin can curb inflammation and oxidative stress, through sodium-proton exchanger (NHE) inhibition, in a model of lipotoxicity in human myeloid angiogenic cells (MAC), which mediate endothelial repairing processes. Aim of this study is to assess in human MAC whether: (1) Stearic acid (SA) induced inflammation and increase in oxidant stress is accompanied by bioenergetic alterations; (2) empagliflozin anti-lipotoxic action is concomitant with coherent changes in bioenergetic metabolism, possibly via NHE blockade.

Methods

MAC were isolated from peripheral blood of healthy volunteers and incubated in the presence/absence of SA (100 μM for 3 h) with/without empagliflozin (EMPA 100 μM) or amiloride (Ami 100 μM) for 1 h. Cell respiration (oxygen consumption rate OCR) and anaerobic glycolysis (measured as proton production rate) were recorded in real-time by Seahorse technology, and ATP production (anaerobic glycolysis- and oxphos-derived) rates were calculated.

Results

SA, at the concentration causing inflammation and increased oxidant stress, altered cell bioenergetics of human MAC, with overall reductions in basal OCR and oxphos-derived ATP production (all p < 0.05), pointing to mitochondrial alterations. EMPA, at the concentration counteracting SA-induced lipotoxicity, both alone and in the presence of SA, caused NHE-independent extensive bioenergetic alterations (from p < 0.05 to p < 0.01), greater than those induced by SA alone.

Conclusions

In human MAC: (1) SA altered cell bioenergetics, concomitantly with inflammation and oxidant stress; (2) EMPA possibly inhibited mitochondrial respiration, (3) the protective effect of EMPA against SA-induced lipotoxicity was unlikely to be mediated through bioenergetic metabolism.

Shifting the distribution: modulation of the lipid profile in Yarrowia lipolytica via iron content

Microbial fermentation offers a sustainable source of fuels, commodity chemicals, and pharmaceuticals, yet strain performance is influenced greatly by the growth media selected. Specifically, trace metals (e.g., iron, copper, manganese, zinc, and others) are critical for proper growth and enzymatic function within microorganisms yet are non-standardized across media formulation. In this work, the effect of trace metal supplementation on the lipid production profile of Yarrowia lipolytica was explored using tube scale fermentation followed by biomass and lipid characterization. Addition of iron (II) to the chemically defined Yeast Synthetic Complete (YSC) medium increased final optical density nearly twofold and lipid production threefold, while addition of copper (II) had no impact. Additionally, dose-responsive changes in lipid distribution were observed, with the percent of oleic acid increasing and stearic acid decreasing as initial iron concentration increased. These changes were reversible with subsequent iron-selective chelation. Use of rich Yeast Peptone Dextrose (YPD) medium enabled further increases in the production of two specialty oleochemicals ultimately reaching 63 and 47% of the lipid pool as α-linolenic acid and cyclopropane fatty acid, respectively, compared to YSC medium. Selective removal of iron (II) natively present in YPD medium decreased this oleochemical production, ultimately aligning the lipid profile with that of non-supplemented YSC medium. These results provide further insight into the proposed mechanisms for iron regulation in yeasts especially as these productions strains contain a mutant allele of the iron regulator, mga2. The work presented here also suggests a non-genetic method for control of the lipid profile in Y. lipolytica for use in diverse applications. KEY POINTS: • Iron supplementation increases cell density and lipid titer in Yarrowia lipolytica. • Iron addition reversibly alters lipid portfolio increasing linolenic acid. • Removal of iron from YPD media provides a link to enhanced oleochemical production.

Preparation of seaweed polysaccharide based hydrophobic composite membranes for the separation of oil/water emulsion and protein

Agarose is a seaweed-based polysaccharide and is widely used for the separation of nucleic acids in molecular biology. Cross-linked agarose beads are also used as solid-phase matrices in size exclusion chromatography for the separation of proteins. To find the application of agarose for the separation of oil/water emulsion and protein, herein hydrophobic derivative of the seaweed biopolymer [M_W (1.27 ± 0.17) × 10 ⁵ g/mol; sulphate content (0.29 ± 0.09) %, gel strength (2242 ± 21) g/cm²] is prepared by reacting the biopolymer with stearic acid and was used to prepare a composite membrane on polyester fabric. The oil and BSA rejection performance of the composite membrane was greater than 98%. The rejection rate increased with the increase in polymer content in the respective membranes for both oil/water and protein separation. The composite membrane showed a stable oil/water emulsion and protein separation performance over a period of six hours. Due to the biodegradable nature of the major components of the membrane, it has the potential for industrial applications.

Solid lipid nanoparticles and nanoemulsions with solid shell: Physical and thermal stability

HYPOTHESIS

Nanoemulsions (NE) and solid lipid nanoparticles (SLN) used for drug delivery should have a solid shell to be stable during long shelf life and become liquid at human body temperature. The core components of lipid nanoparticles can be partially incorporated into the shell and affect the physical and thermal stability.

EXPERIMENTS

We prepared NE and SLN by the phase inversion temperature (PIT) method. Solidification of the surfactants Tween60 and Span 60 on the surface of NE droplets with paraffin oil resulted in the formation of the solid shell. SLN contained stearic acid in the core and the same surfactants in the solid shell. The size, structure and stability of the NE and SLN were studied by DLS and cryo-TEM. Their crystallization and melting were analyzed using DSC.

FINDINGS

The lipid nanoparticles were resistant to aggregation and sedimentation and hold up to at least two cycles of heating to 50-60 °C and subsequent cooling to 5 °C, even though the upper temperatures were higher than the melting point of the surfactant shell. The expected liquid core/solid shell morphology of NE was confirmed. SLN were composed of a semi-liquid core of supercooled stearic acid melt and coated with a solid surfactant shell, so they can be treated as NE. Stearic acid molecules penetrated the shell, leading to an increase in its melting point.

Effect of stearic acid on the microstructural, rheological and 3D printing characteristics of rice starch

The aim of this study was to investigate the changes of the microstructural, rheological and printing properties of rice starch-stearic acid (SA) paste during the hot-extrusion 3D printing (HE-3DP). The results showed that starch chains could complex with SA to form V-type crystalline structure and its molecular kinematic behaviors were changed under shear force, and crystalline structure were then embedded and rearranged to constitute an ordered sea-island structure, thus improving the rigidity and dynamic storage modulus of network structure, leading to the increased layer number. Interestingly, with the increase of SA addition, the network structure became weakened and the viscosity decreased which might due to the destroyed continuity and the breaking of entanglement and hydrogen bonding between starch chains, and finally impairing the printing accuracy of objects. Overall, this study provided important information for the application of lipid in the preparation of starch-based food by HE-3DP.

Magnetic solid-phase extraction of high molecular weight peptides using stearic acid-functionalized magnetic hydroxyapatite nanocomposite: determination of some hypothalamic agents in biological samples

Therapeutic peptides have an important effect on physiological function and human health, so it is momentous to quantify and detect low levels of these biomolecules in biological samples for treatment and diagnostic purposes. In the present study, an efficient magnetic solid-phase extraction (MSPE) method was developed based on stearic acid-functionalized magnetic hydroxyapatite nanocomposite (MHAP/SA) as a novel and cost-effective adsorbent for extraction of five hypothalamic-related peptides (goserelin, octreotide, triptorelin, somatostatin, and cetrorelix) from biological samples. To characterize the morphology and physicochemical properties of MHAP/SA, Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDS), field emission scanning microscopy (FE-SEM), CHNS elemental analysis, Brunauer-Emmett-Teller (BET), and vibrating sample magnetometry (VSM) were applied. Under optimum conditions, the proposed method (MSPE-HPLC-UV) represented favorable linearity with R² ≥ 0.9987, suitable intra- and inter-day precisions (RSD ≤ 6.9% and RSD ≤ 8.1%, respectively, n = 3), and limits of detection and quantification in the range of 0.75-1.12 ng mL^-1 and 2.50-3.75 ng mL^-1, respectively. Eventually, the proposed method was used for the extraction and quantification of target therapeutic peptides in plasma and urine samples, and satisfactory relative recoveries were achieved in the range of 90.6-110.3%.

Unraveling interfacial properties of organic-coated marine aerosol with lipase incorporation

Marine aerosols are believed to have an organic surface coating on which fatty acids act as an important component due to their high surface activity. In addition, various kinds of enzyme species are abundantly found in seawater, some of which have been identified to exist in marine aerosols. Herein, from the perspective of marine aerosol interface simulation, we investigate the effect of Burkholderia cepacia lipase on the surface properties of stearic acid (SA) monolayer at the air-water interface by using surface-sensitive techniques of Langmuir trough and Infrared reflection-absorption spectroscopy (IRRAS). Our findings indicate that the stearic acid film undergoes a significant expansion, especially when the lipase concentration is 500 nM, because of the incorporation of lipase as observed from the surface pressure-area (π-A) isotherms. IRRAS spectra also show reduced intensities and ordering in the methylene stretching vibration region of stearic acid as a result of low surface density and disordered packing as the enzyme concentration increases. In particular, when the concentration of lipase is 500 nM, the lowest I_as/I_s values are shown on both pure water subphase and artificial seawater subphase, indicating more gauche conformations for SA. Furthermore, SA films with lipase incorporation were also studied at three different pH of subphase environment, considering the decrease of pH caused by the reaction with acidic gases during the aerosol aging process. The results reflect a more pronounced expansion of SA monolayer in acidic environment at pH 2.5, suggesting that hydrophobic interaction plays an important role in the disorder of the SA monolayer. In view of the coexistence of fatty acids and enzymes in the marine environment, this study provides a further understanding of the surface organization and behavior of organic-coated marine aerosols and deepen the knowledge of lipid-enzyme interfacial interactions occurring in the atmosphere.

Stearic acid esterified pectin: Preparation, characterization, and application in edible hydrophobic pectin/chitosan composite films

This work investigated the modification of low-methoxy pectin with stearic anhydride through microwave action with 4-dimethylaminopyridine as catalyst. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses indicated that stearic acid was grafted on the pectin through esterification reaction, with the maximum stearic acid grafting ratio (SGR) of 10.7% for the modified pectin. The introduction of stearic acid was shown to significantly improve the emulsifying activity and stability of pectin. Composite films were prepared by blending the modified pectins and chitosan, and compared with the contact angle of 65.3° for the film with native low-methoxy pectin (PC0), the films with modified pectins showed a significant angle increase, with the highest contact angle reaching 101.9°, indicating a hydrophobic surface. Moreover, an appropriate amount of aliphatic chains could improve the tensile strength and elongation at break of the composite films due to the "anchoring effect".

TCONS_00230836 silencing restores stearic acid-induced β cell dysfunction through alleviating endoplasmic reticulum stress rather than apoptosis

BACKGROUND

Chronic exposure of pancreatic β cells to high levels of stearic acid (C18:0) leads to impaired insulin secretion, which accelerates the progression of type 2 diabetes mellitus (T2DM). Recently, long noncoding RNAs (lncRNAs) were found to participate in saturated fatty acid-induced metabolism dysfunction. However, their contribution to stearic acid-induced β-cell dysfunction remains largely unknown. This study evaluated the possible role of the lncRNA TCONS_00230836 in stearic acid-stimulated lipotoxicity to β cells.

METHOD

Using high-throughput RNA-sequencing, TCONS_00230836 was screened out as being exclusively differentially expressed in stearic acid-treated mouse β-TC6 cells. Co-expression network was constructed to reveal the potential mRNAs targeted for lncRNA TCONS_00230836. Changes in this lncRNA's and candidate mRNAs' levels were further assessed by real-time PCR in stearic acid-treated β-TC6 cells and islets of mice fed a high-stearic-acid diet (HSD). The localization of TCONS_00230836 was detected by fluorescent in situ hybridization. The endogenous lncRNA TCONS_00230836 in β-TC6 cells was abrogated by its Smart Silencer.

RESULTS

TCONS_00230836 was enriched in mouse islets and mainly localized in the cytoplasm. Its expression was significantly increased in stearic acid-treated β-TC6 cells and HSD-fed mouse islets. Knockdown of TCONS_00230836 significantly restored stearic acid-impaired glucose-stimulated insulin secretion through alleviating endoplasmic reticulum stress. However, stearic acid-induced β cell apoptosis was not obviously recovered.

CONCLUSION

Our findings suggest the involvement of TCONS_00230836 in stearic acid-induced β-cell dysfunction, which provides novel insight into stearic acid-induced lipotoxicity to β cells. Anti-lncRNA TCONS_00230836 might be a new therapeutic strategy for alleviating stearic acid-induced β-cell dysfunction in the progression of T2DM.

Hepatocyte steatosis inhibits hepatitis B virus secretion via induction of endoplasmic reticulum stress

The effects of hepatocyte steatosis on hepatitis B virus (HBV) DNA replication and HBV-related antigen secretion are incompletely understood. The aims of this study are to explore the effects and mechanism of hepatocyte steatosis on HBV replication and secretion. Stearic acid (SA) and oleic acid (OA) were used to induce HepG2.2.15 cell steatosis in this study. The expressions of glucose-regulated protein 78 (GRP78), phosphorylation of protein kinase R-like endoplasmic reticulum (ER) kinase (p-PERK), and eukaryotic translation initiation factor 2α (p-eIF2α) were detected by Western blotting (WB). HBV DNA, HBsAg, and HBeAg in the supernatant were determined by real-time fluorescent polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay. Intracellular HBV DNA, HBsAg level, and HBV RNA were measured by real-time fluorescent PCR, WB, and real-time quantitative reverse transcriptase-PCR, respectively. The results showed that SA and OA significantly increased intracellular lipid droplets and triglyceride levels. SA and OA significantly induced GRP78, p-PERK, and p-eIF2α expressions from 24 to 72 h. 4-phenylbutyric acid (PBA) alleviated ER stress induced by SA. SA promoted intracellular HBsAg and HBV DNA accumulation; however, it inhibited the transcript of HBV 3.5 kb mRNA and S mRNA. The secretion of HBsAg and HBV DNA inhibited by SA or OA could be partially restored by pretreatment with PBA but not by inhibiting GRP78 expression with siRNA. Hepatocyte steatosis inhibits HBsAg and HBV DNA secretion via induction of ER stress in hepatocytes, but not via induction of GRP78.

Characterization of functional chocolate formulated using oleogels derived from β-sitosterol with γ-oryzanol/lecithin/stearic acid

With an aim to prepare the functional chocolate, corn oil was used as the base oil and β-sitosterol was combined with oryzanol/stearic acid/lecithin to prepare respective oleogels (GO, SO, and LO). Oleogels (12%) were prepared by adding compound oleogelators at different ratios [GO-2:3, SO-1:4, and LO-4:1 (w/w)] in corn oil. The microstructure, interaction, thermodynamic, crystalline, and rheological behavior of formulated oleogels were studied by microscopic observation, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and rotational rheometer, respectively. The results showed that GO had the strongest gel forming ability and the densest gel crystallization network. Moreover, chocolate prepared with GO (cocoa butter and oleogels-1:1) had the similar texture, crystal structure, rheological, and sensory properties to that of dark chocolate. This study provides the possibility for the wider application of oleogel prepared with lower saturated and trans-fatty acids in the chocolate industry.

Long chain fatty acids can form aggregates and affect the membrane integrity

Stearic acid (SA) and oleic acid (OA) which are inherently existing fatty acids (FAs) in the body can alter cell membrane function and interact with each other. However, discrepancies arise as to whether these effects are beneficial or harmful on the body. To resolve this ambiguity, there is a dire need to study how FAs can affect the etiology of diseases and their treatment. In this study, we aimed to investigate long chain FAs aggregation behaviors and their effects on membrane integrity and cell viability. We determined the critical aggregation concentration (CAC) of SA and OA (1110 μM and 300 μM, respectively which were less amount than that used in nanocarriers). In TEM images, hexagonal overlapped or fused structures of SA were seen, whereas quite small spherical clusters of OA were obtained. Membrane integrity assessments demonstrated that SA and OA at their own CAC and below could crack the lipid junctions on membrane mimicking systems. Moreover, they completely disrupt the membrane integrity above the CAC at pH 7.2. Cell viabilities on various cell lines were assessed after exposed to SA or OA aggregates. SA was more aggressive than OA on cell death in all cell lines. The effect of SA on PC3 cell lines was in a concentration-dependent manner. The effect of SA above CAC boosted the inhibition of cell viability. Furthermore, OA showed a proliferation effect on PC3 cells. Consequently, the aggregation behavior of FAs should be considered as a noteworthy factor in physiological functions.

Effects of ultrasonication on the properties of maize starch/stearic acid/ sodium carboxymethyl cellulose composite film

Ultrasonic treatment can improve the compatibility between a hydrophobic material and a hydrophilic polymer. The light transmittance, crystalline structure, microstructure, surface morphology, moisture barrier, and mechanical properties of a composite film with or without ultrasonication were investigated. Ultrasound increases the film's light transmittance, resulting in a film that has good transparency. Ultrasonication did not change the crystalline structure of the polymer film, but promoted V-type complex formation. The surface of the film became smooth and homogeneous after the film-form suspension underwent ultrasonic treatment. Compared to the control film, after ultrasonication at 70% amplitude with a duration of 30 min, the average roughness and maximum roughness declined from 212 nm to 17.6 nm and from 768.7 nm to 86.5 nm, respectively. The composite film with ultrasonication exhibited better tensile and moisture barrier properties than the nonsonicated film. However, long-term and strong ultrasonication will destroy the polymer structure to some extent.

Effects of two consecutive mixed meals high in palmitic acid or stearic acid on 8-h postprandial lipemia and glycemia in healthy-weight and overweight men and postmenopausal women: a randomized controlled trial

Purpose

Palmitic and stearic acids have different effects on fasting serum lipoproteins. However, the effects on postprandial lipemia and glycemia are less clear. Also, the effects of a second meal may differ from those of the first meal. Therefore, we studied the effects of two consecutive mixed meals high in palmitic acid- or stearic acid-rich fat blends on postprandial lipemia and glycemia.

Methods

In a randomized, crossover study, 32 participants followed 4-week diets rich in palmitic or stearic acids, At the end of each dietary period, participants consumed two consecutive meals each containing ± 50 g of the corresponding fat blend.

Results

Postprandial concentrations of triacylglycerol (diet-effect: − 0.18 mmol/L; p = 0.001) and apolipoprotein B48 (diet-effect: − 0.68 mg/L; p = 0.002) were lower after stearic-acid than after palmitic-acid intake. Consequently, total (iAUC_0–8 h) and first meal (iAUC_0–4 h) responses were lower after stearic-acid intake (p ≤ 0.01). Second meal responses (iAUC_4–8 h) were not different. Postprandial changes between the diets in non-esterified fatty acids (NEFA) and C-peptide differed significantly over time (p < 0.001 and p = 0.020 for diet*time effects, respectively), while those for glucose and insulin did not. The dAUC_0–8 h, dAUC_0–4 h, and dAUC_4–8 h for NEFA were larger after stearic-acid intake (p ≤ 0.05). No differences were observed in the iAUCs of C-peptide, glucose, and insulin. However, second meal responses for glucose and insulin (iAUC_4–8 h) tended to be lower after stearic-acid intake (p < 0.10).

Conclusion

Consumption of the stearic acid-rich meals lowered postprandial lipemia as compared with palmitic acid. After the second stearic acid-rich meal, concentrations of C-peptide peaked earlier and those of NEFA decreased more.

Clinical trial registry This trial was registered at clinicaltrials.gov as NCT02835651 on July 18, 2016.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02530-2.

Physicochemical properties of heat-moisture treated, stearic acid complexed starch: The effect of complexation time and temperature

Starch modification has been extensively studied to alter its physicochemical properties based on human needs. Lowering the digestion rate of starch is one of the interests in food science research, since when it is nutritionally improved, it can reduce the risk of human chronic diseases. In this study, heat-moisture treatment (HMT) followed by inclusion complexation with stearic acid at various temperatures and times was applied to improve the functional properties of starch. Thermal analysis suggested the formation of type I and type II complexes after complexation at 90 °C, indicated by a endothermal peak at 107 and 122 °C, respectively, while native starch after complexation only resulted in type I complexes. The formation of crystalline complexes was also confirmed by XRD showing peaks at 2θ = 13.1° and 20.1°. Furthermore, the modified starch displayed a higher pasting temperature, considerably less swelling and significantly lower viscosity behavior. This implied that the starch granules were thermally and mechanically more stable. The granular appearance of the modified starch was confirmed with light microscopy that presented more intact granules and less ruptured granules, even after heating to 90 °C. This study offers a way to upgrade the nutritional properties of starch.

Enhanced brain targeting efficiency using 5-FU (fluorouracil) lipid-drug conjugated nanoparticles in brain cancer therapy

The present investigation was aimed to synthesize, optimize, and characterize lipid/drug conjugate nanoparticles for delivering 5-fluorouracil (5-FU) to treat brain cancer. The Box-Behnken design was used to optimize the formulation, evaluate the particle size, entrapment efficiency, morphology, in vitro drug release study, and stability profiles. The in vitro performance was executed using cell line studies. The in vivo performance was carried out for pharmacokinetic studies, sterility test, biodistribution studies, and distribution lipid-drug conjugated (LDC) nanoparticles in the brain. Particle size, zeta potential, entrapment efficiency, and morphology of the optimized formulation demonstrated desirable results. In vitro release pattern showed initial fast release, followed by sustained release up to 48 h. Cytotoxic effects of blank stearic acid nanoparticles, LDC nanoparticles, and 5-FU solution on human glioma cell lines U373 MG cell showed more cytotoxicity by LDC-NPs compared to others. The values reported for LDC (AUC = 19.37 ± 0.09 µg/mL h and VD 2.4 ± 0.24 mL) and pure drug (AUC = 8.37 ± 0.04 µg/mL h and VD = 5.24 ± 0.29 mL) indicate higher concentrations of LDC in systemic circulation, while pure 5-FU was found to be largely available in tissue rather than blood circulation. The t1/2 for LDC represents an approximate rise by ninefold, while MRT (12.10 ± 0.44 h) denotes 12-fold rise than pure 5-FU indicating the prolonged circulation of LDC. Free 5-FU concentration in the brain was maximum (5.24 ± 0.01 μg/g) after 3 h, while for the optimized formulation of LDC it was twofold greater estimated as 11.52 ± 0.32 μg/g. In conclusion, the efficiency of 5-FU to treat the brain is increased when it is formulated with LDC nanoparticles.

Diet containing stearic acid increases food reward-related behaviors in mice compared with oleic acid

Obesity is currently a worldwide phenomenon. The consumption of calorie-rich foods is responsible for most obesity cases, but not all humans exposed to high-calorie diets develop obesity. According to recent studies, exposure to fat-rich diets may be the actual cause of obesity. Dietary long-chain fatty acids affect brain function and are linked to food intake and motivation-related behaviors. Recently, many studies have shown that different types of fatty acids play different roles in animals. In our study, the effects of stearic acid (a saturated fatty acid) and oleic acid (a monounsaturated fatty acid) in diets on hedonic feeding behaviors were investigated, and changes of feeding-related protein levels in the brain were detected to explore the possible mechanism underlying the effects of these fatty acids. As a result, mice fed a diet containing stearic acid, compared to a diet containing oleic acid, exhibited increased food intake, hedonic eating, and an operant response to sucrose and locomotor activity. Furthermore, stearic acid corresponded to a higher level of leptin in serum than oleic acid. In addition, the stearic acid treated group had lower protein levels of p-JAK2 and p-STAT3 in the VTA and a higher dopamine concentration in the NAc than the oleic acid-treated group. Meanwhile, the protein level of TH in the NAc was higher and the protein level of the DA transporter in the VTA was lower in the stearic acid-fed group than in the oleic acid-fed group. In conclusion, these findings indicated that a diet containing stearic acid can increase hedonic feeding behavior and affect mesolimbic dopamine system signals in mice. Moreover, the lowering of serum leptin and leptin signaling in the VTA may contribute to this effect.

Design of oral intestinal-specific alginate-vitexin nanoparticulate system to modulate blood glucose level of diabetic rats

Vitexin of Ficus deltoidea exhibits intestinal α-glucosidase inhibitory and blood glucose lowering effects. This study designs oral intestinal-specific alginate nanoparticulate system of vitexin. Nanospray-dried alginate, alginate/stearic acid and alginate-C18 conjugate nanoparticles were prepared. Stearic acid was adopted to hydrophobize the matrix and minimize premature vitexin release in stomach, whereas C-18 conjugate as immobilized fatty acid to sustain hydrophobic effect and drug release. Nanoparticles were compacted with polyethylene glycol (PEG 3000, 10,000 and 20,000). The physicochemical, drug release, in vivo blood glucose lowering and intestinal vitexin content of nanoparticles and compact were determined. Hydrophobization of alginate nanoparticles promoted premature vitexin release. Compaction of nanoparticles with PEG minimized vitexin release in the stomach, with stearic acid loaded nanoparticles exhibiting a higher vitexin release in the intestine. The introduction of stearic acid reduced vitexin-alginate interaction, conferred alginate-stearic acid mismatch, and dispersive stearic acid-induced particle breakdown with intestinal vitexin release. Use of PEG 10,000 in compaction brought about PEG-nanoparticles interaction that negated initial vitexin release. The PEG dissolution in intestinal phase subsequently enabled particle breakdown and vitexin release. The PEG compacted nanoparticles exhibited oral intestinal-specific vitexin release, with positive blood glucose lowering and enhanced intestinal vitexin content in vivo.

Rhizomucor miehei lipase-catalysed synthesis of cocoa butter equivalent from palm mid-fraction and stearic acid: Characteristics and feasibility as cocoa butter alternative

In this study, cocoa butter equivalents (CBEs) were prepared through enzymatic interesterification of palm mid-fraction (PMF) with stearic acid (SA). The reaction process parameters were experimented and the performance of the product was analysed. PMF and stearic acid (at a mass ratio of 1:2) were catalysed by 80 g kg^-1 enzyme loading of Lipozyme RM IM fromRhizomucor mieheiat 60 °C for 120 min. The yield of the CBE product was more than 92%, and the CBE resembled cocoa butter (CB) in terms of its triacylglycerol composition. The hardness of the CBE product was higher than that of CB at different storage temperatures, but this difference was not obvious at 25 °C. The polymorphic structures and SFC curve of the CBE were similar to those of the CB. In addition, the CBE could be mixed with CB in any ratio without an obvious eutectic phenomena. Up to 40% CBE could be added to CB without significantly affecting the thermodynamic properties of CB. Thus, replacing CB with the CBE product is feasible.

Dietary stearic acid and palmitic acid do not differently affect ABCA1-mediated cholesterol efflux capacity in healthy men and postmenopausal women: A randomized controlled trial

BACKGROUND

The saturated fatty acid stearic acid (C18:0) lowers HDL cholesterol compared with palmitic acid (C16:0). However, the ability of HDL particles to promote cholesterol efflux from macrophages (cholesterol efflux capacity; CEC) may better predict coronary heart disease (CHD) risk than HDL cholesterol concentrations.

OBJECTIVE

We examined effects of exchanging dietary palmitic acid for stearic acid on ATP-binding cassette transporter A1 (ABCA1)-mediated CEC, and other conventional and emerging cardiometabolic risk makers.

DESIGN

In a double-blind, randomized, crossover study with two 4-week isocaloric intervention periods, 34 healthy men and postmenopausal women (61.5 ± 5.7 years, BMI: 25.4 ± 2.5 kg/m²) followed diets rich in palmitic acids or stearic acids. Difference in intakes was 6% of daily energy. ABCA1-mediated CEC was measured from J774 macrophages to apolipoprotein (apo)B-depleted serum.

RESULTS

Compared with the palmitic-acid diet, the stearic-acid diet lowered serum LDL cholesterol (-0.14 mmol/L; p = 0.010), HDL cholesterol (-0.09 mmol/L; p=<0.001), and apoA1 (-0.05 g/L; p < 0.001). ABCA1-mediated CEC did not differ between diets (p = 0.280). Cholesteryl ester transfer protein (CETP) mass was higher on stearic acid (0.11 mg/L; p = 0.003), but CETP activity was comparable. ApoB100 did not differ, but triacylglycerol concentrations tended to be higher on stearic acid (p = 0.100). Glucose concentrations were comparable. Effects on insulin and C-peptide were sex-dependent. In women, the stearic-acid diet increased insulin concentrations (1.57 μU/mL; p = 0.002), while in men, C-peptide concentrations were lower (-0.15 ng/mL; p = 0.037). Interleukin 6 (0.15 pg/mL; p = 0.039) and tumor necrosis factor alpha (0.18 pg/mL; p = 0.005), but not high-sensitivity C-reactive protein, were higher on stearic acid. Soluble intracellular adhesion molecule (9 ng/mL; p = 0.033), but not soluble vascular cell adhesion molecule and endothelial-selectin concentrations decreased after stearic-acid consumption.

CONCLUSIONS

As expected, stearic-acid intake lowered LDL cholesterol, HDL cholesterol, and apoA1. Insulin sensitivity in women and low-grade inflammation might be unfavorably affected by stearic-acid intake. However, palmitic-acid and stearic-acid intakes did not differently affect ABCA1-mediated CEC.

CLINICAL TRIAL REGISTRY

This trial was registered at clinicaltrials.gov as NCT02835651.

A high fat diet with a high C18:0/C16:0 ratio induced worse metabolic and transcriptomic profiles in C57BL/6 mice

BACKGROUND

Differential effects of individual saturated fatty acids (SFAs), particularly stearic acid (C18:0), relative to the shorter-chain SFAs have drawn interest for more accurate nutritional guidelines. However, specific biologic and pathologic functions that can be assigned to particular SFAs are very limited. The present study was designed to compare changes in metabolic and transcriptomic profiles in mice caused by a high C18:0 diet and high palmitic acid (C16:0) diet.

METHODS

Male C57BL/6 mice were assigned to a normal fat diet (NFD), a high fat diet with high C18:0/C16:0 ratio (HSF) or an isocaloric high fat diet with a low C18:0/C16:0 ratio (LSF) for 10 weeks. An oral glucose tolerance test, 72-h energy expenditure measurement and CT scan of body fat were done before sacrifice. Fasting glucose and lipids were determined by an autobiochemical analyzer. Blood insulin, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels were measured by enzyme-linked immunosorbent assay methods. Free fatty acids (FFAs) profiles in blood and liver were determined by using gas chromatography-mass spectrometry. Microarray analysis was applied to investigate changes in transcriptomic profiles in the liver. Pathway analysis and gene ontology analysis were applied to describe the roles of differentially expressed mRNAs.

RESULTS

Compared with the NFD group, body weight, body fat ratio, fasting blood glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), triglyceride, IL-6, serum and liver FFAs including total FFAs, C16:0 and C18:0 were increased in both high fat diet groups and were much higher in the HSF group than those in the LSF group. Both HSF and LSF mice exhibited distinguishable long non-coding RNA (lncRNA), microRNA and mRNA expression profiles when compared with those of NFD mice. Additionally, more differentially expressed lncRNAs and mRNAs were observed in the HSF group than in the LSF group. Some biological functions and pathways, other than energy metabolism regulation, were identified as differentially expressed mRNAs between the HSF group and the LSF group.

CONCLUSION

The high fat diet with a high C18:0/C16:0 ratio induced more severe glucose and lipid metabolic disorders and inflammation and affected expression of more lncRNAs and mRNAs than an isocaloric low C18:0/C16:0 ratio diet in mice. These results provide new insights into the differences in biological functions and related mechanisms, other than glucose and lipid metabolism, between C16:0 and C18:0.

Development of Floating Tablets of Metformin HCl by Thermoplastic Granulation. Part II: In Vitro Evaluation of the Combined Effect of Acacia Gum/HPMC on Biopharmaceutical Performances

Purpose: The aim of this study was to evaluate the combined effect, acacia gum(AG)/ hydroxypropylmethylcellulose (HPMC), on biopharmaceutical performances of floating tablets of metformin hydrochloride (MTH) prepared by thermoplastic granulation using stearic acid. Methods: We have prepared the matrixes using AG/HPMC as a polymer combination. This combination of polymers which represents 15% of the total mass of tablet was used at various ratios 3:1, 1:1, 1:3, with two viscosity grade of HPMC (k15M and k100M). The developed matrixes have been evaluated for their pharmacotechnical and biopharmaceutical properties. Results: In addition to the satisfactory physical characteristics of matrixes, it was revealed that the Fc3 and Fc6 formulations with AG/HPMC k15M and AG/HPMC k100M respectively, at ratio, 1:3 were considered the most performance. These formulations have shown swelling, fast flotation, 360 and 480 seconds respectively, and remained floating on the surface of the medium for more than 24 hours, with the matrix integrity, while F1, containing only AG, did not show swelling and did not float. In addition, extendedin vitro release (>8 hours) with decreased dissolved MTH rates was demonstrated for Fc3 and Fc6 matrixes, 95% and 91% respectively, compared to F1 where MTH dissolution was complete after 2 hours. The drug release from the highest-performance matrixes (Fc3 and Fc6) was found to follow Korsmeyer-Peppas's model. The mechanism drug release was controlled by diffusion and erosion. Conclusion: The AG/HPMC combination was suitable as a polymer matrix to improve the in vitro biopharmaceutical properties of MTH compared to AG.

Adsorptive removal of oil spill from sea water surface using magnetic wood sawdust as a novel nano-composite synthesized via microwave approach

Water pollution by oil is a serious environmental problem. Developing new generation of benign adsorbents satisfying several criteria required for real practical application is of great need. This work introduces an effort in this direction, by utilizing a facile synthesis of wood sawdust coated magnetite nanoparticles functionalized stearic acid (WSD@Fe₃O₄NPs/SA) as a novel nano composite along with its precursor WSD@Fe₃O₄NPs. SA was covalently bonded to the precursor by amide bond formation via the interaction with the silylating agent 3-aminopropyltrimethoxysilane (3-APTS). This mode of binding is more stronger than the conventional ester bond. Fourier transform infrared (FT-IR), X- ray powder diffraction (XRD), Scanning electron microscope (SEM) and Transmittance electron microscope (TEM) were employed for characterization and follow up the synthesis process. Application of the newly synthesized magnetic nano composite adsorbent under optimized parameters of contact time (min) and composite dosage (g) reveal high removal capacity values (g/g) evaluated to be 28.32 g/g, 5 min and 0.1 g for used motor oil removal and 41.22 g/g, 10 min and 0.1 g for crude oil. The high removal efficiency exhibited by WSD@Fe₃O₄NPs/SA was mainly argued to the long hydrocarbon chain of SA moiety and additional ـــ (CH₂)₃ ـــ groups incorporated 3-ATPS. Moreover, Analysis of the oil adsorption experimental equilibrium data were well fitted with Freundlish model with correlation coefficients r² = 0.9788 and 0.9896 for used motor oil and crude oil, respectively. The kinetic data were correlated using two kinetic models and the results were in harmony with pseudo-second order.

Effects of the chemical and physical reaction conditions on the formation of nanocomposites made of starch and stearic acid

To evaluate the reaction conditions on the physicochemical properties of composites of starch and stearic acid, composites were prepared under reaction conditions that varied the starch concentration (0.5, 1, 3%), stearic acid addition level (5, 10, 25 mg), stearic acid addition rate (2, 4, 8, 16 mL/min), and temperature (70, 80, 90 °C). All conditions significantly impacted the recovery, mean particle size, and zeta potential of samples. Specifically, a higher starch concentration and temperature significantly increased the recovery of stearic acid, but the mean particle size of the composite increased with higher stearic acid addition level and starch concentration. Stearic acid content in the composite exhibited a significant correlation with zeta potential (r = 0.818, p = 0.001). During enzymatic digestion for 20 min, 8% of the stearic acid was released from the composite. Approximately 10 % of the stearic acid was degraded after 36 h of storage at 50°C under 75 % relative humidity.

Improved lipid productivity in Nannochloropsis gaditana in nitrogen-replete conditions by selection of pale green mutants

BACKGROUND

Nannochloropsis gaditana is a photosynthetic unicellular microalgae considered one of the most interesting marine algae to produce biofuels and food additive due to its rapid growth rate and high lipid accumulation. Although microalgae are attractive platforms for solar energy bioconversion, the overall efficiency of photosynthesis is reduced due to the steep light gradient in photobioreactors. Moreover, accumulation of lipids in microalgae for biofuels production is usually induced in a two-phase cultivation process by nutrient starvation, with additional time and costs associated. In this work, a biotechnological approach was directed for the isolation of strains with improved light penetration in photobioreactor combined with increased lipids productivity.

RESULTS

Mutants of Nannochloropsis gaditana were obtained by chemical mutagenesis and screened for having both a reduced chlorophyll content per cell and increased affinity for Nile red, a fluorescent dye which binds to cellular lipid fraction. Accordingly, one mutant, called e8, was selected and characterized for having a 30% reduction of chlorophyll content per cell and an almost 80% increase of lipid productivity compared to WT in nutrient-replete conditions, with C16:0 and C18:0 fatty acids being more than doubled in the mutant. Whole-genome sequencing revealed mutations in 234 genes in e8 mutant among which there is a non-conservative mutation in the dgd1 synthase gene. This gene encodes for an enzyme involved in the biosynthesis of DGDG, one of the major lipids found in the thylakoid membrane and it is thus involved in chloroplast biogenesis. Lipid biosynthesis is strongly influenced by light availability in several microalgae species, including Nannochloropsis gaditana: reduced chlorophyll content per cell and more homogenous irradiance in photobioreactor is at the base for the increased lipid productivity observed in the e8 mutant.

CONCLUSIONS

The results herein obtained presents a promising strategy to produce algal biomass enriched in lipid fraction to be used for biofuel and biodiesel production in a single cultivation process, without the additional complexity of the nutrient starvation phase. Genome sequencing and identification of the mutations introduced in e8 mutant suggest possible genes responsible for the observed phenotypes, identifying putative target for future complementation and biotechnological application.

A novel, biocompatible and electrocatalytic stearic acid/nanosilver modified glassy carbon electrode for the sensing of paraoxon pesticide in food samples and commercial formulations

A simple, biocompatible and an enzyme-free sensing platform was developed for detection of paraoxon. The surface of a glassy carbon electrode was modified with an electrodeposition of stearic acid/nanosilver composite at -0.7 V for 40 s. The paraoxon undergoes electro-reduction at -550 mV on the modified electrode, and the limits of detection (LOD) was calculated as 0.1 nM (S/N = 3) using differential pulse voltammetry which is lower than that of the existing materials reported. The high stability observed with the modified electrode for prolonging period indicated that the sensitivity of the electrode remains active for several runs of the analysis. The developed analytical strategy was implemented for onion and paddy grain samples and good recovery rates were observed. Also, it was applied for analyzing the purity of the commercial paraoxon sample. The reliability of the developed strategy was confirmed by comparing the results of electrochemical approach with that of HPLC technique.

Multi-dimensional visualization for the morphology of lubricant stearic acid particles and their distribution in tablets

The shapes of particles and their distribution in tablets, controlled by pretreatment and tableting process, determine the pharmaceutical performance of excipient like lubricant. This study aims to provide deeper insights to the relationship of the morphology and spatial distribution of stearic acid (SA) with the lubrication efficiency, as well as the resulting tablet property. Unmodified SA particles as flat sheet-like particles were firstly reprocessed by emulsification in hot water to obtain the reprocessed SA particles with spherical morphology. The three-dimensional (3D) information of SA particles in tablets was detected by a quantitative and non-invasive 3D structure elucidation technique, namely, synchrotron radiation X-ray micro-computed tomography (SR-µCT). SA particles in glipizide tablets prepared by using unmodified SA (GUT), reprocessed SA (GRT), as well as reference listed drug (RLD) of glipizide tablets were analyzed by SR-µCT. The results showed that the reprocessed SA with better flowability contributed to similarity of breaking forces between that of GRT and RLD. SA particles in GRT were very similar to those in RLD with uniform morphology and particle size, while SA particles in GUT were not evenly distributed. These findings not only demonstrated the feasibility of SR-µCT as a new method in revealing the morphology and spatial distribution of excipient in drug delivery system, but also deepened insights of solid dosage form design into a new scale by powder engineering.

Vancomycin hydrochloride-loaded stearic acid/lauric acid in situ forming matrix for antimicrobial inhibition in patients with joint infection after total knee arthroplasty

Knee joint infection following total knee arthroplasty (TKA) is a serious condition and the treatments are complicated. The intra-articular solvent exchange-induced in situ forming matrix is of interest for modulating the release of antibiotics with a high drug concentration and a long period of exposed time at the target site. Stearic acid (S) and lauric acid (L) at various ratios were used as matrix formers by dissolving them in biocompatible solvents such as N-methyl pyrrolidone (NMP) and dimethyl sulfoxide (DMSO). Their matrix formation behaviors in phosphate buffer (pH7.4) and hyaluronic acid (HA) solution were evaluated. Also, the density, viscosity, injectability, solvent diffusion, in vitro degradability and drug release using the dialysis tube method were investigated. The L:S ratio of 1:1 in DMSO exhibited rapid matrix formation and a remarkably low viscosity (7.67±0.03 cp) with acceptable injectability (0.608±0.027N and 0.867±0.010N through 18-G and 27-G, respectively). Vancomycin HCl (V)-loaded L/S in situ forming matrix still provided ease of injection (1.079±0.215N and 1.230±0.145N through 18-G and 27-G needle, respectively) with fatty acid matrix formation after solvent exchange within 1min, whilst V sustainably released over 6days. It also presented effective antimicrobial activities against standard Staphylococcus aureus and methicillin-resistant Staphylococcus aureus strains. Therefore, V-loaded solvent exchange-induced in situ forming matrix using L and S as the matrix formers may be a potential local delivery system for treating knee joint infections occurring after TKA in the future.

Oleic acid influences the adipogenesis of 3T3-L1 cells via DNA Methylation and may predispose to obesity and obesity-related disorders

BACKGROUND

Adipogenesis is the process of adipocytes formation from unspecialized progenitor cells called mesenchymal stromal cells. Numerous mechanisms including epigenetic regulation modulate the correct progress of this process. Dietary exposures occurring over a specific period of time might cause long-lasting and even permanent changes in gene expression regulated by epigenetic mechanisms. For that reason, we investigated the adipogenesis of 3 T3-L1 cells with the excess of saturated and monounsaturated fatty acids and their influence on global and site-specific DNA methylation in these cells.

MATERIALS AND METHODS

3T3-L1 cells were cultured in vitro to obtain 100% of confluence, then the adipogenesis was induced by a differentiation cocktail with the addition of the excess of 0.25 mM and 0.5 mM of palmitic (16:0), stearic (18:0) and oleic (18:1n-9) acids. DNA and RNA were extracted at five-time points to assess the adipogenesis process. The phenotype of mature adipocytes (insulin sensitivity, adipokines secretion, fat content) was estimated in fully mature adipocytes. DNA methylation was investigated both during adipogenesis and in mature adipocytes.

RESULTS

Oleic acids stimulated expression of C/ebpα and Pparγ, which was correlated with lower methylation levels at promoters sites. Furthermore, cells cultured with an excess of oleic acid were characterized by higher lipid accumulation rate, higher leptin, and lower adiponectin secretion. Moreover, in all experimental cells, insulin signaling and glucose utilization were impaired.

CONCLUSION

Oleic acid affected the methylation of Pparγ and C/ebpα promoters, what correlated with higher expression. Furthermore, examined free fatty acids influenced the phenotype of mature adipocytes, especially insulin signaling pathway and adipokine secretion.

De novo biosynthesis of fatty acids from α-D-glucose in parasitoid wasps of the Nasonia group

Fatty acids are indispensable primary metabolites for virtually any organism on earth and thus enzymatic machinery enabling de novo production of fatty acids from carbohydrates is highly conserved. A series of studies has questioned the ubiquity of lipogenesis in parasitoid wasps suggesting that the vast majority of species have lost the ability to synthesize fatty acids de novo. One such species is Nasonia vitripennis, which, like the congeneric species N. giraulti and N. longicornis, uses a fatty acid-derived male sex pheromone for sexual communication. Here we demonstrate by feeding fully ¹³C-labeled α-D-glucose and analyzing insect-derived fatty acid methyl esters and the male sex pheromone by coupled gas chromatography/mass spectrometry that both males and females of N. vitripennis as well as N. giraulti and N. longicornis are capable of synthesizing fatty acids de novo. We furthermore show by a proteomics approach that predicted fatty acid synthase, ATP-citrate synthase, and acetyl-CoA carboxylase, key enzymes of lipogenesis, are expressed in the male pheromone gland of N. vitripennis and N. giraulti. Labeling experiments with Urolepis rufipes, a closely related species producing a male sex pheromone independently of fatty acids via the mevalonate pathway, revealed that both sexes are likewise able to synthesize fatty acids de novo. We conclude that the parasitoid wasp species studied here, irrespective of the biosynthetic origin of their sex pheromones, are capable of responding flexibly to lipid shortage during their adult life by keeping enzymatic machinery for lipogenesis running.

Cobalt chromium-layered double hydroxide, α- and β- Co(OH)2 and amorphous Cr(OH)3: synthesis, modification and characterization

Cobalt-chromium layered double hydroxide (CoCr LDH), α- and β- Co(OH)₂ and amorphous Cr(OH)₃ have been synthesized under different reaction conditions. The obtained CoCr LDH was modified by stearic acid (SA) and sodium stearate (SS). The obtained samples have been characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), Ultraviolet-visible- (UV-Vis), Fourier transform infrared- (FTIR) and Energy-dispersive X-ray- (EDX) spectroscopy. The influence of reaction conditions on product composition, structural and optical properties of the samples have been discussed in detail. The basal spacing of CoCr-LDH increased from 7.366 Å to 7.428 Å and 25.214Å after the intercalation by stearic acid and sodium stearate, respectively. The average particles size by SEM analyze was estimated to be approximately 100-150 nm and 30-50 nm for CoCr-LDH_0.6M(90°C) and CoCr-LDH_0.6M(90°C)/SS nanostructures, respectively. Mixed hydroxides like α- and β- Co(OH)₂ have been obtained along with LDH at lower pH value (pH ∼ 7). The number of diffraction peaks corresponding to β-Co(OH)₂ has increased with relatively decreasing of Co²⁺ ions in the reaction medium. At high chromium concentrations (Co²⁺:Cr³⁺ = 1:3 and 1:5), amorphous Cr(OH)₃ were formed in the experiment.

Effects of Stearic Acid on Proliferation, Differentiation, Apoptosis, and Autophagy in Porcine Intestinal Epithelial Cells

BACKGROUND

Stearic acid (SA), a saturated long-chain fatty acid consisting of 18 carbon atoms, is widely found in feed ingredients, such as corn, soybeans, and wheat. However, the roles of SA in the renewal of intestinal epithelial cells remain unclear.

METHODS AND RESULTS

In the present study, we found that 0.01-0.1 mM SA promoted IPEC-J2 cell differentiation and did not affect IPEC-J2 cell viability. In addition, the results showed that the viability of IPEC-J2 cells was inhibited by SA in a time- and dose-dependent manner at high concentrations. Flow cytometry and western blot analysis suggested that SA induced apoptosis, autophagy and ER stress in cells. In addition, the amounts of triglyceride were significantly increased upon challenge with SA. Moreover, the decrease in the viability of cells induced by SA could be attenuated by 4-PBA, an inhibitor of ER stress.

CONCLUSION

In summary, SA accelerated IPEC-J2 cell differentiation at 0.01-0.1 mM. Furthermore, SA induced IPEC-J2 cell apoptosis and autophagy by causing ER stress.