Dietary n-3 polyunsaturated fatty acids increase oxidative stress in rats with intracerebral hemorrhagic stroke

Causal Relationships between Polyunsaturated Fatty Acids and Colon Polyps: A Two-Sample Mendelian Randomization Study

BACKGROUND

Epidemiological studies have shown that fatty acids, especially polyunsaturated fatty acids (PUFAs), influence colorectal carcinogenesis. Colon polyps, particularly those identified as precancerous, are a frequently encountered phenomenon associated with PUFAs. However, the results are inconsistent. Therefore, we investigated the effect of PUFAs on colon polyps in individuals of European ancestry.

METHODS

Single nucleotide polymorphisms correlating with PUFAs and colon polyps were derived from extensive genome-wide association studies, encompassing a discovery cohort of 135,006 samples and a corresponding validation set with 114,999 samples. Causality was assessed by employing a range of techniques, such as inverse variance weighted (IVW), weighted median, MR-Egger, and simple and weighted modes. The analysis was complemented with sensitivity checks using leave-one-out and heterogeneity evaluation through MR-IVW and Cochran's Q.

RESULTS

A thorough analysis was performed to examine the causal effects of PUFAs on the development of colon polyps. The findings indicated that levels of Omega-3 fatty acids (OR = 1.0014, 95% CI 1.0004-1.0024, p = 0.004), the ratio of Docosahexaenoic acid (DHA)/total fatty acids (FAs) (DHA/totalFA; OR = 1.0015, 95% CI 1.0002-1.0028, p = 0.023), and the ratio of Omega-3/totalFA (Omega-3/totalFA; OR = 1.0013, 95% CI 1.0003-1.0022, p = 0.010) were identified as biomarkers associated with an increased risk of colon polyps. Conversely, the ratio of Omega-6/Omega-3 (OR = 0.9986, 95% CI 0.9976-0.9995, p = 0.003) and the ratio of Linoleic acid (LA)/totalFA (LA/totalFA; OR = 0.9981, 95% CI 0.9962-0.9999, p = 0.044) were negatively associated with susceptibility to colon polyps. The MR-Egger and MR-IVW analysis revealed that pleiotropy and heterogeneity did not significantly impact the outcomes.

CONCLUSION

This study has uncovered a possible adverse effect of PUFAs, notably Omega-3, on the formation of colon polyps. Elevated Omega-3 levels were correlated with a heightened risk of colon polyps.

Arachidonic acid level is related to early motor recovery following intracerebral hemorrhage with severe motor paralysis

BACKGROUND

Low arachidonic acid (AA) levels are reportedly associated with unfavorable outcomes in intracerebral hemorrhage (ICH).

OBJECTIVE

We aimed to clarify whether serum AA levels might be associated with a good recovery from severe motor paralysis in the early stage of hospitalization.

METHODS

From among consecutive ICH patients between October 2012 and December 2021, patients with a sum of upper and lower extremity National Institutes of Health stroke scale (NIHSS) scores of 4-8 at admission (severe motor paralysis) were included. We defined good early recovery from severe motor paralysis as a sum of upper and lower extremity NIHSS scores of 0-3 on day 7 after admission, and that of individual upper and lower extremities as NIHSS scores of 0-1 on day 7 after admission. We aimed to assess whether serum AA levels might be associated with good early recovery from severe motor paralysis.

RESULTS

We screened 377 consecutive ICH patients, including 140 with severe motor paralysis (88 (63%) males, median age 64 years). Recovery from severe motor paralysis was seen in 48 (34%). Higher AA levels (PR 1.243, 95% CI 1.042 to 1.483, p = 0.016) were independently associated with good overall recovery, and good recovery of upper and lower extremities separately (upper extremity: PR 1.319, 95% CI 1.101 to 1.580, p = 0.003; lower extremity: PR 1.293, 95% CI 1.115 to 1.499, p = 0.001).

CONCLUSIONS

Higher AA levels may contribute to a good early motor recovery in patients with severe motor paralysis due to ICH.

Lipoic Acid and Fish Oil Combination Potentiates Neuroinflammation and Oxidative Stress Regulation and Prevents Cognitive Decline of Rats After Sepsis

Sepsis causes organ dysfunction due to an infection, and it may impact the central nervous system. Neuroinflammation and oxidative stress are related to brain dysfunction after sepsis. Both processes affect microglia activation, neurotrophin production, and long-term cognition. Fish oil (FO) is an anti-inflammatory compound, and lipoic acid (LA) is a universal antioxidant substance. They exert neuroprotective roles when administered alone. We aimed at determining the effect of FO+LA combination on microglia activation and brain dysfunction after sepsis. Microglia cells from neonatal pups were co-treated with lipopolysaccharide (LPS) and FO or LA, alone or combined, for 24 h. Cytokine levels were measured. Wistar rats were subjected to sepsis by cecal ligation and perforation (CLP) and treated orally with FO, LA, or FO+LA. At 24 h after surgery, the hippocampus, prefrontal cortex, and total cortex were obtained and assayed for levels of cytokines, myeloperoxidase (MPO) activity, protein carbonyls, superoxide dismutase (SOD), and catalase (CAT) activity. At 10 days after surgery, brain-derived neurotrophic factor (BDNF) levels were determined and behavioral tests were performed. The combination diminished in vitro levels of pro-inflammatory cytokines. The combination reduced TNF-α in the cortex, IL-1β in the prefrontal cortex, as well as MPO activity, and decreased protein carbonyls formation in all structures. The combination enhanced catalase activity in the prefrontal cortex and hippocampus, elevated BDNF levels in all structures, and prevented behavioral impairment. In summary, the combination was effective in preventing cognitive damage by reducing neuroinflammation and oxidative stress and increasing BDNF levels.

Effects of fatty and lean fish intake on stroke risk: a meta-analysis of prospective cohort studies

BACKGROUND

Fish intake has been postulated to reduce the risk of stroke. However, whether the beneficial effect of fish are mainly linked to fat content, as a source of omega-3 polyunsaturated fatty acids, remains unclear. We conducted a meta-analysis to compare the effect of fatty and lean fish intake on stroke risk.

METHODS

We performed a literature search on four database (PubMed, Embase, Scopus, and Cochrane Library) through February 1, 2018 to identify prospective studies of fatty and lean fish in relation to stroke risk. A random-effects model was used to calculate the summary estimates.

RESULTS

We identified five prospective studies, including 7 comparisons for fatty fish intake and 5 comparisons for lean fish intake. Compared with the highest category of intake with lowest category, the summary relative risk was 0.88 [95% confidence interval (CI), 0.74-1.04] for fatty fish intake and 0.81 (95% CI, 0.67-0.99) for lean fish intake. No heterogeneity across studies and publication bias were observed.

CONCLUSION

Our findings demonstrated that fatty and lean fish intake has beneficial effects on stroke risk, especially lean fish intake. Additional prospective studies are necessary to confirm these observations.

Proanthocyanidins against Oxidative Stress: From Molecular Mechanisms to Clinical Applications

Proanthocyanidins (PCs) are naturally occurring polyphenolic compounds abundant in many vegetables, plant skins (rind/bark), seeds, flowers, fruits, and nuts. Numerous in vitro and in vivo studies have demonstrated myriad effects potentially beneficial to human health, such as antioxidation, anti-inflammation, immunomodulation, DNA repair, and antitumor activity. Accumulation of prooxidants such as reactive oxygen species (ROS) exceeding cellular antioxidant capacity results in oxidative stress (OS), which can damage macromolecules (DNA, lipids, and proteins), organelles (membranes and mitochondria), and whole tissues. OS is implicated in the pathogenesis and exacerbation of many cardiovascular, neurodegenerative, dermatological, and metabolic diseases, both through direct molecular damage and secondary activation of stress-associated signaling pathways. PCs are promising natural agents to safely prevent acute damage and control chronic diseases at relatively low cost. In this review, we summarize the molecules and signaling pathways involved in OS and the corresponding therapeutic mechanisms of PCs.

Different approaches to establish infertile rooster

Several methods have been developed to suppress spermatogenesis in recipient males before spermatogonial stem cells (SSCs) transplantation. The aim of this study was to compare two different methods of depleting endogenous spermatogenesis in recipient ROSS 308 strain adult roosters. Gamma-radiation and alkylating agent busulfan were utilized to infertilize adult roosters (ROSS 308 strain). Two radiation therapy regimes (based on ⁶⁰co isotope) were conducted locally to testes using 40Gy (5×8Gy with three-day intervals) and 30Gy (3×10Gy with three-day intervals). And two different levels of busulfan 60mg(40+20) and 50mg(30+20) with 10-day intervals were injected intraperitoneally. The results showed that both radiation therapy regimes and both busulfan levels reduced sperm motility and sperm concentration significantly compared with control group. Moreover, there were no significant differences between gamma radiation and busulfan treatments in progressive and total motility of sperm reduction. Sperm concentration reached to zero at the end of the 4th week of experiment in all treatment groups. Also histological examinations revealed that both treatments could significantly reduce the diameter of seminiferous tubules and thickness of epithelium. None of the treatments had significant effect on body weight in comparison with control group and the health status of experimental roosters remained good throughout the study. Given that, the risk probability of high doses of radiation exposure and busulfan, it can be concluded that the 30Gy (3×10Gy) and 50mg (30+20) are appropriate for suppression of endogenous spermatogenesis in mature roosters.

Circulating long-chain n-3 polyunsaturated fatty acid and incidence of stroke: a meta-analysis of prospective cohort studies

Background

Circulating long-chain (LC) n-3 polyunsaturated fatty acid (PUFA) can provide objective measures that reflect both dietary consumption and relevant biological processes. Nevertheless, prospective cohort studies on circulating LC n-3 PUFA in relation to incidence of stroke have yielded inconsistent results. We therefore conducted a meta-analysis to quantitatively evaluate the association.

Results

A total of 2,836 stroke events occurred among 20,460 individuals aged 35–79 yr from 10 prospective cohort studies. Circulating LC n-3 PUFA was significantly associated with reduced risk of stroke (RR: 0.86; 95% CI: 0.76, 0.98; I² = 0.00%), especially 22:5n-3 (RR: 0.74; 95% CI: 0.60, 0.92) and 22:6n-3 (RR: 0.78; 95% CI: 0.65, 0.94). The associations were more pronounced with ischemic stroke (RR: 0.81; 95% CI: 0.68, 0.96), but not with hemorrhagic stroke (RR: 0.95; 95% CI: 0.60, 1.49). A 1% increment of 22:5n-3 and 22:6n-3 proportions in circulating blood was associated with 25% (RR: 0.75; 95% CI: 0.64, 0.87) and 11% (RR: 0.89; 95% CI: 0.83, 0.95) reduced risk of stroke, respectively.

Materials and Methods

Pertinent studies were identified from Cochrane Library, PubMed and EMBASE database through June 2017. Multivariate-adjusted risk ratios (RRs) with 95% confidence interval (CI) for incident stroke when comparing the top with the bottom tertiles of baseline LC n-3 PUFA proportions in blood were pooled using a random-effect model.

Conclusions

Circulating LC n-3 PUFAs were linearly associated with reduced risk of stroke, especially 22:5n-3 and 22:6n-3. Such findings highlight the importance of circulating LC n-3 PUFA in the development of ischemic stroke.

The Role of Omega-3 Polyunsaturated Fatty Acids in Stroke

Stroke is the third commonest cause of death following cardiovascular diseases and cancer. In particular, in recent years, the morbidity and mortality of stroke keep remarkable growing. However, stroke still captures people attention far less than cardiovascular diseases and cancer. Past studies have shown that oxidative stress and inflammation play crucial roles in the progress of cerebral injury induced by stroke. Evidence is accumulating that the dietary supplementation of fish oil exhibits beneficial effects on several diseases, such as cardiovascular diseases, metabolic diseases, and cancer. Omega-3 polyunsaturated fatty acids (n-3 PUFAs), the major component of fish oil, have been found against oxidative stress and inflammation in cardiovascular diseases. And the potential of n-3 PUFAs in stroke treatment is attracting more and more attention. In this review, we will review the effects of n-3 PUFAs on stroke and mainly focus on the antioxidant and anti-inflammatory effects of n-3 PUFAs.

Free radicals, natural antioxidants, and their reaction mechanisms

The normal biochemical reactions in our body, increased exposure to the environment, and higher levels of dietary xenobiotic's result in the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS).

Plasma fatty acid profile in multiple myeloma patients

New membrane formation in the proliferating tumor cells consequently results in hypermetabolism of fatty acids (FA), as seen in many cancer patients, including multiple myeloma (MM). The FA composition of plasma reflects both endogenous synthesis as well as the dietary supply of these compounds. Additionally, obesity is a risk factor for the development of MM. The aim of this study was to compare the FA composition of plasma in 60 MM patients and 60 healthy controls. We noted significant differences in the FA profile of plasma from patients with MM when compared to the control group. Increased levels of saturated and n-6 polyunsaturated fatty acids in MM patients suggest that there may be increased endogenous synthesis of these fatty acids, likely due to increased expression of desaturase and elongase. Furthermore, cluster analysis showed differences in the distribution of FA in plasma from MM patients compared to controls. Dietary fat and a deranged endogenous FA metabolism may contribute to cancer-associated inflammation through an abnormal arachidonic acid metabolism, caused by pro-inflammatory derivatives. Our study supports further research on the biochemistry of lipids in patients with MM.

Fish oil diet associated with acute reperfusion related hemorrhage, and with reduced stroke-related sickness behaviors and motor impairment

Ischemic stroke is associated with motor impairment and increased incidence of affective disorders such as anxiety/clinical depression. In non-stroke populations, successful management of such disorders and symptoms has been reported following diet supplementation with long chain omega-3-polyunsaturated-fatty-acids (PUFAs). However, the potential protective effects of PUFA supplementation on affective behaviors after experimentally induced stroke and sham surgery have not been examined previously. This study investigated the behavioral effects of PUFA supplementation over a 6-week period following either middle cerebral artery occlusion or sham surgery in the hooded-Wistar rat. The PUFA diet supplied during the acclimation period prior to surgery was found to be associated with an increased risk of acute hemorrhage following the reperfusion component of the surgery. In surviving animals, PUFA supplementation did not influence infarct size as determined 6 weeks after surgery, but did decrease omega-6-fatty-acid levels, moderate sickness behaviors, acute motor impairment, and longer-term locomotor hyperactivity and depression/anxiety-like behavior.

Fatting the brain: a brief of recent research

Fatty acids are of paramount importance to all cells, since they provide energy, function as signaling molecules, and sustain structural integrity of cellular membranes. In the nervous system, where fatty acids are found in huge amounts, they participate in its development and maintenance throughout life. Growing evidence strongly indicates that fatty acids in their own right are also implicated in pathological conditions, including neurodegenerative diseases, mental disorders, stroke, and trauma. In this review, we focus on recent studies that demonstrate the relationships between fatty acids and function and dysfunction of the nervous system. Fatty acids stimulate gene expression and neuronal activity, boost synaptogenesis and neurogenesis, and prevent neuroinflammation and apoptosis. By doing so, they promote brain development, ameliorate cognitive functions, serve as anti-depressants and anti-convulsants, bestow protection against traumatic insults, and enhance repairing processes. On the other hand, unbalance between different fatty acid families or excess of some of them generate deleterious side effects, which limit the translatability of successful results in experimental settings into effective therapeutic strategies for humans. Despite these constraints, there exists realistic evidence to consider that nutritional therapies based on fatty acids can be of benefit to several currently incurable nervous system diseases.

Reduced thrombin formation and altered fibrin clot properties induced by polyunsaturated omega-3 fatty acids on top of dual antiplatelet therapy in patients undergoing percutaneous coronary intervention (OMEGA-PCI clot)

OBJECTIVE

The goal of this study was to investigate whether omega-3 polyunsaturated fatty acids (n-3 PUFA) are able to alter plasma fibrin clot properties and reduce thrombin formation in stable coronary artery disease patients undergoing percutaneous coronary intervention (PCI).

METHODS AND RESULTS

In an investigator-initiated, prospective, double-blind, placebo-controlled, randomized study, patients undergoing PCI who received standard pharmacotherapy were assigned to the treatment with 1 g/day n-3 PUFA (n = 30) or placebo (n = 24) for 1 month. Plasma fibrin clot permeability (K(s)); lysis time (t(50%)); prothrombin fragment 1.2; and peak thrombin generation from automated thrombogram, 8-isoprostaglandin F(2α) (8-iso-PGF(2α), an oxidative stress marker), and C-reactive protein were determined at baseline, 3 to 5 days after randomization, and 30 days after randomization. At baseline, both treatment groups did not differ significantly. A 1-month treatment with n-3 PUFA compared with placebo was associated with 15.3% higher K(s), indicating larger pores in the fibrin network (P = 0.0005); 14.3% shorter t(50%), indicating increased susceptibility to fibrinolysis (P<0.0001); 33.8% lower prothrombin fragment 1.2 (P = 0.0013); 13.4% lower peak thrombin generation (P = 0.04); and 13.1% lower 8-iso-PGF(2α) (P = 0.009). Treatment with n-3 PUFA had no effect on fibrinogen and C-reactive protein. After 1 month of treatment, fibrinogen (r = -0.53, P<0.0001), treatment assignment (r = 0.29, P = 0.006) and 8-iso-PGF(2α) (r = -0.27, P = 0.015) were independently associated with clot permeability (P<0.0001, R(2) = 0.66).

CONCLUSIONS

Adding n-3 PUFA to standard therapy in stable patients undergoing PCI significantly decreases thrombin formation and oxidative stress and favorably alters fibrin clot properties. These findings indicate novel antithrombotic effects induced by n-3 PUFA in humans.