Targeting Oxidative Stress with Polyphenols to Fight Liver Diseases

Unveiling the potential of xanthines, discovery of potential 7-benzyl-1,3-dimethyl-3,7-dihydro-1H-purine-2,6-dione derivatives with antifibrotic activity for liver injury

A new series of xanthine-based derivatives were designed, synthesized, and investigated to achieve promising antifibrotic and antioxidant agents for management of liver injury. Structure-based optimizations of the methylxanthine-based KMUP-1 (IX) were performed for inhibiting NF-κB activation pathway. All the newly designed xanthine derivatives 3, 4, 5, 6a-d, 7a-d, and 9a-d were in vitro screened for the antioxidant activity using the DPPH method. Compounds 4 and 5 showed the highest antioxidant activity with an IC50 of 28.02 and 36.02 μM, respectively. Compounds 9c and 9d retained a promising interception of the NF-κB activation pathway in molecular docking simulations within I-κB kinase α (IKKα) crystal structure (PDB ID: 5EBZ). Subsequently, compounds 9c and 9d were evaluated for their in vivo antifibrotic and chemoprotective activity using CCl4-induced hepatic fibrosis rat model. Compounds 9c and 9d successfully ameliorated liver fibrosis, as evidenced by the improved liver histopathological examination and liver enzyme activity levels. Compounds 9c and 9d were evaluated for their effects on mRNA expression levels of key genes involved in liver fibrosis via real-time PCR assays. Compound 9c exhibited a greater inhibitory effect on the expression levels of NF-κB and HIF-1α and a more pronounced stimulation of Nrf2 than compound 9d. Moreover, all the new xanthine derivatives were screened for the cytotoxic activity against the NCI tumor cell lines. Compounds 9c and 9d revealed a non-significant cytotoxic activity against all the assayed tumor cell lines, which indicate their selectivity for the antifibrotic activity. While compounds 6a and 6c displayed promising selective activity against melanoma SK-MEL-5 cell line (GI = 125.6, 90.3 %, respectively), and breast T-47D cell line (GI =87.8, 80.6 %, respectively). The utilized design approach unveiled the versatility of xanthine scaffold to deliver potential antioxidant, liver antifibrotic and chemoprotective agents, along with anticancer candidates via structure modification and optimization.

In vitro antioxidant effects and in vivo hepatoprotective effects of Osbeckia octandra, Vernonia cinerea and Atalantia ceylanica on a high fat diet induced metabolic dysfunction-associated steatotic liver disease mouse model

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD), which was formerly known as nonalcoholic fatty liver disease (NAFLD) has become a global epidemic that is predicted to affect more than 50% of the world population by 2040. However, except for Resmetiron, there are no approved drugs in conventional medicine to treat MASLD. The aim of this study was to explore the hepatoprotective effects of the aqueous extracts (AEs) of Osbeckia octandra (O. octandra), Vernonia cinerea (V. cinerea), and Atalantia ceylanica (A. ceylanica) which have been extensively used to treat hepatic diseases in the Sri Lankan traditional medicine.

METHODS

During initial in vitro experiments, aqueous extracts (AEs) of these three medicinal plants were prepared and evaluated for antioxidant potential using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and Trolox Equivalent Antioxidant Capacity (TEAC) assay. Cytotoxicity was assessed using the MTT assay on Vero cells to determine non-toxic doses for in vivo studies. For in vivo experiments, a high-fat diet (HFD)-induced MASLD mouse model was used. After co-treating the mice with AEs of the tested medicinal plants, their body weight gain was evaluated. Serum ALT, cholesterol, and triglyceride levels were analyzed using standard chemical methods. Hepatic lipid aggregation was evaluated by histopathology. Expression of TNF-α, IL-6, and PPAR-α genes was quantified using qRT-PCR. Data were analyzed using one-way ANOVA followed by Tukey's post hoc test or LSD test. The level of significance was (p < 0.05).

RESULTS

Initial in vitro experiments revealed that AEs of these medicinal plants are rich sources of natural antioxidants with low cytotoxic effects. Subsequent in vivo experiments on the HFD-induced MASLD mouse model also demonstrated that AEs of these medicinal plants can ameliorate HFD-induced weight gain, dyslipidemia, and hepatic lipid aggregation. Reversal of downregulated PPAR-α gene expression confirmed their positive impact on lipid metabolism. Attenuation of increased serum ALT concentration provides evidence for their protective role against hepatic injury. In addition, these extracts could suppress the upregulation of TNF-α and IL-6 genes, which are crucial for inducing steatohepatitis.

CONCLUSION

Aqueous extracts of O. octandra, V. cinerea, and A. ceylanica are rich in antioxidants and have the ability to suppress HFD-induced weight gain, dyslipidemias, hepatic steatosis, and hepatic inflammation providing solid evidence for their beneficial effects against initiation and progression of MASLD. Among these extracts, O. octandra stands out with the highest antioxidant activity, lowest cytotoxicity, and most promising hepatoprotective effects.

Bergamot Leaf Extract as an Agent Against Chronic Liver Diseases? In Vitro and In Vivo Findings on Oxidative Stress Modulation

Oxidative stress is involved in pathophysiological mechanisms associated with a myriad of liver diseases. Bergamot (Citrus bergamia) leaves yield a high level of antioxidant polyphenolic compounds that may hinder the development of liver diseases, while their potential is yet to be fully explored. Thus, the aim of the study was to test the effects of bergamot leaf extract (BLE) on hepatic and mitochondrial oxidative stress in different models. In vivo study: Wistar rats were distributed into two groups: control diet (C) and high-sugar-fat diet (HSF) for twenty weeks. Afterward, the animals were redivided to initiate a ten-week treatment with BLE: C, HSF, and HSF+BLE. In vitro study: Rat hepatic mitochondria were isolated by differential centrifugation and used to assess safety and efficacy of the BLE. Hepatocyte monolayer and spheroids were applied to evaluate the safety of physiologically plausible BLE concentrations and their effects on hydrogen peroxide-induced cytotoxicity. The results showed that BLE improved metabolic parameters, reduced hepatic triglyceride levels, malondialdehyde, and increased catalase activity in vivo. In vitro, BLE decreased lipid peroxidation and increased the ratio of reduced and oxidized glutathione in chemically challenged mitochondria. BLE did not exert cytotoxicity in the hepatocyte monolayer and spheroids, while attenuated oxidative stress-induced cytotoxicity. Data indicate that in vivo and in vitro hepatic oxidative stress is modulated by BLE, reinforcing that BLE may act as an agent against chronic liver diseases.

Curcumin Nanocarriers in the Protection Against Iron- and Alcohol-Induced Oxidative Stress in a Cellular Model of Liver Disease

During chronic alcohol misuse, hepatic iron overload occurs, leading to exacerbated oxidative stress and liver injury. The aim was to study formulations encapsulated with the antioxidant curcumin to assess their ability protect against oxidative stress in a model of alcohol-related liver disease (ALD) combined with iron. HepG2 (VL-17A) cells were treated with iron (50 µM) alone or with alcohol (200 to 350 mM) over 72 h and markers of oxidative damage, cell death, and mitochondrial function were assessed. Nanoformulations encapsulating curcumin were also studied. VL-17A cells treated with both ethanol and iron showed significant decreases in cell viability (64%, p < 0.0001) when compared to control, and a 56% decrease (p = 0.0279) when compared to iron-only treatment. Iron-alone treatment caused a 115% increase (p < 0.0001) in ROS at 48 h as well as increases of up to 118% when treated with 200 mM ethanol + 50 μM iron (p < 0.0001), compared to control DMEM. The study found that 10 µM curcumin DSPE-PEG increased cell viability by 17% and 41% when compared to control and iron treatment alone, respectively. Formulations reduced ROS by 36% (p = 0.0015) when compared to iron-alone treatment. In summary, encapsulated curcumin provided antioxidant capacity and reduced oxidative stress, demonstrating the therapeutic potential for curcumin formulations in ALD combined with iron dysregulation.

Oxidative stress in a cellular model of alcohol-related liver disease: protection using curcumin nanoformulations

Alcohol-related liver disease (ARLD) is a global health issue causing significant morbidity and mortality, due to lack of suitable therapeutic options. ARLD induces a spectrum of biochemical and cellular alterations, including chronic oxidative stress, mitochondrial dysfunction, and cell death, resulting in hepatic injury. Natural antioxidant compounds such as curcumin have generated interest in ARLD due to their ability to scavenge reactive oxygen species (ROS), however, therapy using these compounds is limited due to poor bioavailability and stability. Therefore, the aim of this study was to assess the antioxidant potential of free antioxidants and curcumin entrapped formulations against oxidative damage in an ARLD cell model. HepG2 (VL-17A) cells were treated with varying concentrations of alcohol (from 200 to 350 mM) and parameters of oxidative stress and mitochondrial function were assessed over 72 h. Data indicated 350 mM of ethanol led to a significant decrease in cell viability at 72 h, and a significant increase in ROS at 30 min. A substantial number of cells were in late apoptosis at 72 h, and a reduction in the mitochondrial membrane potential was also found. Pre-treatment with curcumin nanoformulations increased viability, as well as, reducing ROS at 2 h, 48 h and 72 h. In summary, antioxidants and entrapped nanoformulations of curcumin were able to ameliorate reduced cell viability and increased ROS caused by ethanol treatment. This demonstrates their potential at mitigating oxidative damage and warrants further investigation to evaluate their efficacy for ARLD therapy.

Spirulina platensis Peptide-Loaded Nanoliposomes Alleviate Hepatic Lipid Accumulation in Male Wistar Rats by Influencing Redox Homeostasis and Lipid Metabolism via the AMPK Signaling Pathway

Spirulina platensis low-molecular-weight peptides (SP) have been reported to exhibit antioxidant and hepatoprotective properties. However, the limited bioavailability and solubility of SPs limit their potential applications. In this study, to examine the potential anti-obesity effects and underlying mechanisms of SPs, high-fat diet-induced non-alcoholic fatty liver disease (NAFLD) model rats were treated with SPs and SP-loaded nanoliposomes. Furthermore, hepatic biochemical parameters, inflammatory markers, histopathological changes, and genes involved in AMPK signaling were analyzed. SP-loaded nanoliposomes demonstrated a spherical shape with slower and sustained SP release. SP and SP-loaded nanoliposomes mitigated hepatic damage by lowering serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and increasing hepatic antioxidant enzymes, which are manifested in improving histopathological findings. In addition, notably, SP-loaded nanoliposomes downregulated lipogenic fatty acid synthase (FAS) and sterol regulatory element-binding protein-1c (SREBP-1c) in the liver. Meanwhile, an upregulation of phosphorylated AMP-activated protein kinase (P-AMPK), lipid acid oxidation-related genes carnitine palmitoyltransferase-1 (CPT-1), and peroxisome proliferator-activated receptor alpha (PPAR-α) was found in the rat liver. This data implies that SP and SP-loaded nanoliposomes exhibit protective potential in rats against the HFD-induced NAFLD, which is mediated through the activation of the AMPK signaling pathway.

Hepatoprotective and Fat-Accumulation-Reductive Effects of Curcumin on Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Fat accumulation is the hallmark of metabolic dysfunction-associated steatotic liver disease (MASLD). Given the intimidating nature of its treatment, curcumin (CUR) emerges as a potential therapeutic agent due to its proven effectiveness in managing MASLD. This review aimed to evaluate previous reports on the hepatoprotective and fat-accumulation-reductive effects of CUR administration in preventing or treating MASLD. CUR administration can modulate serum liver enzymes and lipid profiles. The fat accumulation of MASLD is the primary cause of oxidative stress and inflammation. By reducing fat accumulation, CUR may attenuate the inflammation and oxidative stress in MASLD. In addition, CUR has been proven to restore the dysfunctional cellular energy metabolism capacity and attenuate fibrogenesis (antifibrotic agent). Their hepatoprotective effects are associated with fat accumulation in MASLD. Lipid metabolism (lipogenesis, lipolysis, and lipophagy) is correlated with their hepatoprotective effects. CUR has prophylactic and therapeutic effects, particularly in early-stage MASLD, primarily when it is used as a fat reducer. It can be considered an excellent natural therapeutic drug for MASLD because it protects the liver and attenuates fat accumulation, especially in the early stage of MASLD development.

Oxidative Stress in Pediatric Asthma: Sources, Mechanisms, and Therapeutic Potential of Antioxidants

Pediatric asthma is a common respiratory condition in children, characterized by a complex interplay of environmental and genetic factors. Evidence shows that the airways of stimulated asthmatic patients have increased oxidative stress, but the exact mechanisms through which this stress contributes to asthma progression are not fully understood. Oxidative stress originates from inflammatory cells in the airways, producing significant amounts of reactive oxygen species (ROS) and reactive nitrogen species (RNS). External factors such as cigarette smoke, particulate matter, and atmospheric pollutants also contribute to ROS and RNS levels. The accumulation of these reactive species disrupts the cellular redox balance, leading to heightened oxidative stress, which activates cellular signaling pathways and modulates the release of inflammatory factors, worsening asthma inflammation. Therefore, understanding the sources and impacts of oxidative stress in pediatric asthma is crucial to developing antioxidant-based treatments. This review examines the sources of oxidative stress in children with asthma, the role of oxidative stress in asthma development, and the potential of antioxidants as a therapeutic strategy for pediatric asthma.

Effects of time restricted feeding combined with Lacto Ovo vegetarian diet on metabolic associated fatty liver disease management: a randomized clinical trial

Metabolic Associated Fatty Liver Disease (MAFLD) is becoming a major global health concern due to its links with obesity, insulin resistance, and cardiovascular risk. This randomized clinical trial assessed the effects of combining time-restricted feeding (TRF; 16/8) with a Lacto-Ovo-Vegetarian (LOV) diet on various factors in overweight and obese patients with MAFLD. Forty-six participants were randomly assigned to either the intervention group (TRF with LOV diet) or the control group, with 21 participants completing the 12-week study in each group. The intervention group showed significant reductions in weight (-8.07 ± 4.31 kg), BMI (-2.70 ± 1.32 kg/m2), waist circumference (-8.00 ± 4.06 cm), as well as ALT (-17.14 ± 14.33 U/L), GGT (-21.09 ± 24.06 U/L), Fatty Liver Index (-26.90 ± 15.81), insulin levels (-3.89 ± 4.69 mU/L), and TNF-α (-11.85 ± 12.52 pg/mL) compared to the control group (all P < 0.05). Lipid profiles also improved with a reduction in triglycerides (-46.85 ± 54.55 mg/dL) and an increase in HDL-C (3.91 ± 5.07 mg/dL) in the intervention group compared to the control group (P < 0.05). These findings imply that TRF combined with a LOV diet enhances metabolic markers, liver health, and weight loss, thus potentially offering a practical dietary approach for managing MAFLD. Further long-term studies are necessary to validate these results and investigate their clinical applications.

Plant polyphenols as natural bioactives for alleviating lipid metabolism disorder: Mechanisms and application challenges

Lipid metabolism disorders will trigger various chronic diseases, which posing a serious threat to human health. Therefore, maintaining lipid metabolism balance is a key preventive and therapeutic strategy against various chronic and metabolic diseases. Various researches have proved that plant polyphenols play a significantly important role in regulating lipid metabolism. However, the mechanisms and application challenges of polyphenols in lipid metabolism disorders have rarely been elucidated. This review elucidates the definition, classification and function of plant polyphenols, summarize the kinds of polyphenols that can be used to regulate lipid metabolism, paying particular attention to the mechanisms for regulating lipid metabolism by plant polyphenols. Moreover, the limitations of polyphenols in the regulation of lipid metabolism are described and the trend of their development is prospective. This review will provide guidance to polyphenols in regulating metabolic diseases.

Grape Seed Proanthocyanidin Extract Improves Growth Performance and Protects Against Hydrogen Peroxide-Induced Oxidative Stress to the Liver and Intestine in Weaned Hyla Rabbits

Three experiments were conducted to investigate the effects of grape seed proanthocyanidin extract (GSPE) on the growth performance of weaned Hyla rabbits and explore its protective effects against oxidative stress in the liver and intestine by establishing a hydrogen peroxide (H2O2)-induced oxidative stress model. In Exp.1, ninety-six weaned rabbits were used to evaluate the effects of dietary GSPE level on growth performance, and the results showed that a 400 mg/kg GSPE addition increased the feed conversion ratio and liver coefficient and promoted cholesterol metabolism. Exp.2 was conducted to explore the H2O2 concentration required to establish an oxidative stress model, indicating that the model could be established by an intraperitoneal injection of 10% H2O2 at a dosage of 1 mL/kg body weight. In Exp.3, seventy-two weaned rabbits were used to investigate the protective effects against H2O2-induced oxidative stress in the liver and intestine. Our findings showed that 400 mg/kg GSPE supplementation could alleviate the adverse effects of H2O2 injection on the antioxidant capacity in the liver and intestine as well as liver morphology. Therefore, an addition of 400 mg/kg GSPE could improve growth performance and alleviate H2O2-induced adverse effects on the liver and small intestine by enhancing the antioxidative capacity in weaned Hyla rabbits.

(-)-Epigallocatechin-3-Gallate and Quercetin Inhibit Quiescin Sulfhydryl Oxidase 1 Secretion from Hepatocellular Carcinoma Cells

Liver cancer is one of the most prevalent cancers worldwide. The first-line therapeutic drug sorafenib offers only a moderate improvement in patients' conditions. Therefore, an approach to enhancing its therapeutic efficacy is urgently needed. It has been revealed that hepatocellular carcinoma (HCC) cells with heightened intracellular quiescin sulfhydryl oxidase 1 (QSOX1) exhibit increased sensitivity to sorafenib. QSOX1 is a secreted disulfide catalyst, and it is widely recognized that extracellular QSOX1 promotes the growth, invasion, and metastasis of cancer cells through its participation in the establishment of extracellular matrix. Inhibiting QSOX1 secretion can increase intracellular QSOX1 and decrease extracellular QSOX1. Such an approach would sensitize HCC cells to sorafenib but remains to be established. Since (-)-epigallocatechin-3-gallate (EGCG) has been demonstrated to be an effective inhibitor of α-fetal protein secretion from HCC cells, we screened QSOX1 secretion inhibition using polyphenolic compounds. We examined eight dietary polyphenols (EGCG, quercetin, fisetin, myricetin, caffeic acid, chlorogenic acid, resveratrol, and theaflavin) and found that EGCG and quercetin effectively inhibited QSOX1 secretion from human HCC cells (HepG2 or Huh7), resulting in high intracellular QSOX1 and low extracellular QSOX1. The combination of EGCG or quercetin, both of which change the cellular distribution of QSOX1, with sorafenib, which has no influence on the cellular distribution of QSOX1, exhibited multiple synergistic effects against the HCC cells, including the induction of apoptosis and inhibition of invasion and metastasis. In conclusion, our current results suggest that dietary EGCG and quercetin have the potential to be developed as adjuvants to sorafenib in the treatment of HCC by modulating the cellular distribution of QSOX1.

In Vitro Determination of Antimicrobial, Antioxidant and Antiviral Properties of Greek Plant Extracts

The medicinal potential of plant extracts, especially their antimicrobial, antioxidant, antiviral and cytotoxic properties, has gained significant attention in recent years. This study examined the in vitro bioactivities of several selected Greek medicinal plants, like Eucalyptus globulus L., Thymus vulgaris L., Salvia rosmarinus L. and Ocimum basilicum L., are well-known for their traditional therapeutic use. Minimum inhibitory concentration (MIC) assays were used to evaluate the antimicrobial activity of the extracts against pathogenic bacteria. The antioxidant activity was carried out using the DPPH method, while the cytotoxicity of the plants was determined using the Alamar Blue method. In addition, the antiviral efficacy of the samples was tested against DENV in different cell lines. The majority of medicinal herbs demonstrated significant antimicrobial action (MIC = 30-3000 μg∙mL-1). The extracts showed great antioxidant activity, while the Salvia rosmarinus L. extract turned out to be the most effective (IC50 = 12.89 ± 0.11 μg∙mL-1). In contrast, the extract of Eucalyptus globulus L. had the lowest antioxidant action (IC50 = 71.02 ± 0.42 μg∙mL-1). The results of the Alamar Blue method were presented with CC50 values, and it was shown that Eucalyptus globulus L. extract exhibited the highest cytotoxicity (CC50 = 5.94% v/v ± 0.04). Similarly, the results of the antiviral potential of extracts were expressed as EC50 values, and Eucalyptus globulus L. was characterized as the most effective sample against dengue virus infection, with EC50 values estimated at 2.37% v/v ± 0.6 (HuhD-2 cells infected with DENV-2) and 0.36% v/v ± 0.004 (Huh7.5 cells infected with DVR2A). These findings provide a foundation for further studies in order to combat infectious diseases and promote human health.

Comparative Study of Phenolic Content and Antioxidant and Hepatoprotective Activities of Unifloral Quillay Tree (Quillaja saponaria Molina) and Multifloral Honeys from Chile

Honey is a natural sweet element that bees make with flower nectar, revered for its distinct flavor, nutritional value, and potential health benefits. Chilean beekeeping has a diverse range of honey varieties, many of which are unique. The quillay (Quillaja saponaria Molina, soapbark tree) is a Chilean endemic tree whose honey has not been studied in depth. We characterized various Chilean honeys with different botanical origins, with a particular focus on quillay tree honey, analyzing its total phenolic and flavonoid content and its antioxidant activities. Cytotoxicity and hepatoprotective activity were also evaluated using HuH-7 cells. The Spearman correlation between the percentage of quillay pollen in the honey samples and the total phenolic content (R = 0.72; p < 0.05), plus the oxygen radical absorbance capacity, suggests that compounds from quillay contribute to the overall antioxidant capacity of honey. Unifloral quillay honey extracts also protect hepatic cells from oxidative damage induced by peroxyl radicals generated by AAPH. This analysis sheds light on the potential of quillay tree honey, underscoring its significance as a natural source of bioactive phenolic compounds with possible hepatoprotective effects.

Comparison of Protective Effects of Polyphenol-Enriched Extracts from Thinned Immature Kiwifruits and Mature Kiwifruits against Alcoholic Liver Disease in Mice

Alcoholic liver disease (ALD) is regarded as one of the main global health problems. Accumulated evidence indicates that fruit-derived polyphenols can lower the risk of ALD, this attributed to their strong antioxidant capacities. Thinned immature kiwifruits (TIK) are the major agro-byproducts in the production of kiwifruits, which have abundantly valuable polyphenols. However, knowledge about the protective effects of polyphenol-enriched extract from TIK against ALD is still lacking, which ultimately restricts their application as value-added functional products. To promote their potential applications, phenolic compounds from TIK and their corresponding mature fruits were compared, and their protective effects against ALD were studied in the present study. The findings revealed that TIK possessed extremely high levels of total phenolics (116.39 ± 1.51 mg GAE/g DW) and total flavonoids (33.88 ± 0.59 mg RE/g DW), which were about 7.4 times and 4.8 times greater than those of their corresponding mature fruits, respectively. Furthermore, the level of major phenolic components in TIK was measured to be 29,558.19 ± 1170.58 μg/g DW, which was about 5.4 times greater than that of mature fruits. In particular, neochlorogenic acid, epicatechin, procyanidin B1, and procyanidin B2 were found as the predominant polyphenols in TIK. In addition, TIK exerted stronger in vitro antioxidant and anti-inflammatory effects than those of mature fruits, which was probably because of their higher levels of polyphenols. Most importantly, compared with mature fruits, TIK exhibited superior hepatoprotective effects on alcohol-induced liver damage in mice. The administration of polyphenol-enriched extract from TIK (YK) could increase the body weight of mice, reduce the serum levels of ALP, AST, and ALT, lower the levels of hepatic TG and TC, and diminish lipid droplet accumulation and hepatic tissue damage. In addition, the treatment of YK could also significantly restore the levels of antioxidant enzymes (e.g., SOD and CAT) in the liver and lower the levels of hepatic proinflammatory cytokines (e.g., IL-6, IL-1β, and TNF-α), indicating that YK could effectively ameliorate ALD in mice by reducing hepatic oxidative stress and hepatic inflammation. Collectively, our findings can provide sufficient evidence for the development of TIK and their extracts as high value-added functional products for the intervention of ALD.

Dual Phytochemical/Activity-Guided Optimal Preparation and Bioactive Material Basis of Orthosiphon Stamineus Benth. (Shen Tea) against Nonalcoholic Fatty Liver Disease

Orthosiphon stamineus Benth. (OSB) is a popular plant used for making "Shen tea" or "Java tea". It has been demonstrated with antioxidant, anti-inflammatory, and hepatoprotective activities. However, its potential beneficial effects and bioactive material basis for nonalcoholic fatty liver disease (NAFLD) has not been convincingly studied. In the present work, we conducted dual phytochemical/activity-guided extraction optimization and component fractionation of OSB, and evaluated its beneficial effects on NAFLD. Flavonoids and polyphenols (caffeic acid/protocatechuic acid derivatives) were determined as the dominant phytochemicals in OSB. The extraction process for these phytochemicals was optimized by using response surface methodology. Noticeably, flavonoids showed a stronger correlation with the antioxidant activities of OSB than polyphenols. Likewise, the flavonoid-rich fraction of OSB exerted antioxidant activities stronger than those of other fractions. As expected, in vitro and in vivo studies demonstrated that the flavonoid-rich fraction effectively attenuated weight increase, improved lipid metabolism, alleviated hepatic steatosis, and reversed hepatic inflammation. Importantly, this fraction showed equivalent beneficial effects to the total extract of OSB, suggesting that flavonoids were the main bioactive constituents of OSB. The action mechanism was indicated as direct antioxidant effect through chemical interaction with free radicals and indirect mitochondria-mediated antioxidant defense. Our research offers bioactive substances for further exploitation and expands the potential application of OSB.

Nano-Formulations of Natural Antioxidants for the Treatment of Liver Cancer

Oxidative stress is a key factor in the pathological processes that trigger various chronic liver diseases, and significantly contributes to the development of hepatocarcinogenesis. Natural antioxidants reduce oxidative stress by neutralizing free radicals and play a crucial role in the treatment of free-radical-induced liver diseases. However, their efficacy is often limited by poor bioavailability and metabolic stability. To address these limitations, recent advances have focused on developing nano-drug delivery systems that protect them from degradation and enhance their therapeutic potential. Among the several critical benefits, they showed to be able to improve bioavailability and targeted delivery, thereby reducing off-target effects by specifically directing the antioxidant to the liver tumor site. Moreover, these nanosystems led to sustained release, prolonging the therapeutic effect over time. Some of them also exhibited synergistic effects when combined with other therapeutic agents, allowing for improved overall efficacy. This review aims to discuss recent scientific advances in nano-formulations containing natural antioxidant molecules, highlighting their potential as promising therapeutic approaches for the treatment of liver cancer. The novelty of this review lies in its comprehensive focus on the latest developments in nano-formulations of natural antioxidants for the treatment of liver cancer.

Polyphenols alleviate metabolic disorders: the role of ubiquitin-proteasome system

Metabolic disorders include obesity, nonalcoholic fatty liver disease, insulin resistance and type 2 diabetes. It has become a major health issue around the world. Ubiquitin-proteasome system (UPS) is essential for nearly all cellular processes, functions as a primary pathway for intracellular protein degradation. Recent researches indicated that dysfunctions in the UPS may result in the accumulation of toxic proteins, lipotoxicity, oxidative stress, inflammation, and insulin resistance, all of which contribute to the development and progression of metabolic disorders. An increasing body of evidence indicates that specific dietary polyphenols ameliorate metabolic disorders by preventing lipid synthesis and transport, excessive inflammation, hyperglycemia and insulin resistance, and oxidative stress, through regulation of the UPS. This review summarized the latest research progress of natural polyphenols improving metabolic disorders by regulating lipid accumulation, inflammation, oxidative stress, and insulin resistance through the UPS. In addition, the possible mechanisms of UPS-mediated prevention of metabolic disorders are comprehensively proposed. We aim to provide new angle to the development and utilization of polyphenols in improving metabolic disorders.

Capsaicin Modulates Hepatic and Intestinal Inflammation and Oxidative Stress by Regulating the Colon Microbiota

We aimed to investigate the role of capsaicin (CAP) in modulating lipopolysaccharide (LPS)-induced hepatic and intestinal inflammation, oxidative stress, and its colonic microflora in mice. Thirty healthy male Kunming mice with similar body weights were randomly assigned to three groups: the control group (CON), the LPS group, and the CAP group, with ten mice in each group. The CON and the LPS groups received a daily dose of normal saline, respectively, while the CAP group received an equivalent dose of CAP. On the 28th day of the experiment, the LPS and the CAP groups were intraperitoneally injected with LPS, while the CON group was injected with an equal volume of normal saline. The results lead to the following conclusions. Compared to the LPS group, CAP improved the loss of hepatic lobular structure and significantly increased the duodenal villus length and ratio of villus length to crypt depth. CAP increased hepatic and colon interleukin-10 (IL-10) and decreased IL-6, IL-1β, and tumor necrosis factor (TNF-α) levels. CAP also increased hepatic catalase (CAT), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) expression, and decreased malondialdehyde (MDA) levels. CAP significantly increased the relative abundances of Mucispirillum, Helicobacter, Prevotellaceae-UCG-001, Colidextribacter, unclassified-f-Oscillospiraceae, and Odoribacter, some of which were closely related to hepatic and colonic immune and oxidative markers. CAP also decreased the overall content of short-chain fatty acids, except for propionic acid. Overall, CAP can regulate the colon microbiota and exert anti-inflammatory and antioxidant effects. Whether CAP exerts its anti-inflammatory and antioxidant effects by modulating the colonic microflora, mainly Mucispirillum spp. and Helicobacter spp., requires further investigation.

Therapeutic Promises of Ferulic Acid and its Derivatives on Hepatic damage Related with Oxidative Stress and Inflammation: A Review with Mechanisms

Ferulic acid (FA) is a naturally occurring phenolic compound commonly found in the plant Ferula communis. This study aims to investigate the hepatoprotective effect of FA and its derivatives (methyl ferulic acid and trans-ferulic acid) against oxidative stress and inflammation-related hepatotoxicity due to toxicants based on the results of different non-clinical and preclinical tests. For this, data was collected from different reliable electronic databases such as PubMed, Google Scholar, and ScienceDirect, etc. The results of this investigation demonstrated that FA and its derivatives have potent hepatoprotective effects against oxidative stress and inflammation-related damage. The findings also revealed that these protective effects are due to the antioxidant and anti-inflammatory effects of the chemical compound. FA and its analogues significantly inhibit free radical generation and hinder the effects of proinflammatory markers and inflammatory enzymes, resulting in diminished cytotoxic and apoptotic hepatocyte death. The compounds also prevent intracellular lipid accumulation and provide protective effects.

The Coming Age of Antisense Oligos for the Treatment of Hepatic Ischemia/Reperfusion (IRI) and Other Liver Disorders: Role of Oxidative Stress and Potential Antioxidant Effect

Imbalances in the redox state of the liver arise during metabolic processes, inflammatory injuries, and proliferative liver disorders. Acute exposure to intracellular reactive oxygen species (ROS) results from high levels of oxidative stress (OxS) that occur in response to hepatic ischemia/reperfusion injury (IRI) and metabolic diseases of the liver. Antisense oligonucleotides (ASOs) are an emerging class of gene expression modulators that target RNA molecules by Watson-Crick binding specificity, leading to RNA degradation, splicing modulation, and/or translation interference. Here, we review ASO inhibitor/activator strategies to modulate transcription and translation that control the expression of enzymes, transcription factors, and intracellular sensors of DNA damage. Several small-interfering RNA (siRNA) drugs with N-acetyl galactosamine moieties for the liver have recently been approved. Preclinical studies using short-activating RNAs (saRNAs), phosphorodiamidate morpholino oligomers (PMOs), and locked nucleic acids (LNAs) are at the forefront of proof-in-concept therapeutics. Future research targeting intracellular OxS-related pathways in the liver may help realize the promise of precision medicine, revolutionizing the customary approach to caring for and treating individuals afflicted with liver-specific conditions.

Resveratrol Effects on Metabolic Syndrome Features: A Systematic Review and Meta-Analysis

Resveratrol is a natural polyphenol with important anti-inflammatory and antioxidant properties for treating cardiometabolic disorders. Therefore, the present meta-analysis aimed to review and investigate the oral resveratrol supplementation effects on metabolic syndrome (MetS) components. The bibliographic search was carried out in 2023 in the following databases: PubMed, Web of Science, and Scopus. Studies that investigated the oral resveratrol effects on the MetS parameters were included. Statistical analyses were performed using RevMan Software V.5.3. The main findings showed that resveratrol significantly decreased systolic and diastolic blood pressure while having no significant effects on waist circumference and high-density lipoprotein levels. In addition, glucose level was significantly decreased in the subgroup of studies reporting change from baseline means, although the overall effect was not statistically significant (p = 0.81), while triglyceride levels were increased after the treatment period. In conclusion, the present meta-analysis evidenced the potential therapeutic effect of resveratrol on improving some MetS features, especially regarding systolic blood pressure, diastolic blood pressure, and glucose reduction; however, the results are still borderline and sometimes controversial, which might be justified by the methodological and statistical heterogeneity of the studies, with the latter varying from 17 to 57%.

The Ocean's Pharmacy: Health Discoveries in Marine Algae

Non-communicable diseases (NCDs) represent a global health challenge, constituting a major cause of mortality and disease burden in the 21st century. Addressing the prevention and management of NCDs is crucial for improving global public health, emphasizing the need for comprehensive strategies, early interventions, and innovative therapeutic approaches to mitigate their far-reaching consequences. Marine organisms, mainly algae, produce diverse marine natural products with significant therapeutic potential. Harnessing the largely untapped potential of algae could revolutionize drug development and contribute to combating NCDs, marking a crucial step toward natural and targeted therapeutic approaches. This review examines bioactive extracts, compounds, and commercial products derived from macro- and microalgae, exploring their protective properties against oxidative stress, inflammation, cardiovascular, gastrointestinal, metabolic diseases, and cancer across in vitro, cell-based, in vivo, and clinical studies. Most research focuses on macroalgae, demonstrating antioxidant, anti-inflammatory, cardioprotective, gut health modulation, metabolic health promotion, and anti-cancer effects. Microalgae products also exhibit anti-inflammatory, cardioprotective, and anti-cancer properties. Although studies mainly investigated extracts and fractions, isolated compounds from algae have also been explored. Notably, polysaccharides, phlorotannins, carotenoids, and terpenes emerge as prominent compounds, collectively representing 42.4% of the investigated compounds.

Relevant Aspects of Combined Protocols for Prevention of N(M)AFLD and Other Non-Communicable Diseases

Obesity is a global health issue characterized by the excessive fat accumulation, leading to an increased risk of chronic noncommunicable diseases (NCDs), including metabolic dysfunction-associated fatty liver disease (MAFLD), which can progress from simple steatosis to steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Currently, there are no approved pharmacological protocols for prevention/treatment of MAFLD, and due the complexity lying beneath these mechanisms, monotherapies are unlikely to be efficacious. This review article analyzes the possibility that NCDs can be prevented or attenuated by the combination of bioactive substances, as they could promote higher response rates, maximum reaction results, additive or synergistic effects due to compounds having similar or different mechanisms of action and/or refraining possible side effects, related to the use of lower doses and exposures times than monotherapies. Accordingly, prevention of mouse MAFLD is observed with the combination of the omega-3 docosahexaenoic acid with the antioxidant hydroxytyrosol, whereas attenuation of mild cognitive impairment is attained by folic acid plus cobalamin in elderly patients. The existence of several drawbacks underlying published monotherapies or combined trials, opens space for adequate and stricter experimental and clinical tryouts to achieve meaningful outcomes with human applicability.

Silybin Alleviated Hepatic Injury by Regulating Redox Balance, Inflammatory Response, and Mitochondrial Function in Weaned Piglets under Paraquat-Induced Oxidative Stress

Silybin (Si) is the main element of silymarin isolated from the seeds of Silybum marianum L. Gaernt., which has superior antioxidant properties. However, the protective role of Si in maintaining liver health under oxidative stress remains ambiguous. This study aimed to investigate the underlying mechanism of the beneficial effect of dietary Si against hepatic oxidative injury induced by paraquat (PQ) in weaned piglets. A total of 24 piglets were randomly allocated to four treatments with six replicates per treatment and 1 piglet per replicate: the control group; Si group; PQ group; and Si + PQ group. Piglets in the control group and PQ group were given a basal diet, while piglets in the Si and Si + PQ groups were given a Si-supplemented diet. On the 18th day, the pigs in the PQ treatment group received an intraperitoneal injection of PQ, and the others were intraperitoneally injected with the same volume of saline. All piglets were sacrificed on day 21 for plasma and liver sample collection. The results showed that dietary Si supplementation mitigated PQ-induced liver damage, as proven by the reduction in liver pathological changes and plasma activity of alanine transaminase and aspartate transaminase. Si also improved superoxide dismutase and glutathione peroxidase activities and total antioxidant capacity, as well as decreased malondialdehyde and hydrogen peroxide concentration in the liver, which were closely related to the activation of the nuclear factor-erythroid 2-related factor 2 signaling pathway. Meanwhile, Si reduced tumor necrosis factor-α and interleukin-8 production and their transcript levels as well as abrogated the overactivation of nuclear factor-κB induced by PQ. Importantly, Si improved mitochondrial function by maintaining mitochondrial energetics and mitochondrial dynamics, which was indicated by the elevated activity of mitochondrial complexes I and V and adenosine triphosphate content, decreased expression of dynamin 1 protein, and increased expression of mitofusin 2 protein. Moreover, Si inhibited excessive hepatic apoptosis by regulating the B-cell lymphoma-2 (Bcl-2)/Bcl-2-associated-X-protein signaling pathway. Taken together, these results indicated that Si potentially mitigated PQ-induced hepatic oxidative insults by improving antioxidant capacity and mitochondrial function and inhibiting inflammation and cell apoptosis in weaned piglets.

The Influence of Diet and Its Components on the Development and Prevention of Hepatocellular Carcinoma (HCC)

Hepatocellular carcinoma (HCC) is diagnosed annually in nearly a million people worldwide, with approximately half of them being diagnosed at an advanced stage of the disease. Non-infectious risk factors for the development of HCC include an unbalanced lifestyle, including poor dietary choices characterized by a low intake of antioxidants, such as vitamins E and C, selenium, and polyphenols, as well as an excessive consumption of energy and harmful substances. Repeated bad dietary choices that contribute to an unbalanced lifestyle lead to the accumulation of fatty substances in the liver and to it entering an inflammatory state, which, without intervention, results in cirrhosis, the main cause of HCC. This review of the English language literature aims to present the food components that, when included in the daily diet, reduce the risk of developing HCC, as well as identifying foods that may have a carcinogenic effect on liver cells.

A high concentrate diet inhibits forkhead box protein A2 expression, and induces oxidative stress, mitochondrial dysfunction and mitochondrial unfolded protein response in the liver of dairy cows

High-concentrate diet induce subacute ruminal acidosis (SARA) and cause liver damage in ruminants. It has been reported that forkhead box protein A2 (FOXA2) can enhance mitochondrial membrane potential but its function in mitochondrial dysfunction induced by high concentrate diets is still unknown. Therefore, the aim of this study was to elucidate the effect of high-concentrate (HC) diet on hepatic FOXA2 expression, mitochondrial unfolded protein response (UPRmt), mitochondrial dysfunction and oxidative stress. A total of 12 healthy mid-lactation Holstein cows were selected and randomized into 2 groups: the low concentrate (LC) diet group (concentrate:forage = 4:6) and HC diet group (concentrate:forage = 6:4). The trial lasted 21 d. The rumen fluid, blood and liver tissue were collected at the end of the experiment. The results showed that the rumen fluid pH level was reduced in the HC group and the pH was lower than 5.6 for more than 4 h/d, indicating that feeding HC diets successfully induced SARA in dairy cows. Both FOXA2 mRNA and protein abundance were significantly reduced in the liver of the HC group compared with the LC group. The activity of antioxidant enzymes (CAT, G6PDH, T-SOD, Cu/Zn SOD, Mn SOD) and mtDNA copy number in the liver tissue of the HC group decreased, while the level of H2O2 significantly increased, this increase was accompanied by a decrease in oxidative phosphorylation (OXPHOS). The balance of mitochondrial division and fusion was disrupted in the HC group, as evidenced by the decreased mRNA level of OPA1, MFN1, and MFN2 and increased mRNA level of Drp1, Fis1, and MFF. At the same time, HC diet downregulated the expression level of SIRT1, SIRT3, PGC-1α, TFAM, and Nrf 1 to inhibit mitochondrial biogenesis. The HC group induced UPRmt in liver tissue by upregulating the mRNA and protein levels of CLPP, LONP1, CHOP, Hsp10, and Hsp60. In addition, HC diet could increase the protein abundance of Bax, CytoC, Caspase 3 and Cleaved-Caspase 3, while decrease the protein abundance of Bcl-2 and the Bcl-2/Bax ratio. Overall, our study suggests that the decreased expression of FOXA2 may be related to UPRmt, mitochondrial dysfunction, oxidative stress, and apoptosis in the liver of dairy cows fed a high concentrate diet.

Molecular Mechanisms of Curcumin in the Pathogenesis of Metabolic Dysfunction Associated Steatotic Liver Disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a multifactorial condition characterized by insulin resistance, oxidative stress, chronic low-grade inflammation, and sometimes fibrosis. To date, no effective pharmacological therapy has been approved for the treatment of metabolic-associated steatohepatitis (MASH), the progressive form of MASLD. Recently, numerous in vitro and in vivo studies have described the efficacy of nutraceutical compounds in the diet has been tested. Among them, curcumin is the most widely used polyphenol in the diet showing potent anti-inflammatory and antifibrotic activities. This review aims to summarize the most important basic studies (in vitro and animal models studies), describing the molecular mechanisms by which curcumin acts in the context of MASLD, providing the rationale for its effective translational use in humans.

Role of Oxidative Stress in Mitochondrial Function: Relevance for Liver Function

The traditional recognition of mitochondria as powerhouses that generate ATP and reactive oxygen species (ROS) via oxidative phosphorylation and the tricarboxylic acid cycle has ceased [...].

The Phytochemical Profiling, In Vitro Antioxidant, and Hepatoprotective Activity of Prenanthes purpurea L. and Caffeoylquinic Acids in Diclofenac-Induced Hepatotoxicity on HEP-G2 Cells

Oxidative stress is a common phenomenon of many liver disorders; it both affects patient survival and directly influences the applicability, effectiveness, and toxicity of drugs. In the pursuit of reliable natural remedies for hepatoprotection, this study reports on the complete phytochemical characterization, antioxidant, and hepatoprotective activities of the Prenanthes purpurea methanol-aqueous extract in an in vitro model of diclofenac-induced liver injury (DILI). An ultra high-performance liquid chromatography-high-resolution mass spectrometry analysis (UHPLC-HRMS) was conducted, delineating more than 100 secondary metabolites for the first time in the species, including a series of phenolic acid-hexosides, acylquinic, acylhydroxyquinic and acyltartaric acids, and flavonoids. Quinic acid, chlorogenic, 3,5-dicaffeoylquinic and 5-feruloylhydroxyquinic acid, caffeoyltartaric and cichoric acids, eryodictiol-O-hexuronide, and luteolin O-hexuronide dominated the phytochemical profile and most likely contributed to the observed hepatoprotective activity of the studied P. purpurea leaf extract. The potency and molecular basis of cellular protection were investigated in parallel with pure caffeoylquinic acids in a series of pretreatment experiments that verified the antiapoptotic and antioxidant properties of the natural products.