Oleic acid prevents apoptotic cell death induced by trans10, cis12 isomer of conjugated linoleic acid via p38 MAP kinase dependent pathway

Oleic acid prevents erythrocyte death by preserving haemoglobin and erythrocyte membrane proteins

Haemolysis of erythrocytes upon exposure to haemato-toxic phenylhydrazine (PHZ), makes it an experimental model of anaemia and a partial model of β-thalassaemia, where oxidative stress (OS) was identified as principal causative factor. Oleic acid (OA) was evidenced to ameliorate such stress with antioxidative potential. Erythrocytes were incubated in vitro using 1 mM PHZ, 0.06 nM OA. Erythrocyte membrane protein densities and haemoglobin (Hb) status were examined. Any interaction of Hb with PHZ/OA was checked by calorimetric and spectroscopic analysis using pure molecules. Occurrence of erythrocyte apoptosis and involvement of free iron in all groups were evaluated. PHZ exposure to erythrocytes results in OS with subsequent apoptosis as evidenced from increased lipid peroxidation and translocation of phosphatidylserine in outer membrane. Preservations of erythrocyte cytoskeletal architecture and membrane bound enzyme activity were found in presence of OA. Moreover, both heme and globin of Hb was examined to be conserved by OA. Presence of OA, impeded apoptosis also, possibly by thwarting Hb breakdown followed by free iron release and consequent free radical generation. Additionally, direct sequential binding of OA with PHZ endorsed another protective mechanism of OA toward erythrocytes. OA affords protection to erythrocytes by conserving its major components and prevents haemolysis which projects OA as a haemato-protective agent. Apart from combating PHZ toxicity, anti-apoptotic action of OA strongly suggests its usage in anaemia and β-thalassaemia patients to curb irreversible erythrocyte breakdown. This research strongly recommends OA in pure form or from dietary sources as a therapeutic against haemolytic disorders.

The palliative effect of mulberry leaf and olive leaf ethanolic extracts on hepatic CYP2E1 and caspase-3 immunoexpression and oxidative damage induced by paracetamol in male rats

This study investigated the possible protective role of mulberry leaf (MLE) and olive leaf (OLE) ethanolic extracts against paracetamol (PTL)-induced liver injury in rats compared to silymarin as a reference drug. Initially, MLE and OLE were characterized using gas chromatography-mass spectrometry (GC/MS). Then, forty male Sprague Dawley rats were divided into five groups: the negative control group orally received distilled water for 35 days, the PTL-treated group (PTG) received 500 mg PTL/kg b. wt. for 7 days, the MLE-treated group (MLTG) received 400 mg MLE/kg b. wt., the OLE-treated group (OLTG) received 400 mg OLE/kg b. wt., and the silymarin-treated group (STG) received 100 mg silymarin/kg b. wt. The last three groups received the treatment for 28 days, then PTL for 7 days. The GC-MS characterization revealed that MLE comprised 19 constituents dominated by ethyl linoleate, phytol, hexadecanoic acid, ethyl ester, and squalene. Moreover, OLE comprised 30 components, and the major components were 11-eicosenoic acid, oleic acid, phytol, and à-tetralone. MLE and OLE significantly corrected the PTL-induced normocytic normochromic anemia, leukocytosis, hypercholesterolemia, and hypoproteinemia. Moreover, the MLE and OLE pretreatment considerably suppressed the PTL-induced increment in serum levels of hepatic enzymes, including alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase. Furthermore, the PTL-induced depletion in antioxidant enzymes, including glutathione peroxidase, superoxide dismutase, and catalase, and the rise in hepatic malondialdehyde content were significantly reversed by the MLE and OLE pretreatment. Besides, MLE and OLE pretreatment significantly protected the hepatic tissue against PTL-induced DNA damage, pathological perturbations, and increased caspase 3 and CYP2E1 immunoexpression. Of note, OLTG showed better enhancement of most indices rather than MLTG. Conclusively, these findings imply that OLE, with its antioxidant and antiapoptotic capabilities, is superior to MLE in protecting against PTL-induced liver injury.

Oleic Acid Protects Endothelial Cells from Silica-Coated Superparamagnetic Iron Oxide Nanoparticles (SPIONs)-Induced Oxidative Stress and Cell Death

Superparamagnetic iron oxide nanoparticles (SPIONs) have great potential for use in medicine, but they may cause side effects due to oxidative stress. In our study, we investigated the effects of silica-coated SPIONs on endothelial cells and whether oleic acid (OA) can protect the cells from their harmful effects. We used viability assays, flow cytometry, infrared spectroscopy, fluorescence microscopy, and transmission electron microscopy. Our results show that silica-coated SPIONs are internalized by endothelial cells, where they increase the amount of reactive oxygen species (ROS) and cause cell death. Exposure to silica-coated SPIONs induced accumulation of lipid droplets (LD) that was not dependent on diacylglycerol acyltransferase (DGAT)-mediated LD biogenesis, suggesting that silica-coated SPIONs suppress LD degradation. Addition of exogenous OA promoted LD biogenesis and reduced SPION-dependent increases in oxidative stress and cell death. However, exogenous OA protected cells from SPION-induced cell damage even in the presence of DGAT inhibitors, implying that LDs are not required for the protective effect of exogenous OA. The molecular phenotype of the cells determined by Fourier transform infrared spectroscopy confirmed the destructive effect of silica-coated SPIONs and the ameliorative role of OA in the case of oxidative stress. Thus, exogenous OA protects endothelial cells from SPION-induced oxidative stress and cell death independent of its incorporation into triglycerides.

Glucose and oleic acid mediate cellular alterations in GLP-1-induced insulin-positive differentiating UCBMSCs

Coordinated effects of glucose and oleic acid on glucagon-like peptide-1 (GLP-1) mediated differentiation of insulin-positive differentiating umbilical cord mesenchymal stromal cells (dUCBMSCs) was studied using a co-culture of NCI-H716 (GLP-1+) and UCBMSCs (insulin+). The addition of 2.5 mM glucose increased the proliferation of NCI-H716 cells by 30% and induced transformation of UCBMSCs into insulin-secreting cells in 18 days as compared to 22 days in control cells. Oleic acid (25 μM) showed decrease in cell proliferation, autophagy, and apoptosis in NCI-H716 cells while no effect was observed in dUCBMSCs. Prolonged glucose and oleic acid resulted in apoptosis and cell cycle changes in dUCBMSCs after day 18 while higher concentrations resulted in cell death. Additionally, the expression of FAS and ACC mRNA was observed in NCI-H716 and dUCBMSCs post 24-hr addition of glucose and/or oleic acid. Absorption of oleic acid was high in NCI-H716 compared to dUCBMSCs. Taken together, optimal concentrations of glucose and oleic acid could be a key factor in stimulating intrinsic GLP-1, which in turn stimulates differentiating MSCs in a glucose-dependent manner. PRACTICAL APPLICATIONS: The aim of this article was to study whether differentiating or differentiated MSCs after mobilization or post-transplant would require optimal glucose and oleic acid to naturally stimulate intrinsic GLP-1, or otherwise, the high or long-term overload of glucose or oleic acid could result in inhibition of differentiated cells resulting in failure of insulin secretion.

Polyunsaturated fatty acids and p38-MAPK link metabolic reprogramming to cytoprotective gene expression during dietary restriction

The metabolic state of an organism instructs gene expression modalities, leading to changes in complex life history traits, such as longevity. Dietary restriction (DR), which positively affects health and life span across species, leads to metabolic reprogramming that enhances utilisation of fatty acids for energy generation. One direct consequence of this metabolic shift is the upregulation of cytoprotective (CyTP) genes categorized in the Gene Ontology (GO) term of "Xenobiotic Detoxification Program" (XDP). How an organism senses metabolic changes during nutritional stress to alter gene expression programs is less known. Here, using a genetic model of DR, we show that the levels of polyunsaturated fatty acids (PUFAs), especially linoleic acid (LA) and eicosapentaenoic acid (EPA), are increased following DR and these PUFAs are able to activate the CyTP genes. This activation of CyTP genes is mediated by the conserved p38 mitogen-activated protein kinase (p38-MAPK) pathway. Consequently, genes of the PUFA biosynthesis and p38-MAPK pathway are required for multiple paradigms of DR-mediated longevity, suggesting conservation of mechanism. Thus, our study shows that PUFAs and p38-MAPK pathway function downstream of DR to help communicate the metabolic state of an organism to regulate expression of CyTP genes, ensuring extended life span.

Effects of conjugated linoleic acid and high oleic acid safflower oil in the treatment of children with HPV-induced laryngeal papillomatosis: a randomized, double-blinded and crossover preliminary study

BACKGROUND

Surgery is the mainstay therapy for HPV-induced laryngeal papillomatosis (LP) and adjuvant therapies are palliative at best. Research revealed that conjugated-linoleic acid (CLA) may improve the outcome of virally-induced diseases. The effects of Clarinol™ G-80 (CLA) and high oleic safflower oil (HOSF) on children with LP (concomitant with surgery) were evaluated.

DESIGN

A randomized, double-blinded, crossover and reference-oil controlled trial was conducted at a South African medical university. Study components included clinical, HPV type/load and lymphocyte/cytokine analyses, according to routine laboratory methods.

PARTICIPANTS

Overall: ten children enrolled; eight completed the trial; five remained randomized; seven received CLA first; all treatments remained double-blinded.

INTERVENTION

Children (4 to 12 years) received 2.5 ml p/d CLA (8 weeks) and 2.5 ml p/d HOSF (8 weeks) with a washout period (6 weeks) in-between. The one-year trial included a post-treatment period (30 weeks) and afterwards was a one-year follow-up period.

MAIN OUTCOME MEASURES

Changes in numbers of surgical procedures for improved disease outcome, total/anatomical scores (staging system) for papillomatosis prevention/viral inhibition, and lymphocyte/cytokine counts for immune responses between baselines and each treatment/end of trial were measured.

FINDINGS

After each treatment all the children were in remission (no surgical procedures); after the trial two had recurrence (surgical procedures in post-treatment period); after the follow-up period three had recurrence (several surgical procedures) and five recovered (four had no surgical procedures). Effects of CLA (and HOSF to a lesser extent) were restricted to mildly/moderately aggressive papillomatosis. Children with low total scores (seven/less) and reduced infections (three/less laryngeal sub-sites) recovered after the trial. No harmful effects were observed. The number of surgical procedures during the trial (n6/available records) was significantly lower [(p 0.03) (95% CI 1.1; 0)]. Changes in scores between baselines and CLA treatments (n8) were significantly lower: total scores [(p 0.02) (95% CI -30.00; 0.00)]; anatomical scores [(p 0.008) (95% CI -33.00: -2.00)]. Immune enhancement could not be demonstrated.

CONCLUSIONS

These preliminary case and group findings pave the way for further research on the therapeutic potential of adjuvant CLA in the treatment of HPV-induced LP.

Oleic acid mitigates TNF-α-induced oxidative stress in rat cardiomyocytes

Some of the effects of tumor necrosis factor alpha (TNF-α) are suggested to be mediated by oxidative stress. It has also been reported that dietary supplements of olive oil result in a reduction in LDL, oxidative stress, and blood pressure and these effects are attributed to oleic acid (OA)-a major component of olive oil. The objective of this study was to examine the beneficial effects of OA against TNF-α-induced oxidative stress and cardiomyocytes injury. Isolated cardiomyocytes from adult rat hearts were treated as follows: (A) control; (B) OA (50 μM); (C) TNF-α (10 ng/ml); and (D) TNF-α + OA. After 4 h of the treatment, cells were assessed for oxidative stress, cellular damage, viability, and apoptosis. Cardiomyocytes treated with TNF-α showed a significant increase (P < 0.05) in reactive oxygen species, decrease in the viability of cells, and increase in creatine kinase release. All these TNF-α-induced changes were prevented by OA. TNF-α also caused a significant increase in the expression of apoptotic proteins Bax, Caspase 3 and PARP cleavage, Bnip3, and TGF-β , whereas OA modulated these changes. It is suggested that TNF-α induced oxidative stress mediates cardiomyocyte cell damage which is prevented by OA.

Contrasting apoptotic responses of conjugated linoleic acid in the liver of obese Zucker rats fed palm oil or ovine fat

We hypothesized that reducing weight properties of conjugated linoleic acid (CLA) are due to adipocyte apoptosis and that CLA differentially modulates the apoptotic responses in hepatic lipotoxicity from rats fed saturated fat diets. Obese Zucker rats were fed atherogenic diets (2%w/w of cholesterol) formulated with high (15%w/w) saturated fat, from vegetable or animal origin, supplemented or not with 1% of a mixture (1:1) of cis-9, trans-11 and trans-10, cis-12 CLA isomers for 14 weeks. CLA induced no changes on retroperitoneal fat depot weight, which was in line with similar levels of apoptosis. Interestingly, CLA had a contrasting effect on cell death in the liver according to the dietary fat. CLA increased hepatocyte apoptosis, associated with upregulation of Fas protein in rats fed palm oil, compared to rats receiving palm oil alone. However, rats fed ovine fat alone displayed the highest levels of hepatic cell death, which were decreased in rats fed ovine fat plus CLA. This reducing effect of CLA was related to positively restoring endoplasmic reticulum (ER) ATF-6α, BiP and CHOP protein levels and increasing phosphorylated c-Jun NH(2)-terminal kinase (JNK) and c-Jun, thus suggesting an adaptive response of cell survival. These findings reinforce the role of CLA as regulator of apoptosis in the liver. Moreover, the dietary fat composition is a key factor in activation of apoptosis.

Hydroxycamptothecin-loaded Fe3O4 nanoparticles induce human lung cancer cell apoptosis through caspase-8 pathway activation and disrupt tight junctions

10-Hydroxycamptothecin (HCPT) elicits strong anti-cancer effects and is less toxic than camptothecin (CPT), making it widely used in recent clinical trials. However, its low solubility limits its application as an effective anti-cancer therapy. In the present study we investigate the hypothesis that the unique water dispersible oleic acid-Triton X-100-coated Fe3O4 nanoparticles loaded with HCPT disrupt epithelial cell-cell junctions and induce human lung cancer cell apoptosis through the caspase-8 pathway. We characterized the HCPT-loaded nanoparticles and determined their effects on lung cancer cell viability and apoptosis by using immunofluorescence light microscopy and SDS-PAGE/immunoblots. We found that HCPT-loaded nanoparticles elicited an anti-proliferative effect in a dose-dependent manner. HCPT-loaded nanoparticles reduced the expression of cell-cell junction protein claudins, E-cadherin and ZO-1, and transmission electron microcopy demonstrated a disrupted tight junction ultrastructure. Transepithelial electric resistance was also reduced, indicating the reduction of tight junction functions. The HCPT-loaded nanoparticles increased phosphorylation of p38 and SAPK/JNK while it showed no effects on p42/44 MAP kinase. Compared with void Fe3O4 nanoparticles or HCPT drug alone, HCPT drug-loaded nanoparticles evoked synergistic effects by increasing cell apoptosis with enhanced activation of the caspase-8 pathway. Therefore, our current study highlights the potential of HCPT drug-loaded nanoparticles as a chemotherapeutic agent for increasing anti-cancer drug efficacy.