Dietary comparison of conjugated linolenic acid (9 cis, 11 trans, 13 trans) and alpha-tocopherol effects on blood lipids and lipid peroxidation in alloxan-induced diabetes mellitus in rats

Conjugated Linolenic Acid (CLnA) vs Conjugated Linoleic Acid (CLA): A Comprehensive Review of Potential Advantages in Molecular Characteristics, Health Benefits, and Production Techniques

Conjugated linoleic acid (CLA) has been extensively characterized due to its many biological activities and health benefits, but conjugated linolenic acid (CLnA) is still not well understood. However, CLnA has shown to be more effective than CLA as a potential functional food ingredient. Current research has not thoroughly investigated the differences and advantages between CLnA and CLA. This article compares CLnA and CLA based on molecular characteristics, including structural, chemical, and metabolic characteristics. Then, the in vivo research evidence of CLnA on various health benefits is comprehensively reviewed and compared with CLA in terms of effectiveness and mechanism. Furthermore, the potential of CLnA in production technology and product protection is analyzed. In general, CLnA and CLA have similar physicochemical properties of conjugated molecules and share many similarities in regulation effects and pathways of various health benefits as well as in the production methods. However, their specific properties, regulatory capabilities, and unique mechanisms are different. The superior potential of CLnA must be specified according to the practical application patterns of isomers. Future research should focus more on the advantageous characteristics of different isomers, especially the effectiveness and safety in clinical applications in order to truly exert the potential value of CLnA.

Pomegranate Seed Oil as a Source of Conjugated Linolenic Acid (CLnA) Has No Effect on Atherosclerosis Development but Improves Lipid Profile and Affects the Expression of Lipid Metabolism Genes in apoE/LDLR-/- Mice

The aim of this study was to evaluate the anti-atherosclerotic effect of pomegranate seed oil as a source of conjugated linolenic acid (CLnA) (cis-9,trans-11,cis-13; punicic acid) compared to linolenic acid (LnA) and conjugated linoleic acid (CLA) (cis-9,trans-11) in apoE/LDLR^-/- mice. In the LONG experiment, 10-week old mice were fed for the 18 weeks. In the SHORT experiment, 18-week old mice were fed for the 10 weeks. Diets were supplied with seed oils equivalent to an amount of 0.5% of studied fatty acids. In the SHORT experiment, plasma TCh and LDL+VLDL cholesterol levels were significantly decreased in animals fed CLnA and CLA compared to the Control. The expression of PPARα in liver was four-fold increased in CLnA group in the SHORT experiment, and as a consequence the expression of its target gene ACO was three-fold increased, whereas the liver's expression of SREBP-1 and FAS were decreased in CLnA mice only in the LONG experiment. Punicic acid and CLA isomers were determined in the adipose tissue and liver in animals receiving pomegranate seed oil. In both experiments, there were no effects on the area of atherosclerotic plaque in aortic roots. However, in the SHORT experiment, the area of atherosclerosis in the entire aorta in the CLA group compared to CLnA and LnA was significantly decreased. In conclusion, CLnA improved the lipid profile and affected the lipid metabolism gene expression, but did not have the impact on the development of atherosclerotic plaque in apoE/LDLR^-/- mice.

Beneficial Impacts of Alpha-Eleostearic Acid from Wild Bitter Melon and Curcumin on Promotion of CDGSH Iron-Sulfur Domain 2: Therapeutic Roles in CNS Injuries and Diseases

Neuroinflammation and abnormal mitochondrial function are related to the cause of aging, neurodegeneration, and neurotrauma. The activation of nuclear factor κB (NF-κB), exaggerating these two pathologies, underlies the pathogenesis for the aforementioned injuries and diseases in the central nervous system (CNS). CDGSH iron-sulfur domain 2 (CISD2) belongs to the human NEET protein family with the [2Fe-2S] cluster. CISD2 has been verified as an NFκB antagonist through the association with peroxisome proliferator-activated receptor-β (PPAR-β). This protective protein can be attenuated under circumstances of CNS injuries and diseases, thereby causing NFκB activation and exaggerating NFκB-provoked neuroinflammation and abnormal mitochondrial function. Consequently, CISD2-elevating plans of action provide pathways in the management of various disease categories. Various bioactive molecules derived from plants exert protective anti-oxidative and anti-inflammatory effects and serve as natural antioxidants, such as conjugated fatty acids and phenolic compounds. Herein, we have summarized pharmacological characters of the two phytochemicals, namely, alpha-eleostearic acid (α-ESA), an isomer of conjugated linolenic acids derived from wild bitter melon (Momordica charantia L. var. abbreviata Ser.), and curcumin, a polyphenol derived from rhizomes of Curcuma longa L. In this review, the unique function of the CISD2-elevating effect of α-ESA and curcumin are particularly emphasized, and these natural compounds are expected to serve as a potential therapeutic target for CNS injuries and diseases.

Uncommon Fatty Acids and Cardiometabolic Health

Cardiovascular disease (CVD) is a major cause of mortality. The effects of several unsaturated fatty acids on cardiometabolic health, such as eicosapentaenoic acid (EPA) docosahexaenoic acid (DHA), α linolenic acid (ALA), linoleic acid (LA), and oleic acid (OA) have received much attention in past years. In addition, results from recent studies revealed that several other uncommon fatty acids (fatty acids present at a low content or else not contained in usual foods), such as furan fatty acids, n-3 docosapentaenoic acid (DPA), and conjugated fatty acids, also have favorable effects on cardiometabolic health. In the present report, we searched the literature in PubMed, Embase, and the Cochrane Library to review the research progress on anti-CVD effect of these uncommon fatty acids. DPA has a favorable effect on cardiometabolic health in a different way to other long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs), such as EPA and DHA. Furan fatty acids and conjugated linolenic acid (CLNA) may be potential bioactive fatty acids beneficial for cardiometabolic health, but evidence from intervention studies in humans is still limited, and well-designed clinical trials are required. The favorable effects of conjugated linoleic acid (CLA) on cardiometabolic health observed in animal or in vitro cannot be replicated in humans. However, most intervention studies in humans concerning CLA have only evaluated its effect on cardiometabolic risk factors but not its direct effect on risk of CVD, and randomized controlled trials (RCTs) will be required to clarify this point. However, several difficulties and limitations exist for conducting RCTs to evaluate the effect of these fatty acids on cardiometabolic health, especially the high costs for purifying the fatty acids from natural sources. This review provides a basis for better nutritional prevention and therapy of CVD.

Punicic acid: A striking health substance to combat metabolic syndromes in humans

Punicic acid, a bioactive compound of pomegranate seed oil has gained wide attention for their therapeutic potential. Different studies conducted on animal and human models have revealed that punicic acid is very effective against various chronic diseases. Substantial laboratory works has been carried out to elaborate punicic acid effectiveness and mechanism of action in animals. The intention of this review article is to explore the facts about the clinical trials of punicic acid and to discuss different future strategies that can be employed to use it in human clinical trials. Although punicic acid may represent a novel therapeutic unconventional approach for some disorders, still further experimental studies are required to demonstrate its effects in human beings.

Antioxidative effect of rice bran oil and medium chain fatty acid rich rice bran oil in arsenite induced oxidative stress in rats

The present study was adopted to evaluate the antioxidant efficacy of medium chain fatty acid (caprylic, capric and lauric) rich rice bran oils in comparison to rice bran oil in terms of altered biochemical parameters of oxidative stress following sodium arsenite treatment in rats. Animals were divided into ten groups; five normal groups and five arsenite treated groups. Results showed that activities of antioxidant enzymes in liver, brain and erythrocyte membrane increased with the administration of rice bran oil and MCFA rich rice bran oils both in normal and arsenite treated cases. Lipid peroxidation increased with the administration of sodium arsenite, but again administration of rice bran oil and MCFA rich rice bran oils decreased the lipid peroxidation. Caprylic acid rich rice bran oil showed the best ameliorative effects.

Conjugated linolenic acids and their bioactivities: a review

Conjugated linolenic acid (CLNA) is a mixture of positional and geometric isomers of octadecatrienoic acid (α-linolenic acid, cis9,cis12,cis15-18:3 n-3) found in plant seeds. Three 8,10,12-18:3 isomers and four 9,11,13-18:3 isomers have been reported to occur naturally. CLNA isomers such as punicic acid, α-eleostearic acid and jacaric acid have been attributed to exhibit several health benefits that are largely based on animal and in vitro studies. This review has summarized and updated the evidence regarding the metabolism and bioactivities of CLNA isomers, and comprehensively discussed the recent studies on the effects of anti-carcinogenic, lipid metabolism regulation, anti-inflammatory, anti-obese and antioxidant activities of CLNA isomers. The available results may provide a potential application for CLNA isomers from natural sources, especially edible plant seeds, as effective functional food ingredients and dietary supplements for the above mentioned disease management. Further research, especially human randomized clinical trials, is warranted to investigate the detailed physiological effects, bioactivity and molecular mechanism of CLNA.

Comparative prophylactic effects of α-eleostearic acid rich nano and conventional emulsions in induced diabetic rats

The present work entailed perspicacious fabrication of Bitter Gourd Seed Oil Nanoemulsion (BGO-NE) for increasing bioavailability of CLnA in oxidative stress induced in vivo system. The BGO-NE was characterized and evaluated for dimensional as well as rheological changes periodically during a 12 week storage period. BGO comprising ∼50 % α-eleostearic acid, was assessed in conventional and NE formulation at different doses, for its ability to stimulate antioxidative enzyme marker paradigm comprising SOD, GPx, CAT and GSH, inherent to the subjects under study. The formulated BGO-NE (d < 100 nm) was found to be stable for 12 weeks compared to BGO-CE as was determined by particle size characterization and associated parameters. Diet supplementation of 0.5 % (w/v) BGO-NE formulation exhibited maximum efficiency in countering oxidative stress as compared to 1 % BGO-NE formulation and equivalent doses of BGO-CE. Higher efficacy at very low dose of the nano-sized formulation was thus, also established. Histopathological data from liver, pancreas and kidney sections corroborated the above findings. The present study with formulated BGO-NE and BGO-CE evaluates and confirms the implications of a NE formulation of a bioactive lipid - conjugated linolenic acid (CLnA), targeting specific in vivo processes to counter the negative influence of excess ROS (Reactive Oxygen Species) in the system. It, thus presents itself as a potent nutraceutical against diabetes mellitus in an optimized delivery system.

Effects of pomegranate seed oil on glucose and lipid metabolism-related organs in rats fed an obesogenic diet

Studies conducted in mice have revealed positive effects of punicic acid (PUA). The aim of this study was to analyze the effects of PUA on fat accumulation and glycemic control in rats fed an obesogenic diet. Rats were randomly divided into two groups: control group and PUA group (diet supplemented with 0.5% PUA). No changes were observed in adipose tissue weights. The glucose tolerance test showed that the glycemic value in the PUA group had decreased significantly at the final time (120 min) (-19.3%), as had fructosamine levels (-11.1%). However, homeostasis model assessment (HOMA-IR) showed that insulin resistance did not improve. No changes were observed in the liver, skeletal muscle composition, or peroxisome proliferator-activated receptors (PPARs) activation. Low levels (mg/g tissue) of PUA (0.04 ± 0.01 in both tissues) and higher levels of cis-9,trans-11 conjugated linoleic acid (0.31 ± 0.08 in liver, 0.52 ± 0.11 in muscle) were found. PUA supplementation induced hypoplasia (-16.1%) due to the antiproliferative effect on hepatocytes. In conclusion, dietary supplementation of 0.5% PUA did not lead to decreased fat accumulation in adipose tissue, liver, or skeletal muscle, or to improved glycemic control. The hypoplasia induced in liver is a negative effect that should be considered before proposing PUA as a functional ingredient.

Protective effect of conjugated linolenic acid isomers present in vegetable oils against arsenite-induced renal toxicity in rat model

OBJECTIVE

The aim of the present study was to investigate the protective effect of conjugated linolenic acid (CLnA), present in vegetable oils against arsenite-induced renal oxidative stress.

METHODS

Albino rats were divided into six groups. Group 1 was control and group 2 was treated with sodium arsenite (Sa; 10 mg/kg BW). Rats in groups 3 and 4 were treated with mixture of α-eleostearic acid and punicic acid (1:1) (0.5% and 1.0%, respectively), whereas rats in the groups 5 and 6 were treated with 0.5% of α-eleostearic acid and 0.5% of punicic acid, respectively, along with Sa by oral gavage once daily.

RESULTS

Results revealed that activity of antioxidant enzymes and total reduced glutathione content, total protein content, and phospholipid content in kidney were decreased significantly in arsenite-treated group compared with control. Activity of nitric oxide synthase, peroxidation of lipid, protein oxidation, total cholesterol content, total lipid content of kidney, and plasma creatinine level were increased significantly (P < 0.05) in arsenite-treated rats compared with control. Fatty-acid composition of renal lipids showed significant decrease in monounsaturated fatty acid, polyunsaturated fatty acid (PUFA) content, and increase in saturated fatty acid content due to oxidative stress. PUFA such as γ-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid decreased significantly with significant (P < 0.05) increase in arachidonic acid content after Sa treatment. Administration of blended product of both the isomers caused better restoration of renal fatty acids and other altered parameters.

CONCLUSION

CLnA isomers caused amelioration of renal oxidative stress and the isomers showed synergistic activity.

Antioxidant and anti-inflammatory effect of conjugated linolenic acid isomers against streptozotocin-induced diabetes

The present study was undertaken to evaluate the effect of α-eleostearic acid and punicic acid, two isomers of conjugated linolenic acid (CLnA) present in bitter gourd (Momordica charantia) and snake gourd oil (Trichosanthes anguina), respectively, against oxidative stress, inflammatory challenge and aberration in erythrocyte morphology due to streptozotocin (STZ)-induced diabetes. Male albino rats were divided into four groups consisting of eight animals in each group. The first group served as control and diabetes was induced in rats in groups 2–4 by a single intraperitoneal injection of STZ. Moreover, rats in groups 3 and 4 were treated with 0·5 % of α-eleostearic acid and 0·5 % of punicic acid of the total lipid given, respectively, by oral administration once per d. After administration, CLnA isomers had significantly reduced oxidative stress, lipid peroxidation and restored antioxidant and pro-inflammatory enzymes such as superoxide dismutase, catalase, and glutathione peroxidase, reduced glutathione, NO synthase level in pancreas, blood and erythrocyte lysate. The ferric reducing antioxidant power (FRAP) assay of plasma showed that CLnA treatment caused improvement in the FRAP value which was altered after STZ treatment due to an increased level of free radicals. Expression of inflammatory cytokines such as TNF-α and IL-6 in blood and expression of hepatic NF-κB (p65) increased significantly after STZ treatment due to increased inflammation which was restored with the administration of CLnA isomers. From the obtained results, it could be concluded that α-eleostearic acid and punicic acid showed potent antioxidant and anti-inflammatory activity with varying effectivity.

Comparison of native and capric acid-enriched mustard oil effects on oxidative stress and antioxidant protection in rats

The present study evaluated the effect of mustard oil enriched in capric acid, a medium-chain fatty acid, on antioxidant enzyme activities in liver and brain and on the levels of malondialdehyde (MDA) in liver, brain and plasma in rats; the effect of adding cholesterol to the diet was also investigated. Charles Foster male albino rats weighing 80–100 g were fed one of four diets for 30 d (six rats per group). In the absence of added dietary cholesterol, the addition of capric acid to the diet resulted in lower plasma total cholesterol, non-HDL-cholesterol and TAG concentrations, higher HDL-cholesterol concentrations, higher antioxidant enzyme activities in liver and brain and lower MDA concentrations in liver, brain and plasma. Adding cholesterol to the diet increased plasma total cholesterol, non-HDL-cholesterol and TAG concentrations, decreased HDL-cholesterol concentration, decreased the activities of antioxidant enzymes and increased tissue and plasma MDA concentrations. Including capric acid in the diet of rats receiving cholesterol at least partly prevented the effects of the increased cholesterol. It is concluded that compared with native mustard oil, capric acid-enriched mustard oil improves blood lipids, enhances antioxidant protection and reduces lipid peroxidation.

Antidiabetic effect of flax and pumpkin seed mixture powder: effect on hyperlipidemia and antioxidant status in alloxan diabetic rats

Reactive oxygen species play a crucial role in the pathogenesis of diabetes and its complications. This study aims to examine the effects of flax and pumpkin powder seed mixture on alloxan induced diabetes in Wistar rats. Animals were allocated into three groups of six rats each: a control group (CD), diabetic group (DD) and diabetic rats fed with flax and pumpkin seed mixture (DMS) group. The diabetic rats (DD) presented a significant increase in glycemia, plasma and liver lipid parameters such as total lipid, total cholesterol and triglycerides compared to the control group (CD). In addition, plasma and liver malonaldialdehyde levels (MDA, an index of lipid peroxidation) significantly increased compared to (CD). Antioxidant enzymes activities such as catalase, superoxide dismutase, and reduced glutathione (GSH) levels significantly decreased in the plasma and liver of diabetic rats compared to controls. Diet supplemented with flax and pumpkin seed mixture in the DMS group ameliorated antioxidant enzymes activities and level of GSH in diabetic rats and significantly decreased MDA levels. The present study revealed a significant increase in the activities of aspartate aminotransferase and alanine aminotransferase on diabetic status, indicating considerable hepatocellular injury. The administration of flax and pumpkin seed mixture attenuated the increased levels of the plasma enzymes produced by the induction of diabetes and caused a subsequent recovery towards normalization comparable to the control group animals. Our results thus suggest that flax and pumpkin seed mixture supplemented to diet may be helpful in preventing diabetic complications in adult rats.

The health promoting properties of the conjugated isomers of α-linolenic acid

The bioactive properties of the conjugated linoleic acid (CLA) isomers have long been recognised and are the subject of a number of excellent reviews. However, despite this prominence the CLA isomers are not the only group of naturally occurring dietary conjugated fatty acids which have shown potent bioactivity. In a large number of in vitro and in vivo studies, conjugated α-linolenic acid (CLNA) isomers have displayed potent anti-inflammatory, immunomodulatory, anti-obese and anti-carcinogenic activity, along with the ability to improve biomarkers of cardio-vascular health. CLNA isomers are naturally present in high concentrations in a large variety of seed oils but can also be produced in vitro by strains of lactobacilli and bifidobactena through the activity of the enzyme linoleic acid isomerase on α-linolenic acid. In this review, we will address the possible therapeutic roles that CLNA may play in a number of conditions afflicting Western society and the mechanisms through which this activity is mediated.

Isomerization of conjugated linolenic acids during methylation

Conjugated linolenic acids (CLnA) need to be converted into their methyl esters when they are analyzed by gas liquid chromatography (GLC) or high performance liquid chromatography (HPLC). We found that methylation under different conditions could cause substantial isomerization of CLnA. The present study was therefore to optimize the acid-catalyzed or base-catalyzed methylation conditions in order to minimize the artifact derived from isomerization. It demonstrated clearly that isomerization was temperature and time-dependent if methylation was conducted by acid catalysis. For the two acid-catalyzed methylation reagents, BF3/methanol caused greater isomerization than H2SO4/methanol. It was found that using H2SO4/methanol as a reagent at 40 degrees C for 10 min was most appropriate to avoid isomerization when free CLnA was methylated. In contrast, base-catalyzed methylation in NaOMe/methanol at 40 degrees C for 10 min could minimize the isomerization of CLnA in triacylglycerol form.

Ameliorative influence of sesame lignans on lipid profile and lipid peroxidation in induced diabetic rats

Sesame lignans are working as antioxidants in various physiological functions. In the present study, the antioxidative effect of sesame lignans is examined in chemically induced diabetes mellitus (DM) in rats against lipid profile and lipid peroxidations. DM was induced in four groups of rats by injection of alloxan. The control groups (non-diabetic and diabetic) received a diet containing sunflower oil while the rest of the three experimental diabetic groups received a diet containing 0.25% alpha-tocopherol (D-Toc), 0.5% sesame lignan (D-SL), and 0.25% alpha-tocopherol+0.25% sesame lignan (D-Toc-SL) in sunflower oil for 4 weeks. Lipid profile and lipid peroxidations of plasma, erythrocyte membrane (EM), and liver tissues were measured. The total cholesterol, non-HDL cholesterol, plasma lipid peroxidation, and also LDL-peroxidation decreased, and HDL cholesterol increased significantly (P<0.05) in all the experimental groups as compared to the control diabetic sunflower oil group. The triacylglycerol (TAG) level in plasma decreased significantly in the D-SL and D-Toc-SL groups as compared to control diabetic group. Significant decrease in TAG level was observed in the D-SL group as compared to the D-Toc group. LDL peroxidation also decreased significantly in the D-Toc-SL group as compared to the D-Toc group. EM lipid peroxidation and liver lipid peroxidation decreased significantly in the D-Toc, D-SL, and D-Toc-SL groups as compared to the control diabetic group. Liver TAG level decreased more significantly in the D-SL and D-Toc-SL groups than in the control diabetic group. So, sesame lignans at 0.5% level and sesame lignan + alpha-tocopherol significantly ameliorate the alteration in lipid profile and the adverse free radical generative influence of DM induced by alloxan.

Antioxidative Effect of Conjugated Linolenic Acid in Diabetic and Non-Diabetic Blood: an in vitro Study

The present study examined the in vitro antioxidant activity of conjugated octadecatrienoic fatty acid (9cis, 11 trans, 13 trans-18:3), alpha-eleostearic acid present in karela seed oil (Momordica charantia) at about 55% level. The in vitro antioxidant properties of alpha-eleostearic acid are investigated on oxidative modification of human plasma, low-density lipoprotein (LDL) and erythrocyte membrane lipid. Blood samples are collected from diabetic and non-diabetic (normal) healthy individuals. alpha-eleostearic acid is added at 0.05% and 0.1% concentrations to plasma, LDL and erythrocyte membrane isolated from the respective blood samples and peroxidations are determined against control samples. A significant increase of respective peroxidation levels has been observed in diabetic control blood than the non-diabetic control blood. alpha-eleostearic acid has decreased lipid peroxidation level against control samples in a dose dependent manner. The present findings suggest that CLnA, 9cis, 11trans, 13trans-18:3 is a potentially effective antioxidant that can protect plasma, low density lipoprotein and erythrocyte membrane from oxidation which may be effective in reducing the risk of coronary heart disease in diabetes mellitus.