Carvacrol inhibits cytochrome P450 and protects against binge alcohol-induced liver toxicity

The possible pathogenesis of liver fibrosis: therapeutic potential of natural polyphenols

Liver fibrosis is the formation of a fibrous scar resulting from chronic liver injury, independently from etiology. Although many of the mechanical details remain unknown, activation of hepatic stellate cells (HSCs) is a central driver of liver fibrosis. Extracellular mechanisms such as apoptotic bodies, paracrine stimuli, inflammation, and oxidative stress are critical in activating HSCs. The potential for liver fibrosis to reverse after removing the causative agent has heightened interest in developing antifibrotic therapies. Polyphenols, the secondary plant metabolites, have gained attention because of their health-beneficial properties, including well-recognized antioxidant and anti-inflammatory activities, in the setting of liver fibrosis. In this review, we present an overview of the mechanisms underlying liver fibrosis with a specific focus on the activation of resident HSCs. We highlight the therapeutic potential and promising role of natural polyphenols to mitigate liver fibrosis pathogenesis, focusing on HSCs activation. We also discuss the translational gap from preclinical findings to clinical treatments involved in natural polyphenols in liver fibrosis.

Effects of carvacrol on ketamine-induced cardiac injury in rats: an experimental study

AIM

We aimed to investigate the preventive effects of carvacrol against ketamine-induced cardiotoxicity biochemically and histopathologically in an experimental model.

MATERIAL AND METHOD

The rats were divided into three groups; healthy control (HC), ketamine alone (KG), and ketamine + carvacrol (KCG) groups. Serum Creatine Kinase Myocardial Band (CK-MB) and Troponin I (TP I) levels were determined. Malondialdehyde (MDA), Glutathione (GSH), Superoxide Dismutase (SOD), Tumor Necrosis Factor α (TNF-α), Interleukin 1 beta (IL-1beta), and Interleukin 6 (IL-6) levels were measured in the heart tissues of the rats. Heart tissues were also evaluated histopathologically.

RESULTS

In the ketamine-treated group, tissue MDA, TNF-α, IL-1beta, and IL-6 levels increased while tissue GSH and SOD levels decreased significantly compared with the control group. However, in the ketamine plus carvacrol applied group, all those alterations were significantly less pronounced, close to the healthy controls. Severe mononuclear cell infiltrations, degenerated myocytes and hemorrhage were determined in the ketamine alone administered group, and these alterations were at a mild level in the carvacrol + ketamine administered group.

CONCLUSION

Prolonged exposure to ketamine resulted in induced oxidative stress in rat heart tissue; concomitant carvacrol application could counteract the negative effects of ketamine by protecting tissues from lipid peroxidation and decreasing the inflammatory response.

Trachyspermum ammi Bioactives Promote Neuroprotection by Inhibiting Acetylcholinesterase, Aβ-Oligomerization/Fibrilization, and Mitigating Oxidative Stress In Vitro

Neurodegenerative diseases (NDs) are a large category of progressive neurological disorders with diverse clinical and pathological characteristics. Among the NDs, Alzheimer's disease (AD) is the most widespread disease, which affects more than 400 million people globally. Oxidative stress is evident in the pathophysiology of nearly all NDs by affecting several pathways in neurodegeneration. No single drug can manage multi-faceted diseases like NDs. Therefore, an alternative therapeutic strategy is required, which can affect several pathophysiological pathways at a time. To achieve this aim, hexane and ethyl acetate extract from Trachyspermum ammi (Carom) were prepared, and GC/MS identified the bioactive compounds. For the cell-based assays, oxidative stress was induced in SH-SY5Y neuroblastoma cells using hydrogen peroxide to evaluate the neuroprotective potential of the Carom extracts/bioactives. The extracts/bioactives provided neuroprotection in the cells by modulating multiple pathways involved in neurodegeneration, such as alleviating oxidative stress and mitochondrial membrane potential. They were potent inhibitors of acetylcholine esterase enzymes and displayed competitive/mixed-type inhibition. Additionally, anti-Aβ1-42 fibrilization/oligomerization and anti-glycation activities were also analyzed. The multi-faceted neuroprotection shown via Carom/Carvacrol makes it a prospective contender in drug development for NDs.

Astragaloside IV ameliorate acute alcohol-induced liver injury in mice via modulating gut microbiota and regulating NLRP3/caspase-1 signaling pathway

PURPOSE

Astragaloside IV (AS-IV) is a natural saponin substance extracted from the plant Radix Astragali with anti-inflammatory, antioxidant, anti-apoptotic, and liver-protecting effects. This study was to evaluate the liver protection effect of AS-IV on mice after acute alcohol stimulation.

MATERIALS AND METHODS

Mice were orally administrated with AS-IV (50, 150, and 500 mg/kg, respectively), and sodium carboxymethyl cellulose (CMC, 50 mg/kg) daily for 7 days, before giving five alcohol-intragastric injections.

RESULTS

Results suggested that the levels of serum ALT and AST, liver SOD, GSH-PX, 4-HNE, and MDA, serum and liver TNF-α, IL-1β, and IL-6, serum lipopolysaccharide (LPS), lipopolysaccharide binding protein (LBP), diamine oxidase (DAO) and Myeloperoxidase (MPO), the mRNA and protein expression of hepatic NLRP3, Caspase-1, IL-1β, and IL-18 were significantly decreased in AS-IV-treated mice compared with the model group. Moreover, the effect of AS-IV on histopathology of liver tissue confirmed its protective function. Furthermore, AS-IV ameliorated the gut microbiota imbalance and adjusted the abundance of the following dysfunctional bacteria closer to the control group: Butyricicoccus, Turicibacter, Akkermansia, Anaerotruncus, and Mucispirillum. A strong correlation between intestinal bacteria and potential biomarkers was found.

CONCLUSION

Together, our findings indicated that AS-IV exert the hepatoprotective effect by modulating the gut microbiota imbalance and regulating NLRP3/Caspase-1 signaling pathway.

Detoxification activity of bioactive food compounds against ethanol-induced injuries and hangover symptoms: A review

Alcohol drinking is a popular activity among adolescents in many countries, largely due to its pleasant, relaxing effects. As a major concern, ethanol consumption put the drinkers at risk of nutrients' deficiency due to the disordered eating, anorexia, and malabsorption of nutrients. Moreover, alcohol drinking may lead to the development of hangover symptoms including diarrhea, thirsty, fatigue, and oxidative stress. A broad range of functional food components with antioxidant and/or anti-inflammatory properties including pectin, aloe vera polysaccharides, chito-oligosaccharides, and other herbal components have been explored due to their detoxification effects against ethanol. The underlying anti-hangover mechanisms include reducing the intestinal absorption of ethanol or its metabolites, increasing the activity of ethanol metabolizing enzymes, development of fatty acid β-oxidation in mitochondria, inhibition of inflammatory response, blocking the target receptors of ethanol in the body, and possession of antioxidant activity under the oxidative stress developed by ethanol consumption. Therefore, the development of bioactive food-based therapeutic formula can assist clinicians and also drinkers in the alleviation of alcohol side effects.

Autophagy, Oxidative Stress, and Alcoholic Liver Disease: A Systematic Review and Potential Clinical Applications

Ethanol consumption triggers oxidative stress by generating reactive oxygen species (ROS) through its metabolites. This process leads to steatosis and liver inflammation, which are critical for the development of alcoholic liver disease (ALD). Autophagy is a regulated dynamic process that sequesters damaged and excess cytoplasmic organelles for lysosomal degradation and may counteract the harmful effects of ROS-induced oxidative stress. These effects include hepatotoxicity, mitochondrial damage, steatosis, endoplasmic reticulum stress, inflammation, and iron overload. In liver diseases, particularly ALD, macroautophagy has been implicated as a protective mechanism in hepatocytes, although it does not appear to play the same role in stellate cells. Beyond the liver, autophagy may also mitigate the harmful effects of alcohol on other organs, thereby providing an additional layer of protection against ALD. This protective potential is further supported by studies showing that drugs that interact with autophagy, such as rapamycin, can prevent ALD development in animal models. This systematic review presents a comprehensive analysis of the literature, focusing on the role of autophagy in oxidative stress regulation, its involvement in organ-organ crosstalk relevant to ALD, and the potential of autophagy-targeting therapeutic strategies.

Hepatoprotective Effect of Albumin Peptide Fractions from Corn Germ Meal against Alcohol-Induced Acute Liver Injury in Mice

Acute alcoholic liver disease can cause serious liver damage. This study reports on the hepatoprotective effect of albumin peptide fractions from corn germ meal (MW < 1 kDa) (APF4) on acute alcohol hepatic damage in mice. In the mice model, the results indicated that APF4 at a dose of 800 mg/kg/bw could markedly boost alcohol metabolism, which was shown in the reduced duration of the loss of the righting reflex; the reduced level of blood alcohol concentration (BAC), cytochrome P450 2E1 (CYP2E1), alanine aminotransferase (ALT), aminotransferase (AST), triglycerides (TG), and malondialdehyde (MDA) (p < 0.01); the enhanced activity of aldehyde dehydrogenase (ALDH); and the superoxide dismutase (SOD) and glutathione (GSH) levels being increased by up to 84.02% and 193.22% (p < 0.01) compared to the control group. The antioxidant capability and lipid peroxidation inhibition activity of APF4 may be responsible for its protective effect against liver damage induced by alcohol. The findings suggested that APF4 had the hepatoprotective property against liver damage induced by alcohol.

Carvacrol prevents acrylamide-induced oxidative and inflammatory liver damage and dysfunction in rats

Background: Acrylamide causes hepatotoxicity with the effect of oxidative stress and inflammatory processes. Carvacrol is a monoterpenic phenol with antioxidant and anti-inflammatory properties. Aims: To determine the effects of carvacrol on oxidative liver injury induced by acrylamide administration in rats. Methods: Rats were divided into three groups of six animals each: healthy group acrylamide group (ACR), and acrylamide + carvacrol group (TACR). First, carvacrol (50 mg/kg) was administered intraperitoneally to the CACR group. One hour later, acrylamide (20 mg/kg) was given orally to the ACR and CACR groups. This procedure was performed for 30 days, after which the animals were sacrificed. The malondialdehyde (MDA) and total glutathione (tGSH) levels, total oxidant (TOS) and total antioxidant status (TAS), tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), and nuclear factor kappa b (NF-κB) were measured in the excised liver tissues. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were determined in blood serum samples. Liver tissues were also examined histopathologically. Results: In the ACR group, malondialdehyde, TOS, ALT, AST levels, and NF-κB, IL-1β, and TNF-α levels were found to be high, and tGSH and total antioxidant status levels were low. In addition, diffuse degenerative changes and necrosis in hepatocytes, and moderate inflammation in the portal region were detected in the liver tissues of the ACR group. While carvacrol prevented the biochemical changes induced by acrylamide, it also alleviated the damage in the histological structure. Conclusion: Carvacrol may be used for liver damage caused by acrylamide.

Therapeutic application of carvacrol: A comprehensive review

Carvacrol is a major natural constituent and is significantly present as an essential oil in aromatic plants and is well known for its numerous biological activities. Therapeutic properties of carvacrol have been demonstrated as anti-oxidant, anticancer, diabetes prevention, cardioprotective, anti-obesity, hepatoprotective and reproductive role, antiaging, antimicrobial, and immunomodulatory properties. The carvacrol biosynthesis has been mediated through mevalonate pathway. Carvacrol has the anticancer ability against malignant cells via decreasing the expressions of matrix metalloprotease 2 and 9, inducing apoptosis, enhancing the expression of pro-apoptotic proteins, disrupting mitochondrial membrane, suppressing extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase signal transduction, and also decreasing the phosphoinositide 3-kinase/protein kinase B. It also decreased the concentrations of alanine aminotransferase, alkaline phosphatase and aspartate aminotransferase, and gamma-glutamyl transpeptidase as well as also restored liver function, insulin level, and plasma glucose level. Carvacrol also has been found to exert antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Coagulase-negative staphylococcus, Salmonella spp., Enterococcus sp. Shigella, and Escherichia coli. The current review article summarizes the health-promoting perspectives of carvacrol through various pathways.

Amelioration of oxidative damage parameters by carvacrol on methanol-induced liver injury in rats

The methanol metabolite that causes hepatotoxicity is formic acid, generating reactive oxygen radical formation and cell damage. Carvacrol is an antioxidant monoterpenic phenol produced from Thymus vulgaris. This study aimed to investigate the effects of carvacrol on methanol-induced oxidative liver damage in rats. Eighteen rats were divided into three groups. Methotrexate was administered orally for 7 days to methotrexate+methanol (MTM) and methotrexate+methanol+carvacrol (MMC) groups. Methotrexate was given before methanol to cause methanol poisoning. Distilled water was given to the healthy group (HG) as a solvent. At the end of the 7th day, 20% methanol was administered orally at a dose of 3 g/kg to the MTM and MMC groups. Four hours after methanol administration, 50 mg/kg carvacrol was injected intraperitoneally into the MMC group. Animals were sacrificed 8 h after carvacrol injection. Biochemical markers were studied in the excised liver tissue and blood serum samples, and histopathological evaluations were made. Severe hemorrhage, hydropic degeneration, pycnosis, and mononuclear cell infiltration were observed in the liver of the MTM group. Additionally, the levels of malondialdehyde (MDA), total oxidant status (TOS), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were significantly higher, and total glutathione (tGSH) and total antioxidant status (TAS) were significantly lower in the MTM group compared to HG (P<0.001). Carvacrol prevented the increase in MDA, TOS, ALT and AST levels with methanol and the decrease in tGSH and TAS levels (P<0.001), and alleviated the histopathological damage. Carvacrol may be useful in the treatment of methanol-induced liver damage.

Beneficial Effects of Carvacrol on In Vitro Models of Metabolically-Associated Liver Steatosis and Endothelial Dysfunction: A Role for Fatty Acids in Interfering with Carvacrol Binding to Serum Albumin

Background:

Carvacrol, a plant phenolic monoterpene, is largely employed as food additive and phytochemical.

Objective:

We aimed to assess the lipid lowering and protective effects of carvacrol in vitro using cellular models of hepatic steatosis and endothelial dysfunction. We also investigated if and how the binding of carvacrol to albumin, the physiological transporter for small compounds in the blood, might be altered by the presence of high levels of fatty acids (FAs).

Methods:

Hepatic FaO cells treated with exogenous FAs mimic hepatosteatosis; endothelial HECV cells exposed to hydrogen peroxide are a model of endothelial dysfunction. In these models, we measured spectrophotometrically lipid accumulation and release, lipoperoxidation, free radical production, and nitric oxide release before and after treatment with carvacrol. The carvacrol binding to albumin in the presence or absence of high levels of FAs was assessed by absorption and emission spectroscopies.

Results:

Carvacrol counteracted lipid accumulation and oxidative stress in hepatocytes and protected endothelial cells from oxidative stress and dysfunction. Moreover, high levels of FAs reduced the binding of carvacrol to albumin.

Conclusion:

The results suggest the good potential of carvacrol in ameliorating dysfunction of hepatic and endothelial cells in vitro. High levels of circulating FAs might compete with carvacrol for binding to albumin thus influencing its transport and bio-distribution.

Carvacrol hinders the progression of hepatic fibrosis via targeting autotaxin and thioredoxin in thioacetamide-induced liver fibrosis in rat

Fibrosis is a common outcome of nearly all chronic diseases of liver that results in changes of its functions which requires medical attention. The current research aims to investigate the potential anti-fibrotic efficacy of Carvacrol against thioacetamide (TAA)-induced liver fibrosis in male rats using Ursodeoxycholic acid (UDCA) as a reference anti-fibrotic product. Carvacrol (25 and 50 mg/kg) markedly declined TAA-increased serum liver enzymes; alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT) as well as total bilirubin (TB) and direct bilirubin (DB) levels as well as increased levels of total protein (TP) and albumin. Carvacrol significantly reduced glutathione depletion (GSH), Nitric oxide (NOX) and malondialdehyde (MDA) accumulation in liver tissue. Additionally, its anti-oxidant effect brightened up via affecting markers of stress found in the cell as nuclear factor erythroid 2-related factor 2 (Nrf-2) where it still had high content and decreased Thioredoxin (Trx) level. The anti-inflammatory effect of Carvacrol was confirmed by decreasing nuclear factor kappa B (NF-κB), interleukin-1beta (IL-1β) and inducible nitric oxide synthase (iNOS) contents. Carvacrol showed anti-fibrotic effect clarified by turning down fibrosis-related markers; TGF-β1, matrix metalloproteinase-3 and 9 (MMP-3 and 9) and Autotaxin (ATX) contents. Furthermore, it decreased alpha smooth muscle actin (α-SMA) and caspase-3 immune-expression. The overall outcome of aforementioned markers results showed that Carvacrol suppresses the progression of liver fibrosis via its anti-oxidant, anti-inflammatory, anti-apoptotic effect and its ability in lowering Thioredoxin and Autotaxin; hence it can be categorized as a hepatoprotective natural substance.

Carvacrol alleviates liver fibrosis by inhibiting TRPM7 and modulating the MAPK signaling pathway

Liver fibrosis is a compensatory response to the tissue repair process. The activation and proliferation of hepatic stellate cells (HSCs) are thought to be related to the occurrence of hepatic fibrosis. Therefore, inhibiting the activation and proliferation of HSCs is a key step in alleviating liver fibrosis. As a non-specific inhibitor of transient receptor potential melastatin 7 (TRPM7), carvacrol has anti-tumor, anti-inflammatory and anti-hepatic fibrosis activities. This study aimed to explore the protective effect of carvacrol on liver fibrosis and related molecular mechanisms. A CCl4-induced liver fibrosis mouse model and platelet-derived growth factor (PDGF-BB)-activated HSC-T6 cells (a rat hepatic stellate cell line) were employed for in vivo and in vitro experiments. C57BL/6J mice were orally administered different concentrations of carvacrol every day for 6 weeks during the development of CCl4-induced liver fibrosis. The results show that carvacrol could effectively reduce liver damage and the progression of liver fibrosis in mice, which are expressed as fibrotic markers levels were reduced and histopathological characteristics were improved. Moreover, carvacrol inhibited the proliferation and activation of HSC-T6 cells induced by PDGF-BB. In addition, it was found that carvacrol inhibits the expression of TRPM7 and mediated through mitogen-activated protein kinases (MAPK). Collectively, our study shows that carvacrol can reduce liver fibrosis by inhibiting the activation and proliferation of hepatic stellate cells, and the MAPK signaling pathway might be involved in this process.

Diet, Immunity, and Microbiota Interactions: An Integrative Analysis of the Intestine Transcriptional Response and Microbiota Modulation in Gilthead Seabream (Sparus aurata) Fed an Essential Oils-Based Functional Diet

Essential oils (EOs) are promising alternatives to chemotherapeutics in animal production due to their immunostimulant, antimicrobial, and antioxidant properties, without associated environmental or hazardous side effects. In the present study, the modulation of the transcriptional immune response (microarray analysis) and microbiota [16S Ribosomal RNA (rRNA) sequencing] in the intestine of the euryhaline fish gilthead seabream (Sparus aurata) fed a dietary supplementation of garlic, carvacrol, and thymol EOs was evaluated. The transcriptomic functional analysis showed the regulation of genes related to processes of proteolysis and inflammatory modulation, immunity, transport and secretion, response to cyclic compounds, symbiosis, and RNA metabolism in fish fed the EOs-supplemented diet. Particularly, the activation of leukocytes, such as acidophilic granulocytes, was suggested to be the primary actors of the innate immune response promoted by the tested functional feed additive in the gut. Fish growth performance and gut microbiota alpha diversity indices were not affected, while dietary EOs promoted alterations in bacterial abundances in terms of phylum, class, and genus. Subtle, but significant alterations in microbiota composition, such as the decrease in Bacteroidia and Clostridia classes, were suggested to participate in the modulation of the intestine transcriptional immune profile observed in fish fed the EOs diet. Moreover, regarding microbiota functionality, increased bacterial sequences associated with glutathione and lipid metabolisms, among others, detected in fish fed the EOs supported the metabolic alterations suggested to potentially affect the observed immune-related transcriptional response. The overall results indicated that the tested dietary EOs may promote intestinal local immunity through the impact of the EOs on the host-microbial co-metabolism and consequent regulation of significant biological processes, evidencing the crosstalk between gut and microbiota in the inflammatory regulation upon administration of immunostimulant feed additives.

Allicin alleviated acrylamide-induced NLRP3 inflammasome activation via oxidative stress and endoplasmic reticulum stress in Kupffer cells and SD rats liver

Acrylamide (AA) in heat-processed food leads to widespread concerns due to its hepatotoxicity. Allicin, a plant-derived antioxidant, possesses a significant protective effect on AA-induced hepatotoxicity, but the mechanism is still unclear. Herein, we investigated the mechanism in Kupffer cells and SD rats liver. Molecular docking, molecular dynamics simulation and LigPlus software speculated that allicin inhibited the activity of CYP2E1 expression by binding to its amino acid residues Phe116, Phe207, Leu210, Phe298, Ala299, Thr303, Val364 and Phe478 through hydrophobic interactions. Allicin decreased the reactive oxygen species (ROS) release and CYP2E1 protein expression and then alleviated the appearance of OS. Meanwhile, allicin significantly reduced ERS characteristic proteins GRP78, CHOP and UPR branch IRE1α pathway key proteins p-IRE, p-ASK, TRAF2 and XBP-1s expression. Simultaneously, allicin ameliorated OS and ERS activation, which inhibited the activation of the MAPK and NF-κB pathways, and down-regulated JNK, ERK, p38, p65 and IκBα phosphorylation. Allicin pre-treatment inhibited AA-induced inflammation as evidenced by reducing NLRP3 inflammasome activation, decreasing Cleaved-Caspase-1 expression as well as IL-1β, IL-18, IL-6 and TNF-α secretion. Taken together, our data provide new insights into possible signaling pathways involved in allicin attenuating AA-induced hepatotoxicity in vivo and in vitro.

Antimicrobial potential of the food-grade additive carvacrol against uropathogenic E. coli based on membrane depolarization, reactive oxygen species generation, and molecular docking analysis

The antibiotic resistance of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli has increased drastically in recent years. In our study, we determined the principle mechanisms of action for the food-grade additive carvacrol against ESBL E. coli isolated from the blood of patients with a urinary tract infection. Carvacrol, which has a minimum inhibitory concentration of 150 μg/ml and a minimum bactericidal concentration of 300 μg/ml, reduced E. coli cell counts in a time-dependent manner. After treatment with carvacrol, the E. coli killing time was found to be 120 min. Fluorescent staining confirmed an increase in bacterial cell death, greater membrane depolarization, and an elevated oxidative burst in carvacrol-treated E. coli. Carvacrol also induced the release of cellular DNA, proteins, and potassium ions from bacterial cells and reduced both the number of E. coli in invasion assays against macrophages and the levels of the inflammatory proteins TNF-α and COX-2. In addition, carvacrol was found to inhibit β-lactamase enzyme activity (in vitro), which was supported by in silico results. Moreover, carvacrol inhibited motility, and protected against bacterial invasion. Overall, the findings suggest that carvacrol has significant antimicrobial potential against ESBL E. coli.