Dietary flaxseed oil and fish oil ameliorates renal oxidative stress, protein glycation, and inflammation in streptozotocin-nicotinamide-induced diabetic rats

Maternal supplementation with n-3 fatty acids affects placental lipid metabolism, inflammation, oxidative stress, the endocannabinoid system, and the neonate cytokine concentrations in dairy cows

BACKGROUND

The placenta plays a crucial role in supporting and influencing fetal development. We compared the effects of prepartum supplementation with omega-3 (n-3) fatty acid (FA) sources, flaxseed oil (FLX) and fish oil (FO), on the expression of genes and proteins related to lipid metabolism, inflammation, oxidative stress, and the endocannabinoid system (ECS) in the expelled placenta, as well as on FA profile and inflammatory response of neonates. Late-pregnant Holstein dairy cows were supplemented with saturated fat (CTL), FLX, or FO. Placental cotyledons (n = 5) were collected immediately after expulsion, and extracted RNA and proteins were analyzed by RT-PCR and proteomic analysis. Neonatal blood was assessed for FA composition and concentrations of inflammatory markers.

RESULTS

FO increased the gene expression of fatty acid binding protein 4 (FABP4), interleukin 10 (IL-10), catalase (CAT), cannabinoid receptor 1 (CNR1), and cannabinoid receptor 2 (CNR2) compared with CTL placenta. Gene expression of ECS-enzyme FA-amide hydrolase (FAAH) was lower in FLX and FO than in CTL. Proteomic analysis identified 3,974 proteins; of these, 51-59 were differentially abundant between treatments (P ≤ 0.05, |fold change| ≥ 1.5). Top canonical pathways enriched in FLX vs. CTL and in FO vs. CTL were triglyceride metabolism and inflammatory processes. Both n-3 FA increased the placental abundance of FA binding proteins (FABPs) 3 and 7. The abundance of CNR1 cannabinoid-receptor-interacting-protein-1 (CNRIP1) was reduced in FO vs. FLX. In silico modeling affirmed that bovine FABPs bind to endocannabinoids. The FLX increased the abundance of inflammatory CD44-antigen and secreted-phosphoprotein-1, whereas prostaglandin-endoperoxide synthase 2 was decreased in FO vs. CTL placenta. Maternal FO enriched neonatal plasma with n-3 FAs, and both FLX and FO reduced interleukin-6 concentrations compared with CTL.

CONCLUSION

Maternal n-3 FA from FLX and FO differentially affected the bovine placenta; both enhanced lipid metabolism and modulated oxidative stress, however, FO increased some transcriptional ECS components, possibly related to the increased FABPs. Maternal FO induced a unique balance of pro- and anti-inflammatory components in the placenta. Taken together, different sources of n-3 FA during late pregnancy enhanced placental immune and metabolic processes, which may affect the neonatal immune system.

Mechanisms of resveratrol against diabetic wound by network pharmacology and experimental validation

BACKGROUND

Resveratrol (RSV) that possesses anti-oxidative, anti-inflammatory, and pro-angiogenic effects is an effective drug for diabetic wound (DW), while its pharmacological mechanism remains to be elucidated. In this study, we apply network pharmacology and experimental validation approach to reveal the potential mechanism of RSV against DW.

METHODS

We obtained potential targets for RSV and DW from the publicly available database. Using interaction networks and conducting GO and KEGG pathway enrichment analyses, we constructed target-pathway networks to explore the relationship between RSV and DW. To validate the pharmacological mechanism of RSV, we induced the DW model.

RESULTS

Ninety overlapped targets between RSV and DW were obtained, and the hub genes of the PPI network included TNF, IL-6, CASP3, MAPK3, VEGFA, IL-1β, AKT1, and JUN. Based on target-pathway networks, the AGE-RAGE signalling pathway was involved in the RSV treatment of DW. Furthermore, in vivo experiments revealed that RSV significantly promoted wound healing in diabetic mice and attenuated the expression of pro-inflammatory cytokines in wound tissue. Meanwhile, RSV could inhibit the AGE-RAGE signalling pathway and thus reduce the activation of NF-κB.

CONCLUSION

This study initially revealed the biological mechanism of RSV for treating DW through multi-target and multi-pathway. AGE-RAGE, FoxO, MAPK, PI3K-AKT and other signalling pathways may be the main pathways of RSV in treating DW. RSV reduces the inflammatory response by inhibiting the AGE-RAGE signalling pathway, which in turn promotes DW healing.

Management of a Patient With Premenstrual Syndrome Using Acupuncture, Supplements, and Meditation: A Case Report

Objective

The purpose of this case report was to describe a multimodal approach for the treatment of premenstrual syndrome (PMS).

Clinical Features

A 36-year-old nulliparous woman presented to a free clinic for veterans and their spouses. She received a PMS diagnosis at age 18. She was previously prescribed hormonal birth control and nonsteroidal anti-inflammatory drugs, which minimally affected her condition. She stopped using conventional medicine therapies at age 27. Laboratory results showed that her progesterone was below 0.5 ng/mL. Her symptom score was 50 out of 60 on the Treatment Strategies for PMS assessment tool. During her menses, she experienced low back pain and stiffness, bloating, swelling, weight gain, breast tenderness, swelling, and pain, and she felt overwhelmed and stressed.

Intervention and Outcome

Traditional Chinese medicine acupuncture was administered in conjunction with 100 mg of coenzyme Q10 (ubiquinol) and a B-100 complex once a day and 400 mg of magnesium citrate, 1000 mg of flaxseed oil (Linum usitatissimum), and 1000 mg of turmeric (Curcuma longa) twice a day. Five days before the onset of her menstrual period, she was to ingest a B-100 complex twice a day and 400 mg of magnesium citrate, 1000 mg of flaxseed oil, and 1000 mg of turmeric 3 times a day. Mindfulness meditation was encouraged twice a day for 10 minutes to reduce stress. After 12 treatments over 3 months, her symptom score decreased to 18 out of 60 and remained below 20 for an additional 32 weeks.

Conclusion

This patient with PMS symptoms positively responded to a multimodal approach using traditional Chinese medicine-style acupuncture, dietary supplements, and mindfulness meditation.

Beneficial Effects of Dietary Flaxseed Oil through Inflammation Pathways and Gut Microbiota in Streptozotocin-Induced Diabetic Mice

Flaxseed oil (FO) has displayed potential anti-diabetes properties by providing a high content of α-linolenic acid. However, the effects and mechanisms of FO on type 1 diabetes are still unclear. The present study aims to explore the effects of different doses of FO feeding on hepatic inflammation and gut microbiota in streptozotocin-induced diabetic mice. Forty-eight six-week-old C57BL/6J male mice were divided into a control group (CON), a diabetic group (MOD), a diabetes with 7.0% w/w FO feeding group (FO-L), and a diabetes with 10.5% w/w FO feeding group (FO-H) for six weeks. The 7.0% w/w and 10.5% w/w FO feeding groups exhibited potential recovery of the number and size of pancreas tissues. The fasting blood glucose level was significantly decreased only after 4 weeks of feeding with 10.5% w/w FO in diabetic mice. The 10.5% w/w FO feeding group significantly decreased the postprandial blood glucose level of mice in the OGTT test. Hepatic glycogen levels were dramatically upregulated in the mice fed with both 7.0% w/w and 10.5% w/w FO. FO feeding significantly attenuated hepatic LPS, TNF-α, and IL-1β levels. In addition, we observed that 7.0% w/w and 10.5% w/w FO feedings notably downregulated hepatic gene and protein expressions of TLR4, MyD88, and P65. Furthermore, only 10.5% FO regulated fecal microbiota by increasing the relative abundance of the Bacteroidetes phylum, Lactococcus family, and Muribaculaceae and Streptococcaceae family and genus in streptozotocin-induced diabetic mice. Therefore, we conclude that FO feeding plays a role in anti-inflammation via the regulation of hepatic LPS/TLR4/MyD88 pathways and gut microbiota. In addition, different doses of FO supplementation may exhibit varying mechanisms in streptozotocin-induced mice.

Encapsulation of Functional Plant Oil by Spray Drying: Physicochemical Characterization and Enhanced Anti-Colitis Activity

In this study, an encapsulation system was developed for functional plant oil delivery. Through a series of orthogonal experiments and single factor experiments, the raw material compositions, emulsification conditions, and spray drying conditions for the preparation of flaxseed oil and safflower seed oil powders were optimized, and the final encapsulation efficiency was as high as 99% with approximately 50% oil loading. The storage stability experiments showed that oil powder’s stability could maintain its physicochemical properties over six months. Oral supplementation of the spray-dried flaxseed oil powder exhibited a significant and better effect than flaxseed oil on alleviating colitis in C57BL/6J mice. It suppressed the pro-inflammatory cell factors, including IL-6 and TNF-α, and repaired gut microbial dysbiosis by increasing the microbial diversity and promoting the proliferation of probiotic taxa such as Allobaculum. This work suggests that spray-dried flaxseed oil powder has great potential as a nutraceutical food, with spray drying being a good alternative technique to improve its bioactivity.

The Nicotinamide/Streptozotocin Rodent Model of Type 2 Diabetes: Renal Pathophysiology and Redox Imbalance Features

Diabetic nephropathy (DN) is a common complication of diabetes mellitus. While there has been a great advance in our understanding of the pathogenesis of DN, no effective managements of this chronic kidney disease are currently available. Therefore, continuing to elucidate the underlying biochemical and molecular mechanisms of DN remains a constant need. In this regard, animal models of diabetes are indispensable tools. This review article highlights a widely used rodent model of non-obese type 2 diabetes induced by nicotinamide (NA) and streptozotocin (STZ). The mechanism underlying diabetes induction by combining the two chemicals involves blunting the toxic effect of STZ by NA so that only a percentage of β cells are destroyed and the remaining viable β cells can still respond to glucose stimulation. This NA-STZ animal model, as a platform for the testing of numerous antidiabetic and renoprotective materials, is also discussed. In comparison with other type 2 diabetic animal models, such as high-fat-diet/STZ models and genetically engineered rodent models, the NA-STZ model is non-obese and is less time-consuming and less expensive to create. Given that this unique model mimics certain pathological features of human DN, this model should continue to find its applications in the field of diabetes research.

Characteristic of Streptozotocin-Nicotinamide-Induced Inflammation in A Rat Model of Diabetes-Associated Renal Injury

Background: Chemical agents such as streptozotocin (STZ) and nicotinamide (NAD) are used in animal models of diabetes mellitus and their related consequences in the kidneys. Several studies have been conducted to determine the modeling, however, the results are still unclear. Moreover, diabetic nephropathy is considered to begin with an inflammatory reaction in the kidneys.  Objectives: This study aims to investigate the metabolic profile STZ and NAD induce inflammation in the kidney.  Methods: The male Wistar rats used were divided into control and STZ-induced diabetes. Half of the diabetes group received a single dose of nicotinamide (230 mg/Kg) 15 minutes after STZ injection and all groups were monitored for 6 weeks. Furthermore, the profiles of creatinine, urea, and uric acid from serum and urine were observed and the kidney inflammation was tested by immunohistochemistry (IHC) with IL-6 and TNF-α parameters.  Results: The result shows that the administration of a single dose of 230 mg/kg NAD in diabetic rats induced with 50 mg/kg and 65 mg/kg STZ affects body weight and kidney organ index. For 6 weeks of testing, both doses of STZ were enhanced several parameters of kidney damage in diabetic rats in blood and urine chemical parameters. Furthermore, the use of NAD to promote inflammation in STZ-induced diabetic rats gave no significant difference. However, NAD can help mice live longer and avoid problems throughout the test.  Conclusions: The use of NAD leads to inflammation in Streptozotocin-induced diabetic rats. Therefore, the administration of Nicotinamide is recommended since it helps the rats live longer during the experiment. 

Beneficial Effects of High Intensity Interval Training and/or Linseed Oil Supplementation to Limit Obesity-Induced Oxidative Stress in High Fat Diet-Fed Rats

High-intensity interval training (HIIT) and linseed oil (LO) supplementation are effective strategies to reduce obesity-induced oxidative stress. Our aim was to determine whether the HIIT + LO combination prevents obesity-induced oxidative stress in high fat diet (HFD)-fed rats. HFD-fed 8-week-old, male, Wistar rats were subdivided in four groups: HFD, LO (2% of sunflower oil replaced with 2% of LO in the HFD), HIIT (4 days/week for 12 weeks), and HIIT + LO. Wistar rats fed a low-fat diet (LFD) were used as controls. Epididymal and subcutaneous adipose tissue, gastrocnemius muscle, liver, and plasma samples were collected to measure oxidative stress markers (AOPP, oxLDL), antioxidant (SOD, CAT, and GPx activities) and pro-oxidant (NOx and XO) enzyme activities. Compared with the LFD, the HFD altered the pro/antioxidant status in different tissues (increase of AOPP, oxLDL, SOD and catalase activities in plasma, and SOD activity increase in liver and decrease in adipose tissues) but not in gastrocnemius. LO upregulated CAT activity and decreased NOx in liver. HIIT alleviated HFD negative effects in liver by reducing SOD and NOx activities. Moreover, the HIIT + LO combination potentiated SOD activity upregulation in subcutaneous tissue. HIIT and LO supplementation have independent beneficial effects on the pro/antioxidant balance. Their association promotes SOD activity in subcutaneous adipose tissue.

MyD88 determines the protective effects of fish oil and perilla oil against metabolic disorders and inflammation in adipose tissue from mice fed a high-fat diet

BACKGROUND

The beneficial effects of ω-3 polyunsaturated fatty acids (PUFA) vary between different sources. However, there is a paucity of comparative studies regarding the effects and mechanisms of marine and plant ω-3 PUFA on obesity.

OBJECTIVE

The aim of this study was to evaluate the effects of fish oil (FO) and perilla oil (PO) on glucolipid metabolism, inflammation, and adipokine in mice fed a high-fat (HF) diet in association with the contribution of toll-like receptor 4 (TLR4)/myeloid differentiation primary response 88 (MyD88) pathway.

METHODS

C57BL/6J mice and MyD88-/- mice were randomly divided into 4 groups: normal chow diet, HF diet, HF diet accompanied by daily gavage with either FO or PO. After 4 weeks, blood biochemistries, adipocyte histology, mRNA, and protein expression of MyD88-dependent and -independent pathways of TLR4 signaling in epididymal adipose tissue were measured.

RESULTS

In C57BL/6J mice, there were no statistical differences between FO and PO in decreasing body weight, glucose, insulin, triglyceride, total cholesterol, interleukin-6, and increasing adipocyte counts. FO and PO decreased mRNA and protein expression of TLR4, MyD88, tumor necrosis factor receptor-associated factor 6, inhibitor of nuclear factor kappa B kinase beta and nuclear factor-kappa B p65. In MyD88-/- mice, the beneficial effects of FO and PO on HF diet-induced metabolism abnormalities and inflammation were abolished. FO and PO had no impacts on mRNA and protein expression of receptor-interacting protein-1, interferon regulate factor 3, and nuclear factor-kappa B p65.

CONCLUSION

FO and PO exhibit similar protective effects on metabolic disorders and inflammation through inhibiting TLR4 signaling in a manner dependent on MyD88. These findings highlight plant ω-3 PUFA as an attractive alternative source of marine ω-3 PUFA and reveal a mechanistic insight for preventive benefits of ω-3 PUFA in obesity and related metabolic diseases.

Apigenin-Loaded Solid Lipid Nanoparticle Attenuates Diabetic Nephropathy Induced by Streptozotocin Nicotinamide Through Nrf2/HO-1/NF-kB Signalling Pathway

Background

Apigenin is known to have a broad-spectrum efficacy in oxidative stress and conditions due to inflammation, although weak absorption, fast metabolic rate and a fast elimination (systemic) limit the pharmacological efficacy of this drug. Hence, we propose the usage of highly bioavailable Apigenin-solid lipid nanoparticles (SLNPs) to recognize such limitations. The defensive function of Apigenin-SLNPs on renal damage induced by streptozotocin (STZ) in animals was studied.

Materials and Methods

We initially injected the rats with 35 mg kg⁻¹ streptozocin intraperitoneally, and after 7 days, the rats were then injected 150 mg kg⁻¹ of metformin intragastrically followed by a once-daily intragastric dose of Apigenin-SLNP (25 or 50 mg kg⁻¹) for a continuous period of 30 days. We then measured the level of insulin and blood glucose, superoxide dismutase, catalase and malondialdehyde in the tissues of the kidney. We also observed messenger-RNA expression of Interleukin-1β, Interleukin-6 and Tumor Necrosis Factor-alpha in renal tissue through RT-PCR technique. Moreover, H&E staining and Western blotting observed the histopathological variations and protein expression of nuclear factor erythroid 2-related factor 2/heme oxygenase/Nuclear Factor-κB signaling pathway, respectively.

Results

An enhancement in the expressing of nuclear factor erythroid 2-related factor 2 and heme oxygenase-1 and a suppression in the expression of Nuclear Factor-κB occurred due to Apigenin-SLNPs treatment, which was a result of the protective mechanism of Apigenin-SLNPs which is because of not only its anti-inflammatory function (by inhibition of release of inflammatory factors) but also their anti-oxidant activity (through reduction of lipid peroxidation production).

Conclusion

We found that a protective effect on diabetic nephropathy was shown due to Apigenin-SLNPs, in rats induced with streptozocin maybe through the pathway of nuclear factor erythroid 2-related factor 2/heme oxygenase-1/Nuclear Factor-κB.

Analysis of the intricate effects of polyunsaturated fatty acids and polyphenols on inflammatory pathways in health and disease

Prevention and treatment of non-communicable diseases (NCDs), including cardiovascular disease, diabetes, obesity, cancer, Alzheimer's and Parkinson's disease, arthritis, non-alcoholic fatty liver disease and various infectious diseases; lately most notably COVID-19 have been in the front line of research worldwide. Although targeting different organs, these pathologies have common biochemical impairments - redox disparity and, prominently, dysregulation of the inflammatory pathways. Research data have shown that diet components like polyphenols, poly-unsaturated fatty acids (PUFAs), fibres as well as lifestyle (fasting, physical exercise) are important factors influencing signalling pathways with a significant potential to improve metabolic homeostasis and immune cells' functions. In the present manuscript we have reviewed scientific data from recent publications regarding the beneficial cellular and molecular effects induced by dietary plant products, mainly polyphenolic compounds and PUFAs, and summarize the clinical outcomes expected from these types of interventions, in a search for effective long-term approaches to improve the immune system response.

The Ratio of Linoleic and Linolenic Acid in the Pre-hibernation Diet Influences NFκB Signaling in Garden Dormice During Torpor

The fatty acid composition of a pre-hibernation diet can influence the depth and duration of metabolic suppression achieved by hibernators. More specifically, a diet high in n-6 polyunsaturated fatty acids (PUFAs) relative to n-3 PUFAs is essential to maximize torpor expression. However, few studies have investigated how diets with different n-6/n-3 PUFA ratios change stress-inducible cell signaling. Garden dormice (Eliomys quercinus) were fed one of three diets designed with different ratios of n-6 PUFA linoleic acid (LA) and n-3 PUFA linolenic acid (ALA). Then, NFκB signaling was assessed in the white adipose, brown adipose, and liver tissues of euthermic and hibernating dormice via multiplex and RT-qPCR analyses of relative protein and transcript levels, respectively. Dormice fed a high LA diet regulated NFκB signaling in a protective manner in all tissues. NFκB signaling was generally decreased in the high LA group, with significant decreases in the protein levels of NFκB mediators IKKα/β, IκBα, and downstream pro-apoptotic protein FADD. Liver and white adipose from torpid dormice fed a high LA diet increased sod2 expression relative to the other diets or relative to euthermic controls, indicating protection against ROS generated from potentially increased β-oxidation of n-6 PUFAs. The low LA diet increased biomarkers for apoptosis relative to other diets and relative to euthermia, suggesting low LA diets may be detrimental to hibernator health. Overall, this study suggests that changes in the ratio of n-6/ n-3 PUFAs in the diet influences apoptotic and antioxidant responses in white adipose, brown adipose, and liver of hibernating garden dormice.

Dietary flaxseed oil rich in omega-3 suppresses severity of type 2 diabetes mellitus via anti-inflammation and modulating gut microbiota in rats

BACKGROUND

Type 2 diabetes mellitus (T2DM) is closely associated with hyperglycemia, abnormal lipid profiles, chronic low-grade inflammation and gut dysbiosis. Dietary intervention plays a crucial role in the control of diabetes. Flaxseed oil (FO), a plant-derived omega-3 (ω-3) polyunsaturated fatty acids (PUFAs), is rich in α-linolenic acid (ALA) which has been proved to benefit for chronic metabolic disease. However, the exact effects of dietary FO on T2DM remains largely unclear.

METHODS

In the present study, SD rats were randomly allocated into four groups: pair-fed (PF) with corn oil (CO) group (PF/CO); DM with CO group (DM/CO); PF with FO group (PF/FO); DM with FO group (DM/FO). A diabetic rat model was generated by a single intraperitoneal injection of streptozotocin-nicotinamide (STZ-NA). After 5 weeks of intervention, rats were euthanized and associated indications were investigated.

RESULTS

Dietary FO significantly reduced fasting blood glucose (FBG), glycated hemoglobin (GHb), blood lipid, plasma lipopolysaccharide (LPS), interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-6, IL-17A and malondialdehyde (MDA), compared to control group, respectively. Moreover, body mass (BM) and superoxide dismutase (SOD) in DM/FO group were dramatically increased respectively, compared with those in DM/CO group. But insulin (INS) and homeostasis model assessment of insulin resistance (HOMA-IR) remained no significant difference between DM/CO group and DM/FO group. Sequencing analysis of gut microbiota showed a reduction in the relative abundance of Firmicutes and Blautia, as well as a reduction in the ratio of Bacteroidetes-Firmicutes in DM/FO group compared to DM/CO group. An elevation in the relative abundance of Bacteroidetes and Alistipes were detected in DM/FO group. Acetic acid, propionic acid and butyric acid belonging to short chain fatty acids (SCFAs) as gut microbiota metabolites, were dramatically increased after FO intervention. Correlation analysis revealed that the relative abundance of Firmicutes and Blautia were positively correlated with IL-1β, TNF-α, IL-6, IL-17A or LPS, respectively. Additionally, Bacteroidetes and Alistipes were negatively correlated with LPS.

CONCLUSIONS

Taken together, dietary FO ameliorated T2DM via suppressing inflammation and modulating gut microbiota, which may potentially contribute to dietary control of diabetes.

Dietary α-Linolenic Acid-Rich Flaxseed Oil Exerts Beneficial Effects on Polycystic Ovary Syndrome Through Sex Steroid Hormones-Microbiota-Inflammation Axis in Rats

Polycystic ovary syndrome (PCOS) represents a common endocrine-metabolic disorder disease with chronic low-grade inflammation and alteration of intestinal flora. Serving as functional food, flaxseed oil (FO), which is rich in plant-derived α-linolenic acid of omega-3 polyunsaturated fatty acids, has been proven to benefit for chronic metabolic diseases. However, the exact role of dietary FO on PCOS remains largely unclear. In the present study, 6-week-old female Sprague-Dawley rats were randomly divided into four groups (eight rats/group), including (a) pair-fed (PF) control (CON) group (PF/CON), (b) FO-fed CON group (FO/CON), (c) PF with letrozole-induced PCOS model (MOD) group (PF/MOD), and (d) FO-fed MOD group (FO/MOD). All rats were fed a standard diet. After 3 weeks of modeling and subsequent 8 weeks of treatment, the rats in diverse groups were euthanized and associated indications were investigated. The results showed that dietary FO ameliorated the disorder of estrous cycle and ovarian morphology. In parallel, dietary FO improved the sex steroid hormone disturbance (luteinizing hormone/follicle-stimulating hormone, estrogen, testosterone, and progesterone), body weights, dyslipidemia, and insulin resistance. Moreover, FO treatment improved plasma and ovary inflammatory interleukin (IL)-1β, IL-6, IL-10, and IL-17A, tumor necrosis factor-α, and monocyte chemoattractant protein-1. Additionally, FO intervention significantly modulated the composition of gut microbiota and vaginal microbiota by increasing the abundances of Allobaculum, Lactobacillus, Butyrivibrio, Desulfovibrio, Bifidobacterium, Faecalibacterium, Parabacteroides as well as decreasing the abundances of Actinobacteria, Bacteroides, Proteobacteria, and Streptococcus, the ratio of Firmicutes/Bacteroidetes. A decrease in plasma lipopolysaccharide level and an increase in short-chain fatty acids, including acetic acid, propionic acid, butyric acid and pentanoic acid, were determined after dietary FO supplementation. Correlation analysis revealed close relationships among sex steroid hormones, inflammation, and gut/vaginal microbiota. Collectively, this study demonstrated that dietary FO ameliorated PCOS through the sex steroid hormones-microbiota-inflammation axis in rats, which may contribute to the understanding of pathogenesis and potentially serve as an inexpensive intervention in the control of PCOS.

Alleviated systemic oxidative stress effects of combined atmospheric oxidant capacity by fish oil supplementation: A randomized, double-blinded, placebo-controlled trial

BACKGROUND

Combined atmospheric oxidant capacity (O_x), represented by the sum of nitrogen dioxide (NO₂) and ozone (O₃), is an important hazardous property of outdoor air pollution mixture. It remains unknown whether its adverse effects can be ameliorated by dietary fish-oil supplementation.

OBJECTIVE

To assess the effects of fish-oil supplementation against oxidative stress induced by acute O_x exposure.

METHODS

We conducted a randomized, double-blinded and placebo-controlled study among 65 young adults in Shanghai, China between September 2017 and January 2018. We randomly assigned participants to receive either 2.5 g/day of fish oil or placebo, and conducted four repeated physical examinations during the last two months of treatments. O_x concentrations were calculated as the sum of hourly measurements of NO₂ and O₃. We measured six biomarkers on systemic oxidative stress and antioxidant activity. Linear mixed-effect models were used to assess the short-term effects of O_x on biomarkers in each group.

RESULTS

During our study period, the 72-h average O_x concentration was 93.6 μg/m³. Short-term exposure to O_x led to weaker changes in all biomarkers in the fish oil group than in the placebo group. Compared with the placebo group, for a 10-μg/m³ increase in O_x, there were smaller decrements in myeloperoxidase (MPO, difference = 5.92%, lag = 0-2 d, p = 0.03) and malondialdehyde (MDA, difference = 5.00%, lag = 1 d, p = 0.04) in the fish-oil group; there were also larger increments in total antioxidant capacity (TAC, difference = 16.33%, lag = 2 d, p = 0.02) and in glutathione peroxidase (GSH-Px, difference = 8.89%, lag = 0-2 d, p = 0.03) in the fish-oil group. The estimated differences for MPO were robust to adjustment for all co-pollutants and the differences for other biomarkers remained for some co-pollutants.

CONCLUSIONS

This trial provides first-hand evidence that dietary fish-oil supplementation may alleviate the systemic oxidative stress induced by O_x.

Ameliorative effect of combined low dose of Pioglitazone and omega-3 on spermatogenesis and steroidogenesis in diabetic rats

BACKGROUND

Chronic hyperglycemia is linked to either subfertility or infertility among diabetic males. Pioglitazone is one of the thiazolidinediones (TZDs) drugs that are selective peroxisome proliferator-activated receptor (PPAR-γ agonists used for treating type 2 diabetes mellitus (T2DM).

AIM

This study aims to explore the possible effect of low Pioglitazone dose and omega (ω-3) on rat male reproductive function. Furthermore, we evaluated the add-on effect of combined use of low Pioglitazone dose of and ω-3 on reproductive functions in adult male T2DM rats.

METHODS

Fifty adult male rats were included and subdivided into control and four test subgroups. T2DM was induced in test groups and subdivided into non-treated T2DM, ω-3 treated, 0.6 mg/kg Pioglitazone treated, and combined treated group (orally by gavage). Following 16 weeks, final body weight, testicular weight, fasting plasma glucose, and serum testosterone levels were measured. Semen analysis, testicular testosterone, malondialdehyde (MDA) concentrations, superoxide dismutase (SOD) activity, immunohistochemistry staining for apoptosis marker B-cell lymphoma protein 2 (Bcl-2), proliferation marker as proliferating cell nuclear antigen (PCNA), estrogen receptor α (ERα), androgen receptor (AR) were determined. Caspase-3, nuclear factor-kappa B (NF-kB), glucose transporter 3 (GLUT3), 17β-hydroxysteroid dehydrogenases (17β-HSD) PPARγ, and PPARα genes expression were analyzed by real-time polymerase chain reaction (RT-PCR).

RESULTS

Our findings revealed that treatment with low dose of Pioglitazone or ω-3 significantly lowered fasting plasma glucose and MDA levels, ameliorated diabetes effects on histological damage, improved antioxidant activity (SOD), significantly improved anti-apoptosis BCL-2 and proliferation (PCNA), remarkably elevated ERα, AR, 17β-HSD PPARγ, and PPARα expression with significant reduction in caspase-3, NF-kB genes expression and improved semen quality as well. Combined use of low dose of and ω-3 has better effects on all measured parameters.

CONCLUSION

Small Pioglitazone dose and ω-3 possess beneficial effects on spermatogenic and steroidogenic functions in adult diabetic rat; while combined use of both has an add-on effect.

Fish oils protects against cecal ligation and puncture‑induced septic acute kidney injury via the regulation of inflammation, oxidative stress and apoptosis

Septic acute kidney injury (AKI) is usually caused by sepsis. ω3 fatty acid has been reported to suppress sepsis-induced organ dysfunction to a certain degree. The present study aimed to investigate the effects of ω3 fatty acid in septic renal injury. Sprague Dawley rats were used to establish a cecal ligation and puncture (CLP) model in order to mimic the development of septic injury. The rats were treated with dexamethasone and fish oils (FOs) for 4 days prior to CLP. Alterations in the morphology of the tissues, the renal function and the induction of inflammation, oxidative stress and apoptosis were evaluated. The effects of FOs on nuclear factor-κB (NF-κB), JAK2/STAT3 and p38-MAPK were determined. The rats of the CLP model group exhibited low survival rates and increased expression of serum creatine, blood urea nitrogen, neutrophil gelatinase-associated lipocalin, kidney injury molecule-1 and of proinflammatory cytokines. In addition, the levels of the markers of oxidative injury and apoptosis were increased. The induction of renal injury was notably reversed by administration of dexamethasone and FOs. The expression levels of the protein markers involved in inflammation and apoptosis were measured and the results indicated that FOs inhibited JAK/STAT3 and p-38MAPK signaling, while they concomitantly increased the expression of NF-κB. The present study highlighted that FOs improve CLP-induced mortality and renal injury by inhibiting inflammation, oxidative stress and apoptosis.

Effect of Early and Late Interventions with Dietary Oils on Vascular and Neural Complications in a Type 2 Diabetic Rat Model

AIMS

Determine the effect of dietary oils enriched in different mono- or polyunsaturated fatty acids, i.e., olive oil (18 : 1, oleic acid), safflower oil (18 : 2 n-6, linoleic acid), flaxseed oil (18 : 3 n-3, alpha linolenic acid), evening primrose oil (18 : 3 n-6, gamma linolenic acid), or menhaden oil (20:5/22 : 6 n-3 eicosapentaenoic/docosahexaenoic acids), on vascular and neural complications in high-fat-fed low-dose streptozotocin-treated Sprague-Dawley rats, an animal model for late-stage type 2 diabetes.

MATERIALS AND METHODS

Rats were fed a high-fat diet (45% kcal as fat primarily derived from lard) for 8 weeks and then treated with a low dose of streptozotocin (30 mg/kg) in order to induce hyperglycemia. After an additional 8 (early intervention) or 20 (late intervention) weeks, the different groups of rats were fed diets with 1/2 of the kcal of fat derived from lard replaced by the different dietary oils. In addition, a control group fed a standard diet (4.25% kcal as fat) and a diabetic group maintained on the high-fat diet were maintained. The treatment period was approximately 16 weeks. The endpoints evaluated included vascular reactivity of epineurial arterioles, motor and sensory nerve conduction velocity, thermal and corneal sensitivity, and innervation of sensory nerves in the cornea and skin.

RESULTS

Our findings show that menhaden and flaxseed oil provided the greatest benefit for correcting peripheral nerve damage caused by diabetes, whereas enriching the high-fat diet with menhaden oil provided the most benefit to acetylcholine-mediated vascular relaxation of epineurial arterioles of the sciatic nerve. Enriching the diets with fatty acids derived from the other oils provided none to partial improvements.

CONCLUSIONS

These studies imply that long-chain n-6 and n-3 polyunsaturated fatty acids could be an effective treatment for diabetic peripheral neuropathy with n-3 polyunsaturated fatty acids derived from fish oil being the most effective.

The potential protective influence of flaxseed oil against renal toxicity induced by thioacetamide in rats

The present study was aimed to evaluate the influence of flaxseed oil on renal toxicity induced by thioacetamide in male rats. The animals were distributed into four groups. Rats of the first group were served as control. Rats of the second group were exposed to thioacetamide. Rats of the third group were treated with flaxseed oil and thioacetamide. Rats of the fourth group were treated with flaxseed oil. Significant increases of blood creatinine and uric acid were observed in TAA-treated rats after three weeks. In thioacetamide group, the levels of serum creatinine, blood urea nitrogen and uric acid were significantly elevated after six weeks. Histopathologically, the renal sections from thioacetamide-treated rats showed severe alterations in the structure of renal corpuscles including a degeneration of glomeruli and Bowman's capsules. Administration of flaxseed oil protects the observed biochemical and histopathological alterations induced by thioacetamide exposure. Hence, the results of this study suggest that flaxseed oil protects against thioacetamide-induced renal injury and the protective influence of flaxseed oil may be attributed to its antioxidant role.

Chitosan oligosaccharide ameliorates acute lung injury induced by blast injury through the DDAH1/ADMA pathway

Objective

To investigate the protective effect of chitosan oligosaccharide (COS) on acute lung injury (ALI) caused by blast injury, and explore possible molecular mechanisms.

Methods

A mouse model of blast injury-induced ALI was established using a self-made explosive device. Thirty mice were randomly assigned to control, ALI and ALI + COS groups. An eight-channel physiological monitor was used to determine the mouse physiological index. Enzyme linked immunosorbent assay was used to measure serum inflammatory factors. Hematoxylin-eosin staining, terminal deoxynucleotidyl transferase dUTP nick end labeling assay, immunofluorescence staining, real time-polymerase chain reaction and western blot assay were used to detect inflammatory reactions, oxidative stress and apoptosis.

Results

Mice were sacrificed 24 hours after successful model induction. Compared with the ALI group, the heart rate, respiration and PCO₂ were significantly lower, but the PO₂, TCO₂ and HCO₃^- were significantly higher in the ALI + COS group. Compared to ALI alone, COS treatment of ALI caused a significant decrease in the wet/dry lung weight ratio, indicating a reduction in lung edema, inflammatory cell infiltration, levels of tumor necrosis factor-α, interleukin (IL)-1β, IL-4, IL-6 and nuclear factor kappa B mRNA and protein expression were reduced and IL-10 mRNA and protein expression was increased (P < 0.05). COS significantly inhibited reactive oxygen species, MDA5 and IREα mRNA and protein expressions, cell apoptosis and Bax and Caspase-3 mRNA and protein expressions, and significantly increased superoxide dismutase-1 mRNA expression, and Bcl-2 and Caspase-8 mRNA and protein expression (all P<0.05). COS significantly increased dimethylarginine dimethylaminohydrolase 1 (DDAH1) protein expression, and reduced ADMA and p38 protein expression (P< 0.05).

Conclusion

Blast injury causes inflammation, oxidative stress and apoptosis in the lung tissues of mice. COS has protective effects on blast injury-induced ALI, possibly by promoting DDAH1 expression and inhibiting ADMA and mitogen-activated protein kinase pathways.

MicroRNA‑146a/NAPDH oxidase4 decreases reactive oxygen species generation and inflammation in a diabetic nephropathy model

The present study investigated the role of microRNA (miR)‑146a in a diabetic nephropathy (DN) model, and its molecular mechanism. DN mice were given intraperitoneal injections of streptozotocin (55 mg/kg/day) for 5 consecutive days as an in vivo DN model. The HK‑2 human kidney cell line were exposed to 45% D‑glucose as an in vitro DN model. Firstly, it was demonstrated that miR‑146a expression was inhibited and NAPDH oxidase 4 (Nox4) was increased in DN mice. In HK‑2 cells, overexpression of miR‑146a inhibited Nox4 protein expression and decreased reactive oxygen species (ROS) generation, oxidative stress and inflammation, and suppressed vascular cell adhesion molecule‑1 (VCAM‑1) and intracellular adhesion molecule‑1 (ICAM‑1) protein expression. Nacetylcysteine, a Nox4 inhibitor, was demonstrated to inhibit ROS generation, suppress VCAM‑1 and ICAM‑1 protein expression, and decrease oxidative stress and inflammation in HK‑2 cells following overexpression of miR‑146a. In conclusion, these results indicated that miR‑146a/Nox4 decreases ROS generation and inflammation and prevents DN. Therefore, miR‑146a may represent a novel anti‑inflammatory and ‑oxidative modulator of DN.

Dietary Flaxseed Oil Prevents Western-Type Diet-Induced Nonalcoholic Fatty Liver Disease in Apolipoprotein-E Knockout Mice

The prevalence of nonalcoholic fatty liver disease (NAFLD) has dramatically increased globally during recent decades. Intake of n-3 polyunsaturated fatty acids (PUFAs), mainly eicosapentaenoic acid (EPA, C20:5n-3) and docosahexaenoic acid (DHA, C22:6n-3), is believed to be beneficial to the development of NAFLD. However, little information is available with regard to the effect of flaxseed oil rich in α-linolenic acid (ALA, C18:3n-3), a plant-derived n-3 PUFA, in improving NAFLD. This study was to gain the effect of flaxseed oil on NAFLD and further investigate the underlying mechanisms. Apolipoprotein-E knockout (apoE-KO) mice were given a normal chow diet, a western-type high-fat and high-cholesterol diet (WTD), or a WTD diet containing 10% flaxseed oil (WTD + FO) for 12 weeks. Our data showed that consumption of flaxseed oil significantly improved WTD-induced NAFLD, as well as ameliorated impaired lipid homeostasis, attenuated oxidative stress, and inhibited inflammation. These data were associated with the modification effects on expression levels of genes involved in de novo fat synthesis (SREBP-1c, ACC), triacylglycerol catabolism (PPARα, CPT1A, and ACOX1), inflammation (NF-κB, IL-6, TNF-α, and MCP-1), and oxidative stress (ROS, MDA, GSH, and SOD).