Molecular and Therapeutic Insights of Alpha-Lipoic Acid as a Potential Molecule for Disease Prevention

Lipoic acid improves wound healing through its immunomodulatory and anti-inflammatory effects in a diabetic mouse model

Objectives

Diabetes mellitus is a chronic disease that has become more prevalent worldwide because of lifestyle changes. It leads to serious complications, including increased atherosclerosis, protein glycosylation, endothelial dysfunction, and vascular denervation. These complications impair neovascularization and wound healing, resulting in delayed recovery from injuries and an elevated risk of infections. The present study aimed to investigate the effect of lipoic acid (LA) on the key mediators involved in the wound healing process, specifically CD4 + CD25 + T cell subsets, CD4 + CD25 + Foxp3 + regulatory T (Treg) cells, T-helper-17 (Th17) cells that generate IL-17 A, glucocorticoid-induced tumor necrosis factor receptor (GITR) expressing cells, as well as cytokines such as IL-2, IL-1β, IL-6, and TNF-α and IFN-γ. These mediators play crucial roles in epidermal and dermal proliferation, hypertrophy, and cell migration.

Methods

We divided mice into 5 groups: the non-diabetic (normal control; NC), wounded non-diabetic mice (N + W), wounded diabetic mice (D + W), wounded diabetic mice treated with 50 mg/kg lipoic acid (D + W + L50) for 14 days, and wounded diabetic mice treated with 100 mg/kg lipoic acid (D + W + L100) for 14 days.

Results

Flow cytometric analysis indicated that lipoic acid-treated mice exhibited a significant decrease in the frequency of intracellular cytokines (IL-17 A, TNF-α and IFN-γ) in CD4 + T cells, as well as a reduction in the number of GITR-expressing cells. Conversely, a significant upregulation in the number CD4+, CD25+, FOXp3 + and CD4 + CD25 + Foxp3 + regulatory T (Treg) cells was observed in this group compared to both the normal + wounded (N + W) and diabetic + wounded (D + W) groups. Additionally, the mRNA Levels of inflammatory mediators (IL-2, IL-1β, IL-6, and TNF-α) were downregulated in lipoic acid-treated mice compared to other groups. T thereby he histological findings of diabetic skin wounds treated with lipoic acid showed well-healed surgical wounds.

Conclusions

These findings support the beneficial role of lipoic acid in fine-tuning the balance between anti-inflammatory and pro-inflammatory cytokines, influencing both their release and gene expression.

Effect of precursors on carbon dot functionalization and applications: a review

Carbon dots (CDs) are a type of carbon-based nanoparticle (NP) that have risen in popularity due to their unique tuneable physicochemical and optical properties. CDs have received a significant amount of attention in biological based applications due to their low cytotoxicity, stable photoluminescence, and small size. They have demonstrated the ability to retain certain properties from their carbon precursors, enabling NP design via precursor selection. Thus, direct functionalization of a CD can be achieved without the need for post synthesis modification. However, CDs derived from the same class of carbon precursor can also have profoundly variable applications. Indicating that, in conjunction with precursor properties, other functional attributes can be imposed on the CD during the synthesis process to enable cross-cutting applications from a single carbon precursor. Here, we will highlight various CD precursors and the resulting multifunctional CDs, as well as rational design of CDs for specific biological and materials science applications via precursor selection.

Alpha-lipoic acid alleviates oxidative stress and brain damage in patients with sevoflurane anesthesia

Sevoflurane, the most commonly used inhalational anesthetic, may negatively impact the brain by inducing oxidative stress. This study investigated the potential protective role of alpha-lipoic acid (ALA) in mitigating sevoflurane-induced oxidative stress and brain damage. A total of 155 patients undergoing sevoflurane anesthesia for liver resection surgery were randomly assigned to receive either ALA or a placebo. Perioperative internal jugular venous blood samples were collected to measure oxidative stress markers (8-OHdG, sORP, and cORP) and brain injury biomarkers (S100β and UCH-L1). Postoperative cognitive function was also evaluated. The results demonstrated that, compared to the placebo group, the ALA group exhibited a significant reduction in 8-OHdG levels by 0.007 nmol/L (95% CI, -0.011 to -0.003; P = 0.03) 24 h after surgery, accompanied by lower sORP levels and higher cORP levels. Furthermore, postoperative levels of S100β and UCH-L1 were significantly lower in the ALA group than in the placebo group (S100β, P = 0.02; UCH-L1, P = 0.03). Additionally, oxidative stress markers were significantly correlated with brain damage 24 h after surgery. Our findings suggest that ALA significantly reduces sevoflurane-induced oxidative stress and brain damage, while also improving postoperative cognitive function, indicating its potential neuroprotective effect. Clinical Trial Registration: https://www.chictr.org.cn/, identifier ChiCTR2300077321.

Functional modulation of the human gut microbiome by bacteria vehicled by cheese

Since cheese is one of the most commonly and globally consumed fermented foods, scientific investigations in recent decades have focused on determining the impact of this dairy product on human health and well-being. However, the modulatory effect exerted by the autochthonous cheese microbial community on the taxonomic composition and associated functional potential of the gut microbiota of human is still far from being fully dissected or understood. Here, through the use of an in vitro human gut-simulating cultivation model in combination with multi-omics approaches, we have shown that minor rather than dominant bacterial players of the cheese microbiota are responsible for gut microbiota modulation of cheese consumers. These include taxa from the genera Enterococcus, Bacillus, Clostridium, and Hafnia. Indeed, they contribute to expand the functional potential of the intestinal microbial ecosystem by introducing genes responsible for the production of metabolites with relevant biological activity, including genes involved in the synthesis of vitamins, short-chain fatty acids, and amino acids. Furthermore, tracing of cheese microbiota-associated bacterial strains in fecal samples from cheese consumers provided evidence of horizontal transmission events, enabling the detection of particular bacterial strains transferred from cheese to humans. Moreover, transcriptomic and metabolomic analyses of a horizontally transmitted (cheese-to-consumer) bacterial strain, i.e., Hafnia paralvei T10, cultivated in a human gut environment-simulating medium, confirmed the concept that cheese-derived bacteria may expand the functional arsenal of the consumer's gut microbiota. This highlights the functional and biologically relevant contributions of food microbes acquired through cheese consumption on the human health.IMPORTANCEDiet is universally recognized as the primary factor influencing and modulating the human intestinal microbiota both taxonomically and functionally. In this context, cheese, being a fermented food with its own microbiota, serves not only as a source of nourishment for humans, but also as a source of nutrients for the consumer's gut microbiota. Additionally, it may act as a vehicle for autochthonous food-associated microorganisms which undergo transfer from cheese to the consumer, potentially influencing host gut health. The current study highlights not only that cheese microbiota-associated bacteria can be traced in the human gut microbiota, but also that they may expand the functional repertoire of the human gut microbiota, with potentially significant implications for human health.

Effects of Alpha-Lipoic Acid Supplementation on Weight Loss, Inflammatory, Lipid, and Hematological Levels in Patients With Chronic Kidney Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVES

The effects of alpha-lipoic acid (ALA) supplementation on cardiovascular-related factors have been evaluated in a number of randomized clinical trials, with different results. Thus, in this meta-analysis, the effects of ALA on blood levels of inflammatory, lipid, and hematological markers as well as anthropometric indices in patients with chronic kidney disease (CKD) were evaluated.

METHODS

Five electronic databases were used to conduct a comprehensive search through October 2023. Risk of bias assessment and data extraction were carried out separately by 2 reviewers on the included papers. The data were analyzed using the random-effects model in meta-analyses. The data were analyzed using the random-effects model in meta-analyses. We assessed inter-study heterogeneity with I2 and Cochran's Q test.

RESULTS

Nine of the 421 potential reports were included. Using random-effects models, no significant changes were observed in weight loss, body mass index, hemoglobin, and iron following ALA supplementation (600 mg/day). Results exhibited that ALA significantly reduced high-sensitivity C-reactive protein levels in individuals with CKD (weighted mean difference (WMD) = -2.91 mg/L, 95% CI: -4.65, -1.17, I2 = 50.5%, P = .09); however, there were no significant variations in levels of interleukin-6 (IL-6) or malondialdehyde. Regarding lipid profiles, findings revealed that ALA administration had no significant impact on high-density lipoprotein cholesterol and triglycerides levels among patients with CKD. However, compared to the control group, total cholestrol levels were considerably lower in CKD patients (WMD = -5.48 mg/dL, 95% CI: -10.55, -0.41, I2 = 0.0%, P = .50). Moreover, the sensitivity analyses showed that pooled WMDs for low-density lipoprotein cholesterol levels were significantly changed (-6.88 mg/dL, 95% CI, -12.78, -0.98).

CONCLUSIONS

These findings revealed that ALA supplementation slightly but significantly reduced blood levels of high-sensitivity C-reactive protein, total cholestrol, and low-density lipoprotein cholesterol, but did not affect IL-6, malondialdehyde, high-density lipoprotein cholesterol, weight, body mass index, iron, and hemoglobin in patients with CKD.

Microemulsions Improve the Cutaneous Co-Localization of Lipoic Acid and Quercetin and Antioxidant Effects in Cutaneous Cells and Tissue

Quercetin and α-lipoic acid are antioxidants with potential applications in the treatment of various skin conditions, such as wounds and chemoprevention of skin cancer. To enable their effective topical co-delivery and co-localization in the tissue, we developed microemulsions (ME). The selected ME (ME-50) formed a stable system with a mean droplet size of 134.4 ± 17.9 nm, increasing to 224.9 ± 19.9 nm upon antioxidants co-incorporation. The ME preserved the antioxidant capacities of the molecules, with DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging assay showing an IC50 of 6.2 ± 0.1 µg/mL, similar to the solution. Skin penetration studies revealed a 2.4-fold increase in quercetin (Q) accumulation in the stratum corneum and a 3.5-fold increase in the delivery to viable epidermis and dermis (ED) after a 12 h-treatment with the ME compared to control solutions; α-lipoic acid (LA) penetration improved up to 1.9-fold in ED upon ME incorporation. Treatment with Q + LA co-loaded ME enhanced the antioxidant activity in the stratum corneum and ED by 1.3-fold and 2.0-fold, respectively, compared to solutions. Treatment with the ME for 24 h also reduced oxidative species levels by 55% in H2O2-exposed keratinocytes compared to the control (untreated) cells. Taken together, these results suggest that ME-50 is a promising delivery system for enhancing the cutaneous co-delivery of quercetin and α-lipoic acid and the antioxidant effects in the tissue, offering a potential topical treatment for oxidative stress-related skin conditions.

Alpha-Lipoic Acid Reduces Neuroinflammation and Oxidative Stress Induced by Dapsone in an Animal Model

Background/Objectives: Chronic treatment with dapsone (DDS) has been linked to adverse reactions involving all organ systems, such as dapsone hypersensitivity syndrome, methemoglobinemia and hemolytic anemia, besides neuroinflammation and neurodegeneration due to iron accumulation and oxidative stress. These effects probably occur due to the presence of its toxic metabolite DDS-NOH, which can generate reactive oxygen species (ROS) and iron overload. In this sense, antioxidant compounds with chelating properties, such as alpha-lipoic acid (ALA), may be an interesting adjuvant therapy strategy in treating or preventing these effects. Thus, the aim of this study was to evaluate the effects of ALA on oxidative and neuroinflammatory changes caused by DDS treatment in the prefrontal cortex and hippocampus of mice. Materials and Methods:Mus musculus male mice that were pre-treated with DDS (40 mg/kg) and post-treated with ALA (25 mg/kg) underwent analyses for oxidative stress, antioxidant capacity, cytokine expression and microglial/astrocytic activity. Results: DDS did not activate macrophages/microglia or astrocytes in the prefrontal cortex but induced their activation in the hippocampus. ALA stimulated a protective microglial profile and reduced astrocyte reactivity, especially in the hippocampus. DDS increased the pro-inflammatory cytokine IL-1β and reduced brain-derived neurotrophic factor (BDNF), effects reversed by ALA. DDS also reduced antioxidant capacity (TEAC, GSH, SOD, CAT) and increased oxidative damage (lipid peroxidation, iron accumulation), while ALA restored antioxidant levels and reduced oxidative stress. Conclusions: ALA was able to reduce the effects of DDS, such as reducing microglial and astrocytic activation, as well as to decrease the levels of pro-inflammatory cytokines and increase BDNF, in addition to increasing antioxidant capacity and reducing oxidative damage caused by iron accumulation. Therefore, ALA is considered a useful and promising therapeutic alternative for the treatment of diseases related to oxidative stress and neuroinflammation.

Alpha-lipoic Acid: An Antioxidant with Anti-aging Properties for Disease Therapy

The anti-aging effects of alpha-lipoic acid (αLA), a natural antioxidant synthesized in human tissues, have attracted a growing interest in recent years. αLA is a short- -chain sulfur-containing fatty acid occurring in the mitochondria of all kinds of eukaryotic cells. Both the oxidized disulfide of αLA and its reduced form (dihydrolipoic acid, DHLA) exhibit prominent antioxidant function. The amount of αLA inside the human body gradually decreases with age resulting in various health disorders. Its lack can be compensated by supplying from external sources such as dietary supplements or medicinal dosage forms. The primary objectives of this study were the analysis of updated information on the latest two-decade research regarding the use of αLA from an anti-aging perspective. The information was collected from PubMed, Wiley Online Library, Scopus, ScienceDirect, SpringerLink, Google Scholar, and clinicaltrials.gov. Numerous in silico, in vitro, in vivo, and clinical studies revealed that αLA shows a protective role in biological systems by direct or indirect reactive oxygen/nitrogen species quenching. αLA demonstrated beneficial properties in the prevention and treatment of many age-related disorders such as neurodegeneration, metabolic disorders, different cancers, nephropathy, infertility, and skin senescence. Its preventive effects in case of Alzheimer's and Parkinson's diseases are of particular interest. Further mechanistic and clinical studies are highly recommended to evaluate the wide spectrum of αLA therapeutic potential that could optimize its dietary intake for prevention and alleviation disorders related to aging.

Alpha Lipoic Acid Supplementation and Iron Homeostasis: A Comprehensive Systematic Review and Meta-Analysis of Randomized Controlled Clinical Trials

BACKGROUND

A growing body of evidence indicates the regulating effects of alpha-lipoic acid on iron metabolism. However, findings from clinical trials are equivocal. This systematic review and meta-analysis aimed to evaluate the quantitative effect of alpha lipoic acid (ALA) supplementation on iron metabolism parameters including serum iron, total iron binding capacity, hemoglobin, and ferritin.

METHODOLOGY

Online databases, including PubMed, Scopus, and Web of Science were searched, up to 29 May 2022, to obtain all relevant studies.

RESULTS

A total of 1901 publications were identified in the systematic search; of which, 10 studies with a total of 529 participants were included in this meta-analysis. Pooled analysis of the studies showed no statistically significant effects of ALA on ferritin (weighted mean difference (WMD) = -11.01 ng/mL; 95% CI: -40.07, 18.05 ng/mL; I2 = 0.0%, p = 0.670), serum iron (WMD = -0.47 μ/dL; 95% CI: -24.48, 23.54 μ/dL; I2 = 94.7%, p < 0.001), hemoglobin (WMD = 0.49 g/dL; 95% CI: -0.54, 1.52 g/dL; I2 = 95.7%, p < 0.001), and total iron binding capacity (TIBC) (WMD = 3.95 μ/dL; 95% CI: -21.3, 29.2 μ/dL; I2 = 53.1%, p = 0.094). In subgroup analysis, ALA significantly increased hemoglobin in patients with hematological disorders (WMD = 1.23 g/dL; 95% CI: 1.00, 1.45 g/dL; I2 = 96.6%, p < 0.001) and in studies with durations longer than 8 weeks (WMD = 1.03 g/dL; 95% CI: 0.82, 1.25 g/dL; I2 = 96.5%, p = 0.02).

CONCLUSION

ALA supplementation had no statistically significant effect on iron-related parameters. Subgroup analysis revealed a significant increasing effect of ALA on hemoglobin in patients with hematological disorders and in studies with durations >8 weeks.

Facts, Dogmas, and Unknowns About Mitochondrial Reactive Oxygen Species in Cancer

Cancer metabolism is sustained both by enhanced aerobic glycolysis, characteristic of the Warburg phenotype, and oxidative metabolism. Cell survival and proliferation depends on a dynamic equilibrium between mitochondrial function and glycolysis, which is heterogeneous between tumors and even within the same tumor. During oxidative phosphorylation, electrons from NADH and FADH2 originated in the tricarboxylic acid cycle flow through complexes of the electron transport chain. Single electron leaks at specific complexes of the electron transport chain generate reactive oxygen species (ROS). ROS are a concentration-dependent double-edged sword that plays multifaceted roles in cancer metabolism. ROS serve either as signaling molecules favoring cellular homeostasis and proliferation or damage DNA, protein and lipids, causing cell death. Several aspects of ROS biology still remain unsolved. Among the unknowns are the actual levels at which ROS become cytotoxic and if toxicity depends on specific ROS species or if it is caused by a cumulative effect of all of them. In this review, we describe mechanisms of mitochondrial ROS production, detoxification, ROS-induced cytotoxicity, and the use of antioxidants in cancer treatment. We also provide updated information about critical questions on the biology of ROS on cancer metabolism and discuss dogmas that lack adequate experimental demonstration. Overall, this review brings a comprehensive perspective of ROS as drivers of cancer progression, inducers of cell death, and the potential use of antioxidants as anticancer therapy.

Effects of antioxidants on in vitro growth of Thecaphora frezzii

AIMS

Thecaphora frezzii, the causal agent of peanut smut, causes significant grain losses in Argentina. Current control strategies are insufficient to manage this pathogen. We investigate the effect of antioxidants on the in vitro development of T. frezzii hyphae, to identify compounds with antifungal activity, also evaluate protein and lipid profiles as potential targets for these compounds.

METHODS AND RESULTS

The antifungal activity was evaluated in both, solid and liquid media, and minimum inhibitory concentration and minimum fungicidal concentration were calculated. The protein profile was assessed using sodium dodecyl sulfate polyacrylamide gel electrophoresis, while lipids were analyzed by thin-layer chromatography (TLC) and gas chromatography with flame ionization detection, both before and after hyphal treatment. Lipase activity was analyzed using agar Tween 20 and TLC, while lipid peroxidation was evaluated by the thiobarbituric acid-reactive substance (TBARS)assay. Microscopy was used to observe morphological and metabolic changes. Butylated hydroxyanisole, methylparaben, and lipoic acid showed inhibitory effects on T. frezzii. Lipoic acid was chosen for further study due to its lack of environmental toxicity. Lipoic acid induced the loss of cytosolic proteins, hydrolysis of triglycerides, and increased levels of free fatty acids, monoacylglycerols, and diacylglycerols. It also caused a decrease in ergosterol levels and alterations in the fungal cell wall and membrane, ultimately leading to cell death.

CONCLUSIONS

This study demonstrates the efficacy of lipoic acid in inhibiting the in vitro development of T. frezzii.

Antistress and Antiaging Potentials of Alpha-Lipoic Acid: Insights from Cell Culture-Based Experiments

Chronic stress has been linked to a large number of pathologies, including cancer, premature aging, and neurodegenerative diseases. The accumulation of molecular waste resulting from oxidative and heavy metal-induced stress has been ascribed as a major factor contributing to these diseases. With this in mind, we started by screening 13 small molecules to determine their antistress potential in heavy metal stress-exposed C6 glioblastoma and found that alpha-lipoic acid (ALA) (a natural antioxidant abundantly present in yeast, spinach, broccoli, and meat) was the most effective candidate. We then conducted molecular analyses to validate its mechanism of action. Dose-dependent toxicity assays of cells treated with two ALA enantiomers, R-ALA and S-ALA, showed that they are nontoxic and can be tolerated at relatively high doses. Cells exposed to heavy metal, heat, and oxidative stress showed better recovery when cultured in R-ALA-/S-ALA-supplemented medium, supported by reduction of reactive oxygen species (ROS), aggregated proteins, and mitochondrial and deoxyribonucleic acid (DNA) damage. Molecular analyses revealed protection against stress-induced apoptosis and induction of autophagy in R-ALA- and S-ALA-treated C6/U2OS cells. Consistent with these findings, normal human fibroblasts showed lifespan extension. Taken together, this study demonstrates that lipoic acid has antiaging and antistress potential and warrants further attention in laboratory and clinical studies.

Effect of (R)-(-)-Linalool on endothelial damage: Sex differences

Oxidative stress and inflammation are responsible for endothelial damage displaying many sex differences. Lipopolysaccharide (LPS) is a pathogenic stimulus that can trigger inflammation, contributing to endothelial dysfunction. Given the scientific evidence on the effectiveness of herbal extracts in managing endothelial dysfunction, we considered the (R)-(-)-Linalool (LIN), an aromatic monoterpene alcohol, as a bioactive phytochemical compound that could prevent and improve endothelial injury. In this study, we evaluated the effect of the LIN on LPS-induced damage in female and male human umbilical vein endothelial cells (FHUVECs and MHUVECs), measuring cell viability, cytokines release (IL-6 and TNF-α), malondialdehyde (MDA), and nitrites. LPS significantly reduced viability both in MHUVECs and FHUVECs. Moreover, LPS increased the IL-6, TNF-α, and MDA level only in FHUVECs if compared to basal value; despite that, LPS reduced nitrites only in MHUVECs. LIN alone did not affect the parameters measured except for an increase in nitrites in FHUVECs. Nevertheless, LIN reduced damage and restored endothelium viability reduced by LPS without a clear sex difference. Under LPS, LIN inhibited IL-6 release and reduced MDA levels only in FHUVECs. The present data confirm the existence of sex differences in the behavior of HUVECs under LPS conditions. The administration of LIN seems to have a more evident effect on FHUVECs after damage induced by LPS. These LIN effects are important to conduct further well-designed studies on the sex-specific use of this compound on vascular endothelial injury.

The effects of alpha-lipoic acid transdermal patch for local subcutaneous fat reduction: A randomized, placebo-controlled, clinical trial in overweight volunteers

Background

Combating obesity is challenging, as anti-obesity compounds lose effectiveness or cause severe side effects when delivered via conventional routes. Thus, there is a need for new, effective treatment routes that are home-based and safe for long-term use. This double-blind, placebo-controlled clinical trial aimed to investigate the efficacy of a biocellulose transdermal patch containing α-lipoic acid (ALA), an anti-obesity compound, in reducing subcutaneous fat accumulation.

Methods

One hundred and sixteen overweight participants (average age 37.96 ± 7.80 years) were recruited for the study. They were randomly assigned to apply either the calcium citrate nanoparticle-encapsulated ALA transdermal patch or a placebo on their arm. The participants' body weight, height, blood lipid profile (cholesterol, triglyceride, low-density lipoprotein, and high-density lipoprotein), arm circumference, triceps skin fold, and subcutaneous fat thickness were recorded at baseline and at the 2-week follow-up.

Results

The mean arm circumference did not show any significant difference from baseline, whereas the triceps skinfold and subcutaneous fat thickness showed a significant reduction. The 2-week treatment did not significantly alter the plasma LDL, HDL, and triglyceride levels of the participants, but it significantly reduced the total cholesterol level.

Conclusion

This study reports the successful reduction of subcutaneous fat of the calcium citrate nanoparticle-encapsulated ALA transdermal patches. The transdermal patches could be used as a safe and effective home-based solution for combating obesity.

Design, synthesis, and biological evaluation of imidazolylacetophenone oxime derivatives as novel brain-penetrant agents for Alzheimer's disease treatment

Alzheimer's disease (AD, also known as dementia) has become a serious global health problem along with population aging, and neuroinflammation is the underlying cause of cognitive impairment in the brain. Nowadays, the development of multitarget anti-AD drugs is considered to be one effective approach. Imidazolylacetophenone oxime ethers or esters (IOEs) were multifunctional agents with neuroinflammation inhibition, metal chelation, antioxidant and neuroprotection properties against Alzheimer's disease. In this study, IOEs derivatives 1-8 were obtained by structural modifications of the oxime and imidazole groups, and the SARs showed that (Z)-oxime ether (derivative 2) had stronger anti-neuroinflammatory and neuroprotective ability than (E)-congener. Then, IOEs derivatives 9-30 were synthesized based on target-directed ligands and activity-based groups hybridization strategy. In vitro anti-AD activity screening revealed that some derivatives exhibited potentially multifunctional effects, among which derivative 28 exhibited the strongest inhibitory activity on NO production with EC50 value of 0.49 μM, and had neuroprotective effects on 6-OHDA-induced cell damage and RSL3-induced ferroptosis. The anti-neuroinflammatory mechanism showed that 28 could inhibit the release of pro-inflammatory factors PGE2 and TNF-α, down-regulate the expression of iNOS and COX-2 proteins, and promote the polarization of BV-2 cells from pro-inflammatory M1 phenotype to anti-inflammatory M2 phenotype. In addition, 28 can dose-dependently inhibit acetylcholinesterase (AChE) and Aβ42 aggregation. Moreover, the selected nuclide [18F]-labeled 28 was synthesized to explore its biodistribution by micro-PET/CT, of which 28 can penetrate the blood-brain barrier (BBB). These results shed light on the potential of 28 as a new multifunctional candidate for AD treatment.

An Exquisite Analysis on the Significance of Nutrient Supplementation in the Holistic Management of Poly-cystic Ovarian Syndrome

Abstract:

The complex heterogeneous disorder known as polycystic ovarian syndrome (PCOS) includes endocrine, reproductive, metabolic, psychological, and other pathological aspects. Yet, nothing is understood regarding the cause of PCOS. Insulin resistance and hyperandrogenism are major contributors to the pathophysiology of PCOS, according to various studies. Because of this, a lot of PCOS treatment regimens include changing a person's lifestyle through practices, like exercise, nutrition, and vitamin supplementation. Recent studies have indicated a number of nutrients, including vitamins, minerals, and vitamin-like substances, for the therapy of PCOS since they all have at least one functional characteristic in the pathways that are affected by PCOS. As a result, it is claimed that PCOS may be caused by a vitamin or mineral deficiency. It is the goal of this review to conduct a critical literature analysis on nutritional supplementation for the management of PCOS.

Oxidative stress: fundamentals and advances in quantification techniques

Oxidative species, generated endogenously via metabolism or from exogenous sources, play crucial roles in the body. At low levels, these species support immune functions by participating in phagocytosis. They also aid in cellular signaling and contribute to vasomodulation. However, when the levels of oxidative species exceed the body's antioxidant capacity to neutralize them, oxidative stress occurs. This stress can damage cellular macromolecules such as lipids, DNA, RNA, and proteins, driving the pathogenesis of diseases and aging through the progressive deterioration of physiological functions and cellular structures. Therefore, the body's ability to manage oxidative stress and maintain it at optimal levels is essential for overall health. Understanding the fundamentals of oxidative stress, along with its reliable quantification, can enable consistency and comparability in clinical practice across various diseases. While direct quantification of oxidant species in the body would be ideal for assessing oxidative stress, it is not feasible due to their high reactivity, short half-life, and the challenges of quantification using conventional techniques. Alternatively, quantifying lipid peroxidation, damage products of nucleic acids and proteins, as well as endogenous and exogenous antioxidants, serves as appropriate markers for indicating the degree of oxidative stress in the body. Along with the conventional oxidative stress markers, this review also discusses the role of novel markers, focusing on their biological samples and detection techniques. Effective quantification of oxidative stress may enhance the understanding of this phenomenon, aiding in the maintenance of cellular integrity, prevention of age-associated diseases, and promotion of longevity.

Enzymatic Synthesis of a Novel Antioxidant Octacosanol Lipoate and Its Antioxidant Potency in Sunflower Oil

α-Lipoic acid possesses remarkable antioxidant activity; however, its poor lipid solubility greatly restricts its practical utilization. The present study was the first (i) to synthesize a novel lipophilic antioxidant of octacosanol lipoate and (ii) to assess its antioxidant potency in sunflower oil by hydrogen nuclear magnetic resonance (1H NMR) spectroscopy. In brief, octacosanol lipoate was successfully synthesized using octacosanol and lipoic acid as substrates and Candida sp. 99-125 lipase as a catalyst. The conversion of octacosanol lipoate could reach as high as 98.1% within merely 2 h, with an overall yield of 87.9%. The hydrophobicity of lipoic acid was significantly enhanced upon esterification with octacosanol. Interestingly, both traditional methods and 1H NMR analysis consistently indicated that octacosanol lipoate exhibited superior antioxidant activity compared with butyl hydroxytoluene at high temperatures. It was concluded that octacosanol lipoate has the potential to be developed into a safe and efficient natural antioxidant which can be utilized not only in daily cooking oils but also in frying oils.

Exploring the Mechanisms and Therapeutic Approaches of Mitochondrial Dysfunction in Alzheimer's Disease: An Educational Literature Review

Alzheimer's disease (AD) presents a significant challenge to global health. It is characterized by progressive cognitive deterioration and increased rates of morbidity and mortality among older adults. Among the various pathophysiologies of AD, mitochondrial dysfunction, encompassing conditions such as increased reactive oxygen production, dysregulated calcium homeostasis, and impaired mitochondrial dynamics, plays a pivotal role. This review comprehensively investigates the mechanisms of mitochondrial dysfunction in AD, focusing on aspects such as glucose metabolism impairment, mitochondrial bioenergetics, calcium signaling, protein tau and amyloid-beta-associated synapse dysfunction, mitophagy, aging, inflammation, mitochondrial DNA, mitochondria-localized microRNAs, genetics, hormones, and the electron transport chain and Krebs cycle. While lecanemab is the only FDA-approved medication to treat AD, we explore various therapeutic modalities for mitigating mitochondrial dysfunction in AD, including antioxidant drugs, antidiabetic agents, acetylcholinesterase inhibitors (FDA-approved to manage symptoms), nutritional supplements, natural products, phenylpropanoids, vaccines, exercise, and other potential treatments.

The Unprecedented Biodegradable Polyzwitterion: A Removal-Free Patch for Accelerating Infected Diabetic Wound Healing

Zwitterionic polymers have emerged as an important class of biomaterials to construct wound dressings and antifouling coatings over the past decade due to their excellent hydrophilicity. However, all the reported zwitterionic polymers as wound dressings are nondegradable because of noncleavable carbon─carbon bonding backbones, and must be removed periodically after treatment to avoid hypoxia in the wound, thus leading to potential secondary injury. In this work, a biodegradable polyzwitterion patch is fabricated for the first time by ring-opening polymerization of carboxybetaine dithiolane (CBDS), which is self-crosslinked via inter-amide hydrogen bonds and zwitterionic dipole-dipole interactions on the side chains. The unprecedented polyCBDS (PCBDS) patch demonstrates enough ductility owing to the intermolecular physical interactions to fully cover irregular wounds, also showing excellent biodegradability and antifouling performance resulted from the existence of disulfide bonds and carboxybetaine groups. Besides, the PCBDS degradation-induced released CBDS owns potent antioxidant and antibacterial activities. This PCBDS patch is used as a diabetic wound dressing, inhibiting bacterial adhesion on the external surface, and its degradation products can exactly kill bacteria and scavenge excessive reactive oxygen species (ROS) at the wound site to regulate local microenvironment, including regulation of cytokine express and macrophage polarization, accelerating infected diabetic wound repair, and also avoiding the potential secondary injury.

Nanotechnological Approaches to Enhance the Potential of α-Lipoic Acid for Application in the Clinic

α-lipoic acid is a naturally occurring compound with potent antioxidant properties that helps protect cells and tissues from oxidative stress. Its incorporation into nanoplatforms can affect factors like bioavailability, stability, reactivity, and targeted delivery. Nanoformulations of α-lipoic acid can significantly enhance its solubility and absorption, making it more bioavailable. While α-lipoic acid can be prone to degradation in its free form, encapsulation within nanoparticles ensures its stability over time, and its release in a controlled and sustained manner to the targeted tissues and cells. In addition, α-lipoic acid can be combined with other compounds, such as other antioxidants, drugs, or nanomaterials, to create synergistic effects that enhance their overall therapeutic benefits or hinder their potential cytotoxicity. This review outlines the advantages and drawbacks associated with the use of α-lipoic acid, as well as various nanotechnological approaches employed to enhance its therapeutic effectiveness, whether alone or in combination with other bioactive agents. Furthermore, it describes the engineering of α-lipoic acid to produce poly(α-lipoic acid) nanoparticles, which hold promise as an effective drug delivery system.

The allostery and modification of hGHRH molecules and specific dimer produced significant fertility effect by proliferating and activating in-situ ovarian mesenchymal stem cells

The negative coordination of growth hormone secretagogue receptor (GHS-R) and growth hormone-releasing hormone receptor (GHRH-R) involves in the repair processes of cellular injury. The allosteric U- or H-like modified GHRH dimer Grinodin and 2Y were comparatively evaluated in normal Kunming mice and hamster infertility models induced by CPA treatment. 1-3-9 µg of Grinodin or 2Y per hamster stem-cell-exhaustion model was subcutaneously administered once a week, respectively inducing 75-69-46 or 45-13-50 % of birth rates. In comparison, the similar mole of human menopausal gonadotropin (hMG) or human growth hormone (hGH) was administered once a day but caused just 25 or 20 % of birth rates. Grinodin induced more big ovarian follicles and corpora lutea than 2Y, hMG, hGH. The hMG-treated group was observed many distorted interstitial cells and more connective tissues and the hGH-treated group had few ovarian follicles. 2Y had a plasma lifetime of 21 days and higher GH release in mice, inducing lower birth rate and stronger individual specificity in reproduction as well as only promoting the proliferation of mesenchymal-stem-cells (MSCs) in the models. In comparison, Grinodin had a plasma lifetime of 30 days and much lower GH release in mice. It significantly promoted the proliferation and activation of ovarian MSCs together with the development of follicles in the models by increasing Ki67 and GHS-R expressions, and decreasing GHRH-R expression in a dose-dependent manner. However, the high GH and excessive estrogen levels in the models showed a dose-dependent reduction in fertility. Therefore, unlike 2Y, the low dose of Grinodin specifically shows low GHS-R and high GHRH-R expressions thus evades GH and estrogen release and improves functions of organs, resulting in an increase of fertility.

Alpha-Lipoic Acid Reduces Cell Growth, Inhibits Autophagy, and Counteracts Prostate Cancer Cell Migration and Invasion: Evidence from In Vitro Studies

Alpha-lipoic acid (ALA) is a natural antioxidant dithiol compound, exerting antiproliferative and antimetastatic effects in various cancer cell lines. In our study, we demonstrated that ALA reduces the cell growth of prostate cancer cells LNCaP and DU-145. Western blot results revealed that in both cancer cells, ALA, by upregulating pmTOR expression, reduced the protein content of two autophagy initiation markers, Beclin-1 and MAPLC3. Concomitantly, MTT assays showed that chloroquine (CQ) exposure, a well-known autophagy inhibitor, reduced cells' viability. This was more evident for treatment using the combination ALA + CQ, suggesting that ALA can reduce cells' viability by inhibiting autophagy. In addition, in DU-145 cells we observed that ALA affected the oxidative/redox balance system by deregulating the KEAP1/Nrf2/p62 signaling pathway. ALA decreased ROS production, SOD1 and GSTP1 protein expression, and significantly reduced the cytosolic and nuclear content of the transcription factor Nrf2, concomitantly downregulating p62, suggesting that ALA disrupted p62-Nrf2 feedback loop. Conversely, in LNCaP cells, ALA exposure upregulated both SOD1 and p62 protein expression, but did not affect the KEAP1/Nrf2/p62 signaling pathway. In addition, wound-healing, Western blot, and immunofluorescence assays evidenced that ALA significantly reduced the motility of LNCaP and DU-145 cells and downregulated the protein expression of TGFβ1 and vimentin and the deposition of fibronectin. Finally, a soft agar assay revealed that ALA decreased the colony formation of both the prostate cancer cells by affecting the anchorage independent growth. Collectively, our in vitro evidence demonstrated that in prostate cancer cells, ALA reduces cell growth and counteracts both migration and invasion. Further studies are needed in order to achieve a better understanding of the underlined molecular mechanisms.

The Roles of NFR2-Regulated Oxidative Stress and Mitochondrial Quality Control in Chronic Liver Diseases

Chronic liver disease (CLD) affects a significant portion of the global population, leading to a substantial number of deaths each year. Distinct forms like non-alcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (ALD), though they have different etiologies, highlight shared pathologies rooted in oxidative stress. Central to liver metabolism, mitochondria are essential for ATP production, gluconeogenesis, fatty acid oxidation, and heme synthesis. However, in diseases like NAFLD, ALD, and liver fibrosis, mitochondrial function is compromised by inflammatory cytokines, hepatotoxins, and metabolic irregularities. This dysfunction, especially electron leakage, exacerbates the production of reactive oxygen species (ROS), augmenting liver damage. Amidst this, nuclear factor erythroid 2-related factor 2 (NRF2) emerges as a cellular protector. It not only counters oxidative stress by regulating antioxidant genes but also maintains mitochondrial health by overseeing autophagy and biogenesis. The synergy between NRF2 modulation and mitochondrial function introduces new therapeutic potentials for CLD, focusing on preserving mitochondrial integrity against oxidative threats. This review delves into the intricate role of oxidative stress in CLD, shedding light on innovative strategies for its prevention and treatment, especially through the modulation of the NRF2 and mitochondrial pathways.

The effects of alpha lipoic acid (ALA) supplementation on blood pressure in adults: a GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials

Introduction

There have been various clinical studies on the effect of Alpha lipoic acid (ALA) supplementation on blood pressure (BP), but the findings from these are contradictory. Therefore, we performed a systematic review and dose-response meta-analysis to summarize the relation of ALA supplementation and systolic blood pressure (SBP) and diastolic blood pressure (DBP) in adults.

Methods

A comprehensive search was conducted in Medline (PubMed), Embase, Scopus, and ProQuest up to July 2023. Randomized controlled trials (RCTs) evaluating the effect of ALA on SBP and DBP were included. The pooled weighted mean difference (WMD) of included trials was estimated using a random-effects model. The dose-dependent effect was also assessed.

Results and discussion

A total of 11 RCTs with the participation of 674 patients were included. The result of the meta-analysis indicated that using ALA supplementation significantly reduced the SBP (WMD = -5.46 mmHg; 95% CI: -9.27, -1.65; p < 0.001) and DBP (WMD = -3.36 mmHg, 95% CI: -4.99, -1.74; p < 0.001). The ALA administrations significantly reduced SBP and DBP at the dosages of <800 mg/day, when administered for ≤12 weeks. The present meta-analysis revealed that ALA supplementation could exert favorable effects on SBP and DBP. Further well-designed studies with larger samples are needed to ascertain the long-term effects of ALA on BP.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=447658, identifier PROSPERO: CRD42023447658.

Recent Advances in Electrochemical Sensors for Sulfur-Containing Antioxidants

Sulfur-containing antioxidants are an important part of the antioxidant defense systems in living organisms under the frame of a thiol-disulfide equilibrium. Among them, l-cysteine, l-homocysteine, l-methionine, glutathione, and α-lipoic acid are the most typical representatives. Their actions in living systems are briefly discussed. Being electroactive, sulfur-containing antioxidants are interesting analytes to be determined using various types of electrochemical sensors. Attention is paid to the chemically modified electrodes with various nanostructured coverages. The analytical capabilities of electrochemical sensors for sulfur-containing antioxidant quantification are summarized and discussed. The data are summarized and presented on the basis of the electrode surface modifier applied, i.e., carbon nanomaterials, metal and metal oxide nanoparticles (NPs) and nanostructures, organic mediators, polymeric coverage, and mixed modifiers. The combination of various types of nanomaterials provides a wider linear dynamic range, lower limits of detection, and higher selectivity in comparison to bare electrodes and sensors based on the one type of surface modifier. The perspective of the combination of chromatography with electrochemical detection providing the possibility for simultaneous determination of sulfur-containing antioxidants in a complex matrix has also been discussed.