Gamma-tocopherol ameliorates hyperglycemia-induced hepatic inflammation associated with NLRP3 inflammasome in alloxan-induced diabetic mice

Gamma-Tocopherol: A Comprehensive Review of Its Antioxidant, Anti-Inflammatory, and Anticancer Properties

Gamma-tocopherol (γ-tocopherol), a major isoform of vitamin E, exhibits potent antioxidant, anti-inflammatory, and anticancer properties, making it a promising therapeutic candidate for treating oxidative stress-related diseases. Unlike other tocopherol isoforms, γ-tocopherol effectively neutralizes reactive oxygen species (ROS) and reactive nitrogen species (RNS), providing robust cellular protection against oxidative damage and lipid peroxidation. Its anti-inflammatory effects are mediated through the modulation of pathways involving cyclooxygenase-2 (COX-2) and tumor necrosis factor-alpha (TNF-α), reducing chronic inflammation and its associated risks. In cancer therapy, γ-tocopherol demonstrates multifaceted activity, including the inhibition of tumor growth, induction of apoptosis, and suppression of angiogenesis, with significant efficacy observed in cancers such as prostate, lung, and colon. Preclinical and clinical studies support its efficacy in mitigating oxidative stress, inflammation, and cancer progression, with excellent tolerance at physiological levels. However, high doses necessitate careful evaluation to minimize adverse effects. This review consolidates current knowledge on γ-tocopherol's biological activities and clinical implications, underscoring its importance as a natural compound for managing inflammation, oxidative stress, and cancer. As a perspective, advancements in nanoformulation technology could enhance γ-tocopherol's bioavailability, stability, and targeted delivery, offering the potential to optimize its therapeutic application in the future.

The protective effect of Argan oil and its main constituents against xenobiotics-induced toxicities

BACKGROUND

Argan oil (AO) is a vegetable oil extracted from the fruits of Argania spinosa L. tree, belonging to the Sapotaceae family, primarily found in Morocco. Research studies have demonstrated that AO exhibits diverse pharmacological properties, including antioxidant, antimicrobial, anticancer, antiinflammatory, antidiabetic, antihypercholesterolemic, antiatherogenic, and immunomodulatory effects. These effects are attributed to its main constituents, including oleic acid, linoleic acid, γ-tocopherol, α-tocopherol, and ferulic acid.

OBJECTIVE

This review aimed to present the protective role of AO and its main constituents against xenobiotics-induced toxicities.

MATERIAL AND METHODS

Based on results from various in vitro and in vivo investigations published in the main scientific databases, the beneficial action of AO against xenobiotics-induced toxicities was analyzed.

RESULTS

AO and its main constituents have reduced neurotoxicity, hepatotoxicity, nephrotoxicity, pneumotoxicity, thyroid toxicity, hematotoxicity, immunotoxicity, genotoxicity, and colon toxicity induced by different natural and chemical xenobiotics. Different mechanisms of action are involved in these effects, including enhancement of antioxidant defense, reduction of oxidative stress, modulation of inflammation, stimulation of fatty acid oxidation, suppression of apoptosis, regulation of miRNAs expression, elevation of acetylcholinesterase activity, activation of Krebs cycle enzymes, and restoration of mitochondrial function.

CONCLUSION

The study shows clearly the beneficial effect of Argan oil against xenobiotics-induced toxicities was analyzed. However, clinical trials are necessary to verify the protective effects of this oil in human intoxications caused by both natural and chemical xenobiotics.

Haptoglobin polymorphism, vitamin E and mortality: the Ludwigshafen Risk and Cardiovascular Health Study

Objective

In humans, haptoglobin (Hp) exists in two allelic forms, Hp1 and Hp2, that differ significantly in their ability to protect the organism from oxidative stress. It has been proposed that in patients with diabetes mellitus carriers of the Hp2-2 genotype may benefit from vitamin E supplementation. Aim of our study was to investigate if there is evidence regarding a potential interaction between the Hp polymorphism and vitamin E with regard to mortality in individuals at medium-to-high cardiovascular risk with and without diabetes mellitus.

Research design and methods

Data from 3176 participants of the Ludwigshafen Risk and Cardiovascular Health study, a monocentric hospital-based study of patients referred for coronary angiography, were analysed using Cox proportional hazard regression.

Results

Participants with the Hp2-2 genotype demonstrated significantly lower Hp levels, while carriers of at least one Hp-2 allele displayed elevated levels of the inflammatory markers high-sensitive C reactive protein and serum amyloid A. No notable differences in comorbidities were observed among the various HP genotype groups. While the HP genotype showed no direct association with mortality, a borderline significant correlation between α-tocopherol plasma concentration and overall mortality was noted. An interaction between vitamin E status and the HP genotype regarding mortality risk was evident, particularly among patients with diabetes mellitus, with a p value of 0.021 for the interaction term. In restricted cubic splice analysis, patients with diabetes mellitus who are carriers of the Hp2-2 genotype seem to benefit from higher γ-tocopherol concentrations whereas for the other genotype groups there was a direct association with mortality risk.

Conclusion

Particularly in patients with diabetes mellitus we could show a significant interaction of γ-tocopherol plasma concentration and HP genotype. Carriers of the Hp2-2 genotype seemed to benefit from higher plasma concentrations of γ-tocopherol. Further research is warranted to elucidate the underlying mechanisms and potential therapeutic implications in cardiovascular disease management.

Vitamin E and conflicting understandings in noncommunicable diseases: Is it worth supplementing?

Vitamin E is a lipid-soluble nutrient found mainly in vegetable oils and oilseeds. It is divided into eight homologous compounds; however, only α-tocopherol exhibits vitamin activity. Many advantages are related to these compounds, including cellular protection through antioxidant and anti-inflammatory activity, and improving lipid metabolism. Physiopathology of many diseases incepts with reduced antioxidant defense, characterized by an increased reactive oxygen species production and activation of transcription factors involved in inflammation, such as nuclear factor-kappa B (NF-κB), that can be linked to oxidative stress. Moreover, disorders of lipid metabolism can increase the risk of cardiovascular diseases. In addition, intestinal dysbiosis plays a vital role in developing chronic non-communicable diseases. In this regard, vitamin E can be considered to mitigate those disorders, but data still needs to be more conclusive. This narrative review aims to elucidate the mechanisms of action of vitamin E and if supplementation can be beneficial in a disease scenario regarding non-communicable diseases.

Protective role of Dodonaea viscosa extract against streptozotocin-induced hepatotoxicity and nephrotoxicity in rats

Previous investigations have shown that D. viscosa herbal extract is often used to treat a variety of diseases. Therefore, the purpose of this study was to investigate any additional potential impacts on rat liver and kidney damage induced by diabetes. Streptozotocin (STZ) (60 mg/kg/day) was given as a single dosage to cause type 1 diabetes. After then, diabetic rats received oral doses of D. viscosa for four weeks at 150 and 300 mg/kg/day. Blood, liver, and kidney tissues were collected at the end of the treatment and examined. Analysis was made of the serum lipid profile, liver, and kidney functions, as well as blood biochemistry. Moreover, the levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1 beta (IL-1β), prostaglandin E-2 (PGE-2), and nitric oxide (NO) were estimated in serum. In liver and kidney samples, thiobarbituric acid reactive substances (TBARs) and reduced glutathione (GSH), as well as the pro-inflammatory cytokines and enzymatic activities of glutathione peroxidase (GPx), glutathione reeducates (GR), glutathione-S-transferase (GST), catalase (CAT), and superoxide dismutase (SOD) were analyzed. Histological changes in liver and kidney cross-sections were also observed. Our findings demonstrated that D. viscosa dramatically decreased pro-inflammatory indicators in blood, kidney, and liver tissues as well as blood glucose, and restored insulin levels, and lipid profiles. Additionally, it significantly raises the antioxidant enzyme activity SOD, CAT, GPx, and GST, while significantly lowering TBARs levels. The above-mentioned biochemical changes that took place in tissues were further supported by histological alterations. These findings imply that D. viscosa protects against STZ-induced hyperglycemia, aberrant lipid synthesis, and oxidative stress and that these benefits may be mediated by interacting with various targets to increase the levels of antioxidant enzymes in the liver and kidneys. Its mode of action and safety for use as medicine against various metabolic problems caused by diabetes require more research.

Rescuing fertility during COVID-19 infection: exploring potential pharmacological and natural therapeutic approaches for comorbidity, by focusing on NLRP3 inflammasome mechanism

The respiratory system was primarily considered the only organ affected by Coronavirus disease 2019 (COVID-19). As the pandemic continues, there is an increasing concern from the scientific community about the future effects of the virus on male and female reproductive organs, infertility, and, most significantly, its impact on the future generation. The general presumption is that if the primary clinical symptoms of COVID-19 are not controlled, we will face several challenges, including compromised infertility, infection-exposed cryopreserved germ cells or embryos, and health complications in future generations, likely connected to the COVID-19 infections of parents and ancestors. In this review article, we dedicatedly studied severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) virology, its receptors, and the effect of the virus to induce the activation of inflammasome as the main arm of the innate immune response. Among inflammasomes, nucleotide oligomerization domain-like receptor protein, pyrin domain containing 3 (NLRP3) inflammasome pathway activation is partly responsible for the inflicted damages in both COVID-19 infection and some reproductive disorders, so the main focus of the discussion is on NLRP3 inflammasome in the pathogenesis of COVID-19 infection alongside in the reproductive biology. In addition, the potential effects of the virus on male and female gonad functions were discussed, and we further explored the potential natural and pharmacological therapeutic approaches for comorbidity via NLRP3 inflammasome neutralization to develop a hypothesis for averting the long-term repercussions of COVID-19. Since activation of the NLRP3 inflammasome pathway contributes to the damage caused by COVID-19 infection and some reproductive disorders, NLRP3 inflammasome inhibitors have a great potential to be considered candidates for alleviating the pathological effects of the COVID-19 infection on the germ cells and reproductive tissues. This would impede the subsequent massive wave of infertility that may threaten the patients.

Rodent Models of Diabetic Retinopathy as a Useful Research Tool to Study Neurovascular Cross-Talk

Diabetes is a group of metabolic diseases leading to dysfunction of various organs, including ocular complications such as diabetic retinopathy (DR). Nowadays, DR treatments involve invasive options and are applied at the sight-threatening stages of DR. It is important to investigate noninvasive or pharmacological methods enabling the disease to be controlled at the early stage or to prevent ocular complications. Animal models are useful in DR laboratory practice, and this review is dedicated to them. The first part describes the characteristics of the most commonly used genetic rodent models in DR research. The second part focuses on the main chemically induced models. The authors pay particular attention to the streptozotocin model. Moreover, this section is enriched with practical aspects and contains the current protocols used in research in the last three years. Both parts include suggestions on which aspect of DR can be tested using a given model and the disadvantages of each model. Although animal models show huge variability, they are still an important and irreplaceable research tool. Note that the choice of a research model should be thoroughly considered and dependent on the aspect of the disease to be analyzed.

ATP-Activated P2X7R Promote the Attack of Acute Gouty Arthritis in Rats Through Activating NLRP3 Inflammasome and Inflammatory Cytokine Production

Objective

To investigate the effect of P2X7R on MSU crystal-induced acute gouty arthritis in rats and its mechanism on inflammatory responses.

Methods

In vivo activation or inhibition of P2X7R was examined in the ATP group or the BBG group of rats, and the control group were injected with PBS. All three groups of rats were injected with MSU in the right joint cavity. The development of acute gouty arthritis was observed and evaluated at 6h, 12h, 24h, 48h and 72h. The clinical manifestations of acute arthritis, the expression level of P2X7R in spleen macrophages, the ability of macrophages to take up YO-PRO-1, and the level of Tregs, Th17 cells and inflammatory cytokines were assessed. Besides, mRNA expression levels of P2X7R, NLRP3 and IL-1β were also detected.

Results

After 12h and 24h administration, P2X7R agonist ATP significantly accelerated the development of acute gouty arthritis, while the P2X7R inhibitor BBG had the opposite effect on this process. Activation of P2X7R significantly aggravated the ankle joint arthritis of the rat and promoted the infiltration of neutrophils and macrophages in the synovial tissue. In addition, the expression of P2X7R in macrophages of ATP group, the uptake of YO-PRO-1 and the expression of NLRP3 mRNA were significantly higher than that in other two groups. At 12h or 24h, activation or inhibition P2X7R had a significant effect on the IL-1β, IL-6, IL-17, IL-10 and TGF-β1. The ratios of Treg/Th17 gradually decreased in the First three time points, it was the lowest at 24h.

Conclusion

Activation of P2X7R by ATP aggravated the development of acute gouty arthritis through P2X7R/NLRP3 pathway, promoted the secretion of related inflammatory cytokines, which affected radio of Tregs/Th17 cells. The whole pathogenesis process appeared a pattern from acute attack to remission in time-dependent trend.

Vitamin E in foodstuff: Nutritional, analytical, and food technology aspects

Vitamin E is a group of isoprenoid chromanols with different biological activities. It comprises eight oil-soluble compounds: four tocopherols, namely, α-, β-, γ-, and δ-tocopherols; and four tocotrienols, namely, α-, β-, γ, and δ-tocotrienols. Vitamin E isomers are well-known for their antioxidant activity, gene-regulation effects, and anti-inflammatory and nephroprotective properties. Considering that vitamin E is exclusively synthesized by photosynthetic organisms, animals can only acquire it through their diet. Plant-based food is the primary source of vitamin E; hence, oils, nuts, fruits, and vegetables with high contents of vitamin E are mostly consumed after processing, including industrial processes and home-cooking, which involve vitamin E profile and content alteration during their preparation. Accordingly, it is essential to identify the vitamin E content and profile in foodstuff to match daily intake requirements. This review summarizes recent advances in vitamin E chemistry, metabolism and metabolites, current knowledge on their contents and profiles in raw and processed plant foods, and finally, their modern developments in analytical methods.

Modulatory Properties of Food and Nutraceutical Components Targeting NLRP3 Inflammasome Activation

Inflammasomes are key intracellular multimeric proteins able to initiate the cellular inflammatory signaling pathway. NLRP3 inflammasome represents one of the main protein complexes involved in the development of inflammatory events, and its activity has been largely demonstrated to be connected with inflammatory or autoinflammatory disorders, including diabetes, gouty arthritis, liver fibrosis, Alzheimer’s disease, respiratory syndromes, atherosclerosis, and cancer initiation. In recent years, it has been demonstrated how dietary intake and nutritional status represent important environmental elements that can modulate metabolic inflammation, since food matrices are an important source of several bioactive compounds. In this review, an updated status of knowledge regarding food bioactive compounds as NLRP3 inflammasome modulators is discussed. Several chemical classes, namely polyphenols, organosulfurs, terpenes, fatty acids, proteins, amino acids, saponins, sterols, polysaccharides, carotenoids, vitamins, and probiotics, have been shown to possess NLRP3 inflammasome-modulating activity through in vitro and in vivo assays, mainly demonstrating an anti-NLRP3 inflammasome activity. Plant foods are particularly rich in important bioactive compounds, each of them can have different effects on the pathway of inflammatory response, confirming the importance of the nutritional pattern (food model) as a whole rather than any single nutrient or functional compound.

Vitamin E beyond Its Antioxidant Label

Vitamin E, comprising tocopherols and tocotrienols, is mainly known as an antioxidant. The aim of this review is to summarize the molecular mechanisms and signaling pathways linked to inflammation and malignancy modulated by its vitamers. Preclinical reports highlighted a myriad of cellular effects like modulating the synthesis of pro-inflammatory molecules and oxidative stress response, inhibiting the NF-κB pathway, regulating cell cycle, and apoptosis. Furthermore, animal-based models have shown that these molecules affect the activity of various enzymes and signaling pathways, such as MAPK, PI3K/Akt/mTOR, JAK/STAT, and NF-κB, acting as the underlying mechanisms of their reported anti-inflammatory, neuroprotective, and anti-cancer effects. In clinical settings, not all of these were proven, with reports varying considerably. Nonetheless, vitamin E was shown to improve redox and inflammatory status in healthy, diabetic, and metabolic syndrome subjects. The anti-cancer effects were inconsistent, with both pro- and anti-malignant being reported. Regarding its neuroprotective properties, several studies have shown protective effects suggesting vitamin E as a potential prevention and therapeutic (as adjuvant) tool. However, source and dosage greatly influence the observed effects, with bioavailability seemingly a key factor in obtaining the preferred outcome. We conclude that this group of molecules presents exciting potential for the prevention and treatment of diseases with an inflammatory, redox, or malignant component.

Protective Role of Loranthus regularis against Liver Dysfunction, Inflammation, and Oxidative Stress in Streptozotocin Diabetic Rat Model

Earlier studies revealed the potential therapeutic values of Loranthus regularis (L. regularis). This study evaluated Loranthus regularis (L. regularis) extract systemic antidiabetic effects and benefits against diabetic hepatocellular injuries through antioxidant and anti-inflammatory pathways using the streptozotocin (STZ) model in Wistar albino rats. After diabetes induction, animals were orally treated with L. regularis extract for 4 weeks. Serum levels of glucose, insulin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), total triglycerides (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) were estimated. Furthermore, tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), caspase-3, nitric oxide (NO), and prostaglandin E-2 (PGE-2) were estimated in serum. In liver, thiobarbituric acid reactive substances (TBARSs) and reduced glutathione (GSH) as well as the proinflammatory cytokines and enzymatic activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reeducates (GR), and glutathione-S-transferase (GST) were assayed. Finally, the degree of hepatic tissue damage was evaluated histologically. Treatment of the diabetic rats with L. regularis extract markedly reduced the elevated serum levels of glucose, ALT, AST, TC, TG, LDL, TNF-α, IL-1β, IL-6, caspase-3, NO, and PGE-2. L. regularis extract also improved serum levels of insulin and HDL. The elevated TBARS, TNF-α, IL-1β, and IL-6 levels in hepatic tissue of diabetic animals were reduced by L. regularis. Moreover, L. regularis extract significantly restored the diminished hepatic GSH level and enzymatic activities of SOD, CAT, GPx, GR, and GST in diabetic animals. The biochemical protective effects of L. regularis were associated with improved histological hepatocellular integrity and architecture. Taken together, L. regularis has therapeutic effects against diabetic-induced hepatic complications. The restored liver functions and cellular damage might be mediated through free radicals scavenging and proinflammatory cytokine inhibition.

Protective effect of exogenous hydrogen sulfide on diaphragm muscle fibrosis in streptozotocin-induced diabetic rats

IMPACT STATEMENT

Diabetes mellitus is a group of chronic metabolic disorders, which causes serious damage to a variety of organs, such as the retina, heart, and skeletal muscle. The diaphragm is an important skeletal muscle involved in respiration in mammals. Fibrosis of the diaphragm muscle affects its contractility, which in turn impairs respiratory function. Accumulating evidence suggests that exogenous hydrogen sulfide (H₂S) exhibits anti-fibrotic activity in diabetes mellitus, but whether and how H₂S exerts this anti-fibrotic effect in the diabetic diaphragm remains unclear. The current work for the first time reveals that exogenous H₂S attenuates hyperglycemia-induced fibrosis of the diaphragm muscle and strengthens diaphragmatic biomechanical properties in diabetes mellitus, and the mechanism may involve the alleviation of collagen deposition by suppression of the nucleotide-binding oligomerization domain-like receptor protein (NLRP) 3 inflammasome-mediated inflammatory reaction. Therefore, H₂S supplementation could be used as an efficient targeted therapy against the NLRP3 inflammasome in the diabetic diaphragm.