Astaxanthin: A promising therapeutic agent for organ fibrosis

Photosensitive Biomimetic Nanomedicine-Mediated Recombination of Adipose Microenvironments for Antiobesity Therapy

Obesity-induced insulin resistance is a hallmark of metabolic syndrome, and chronic low-grade inflammation links obesity to insulin resistance through the activation of tissue-infiltrating immune cells. Current treatments are lacking in efficacy and immunosuppression. Therefore, novel therapies are needed to prevent chronic inflammation and alleviate obesity-related insulin resistance. In this work, novel red light-responsive biomimetic nanoparticles (RSCP NPs) are reported to perform targeted delivery of multiple drugs and effectively reduce nonspecific enrichment. These results showed that the dual-targeting and multiple-signaling response (red light signaling and different pH microenvironments) of the RSCP NPs enabled the precise delivery of astaxanthin (Asta) and rosiglitazone (Rosi) to M1-like macrophages and white adipocytes, respectively, to alleviate the low-grade inflammation of white adipose tissue (WAT) and promote white adipocyte browning. Moreover, RSCP NPs-mediated Asta and Rosi treatment robustly alleviated insulin resistance and other metabolic disorders in the obese animal models (high-fat diet (HFD)-induced or genetically obese mice). Overall, this study provides a theoretical and practical basis for the development and application of novel drug delivery systems for metabolic diseases by elucidating the synergistic long-term targeting mechanism and target molecule stability of red light-sensitive bionic nanodrug delivery systems.

Mitochondrial Dysfunction as a Pathogenesis and Therapeutic Strategy for Metabolic-Dysfunction-Associated Steatotic Liver Disease

Metabolic-dysfunction-associated steatotic liver disease (MASLD) has emerged as a significant public health concern, attributed to its increasing prevalence and correlation with metabolic disorders, including obesity and type 2 diabetes. Recent research has highlighted that mitochondrial dysfunction can result in the accumulation of lipids in non-adipose tissues, as well as increased oxidative stress and inflammation. These factors are crucial in advancing the progression of MASLD. Despite advances in the understanding of MASLD pathophysiology, challenges remain in identifying effective therapeutic strategies targeting mitochondrial dysfunction. This review aims to consolidate current knowledge on how mitochondrial imbalance affects the development and progression of MASLD, while addressing existing research gaps and potential avenues for future research. This review was conducted after a systematic search of comprehensive academic databases such as PubMed, Embase, and Web of Science to gather information on mitochondrial dysfunction as well as mitochondrial-based treatments for MASLD.

Synthesis and application of astaxanthin-loaded procyanidins/sea cucumber peptide nanoparticles with good antioxidant and pH-responsive capacities

Astaxanthin (AXT), a keto-carotenoid with potent antioxidant properties, has the ability to reduce lipid peroxidation and effectively inhibit lipid peroxidation caused by free radicals. Given the oxidative susceptibility of AXT during processing, storage, and digestion, along with the effectiveness of novel food-grade drug delivery systems, we engineered an AXT-loaded procyanidins (PCs) and sea cucumber peptide (SCP) nanoparticles (AXT@NPs) to enhance its bioavailability. The research results indicatedthat spherical AXT@NPs, approximately 686 nm in size, had a higher drug-loading capacity and an intelligent pH-response performance. Additionally, this carrier demonstrated excellent stability against temperature and ultra-violet radiation, as well as DPPH and ABTS free radical scavenging properties. In vitro cell experiments revealed that AXT@NPs significantly inhibited the production of reactive oxygen species (ROS) and the reduction of mitochondrial membrane potential caused by H2O2. The oxidative stress plays a pivotal role in the formation of liver fibrosis. In vivo liver fibrosis studies in mice confirmed that AXT@NPs could effectively alleviate damaged liver tissues, decreasing collagen deposition, and reducing oxidative damage by extending the action time of AXT in liver tissue. These findings indicate that AXT@NPs offer a novel nutritional intervention strategy for antifibrosis therapy by significantly enhancing bioavailability and effectively reducing oxidative stress.

Astaxanthin mitigates doxorubicin-induced cardiotoxicity via inhibiting ferroptosis and autophagy: a study based on bioinformatic analysis and in vivo/vitro experiments

Background

Doxorubicin (DOX), a widely employed chemotherapeutic agent in cancer treatment, has seen restricted use in recent years owing to its associated cardiotoxicity. Current reports indicate that doxorubicin-induced cardiotoxicity (DIC) is a complex phenomenon involving various modes of cell death. Astaxanthin (ASX), a natural carotenoid pigment, has garnered significant attention for its numerous health benefits. Recent studies have shown that ASX has a broad and effective cardiovascular protective effect. Our study aims to investigate the protective effects of ASX against DIC and elucidate its underlying mechanisms. This has substantial practical significance for the clinical application of DOX.

Methods

Bioinformatic analyses were conducted using transcriptomic data from the gene expression omnibus (GEO) database to identify key mechanisms underlying DIC. Network pharmacology was employed to predict the potential pathways and targets through which ASX exerts its effects on DIC. In vitro experiments, following pretreatment with ASX, H9C2 cells were exposed to DOX. Cell viability, injury and the protein expression levels associated with ferroptosis and autophagy were assessed. In the animal experiments, rats underwent 4 weeks of gavage treatment with various doses of ASX, followed by intraperitoneal injections of DOX every 2 days during the final week. Histological, serum, and protein analyses were conducted to evaluate the effects of ASX on DIC.

Results

The bioinformatics analysis revealed that ferroptosis and autophagy are closely associated with the development of DIC. ASX may exert an anti-DIC effect by modulating ferroptosis and autophagy. The experimental results show that ASX significantly mitigates DOX-induced myocardial tissue damage, inflammatory response, oxidative stress, and damage to H9C2 cells. Mechanistically, ASX markedly ameliorates levels of ferroptosis and autophagy both in vitro and in vivo. Specifically, ASX upregulates solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4), while downregulating the expression of transferrin receptor 1 (TFRC), ferritin heavy chain (FTH1) and ferritin light chain (FTL). Additionally, ASX enhances the expression of P62 and decreases levels of Beclin1 and microtubule-associated proteins light chain 3 (LC3).

Conclusion

Our results indicate that ferroptosis and autophagy are critical factors influencing the occurrence and progression of DOX-induced cardiotoxicity. ASX can alleviate DIC by inhibiting ferroptosis and autophagy.

Astaxanthin attenuates diabetic kidney injury through upregulation of autophagy in podocytes and pathological crosstalk with mesangial cells

Objectives: Astaxanthin (ATX) is a strong antioxidant drug. This study aimed to investigate the effects of ATX on podocytes in diabetic nephropathy and the underlying renal protective mechanism of ATX, which leads to pathological crosstalk with mesangial cells.Methods: In this study, diabetic rats treated with ATX exhibited reduced 24-h urinary protein excretion and decreased blood glucose and lipid levels compared to vehicle-treated rats. Glomerular mesangial matrix expansion and renal tubular epithelial cell injury were also attenuated in ATX-treated diabetic rats compared to control rats.Results: ATX treatment markedly reduced the α-SMA and collagen IV levels in the kidneys of diabetic rats. Additionally, ATX downregulated autophagy levels. In vitro, compared with normal glucose, high glucose inhibited LC3-II expression and increased p62 expression, whereas ATX treatment reversed these changes. ATX treatment also inhibited α-SMA and collagen IV expression in cultured podocytes. Secreted factors (vascular endothelial growth factor B and transforming growth factor-β) generated by high glucose-induced podocytes downregulated autophagy in human mesangial cells (HMCs); however, this downregulation was upregulated when podocytes were treated with ATX.Conclusions: The current study revealed that ATX attenuates diabetes-induced kidney injury likely through the upregulation of autophagic activity in podocytes and its antifibrotic effects. Crosstalk between podocytes and HMCs can cause renal injury in diabetes, but ATX treatment reversed this phenomenon.

Anti-ischemic drug trimetazidine blocks mercury nephrotoxicity by suppressing renal redox imbalance, inflammatory stress and caspase-dependent apoptosis in rats

Trimetazidine (TMZ) is a promising emerging therapeutic piperazine derivative for renal pathologies. However, the nephroprotective mechanism of TMZ against heavy metal-induced toxicity is unknown. This study, therefore, aimed to explore whether TMZ could mitigate mercury-induced nephrotoxicity in rats. Rats were injected TMZ (3 mg/kg bw) and/or mercury chloride (HgCl2) (4 mg/kg bw) for 4 days (n = 6 rats per group). The blood analysis revealed marked increases in creatinine, urea and uric acid levels in HgCl2 group compared to the control. HgCl2 induced prominent decreases in renal superoxide dismutase (SOD), catalase (CAT), glutathione peroxide (GPx) activities compared to the control followed by marked increases in the levels of malondialdehyde (MDA), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), caspase-3 and caspase-9. Whereas the renal levels of anti-inflammatory cytokines interleukin-4 (IL-4) and interleukin-10 (IL-10) reduced considerably compared to the control. Contrarily, it was found that in the rats administered TMZ + HgCl2, levels of renal markers, MDA, TNF-α, IL-6 and caspases-3/-9 were prominently reduced compared to the HgCl2 group. The renal SOD, CAT, GPx, IL-4, and IL-10 were markedly elevated along with ameliorated histopathological lesions. On the whole, therefore, TMZ could be repurposed for blocking HgCl2 nephrotoxicity via inhibition of oxidative inflammation and apoptosis in rats.

Astaxanthin Rescues Memory Impairments in Rats with Vascular Dementia by Protecting Against Neuronal Death in the Hippocampus

Vascular dementia (VaD) is a cognitive disorder characterized by a decline in cognitive function resulting from cerebrovascular disease. The hippocampus is particularly susceptible to ischemic insults, leading to memory deficits in VaD. Astaxanthin (AST) has shown potential therapeutic effects in neurodegenerative diseases. However, the mechanisms underlying its protective effects in VaD and against hippocampal neuronal death remain unclear. In this study, We used the bilateral common carotid artery occlusion (BCCAO) method to establish a chronic cerebral hypoperfusion (CCH) rat model of VaD and administered a gastric infusion of AST at 25 mg/kg per day for 4 weeks to explore its therapeutic effects. Memory impairments were assessed using Y-maze and Morris water maze tests. We also performed biochemical analyses to evaluate levels of hippocampal neuronal death and apoptosis-related proteins, as well as the impact of astaxanthin on the PI3K/Akt/mTOR pathway and oxidative stress. Our results demonstrated that AST significantly rescued memory impairments in VaD rats. Furthermore, astaxanthin treatment protected against hippocampal neuronal death and attenuated apoptosis. We also observed that AST modulated the PI3K/Akt/mTOR pathway, suggesting its involvement in promoting neuronal survival and synaptic plasticity. Additionally, AST exhibited antioxidant properties, mitigating oxidative stress in the hippocampus. These findings provide valuable insights into the potential therapeutic effects of AST in VaD. By elucidating the mechanisms underlying the actions of AST, this study highlights the importance of protecting hippocampal neurons and suggests potential targets for intervention in VaD. There are still some unanswered questions include long-term effects and optimal dosage of the use in human. Further research is warranted to fully understand the therapeutic potential of AST and its application in the clinical treatment of VaD.

Readily Available Oral Prebiotic Protein Reactive Oxygen Species Nanoscavengers for Synergistic Therapy of Inflammation and Fibrosis in Inflammatory Bowel Disease

A significant gap exists in the demand for safe and effective drugs for inflammatory bowel disease (IBD), and its associated intestinal fibrosis. As oxidative stress plays a central role in the pathogenesis of IBD, astaxanthin (AST), a good antioxidant with high safety, holds promise for treating IBD. However, the application of AST is restricted by its poor solubility and easy oxidation. Herein, different protein-based nanoparticles (NPs) are fabricated for AST loading to identify an oral nanovehicle with potential clinical applicability. Through systematic validation via molecular dynamics simulation and in vitro characterization of properties, whey protein isolate (WPI)-driven NPs using a simple preparation method without the need for cross-linking agents or emulsifiers were identified as the optimal carrier for oral AST delivery. Upon oral administration, the WPI-driven NPs, benefiting from the intrinsic pH sensitivity and mucoadhesive properties, effectively shielded AST from degradation by gastric juices and targeted release of AST at intestinal lesion sites. Additionally, the AST NPs displayed potent therapeutic efficacy in both dextran sulfate sodium (DSS)-induced acute colitis and chronic colitis-associated intestinal fibrosis by ameliorating inflammation, oxidative damage, and intestinal microecology. In conclusion, the AST WPI NPs hold a potential therapeutic value in treating inflammation and fibrosis in IBD.

The pharmacological role of Ginsenoside Rg3 in liver diseases: A review on molecular mechanisms

Liver diseases are a significant global health burden and are among the most common diseases. Ginssennoside Rg3 (Rg3), which is one of the most abundant ginsenosides, has been found to have significant preventive and therapeutic effects against various types of diseases with minimal side effects. Numerous studies have demonstrated the significant preventive and therapeutic effects of Rg3 on various liver diseases such as viral hepatitis, acute liver injury, nonalcoholic liver diseases (NAFLD), liver fibrosis and hepatocellular carcinoma (HCC). The underlying molecular mechanism behind these effects is attributed to apoptosis, autophagy, antioxidant, anti-inflammatory activities, and the regulation of multiple signaling pathways. This review provides a comprehensive description of the potential molecular mechanisms of Rg3 in the development of liver diseases. The article focuses on the regulation of apoptosis, oxidative stress, autophagy, inflammation, and other related factors. Additionally, the review discusses combination therapy and liver targeting strategy, which can accelerate the translation of Rg3 from bench to bedside. Overall, this article serves as a valuable reference for researchers and clinicians alike.

Clinically Effective Molecules of Natural Origin for Obesity Prevention or Treatment

The prevalence and incidence of obesity and the comorbidities linked to it are increasing worldwide. Current therapies for obesity and associated pathologies have proven to cause a broad number of adverse effects, and often, they are overpriced or not affordable for all patients. Among the alternatives currently available, natural bioactive compounds stand out. These are frequently contained in pharmaceutical presentations, nutraceutical products, supplements, or functional foods. The clinical evidence for these molecules is increasingly solid, among which epigallocatechin-3-gallate, ellagic acid, resveratrol, berberine, anthocyanins, probiotics, carotenoids, curcumin, silymarin, hydroxy citric acid, and α-lipoic acid stand out. The molecular mechanisms and signaling pathways of these molecules have been shown to interact with the endocrine, nervous, and gastroenteric systems. They can regulate the expression of multiple genes and proteins involved in starvation-satiety processes, activate the brown adipose tissue, decrease lipogenesis and inflammation, increase lipolysis, and improve insulin sensitivity. This review provides a comprehensive view of nature-based therapeutic options to address the increasing prevalence of obesity. It offers a valuable perspective for future research and subsequent clinical practice, addressing everything from the molecular, genetic, and physiological bases to the clinical study of bioactive compounds.

Efficacy and Safety of Astaxanthin in the Management of Oral Submucous Fibrosis: A Preliminary Randomized Controlled Trial

BACKGROUND

Oral submucous fibrosis (OSMF) is a chronic, potentially malignant disorder characterized by progressive fibrosis of the oral mucosa, leading to restricted mouth opening and discomfort. This study investigates the efficacy and safety of astaxanthin, a potent antioxidant and anti-inflammatory carotenoid, in the comprehensive management of OSMF.

METHODS

A randomized, double-blind, placebo-controlled trial was conducted with 68 eligible participants diagnosed with OSMF. Participants were randomly assigned to the experimental group (astaxanthin capsules, 5 mg twice daily) or the control group (placebo capsules) for 12 weeks. Primary outcomes included changes in mouth opening and burning sensation assessed by Visual Analog Scale (VAS). Adverse events were monitored to evaluate safety.

RESULTS

The experimental group demonstrated a statistically significant improvement in mouth opening compared to the control group over the 12-week intervention (p < 0.001). Additionally, the experimental group reported a significant reduction in burning sensation, as indicated by VAS scores (p < 0.001). Adverse events were generally mild and comparable between groups.

CONCLUSION

This study suggests that astaxanthin may have a positive impact on mouth opening and burning sensation in individuals with OSMF. The safety profile observed supports the feasibility of astaxanthin as a potential therapeutic adjunct in OSMF management. Further research with larger sample sizes and extended follow-up periods is warranted to validate these findings.

Natural killer cells immunosenescence and the impact of lifestyle management

Natural killer cells (NKs) are lymphocytes of the innate immune system that quickly respond to viruses, infections, and tumors during their short cell life cycle. However, it was recently found that NKs undergo quantitative, distributional, structural, and functional phenotypic changes during aging that suppress immune responses, which is known as immunosenescence. The aging host environment, cytokine regulation, cytomegalovirus status, and hypothalamic‒pituitary‒adrenal axis have significant effects on NK function. Different lifestyle management interventions modulate the number and cytotoxic activity of NKs, which are essential for rebuilding the immune barrier against pathogens in elderly individuals. Based on recent studies, we review the phenotypic changes of and potential threats of NKs during aging and explore the underlying mechanisms. By summarizing the effects of lifestyle management on NKs and their application prospects, we aim to provide evidence for enhancing immune system function against immune diseases in elderly individuals.

Astaxanthin alleviates PM2.5-induced cardiomyocyte injury via inhibiting ferroptosis

BACKGROUND

Long-term exposure of humans to air pollution is associated with an increasing risk of cardiovascular diseases (CVDs). Astaxanthin (AST), a naturally occurring red carotenoid pigment, was proved to have multiple health benefits. However, whether or not AST also exerts a protective effect on fine particulate matter (PM2.5)-induced cardiomyocyte damage and its underlying mechanisms remain unclear.

METHODS

In vitro experiments, the H9C2 cells were subjected to pretreatment with varying concentrations of AST, and then cardiomyocyte injury model induced by PM2.5 was established. The cell viability and the ferroptosis-related proteins expression were measured in different groups. In vivo experiments, the rats were pretreated with different concentrations of AST for 21 days. Subsequently, a rat model of myocardial PM2.5 injury was established by intratracheal instillation every other day for 1 week. The effects of AST on myocardial tissue injury caused by PM2.5 indicating by histological, serum, and protein analyses were examined.

RESULTS

AST significantly ameliorated PM2.5-induced myocardial tissue injury, inflammatory cell infiltration, the release of inflammatory factors, and cardiomyocyte H9C2 cell damage. Mechanistically, AST pretreatment increased the expression of SLC7A11, GPX4 and down-regulated the expression of TfR1, FTL and FTH1 in vitro and in vivo.

CONCLUSIONS

Our study suggest that ferroptosis plays a significant role in the pathogenesis of cardiomyocyte injury induced by PM2.5. AST may serve as a potential therapeutic agent for mitigating cardiomyocyte injury caused by PM2.5 through the inhibition of ferroptosis.

Microfluidic fabrication of size-controlled nanocarriers with improved stability and biocompatibility for astaxanthin delivery

Improving the stability of astaxanthin (AST) is a vital way to enhance its oral bioavailability. In this study, a microfluidic strategy for the preparation of astaxanthin nano-encapsulation system was proposed. Thanks to the precise control of microfluidic and the rapid preparation ability of the Mannich reaction, the resulting astaxanthin nano-encapsulation system (AST-ACNs-NPs) was obtained with average sizes of 200 nm, uniform spherical shape and high encapsulation rate of 75%. AST was successfully doped into the nanocarriers, according to the findings of the DFT calculation, fluorescence spectrum, Fourier transform spectroscopy, and UV-vis absorption spectroscopy. Compared with free AST, AST-ACNs-NPs showed better stability under the conditions of high temperature, pH and UV light with<20% activity loss rate. The nano-encapsulation system containing AST could significantly reduce the hydrogen peroxide produced by reactive oxygen species, keep the potential of the mitochondrial membrane at a healthy level, and improve the antioxidant ability of H₂O₂-induced RAW 264.7 cells. These results indicated that microfluidics-based astaxanthin delivery system is an effective solution to improve the bioaccessibility of bioactive substances and has potential application value in food industry.

Bioactive Compounds and Cardiac Fibrosis: Current Insight and Future Prospect

Cardiac fibrosis is a pathological condition characterized by excessive deposition of collagen and other extracellular matrix components in the heart. It is recognized as a major contributor to the development and progression of heart failure. Despite significant research efforts in characterizing and identifying key molecular mechanisms associated with myocardial fibrosis, effective treatment for this condition is still out of sight. In this regard, bioactive compounds have emerged as potential therapeutic antifibrotic agents due to their anti-inflammatory and antioxidant properties. These compounds exhibit the ability to modulate fibrogenic processes by inhibiting the production of extracellular matrix proteins involved in fibroblast to myofibroblast differentiation, or by promoting their breakdown. Extensive investigation of these bioactive compounds offers new possibilities for preventing or reducing cardiac fibrosis and its detrimental consequences. This comprehensive review aims to provide a thorough overview of the mechanisms underlying cardiac fibrosis, address the limitations of current treatment strategies, and specifically explore the potential of bioactive compounds as therapeutic interventions for the treatment and/or prevention of cardiac fibrosis.

Depot-specific adaption of adipose tissue for different exercise approaches in high-fat diet/streptozocin-induced diabetic mice

Background: Adipose tissue pathology plays a crucial role in the pathogenesis of type 2 diabetes mellitus. Understanding the impact of exercise training on adipose tissue adaptation is of paramount importance in enhancing metabolic health. In this study, we aimed to investigate the effects of various exercise modalities on three distinct adipose tissue depots, namely, interscapular brown adipose tissue (iBAT), subcutaneous white adipose tissue (sWAT), and epididymal white adipose tissue (eWAT), in a murine model of diabetes. Methods: Male C57BL/6J mice received a 12-week high-fat diet and a single injection of streptozotocin, followed by an 8-week exercise intervention. The exercise intervention included swimming, resistance training, aerobic exercise, and high-intensity interval training (HIIT). Results: We found that exercise training reduced body weight and body fat percentage, diminished adipocyte size and increased the expression of mitochondria-related genes (PGC1, COX4, and COX8B) in three adipose tissue depots. The effects of exercise on inflammatory status include a reduction in crown-like structures and the expression of inflammatory factors, mainly in eWAT. Besides, exercise only induces the browning of sWAT, which may be related to the expression of the sympathetic marker tyrosine hydroxylase. Among the four forms of exercise, HIIT was the most effective in reducing body fat percentage, increasing muscle mass and reducing eWAT adipocyte size. The expression of oxidative phosphorylation and thermogenesis-related genes in sWAT and eWAT was highest in the HIIT group. Conclusion: When targeting adipose tissue to improve diabetes, HIIT may offer superior benefits and thus represents a more advantageous choice.

IFN-γ blockade after genetic inhibition of PD-1 aggravates skeletal muscle damage and impairs skeletal muscle regeneration

BACKGROUND

Innate immune responses play essential roles in skeletal muscle recovery after injury. Programmed cell death protein 1 (PD-1) contributes to skeletal muscle regeneration by promoting macrophage proinflammatory to anti-inflammatory phenotype transition. Interferon (IFN)-γ induces proinflammatory macrophages that appear to hinder myogenesis in vitro. Therefore, we tested the hypothesis that blocking IFN-γ in PD-1 knockout mice may dampen inflammation and promote skeletal muscle regeneration via regulating the macrophage phenotype and neutrophils.

METHODS

Anti-IFN-γ antibody was administered in PD-1 knockout mice, and cardiotoxin (CTX) injection was performed to induce acute skeletal muscle injury. Hematoxylin and eosin (HE) staining was used to view morphological changes of injured and regenerated skeletal muscle. Masson's trichrome staining was used to assess the degree of fibrosis. Gene expressions of proinflammatory and anti-inflammatory factors, fibrosis-related factors, and myogenic regulator factors were determined by real-time polymerase chain reaction (PCR). Changes in macrophage phenotype were examined by western blot and real-time PCR. Immunofluorescence was used to detect the accumulation of proinflammatory macrophages, anti-inflammatory macrophages, and neutrophils.

RESULTS

IFN-γ blockade in PD-1 knockout mice did not alleviate skeletal muscle damage or improve regeneration following acute cardiotoxin-induced injury. Instead, it exacerbated skeletal muscle inflammation and fibrosis, and impaired regeneration via inhibiting macrophage accumulation, blocking macrophage proinflammatory to anti-inflammatory transition, and enhancing infiltration of neutrophils.

CONCLUSION

IFN-γ is crucial for efficient skeletal muscle regeneration in the absence of PD-1.