Effects of Fish Oil Supplementation on Oxidative Stress Biomarkers and Liver Damage in Hypercholesterolemic Rats

Synergistic Effects of Omega-3 Fatty Acids and Physical Activity on Oxidative Stress Markers and Antioxidant Mechanisms in Aged Rats

BACKGROUND

Aging induces degenerative processes in the body, contributing to the onset of various age-associated diseases that affect the population. Inadequate dietary habits and low physical activity are major contributors to increased morbidity during aging. This study aimed to investigate the combined effects of omega-3 fatty acid supplementation and physical activity on the markers of oxidative stress and antioxidant defense mechanisms in aged male Wistar rats (23-24 months).

METHODS

The rats were randomly divided into four experimental groups: a sedentary control (placebo, no exercise), a trained (placebo and moderate-intensity graded aerobic exercise; Ex), and two trained groups supplemented with low (160 mg/kg of body weight; O1 + Ex) and high (320 mg/kg of body weight; O2 + Ex) doses of omega-3 fatty acids. The biochemical and functional parameters related to sarcopenia and the markers of oxidative stress were measured in blood and gastrocnemius muscle.

RESULTS

The results demonstrated dose-dependent, synergistic effects of omega-3 fatty acid supplementation and physical activity. The higher dose (320 mg/kg of body weight) improved plasma antioxidant capacity (TEAC, +21.01%, p < 0.01) and GPx activity (+78.05%, p < 0.05) while reducing CAT activity in erythrocytes (-19.92%, p < 0.05), likely as an adaptive stress response. Combined interventions also normalized cholesterol levels, improved the functional parameters of sarcopenia (stride length, +14.82%, p < 0.001), and enhanced antioxidant protection in aged rats.

CONCLUSIONS

These findings highlight the potential of combining omega-3 fatty acid supplementation and physical activity to counteract aging-related degenerative changes. Further research is needed to elucidate the underlying mechanisms and evaluate the long-term benefits of these strategies in aging populations.

Comparison of Dietary Supplementation with Krill Oil, Fish Oil, and Astaxanthin on an Experimental Ethanol-Induced Gastric Ulcer Model: A Biochemical and Histological Study

BACKGROUND/OBJECTIVES

Despite advances in ulcer treatment research, the search for new, safe, and effective strategies for preventing and treating ulcer diseases persists.

METHODS

In this study, the protective effects of dietary supplementation with krill oil (KO), fish oil (FO), and astaxanthin (ASX) on an ethanol-induced gastric ulcer model were compared during biochemical and histological observations. Sprague-Dawley (n = 64) rats randomly divided into four groups-normal control (vehicle), KO, FO, and ASX groups-received the supplements via the orogastric route at a rate of 2.5% (v/w) of their daily feed consumption for 4 weeks. Then, ulcer induction was performed with ethanol.

RESULTS

The ulcer group showed increased levels of malondialdehyde (MDA), chemiluminescence (CL), and myeloperoxidase (MPO) activity and decreased levels of glutathione in the gastric tissues. While KO, FO, and ASX supplementation decreased chemiluminescence levels in the ulcer group, only ASX supplementation decreased MDA levels and MPO activity.

CONCLUSIONS

In conclusion, supplementation with KO or FO has a similar protective effect against ethanol-induced ulcer damage, as it inhibits ROS formation and reduces lipid peroxidation. However, ASX supplementation has a higher protective effect than KO or FO supplementations against experimental ethanol-induced gastric lesions in rats, as it inhibits ROS formation and reduces neutrophil infiltration and lipid peroxidation.

Therapeutic Benefits of Tuna Oil by In Vitro and In Vivo Studies Using a Rat Model of Acetic Acid-Induced Ulcerative Colitis

Ulcerative colitis (UC), an inflammation of the colon lining, represents the main form of inflammatory bowel disease IBD. Nutritional therapy is extremely important in the management of ulcerative colitis. Fish oil contains long-chain omega-3 polyunsaturated fatty acids, which have beneficial effects on health, including anti-inflammatory effects. This study aims to investigate the benefits of bluefin tuna oil extracted by the Soxhlet method in vitro by determining the anti-radical and anti-inflammatory activities and in vivo by evaluating the preventive and curative effects. The experiments were carried out using two doses of oil (100 and 260 mg/kg) and glutamine (400 and 1000 mg/kg) on the acetic acid-induced UC model. UC has been induced in Wistar rats by intrarectal administration of a single dose of 1 mL acetic acid (5% v/v in distilled water). The obtained results indicate that tuna oil and glutamine have a significant anti-free radical effect. Tuna oil has a marked anti-inflammatory power based on membrane stabilization and inhibiting protein denaturation. The reduction of various UC parameters, such as weight loss, disease activity score DAS, and colonic ulceration in rats pre-treated with tuna oil and glutamine, demonstrate that these treatments have a significant effect on UC. Total glutathione GSH, superoxide dismutase SOD, and catalase activities are significantly restored in the tuna oil and glutamine groups, while lipid peroxidation has been markedly reduced.

A Preliminary Study on Hepatoprotective, Hypolipidemic and Aortic Morphometric Effects of Omega-3-Rich Fish Oil in Hypercholesterolemic Mice

This study aims to evaluate the hepatoprotective, hypolipidemic and aortic morphometric effects of fish oil rich in omega-3 in hypercholesterolemic BALB/c mice. This is an experimental model that included 16 male BALB/c mice (Mus musculus) divided into three groups (G1 (standard commercial chow and 0.9% saline solution), G2 (hypercholesterolemic diet and 0.9% saline solution) and G3 (hypercholesterolemic diet and fish oil)) for 8 weeks. There was no significant difference in the treatment with omega-3-rich fish oil in the lipid profile (p > 0.05). In the histological analysis, group G2 detected the presence of hepatitis and liver tissue necrosis, but this was not observed in group G3. As for the morphometry in the light area of the vessel, the G1 group had a higher score (2.62 ± 0.36 mm2) when compared to G2 (2.10 ± 0.16 mm2) and G3 (2.26 ± 0.25 mm2) (p < 0.05). The vessel wall thickness did not differ between the groups (p > 0.05). It is concluded that supplementation with fish oil rich in omega-3 carried out in this study may have a protective effect on liver tissue, but it has not yet improved the lipid and morphometric profile. Despite this research being preliminary, it is a relevant study with future prospects for improving the doses of EPA and DHA in order to better elucidate the benefits of fish oil in models of dyslipidemia.

Associations of fatty acids composition and estimated desaturase activities in erythrocyte phospholipids with biochemical and clinical indicators of cardiometabolic risk in non-diabetic Serbian women: the role of level of adiposity

Introduction

Fatty acids (FAs) composition and desaturase activities can be altered in different metabolic conditions, but the adiposity-independent associations with clinical and biochemical indicators of cardiometabolic risk are still unclear. This study aimed to analyze the associations of FAs composition and estimated desaturase activities with anthropometric, clinical, and biochemical cardiometabolic risk indicators in non-diabetic Serbian women, and to investigate if these associations were independent of the level of adiposity and other confounders.

Methods

In 76 non-diabetic, otherwise healthy Serbian women, aged 24-68 years, with or without metabolic syndrome or obesity (BMI=23.6±5.6 kg/m2), FA composition in erythrocyte phospholipids was measured by gas-liquid chromatography. Desaturase activities were estimated from product/precursor FAs ratios (D9D:16:1n-7/16:0; D6D:20:3n-6/18:2n-6; D5D:20:4n-6/20:3n-6). Correlations were made with anthropometric, biochemical (serum glucose, triacylglycerols, LDL-C, HDL-C, ALT, AST, and their ratios) and clinical (blood pressure) indicators of cardiometabolic risk. Linear regression models were performed to test the independence of these associations.

Results

Estimated desaturase activities and certain FAs were associated with anthropometric, clinical and biochemical indicators of cardiometabolic risk: D9D, D6D, 16:1n-7 and 20:3n-6 were directly associated, while D5D and 18:0 were inversely associated. However, the associations with clinical and biochemical indicators were not independent of the associations with the level of adiposity, since they were lost after controlling for anthropometric indices. After controlling for multiple confounders (age, postmenopausal status, education, smoking, physical activity, dietary macronutrient intakes, use of supplements, alcohol consumption), the level of adiposity was the most significant predictor of desaturase activities and aforementioned FAs levels, and mediated their association with biochemical/clinical indicators. Vice versa, desaturase activities predicted the level of adiposity, but not other components of cardiometabolic risk (if the level of adiposity was accounted). While the associations of anthropometric indices with 16:1n-7, 20:3n-6, 18:0 and D9D and D6D activities were linear, the associations with D5D activity were the inverse U-shaped. The only adiposity-independent association of FAs profiles with the indicators of cardiometabolic risk was a positive association of 20:5n-3 with ALT/AST ratio, which requires further exploration.

Discussion

Additional studies are needed to explore the mechanisms of the observed associations.

Fish oil supplementation protects against protein undernutrition-induced testicular and ovarian biochemical alterations in rats

Proteins are required for biological functions and their inadequacy might impair the growth and development of the reproductive system. The study investigated the effects of fish oil (FO) supplementation on low-protein diet-induced alterations in male and female reproductive organs. Male and female rats were assigned randomly to four groups respectively. The NPD rats had five rats per group and were given 16% casein diet while the LPD rats had eight rats per group and received 5% casein diet. After the 8th week, FO was administered for 3 weeks via oral gavage at a concentration of 400mg Kg^-1 after which the rats were sacrificed and testes and ovaries were excised. LPD-fed rats showed lower body weights for both genders. In LPD-fed rats, NO was significantly increased while GSH, vitamins C and E levels, the activities of CAT (except in ovaries), and GST were significantly reduced in both tissues. The activities of SOD and GPx were only reduced in the testes including sperm count, motility, and increase deformed sperm cells. Testosterone and progesterone levels were also reduced and lipid homeostasis was disrupted in the plasma of LPD-fed rats. FO supplementation reduces the NO, CHOL, TG, LDL (in females), and VLDL but significantly improves HDL (in females), testosterone, and progesterone levels, sperm count, motility, and morphology. The antioxidant status of both tissues also increased significantly in LPD-fed rats. Conclusively, FO might be effective in improving testicular and ovarian functions and for the maintenance of plasma lipid homeostasis in LPD-fed rats.

The In Vitro, Ex Vivo, and In Vivo Effect of Edible Oils: A Review on Cell Interactions

Consumption of edible oils is a significant part of the dietary pattern in the developed and developing world. Marine and vegetable oils are assumed to be part of a healthy food pattern, especially if one takes into account their potential role in protecting against inflammation, cardiovascular disease, and metabolic syndrome due to the presence of polyunsaturated fatty acids and minor bioactive compounds. Exploring the potential effect of edible fats and oils on health and chronic diseases is an emerging field worldwide. This study reviews the current knowledge of the in vitro, ex vivo, and in vivo effect of edible oils in contact with various cell types and aims to demonstrate which nutritional and bioactive components of a variety of edible oils present biocompatibility, antimicrobial properties, antitumor activity, anti-angiogenic activity, and antioxidant activity. Through this review, a wide variety of cell interactions with edible oils and their potential to counteract oxidative stress in pathological conditions are presented as well. Moreover, the gaps in current knowledge are also highlighted, and future perspectives on edible oils and their health benefits and potential to counteract a wide variety of diseases through possible molecular mechanisms are also discussed.

Effects of Fish Oil, Lipid Mediators, Derived from Docosahexaenoic Acid, and Their Co-Treatment against Lipid Metabolism Dysfunction and Inflammation in HFD Mice and HepG2 Cells

Although fish oil (FO) and lipid mediators (LM) derived from polyunsaturated fatty acids can prevent obesity, their combined effects and cellular metabolism remain unclear. Therefore, this study aimed to examine the potential protective and metabolic effects of FO in combination with LM (a mixture of 17S-monohydroxy docosahexaenoic acid, resolvin D5, and protectin DX [3:47:50], derived from docosahexaenoic acid (DHA)) on palmitic acid (PA)-induced HepG2 cells and high-fat- diet (HFD)-induced C57BL/6J mice after 9-week treatment. Lipid metabolism disorders and inflammation induced by HFD and PA were substantially reduced after FO and LM treatment. Further, FO and LM treatments reduced lipid accumulation by increasing fatty acid oxidation via peroxisome proliferator-activated receptor α and carnitine-palmitoyl transferase 1 as well as by decreasing fatty acid synthesis via sterol regulatory element-binding protein-1c and fatty acid synthase. Finally, FO and LM treatment reduced inflammation by blocking the NF-κB signaling pathway. Importantly, the combination of FO and LM exhibited more robust efficacy against nonalcoholic fatty liver disease, suggesting that FO supplemented with LM is a beneficial dietary strategy for treating this disease.

Dietary EPA+DHA Mitigate Hepatic Toxicity and Modify the Oxylipin Profile in an Animal Model of Colorectal Cancer Treated with Chemotherapy

Irinotecan (CPT-11) and 5-fluorouracil (5-FU) are commonly used to treat metastatic colorectal cancer, but chemotherapy-associated steatosis/steatohepatitis (CASSH) frequently accompanies their use. The objective of this study was to determine effect of CPT-11+5-FU on liver toxicity, liver oxylipins, and cytokines, and to explore whether these alterations could be modified by dietary eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the form of fish oil (EPA+DHA). Tumor-bearing animals were administered CPT-11+5-FU and maintained on a control diet or a diet containing EPA+DHA (2.3 g/100 g). Livers were collected one week after chemotherapy for the analysis of oxylipins, cytokines, and markers of liver pathology (oxidized glutathione, GSSH; 4-hydroxynonenal, 4-HNE, and type-I collagen fiber). Dietary EPA+DHA prevented the chemotherapy-induced increases in liver GSSH (p < 0.011) and 4-HNE (p < 0.006). Compared with the tumor-bearing animals, ten oxylipins were altered (three/ten n-6 oxylipins were elevated while seven/ten n-3 oxylipins were reduced) following chemotherapy. Reductions in the n-3 fatty-acid-derived oxylipins that were evident following chemotherapy were restored by dietary EPA+DHA. Liver TNF-α, IL-6 and IL-10 were elevated (p < 0.05) following chemotherapy; dietary EPA+DHA reduced IL-6 (p = 0.09) and eotaxin (p = 0.007) levels. Chemotherapy-induced liver injury results in distinct alterations in oxylipins and cytokines, and dietary EPA+DHA attenuates these pathophysiological effects.

Histological, ultrastructural and immunohistochemical studies on the ameliorative role of Cinnamon zeylanicum against high cholesterol diet-induced hypercholesterolemia in the kidney of adult male albino rats

Cholesterol is an important type of lipid as it is involved in the structure of cell membrane, synthesis of steroid hormones, bile acid and vitamin D. Many diseases affect various mammalian organs, including the kidney, as a result of high cholesterol levels (hypercholesterolemia). Cinnamon zeylanicum (C. zeylanicum) proves its efficiency as it has anti-inflammatory and antioxidant prosperities. This study aimed to investigate the possible ameliorative role of C. zeylanicum on hypercholesterolemia-induced the renal toxicity in albino rats. Forty adult male albino rats were equally divided into four groups. The first group served as the control one. The second group was supplemented with C. zeylanicum powder (15% w/w) with the standard diet. The third group was fed high cholesterol diet (HCD) to induce acute hypercholesterolemia. The fourth group was fed HCD provided with C. zeylanicum powder (15% w/w). At the end of the experiment (8^th weeks), kidneys were removed and prepared for histological, immunohistochemical and ultrastructure studies. Rats-fed HCD showed degenerated glomeruli and tubular cells with vacuolated or coagulated cytoplasm and pyknotic nuclei. Moreover, the renal cortex ultrastructural examination showed degenerated podocytes, parietal and mesangial cells, as well as the proximal and distal tubular cells appeared with rarified cytoplasm, degenerated mitochondria, large fat vacuoles and complete damaged microvilli. The same group showed a significant increase in the expression of desmin and inducible nitric oxide synthase. On the other hand, animals fed HCD provided with C. zeylanicum showed an obvious improvement in the observed histological, ultrastructural and immunohistochemical changes. The architecture of the renal cortex appeared mostly similar to the control one. This study concluded that C. zeylanicum has a promising role in treating the nephron-toxicity of HCD due to its natural constituent that is responsible for its pharmaceutical effects.

Lowering n-6/n-3 Ratio as an Important Dietary Intervention to Prevent LPS-Inducible Dyslipidemia and Hepatic Abnormalities in ob/ob Mice

Obesity is closely associated with low-grade chronic and systemic inflammation and dyslipidemia, and the consumption of omega-3 polyunsaturated fatty acids (n-3 PUFAs) may modulate obesity-related disorders, such as inflammation and dyslipidemia. An emerging research question is to understand the dietary intervention strategy that is more important regarding n-3 PUFA consumption: (1) a lower ratio of n-6/n-3 PUFAs or (2) a higher amount of n-3 PUFAs consumption. To understand the desirable dietary intervention method of n-3 PUFAs consumption, we replaced lard from the experimental diets with either perilla oil (PO) or corn oil (CO) to have identical n-3 amounts in the experimental diets. PO had a lower n-6/n-3 ratio, whereas CO contained higher amounts of PUFAs; it inherently contained relatively lower n-3 but higher n-6 PUFAs than PO. After the 12-week dietary intervention in ob/ob mice, dyslipidemia was observed in the normal chow and CO-fed ob/ob mice; however, PO feeding increased the high density lipoprotein-cholesterol (HDL-C) level; further, not only did the HDL-C level increase, the low density lipoprotein-cholesterol (LDL-C) and triglyceride (TG) levels also decreased significantly after lipopolysaccharide (LPS) injection. Consequently, extra TG accumulated in the liver and white adipose tissue (WAT) of normal chow- or CO-fed ob/ob mice after LPS injection; however, PO consumption decreased serum TG accumulation in the liver and WAT. PUFAs replacement attenuated systemic inflammation induced by LPS injection by increasing anti-inflammatory cytokines but inhibiting pro-inflammatory cytokine production in the serum and WAT. PO further decreased hepatic inflammation and fibrosis in comparison with the ND and CO. Hepatic functional biomarkers (aspartate aminotransferase (AST) and alanine transaminase (ALT) levels) were also remarkably decreased in the PO group. In LPS-challenged ob/ob mice, PO and CO decreased adipocyte size and adipokine secretion, with a reduction in phosphorylation of MAPKs compared to the ND group. In addition, LPS-inducible endoplasmic reticulum (ER) and oxidative stress decreased with consumption of PUFAs. Taken together, PUFAs from PO and CO play a role in regulating obesity-related disorders. Moreover, PO, which possesses a lower ratio of n-6/n-3 PUFAs, remarkably alleviated metabolic dysfunction in LPS-induced ob/ob mice. Therefore, an interventional trial considering the ratio of n-6/n-3 PUFAs may be desirable for modulating metabolic complications, such as inflammatory responses and ER stress in the circulation, liver, and/or WAT.