Mechanism of protective effects of Danshen against iron overload-induced injury in mice

Synergistic Differential DNA Demethylation Activity of Danshensu (Salvia miltiorrhiza) Associated with Different Probiotics in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a major hepatic disorder occurring in non-alcohol-drinking individuals. Salvianic acid A or Danshensu (DSS, 3-(3, 4-dihydroxyphenyl)-(2R)-lactic acid), derived from the root of Danshen (Salvia miltiorrhiza), has demonstrated heart and liver protective properties. In this work, we investigated the antioxidant activity and hepatoprotective activity of Danshensu alone and in combination with different agents, such as probiotic bacteria (Lactobacillus casei and Lactobacillus acidophilus), against several assays. The inhibition mechanism of the methylation gene biomarkers, such as DNMT-1, MS, STAT-3, and TET-1, against DSS was evaluated by molecular docking and RT-PCR techniques. The physicochemical and pharmacokinetic ADMET properties of DSS were determined by SwissADME and pkCSM. The results indicated that all lipid blood test profiles, including cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C), were reduced after the oral administration of Danshensu combined with probiotics (L. casei and L. acidophilus) that demonstrated good, efficient free radical scavenging activity, measured using anti-oxidant assays. ADMET and drug-likeness properties certify that the DSS could be utilized as a feasible drug since DSS showed satisfactory physicochemical and pharmacokinetic ADMET properties.

Salvianolic acid A attenuates arsenic-induced ferroptosis and kidney injury via HIF-2α/DUOX1/GPX4 and iron homeostasis

Arsenic (As) is a prevalent pollutant in the environment and causes a high frequency of kidney disease in areas of high arsenic contamination, but its pathogenic mechanisms have yet to be completely clarified. Ferroptosis is a new form of cell death mainly dependent on lipid peroxidation and iron accumulation. Several reports have suggested that ferroptosis is operative in a spectrum of diseases caused by arsenic exposure, including in the lungs, pancreas, and testis. However, the mechanism and exact role of ferroptosis in arsenic-induced kidney injury is not known. Firstly, by constructing in vivo and in vitro arsenic exposure models, we confirmed the occurrence of ferroptosis based on the identification of the ability of NaASO2 to cause kidney injury. In addition, we found that arsenic exposure could upregulate DUOX1 expression in kidney and HK-2 cells, and after knocking down DUOX1 using siRNA was able to significantly upregulate GPX4 expression and attenuate ferroptosis. Subsequently using bioinformatics, we identified and proved the involvement of HIF-2α in the course of ferroptosis, and further confirmed by dual luciferase assay that HIF-2α promotes DUOX1 transcription to increase its expression. Finally, intervention with the natural ingredient SAA significantly attenuated arsenic-induced ferroptosis and kidney injury. These results showed that arsenic could cause ferroptosis and kidney injury by affecting HIF-2α/DUOX1/GPX4 and iron homeostasis and that SAA was an effective intervention component. This study not only discovered the molecular mechanism of sodium arsenite-induced kidney injury but also explored an active ingredient with intervention potential, providing a scientific basis for the prevention and treatment of sodium arsenite-induced kidney injury.

Vanillin serves as a potential substitute for chemical chelator desferal in iron-overloaded mice

PURPOSE

Iron toxicity occurs under iron-overloaded settings, such as a high iron diet and blood transfusion, and damages important organs. Vanillin has been proven to have potential iron chelation capability. Given the negative effects of commonly used iron chelators like deferoxamine (DFO), we sought to examine the iron chelation potency of vanillin and evaluate its potential effect in the treatment of iron overload-related disorders.

METHODS

42 male NMRI mice were prepared for this purpose, and except for the negative control group, iron overload conditions were generated in them by injecting iron. Then normal saline (as a control), vanillin, and DFO (n = 7) were subsequently given to iron-overloaded mice. In the following, the activity of antioxidant enzymes catalase and superoxide dismutase were measured in the blood serum, brain, kidney, spleen, lung, and liver tissues of mice. Furthermore, the level of lipid peroxidation was determined by measuring the amount of malondialdehyde. Also, Perl's and H&E staining were used to examine the physiopathology changes of tissues.

FINDINGS

Vanillin, a natural antioxidant compound, outperformed deferoxamine, a chemical iron chelator. Along with a decrease in iron content, the activity of catalase and superoxide dismutase enhanced in the iron-overloaded groups that were treated with vanillin. The level of lipid peroxidation was also declined in the iron-overloaded mice receiving vanillin.

CONCLUSION

Vanillin can be used as a suitable substitute for chemical chelators with fewer side effects and equivalent efficiency. We encourage the use of this compound as a natural iron chelator following performing additional safety and efficacy studies.

Excess iron intake induced liver injury: The role of gut-liver axis and therapeutic potential

Excessive iron intake is detrimental to human health, especially to the liver, which is the main organ for iron storage. Excessive iron intake can lead to liver injury. The gut-liver axis (GLA) refers to the bidirectional relationship between the gut and its microbiota and the liver, which is a combination of signals generated by dietary, genetic and environmental factors. Excessive iron intake disrupts the GLA at multiple interconnected levels, including the gut microbiota, gut barrier function, and the liver's innate immune system. Excessive iron intake induces gut microbiota dysbiosis, destroys gut barriers, promotes liver exposure to gut microbiota and its derived metabolites, and increases the pro-inflammatory environment of the liver. There is increasing evidence that excess iron intake alters the levels of gut microbiota-derived metabolites such as secondary bile acids (BAs), short-chain fatty acids, indoles, and trimethylamine N-oxide, which play an important role in maintaining homeostasis of the GLA. In addition to iron chelators, antioxidants, and anti-inflammatory agents currently used in iron overload therapy, gut barrier intervention may be a potential target for iron overload therapy. In this paper, we review the relationship between excess iron intake and chronic liver diseases, the regulation of iron homeostasis by the GLA, and focus on the effects of excess iron intake on the GLA. It has been suggested that probiotics, fecal microbiota transfer, farnesoid X receptor agonists, and microRNA may be potential therapeutic targets for iron overload-induced liver injury by protecting gut barrier function.

Chia seeds and coenzyme Q10 alleviate iron overload induced hepatorenal toxicity in mice via iron chelation and oxidative stress modulation

Iron overload (IOL) can cause hepatorenal damage due to iron-mediated oxidative and mitochondrial damage. Remarkably, combining a natural iron chelator with an antioxidant can exert greater efficacy than monotherapy. Thus, the present study aimed to evaluate the efficacy of Chia and CoQ10 to chelate excess iron and prevent hepatorenal oxidative damage in IOL mice. Male Swiss albino mice (n = 49) were randomly assigned to seven groups: control, dietary Chia, CoQ10, IOL, IOL + Chia, IOL + CoQ10, and IOL + Chia + CoQ10. Computational chemistry indicates that the phytic acid found in the Chia seeds is stable, reactive, and able to bind to up to three iron ions (both Fe2+ and Fe3+). IOL induced a significant (P < 0.05) increase in serum iron, ferritin, transferrin, TIBC, TSI, RBCs, Hb, MCV, MCH, WBCs, AST, ALT, creatinine, and MDA. IOL causes a significant (P < 0.05) decrease in UIBC, platelets, and antioxidant molecules (GSH, SOD, CAT, and GR). Also, IOL elicits mitochondrial membrane change depolarization, and DNA fragmentation and suppresses mitochondrial DNA copies. Furthermore, substantial changes in hepatic and renal tissue, including hepatocellular necrosis and apoptosis, glomerular degeneration, glomerular basement membrane thickening, and tubular degeneration, were observed in the IOL group. Dietary Chia and CoQ10 induced significant (P < 0.05) amelioration in all the mentioned parameters. They can mostly repair the abnormal architecture of hepatic and renal tissues induced by IOL, as signified by normal sinusoids, normal central veins, and neither glomerular damage nor degenerated tubules. In conclusion, the combined treatment with Chia + CoQ10 exerts more pronounced efficacy than monotherapy in hepatorenal protection via chelating excess iron and improved cellular antioxidant status and hepatorenal mitochondrial function in IOL mice.

Progress on traditional Chinese medicine in improving hepatic fibrosis through inhibiting oxidative stress

Hepatic fibrosis is a common pathological process that occurs in the development of various chronic liver diseases into cirrhosis and liver cancer, characterized by excessive deposition of the extracellular matrix. In the past, hepatic fibrosis was thought to be a static and irreversible pathological process. In recent years, with the rapid development of molecular biology and the continuous in-depth study of the liver at the microscopic level, more and more evidence has shown that hepatic fibrosis is a dynamic and reversible process. Therefore, it is particularly important to find an effective, simple, and inexpensive method for its prevention and treatment. Traditional Chinese medicine (TCM) occupies an important position in the treatment of hepatic fibrosis due to its advantages of low adverse reactions, low cost, and multi-target effectiveness. A large number of research results have shown that TCM monomers, single herbal extracts, and TCM formulas play important roles in the prevention and treatment of hepatic fibrosis. Oxidative stress (OS) is one of the key factors in the occurrence and development of hepatic fibrosis. Therefore, this article reviews the progress in the understanding of the mechanisms of TCM monomers, single herbal extracts, and TCM formulas in preventing and treating hepatic fibrosis by inhibiting OS in recent years, in order to provide a reference and basis for drug therapy of hepatic fibrosis.

Protective benefits of salvianic acid A against retinal iron overload by inhibition of ferroptosis

BACKGROUND

Both the accumulation of reactive oxygen species (ROS) and iron overload are significant variables that enhance the incidence of photoreceptor cell death and retinal degeneration. The discovery of ferroptosis, which is characterized by iron-dependent lipid peroxidation, has led to a new perspective on how retinal degeneration develops. As a natural phenolic acid, salvianic acid A (SAA) from Salvia miltiorrhiza has promise in treating eye diseases. The purpose of this research was to learn more about SAA and its function in the development of iron-overload-induced retinal degeneration.

METHODS

Models of iron overload in Kunming mice and the murine photoreceptor cell line 661 W were established, then the protective and antiferroptotic properties of SAA were assessed in vivo and in vitro.

RESULTS

Biochemical and histopathological findings on the retina confirmed that SAA successfully alleviated retinal injury. In photoreceptor cells, iron overload caused cell death, mitochondrial dysfunction, ROS generation, and iron deposition. Salvianic acid A relieved lipid peroxidation and decreased iron accumulation by modulating Acyl-CoA synthetase long-chain family member 4, glutathione peroxidase 4, solute carrier family 7 member 11, and iron-metabolism-related proteins. The mitochondrial morphology suggests that the retinal protective effect of SAA is mediated via antiferroptotic action.

CONCLUSION

Ferroptosis plays an important role in the pathogenesis of iron-overload-induced retinal degeneration. New roles of SAA in ferroptosis prevention via iron deposit inhibition, lipid peroxidation inhibition, and mitochondrial dysfunction reduction, were identified.

Reduction of iron toxicity in the heart of iron-overloaded mice with natural compounds

BACKGROUND

Iron-overload is one of the risk factors in susceptible individuals. Iron-overload causes complications such as diastolic dysfunction, arrhythmias, ventricular dilation, and systolic dysfunction in the heart. Therefore, particular care is needed for those who need blood transfusions or patients with underlying heart diseases.

PURPOSE

In this study, we examined the ability of six compounds, hesperidin, coumarin, caffeic acid, ferulic acid, and vanillin, to reduce the effects of iron-overdose in the heart of iron-overloaded mice.

METHODS

For this purpose, 84 mice were prepared and except for the control group, iron-overload conditions were created in them by injecting iron. The hearts of mice were then harvested and the activities of the antioxidant enzymes catalase and superoxide dismutase were evaluated. Additionally, the amount of lipid peroxidation was measured by assessing the quantity of malondialdehyde. The physiopathology of cardiac tissue was considered by Perl's and H&E staining.

RESULTS

According to the results, almost all natural compounds showed better performance than desferal, as an iron chelator chemical. Meanwhile, hesperidin, vanillin, and ferulic acid were the best antioxidant compounds and were able to improve the activity of antioxidant enzymes by reducing the amount of deposited iron.

CONCLUSION

We recommend the use of the above compounds as natural iron chelators after completing additional studies.

Berberine Is a Promising Alkaloid to Attenuate Iron Toxicity Efficiently in Iron-Overloaded Mice

Iron toxicity in iron-overloaded conditions, including high iron diet and blood transfusion, causes deleterious effects on vital organs. There currently are a number of chemical chelators in clinics to reduce iron concentration, for example , deferoxamine and deferiprone, but these produce diverse side effects. Hence, the need for a safe and effective iron chelator is demanded. To evaluate rigorously the potential of berberine on iron chelation and its anti-oxidant effect, 30 mice were divided into 5 groups of 6. Except for the control group, other groups received iron sucrose 5 times a week for 4 successive weeks as an i.p injection. Afterward, either berberine or deferoxamine was injected for 1 month. The mice were then euthanized and liver, kidney and lungs were carefully removed for biochemical and pathological analysis. In comparison with the iron group with an extraordinary amount of iron deposits, berberine (20 mg/kg/day) dramatically reduced iron sedimentation in all tissues ( P < 0.01). Moreover, berberine lowered clinical symptoms of iron overdose, including inflammation, fibrosis and tissue degeneration. In terms of the activity of antioxidant enzymes, catalase and superoxide dismutase, iron overdose greatly reduced their activity compared to the control group. Berberine progressively increased their activity in comparison with the controls by lowering oxidative conditions ( P < 0.05). Iron overdose similarly increased lipid peroxidation by increasing the level of malondialdehyde. Berberine promptly suppressed lipid peroxidation in an efficient manner and reduced the level of malondialdehyde, a marker of lipid peroxidation in the tissues. Accordingly, berberine, as a natural antioxidant compound, could adequately serve as a substitute for chemical chelators with fewer side effects and comparable effectiveness.

Lipidomics reveals perturbations in the liver lipid profile of iron-overloaded mice

Iron overload is an important contributor to disease. The liver, the major site of iron storage in the body, is a key organ impacted by iron overload. While several studies have reported perturbations in liver lipids in iron overload, it is not clear, on a global scale, how individual liver lipid ions are altered. Here, we used lipidomics to study the changes in hepatic lipid ions in iron-overloaded mice. Iron overload was induced by daily intraperitoneal injections of 100 mg/kg body weight iron dextran for 1 week. Iron overload was verified by serum markers of iron status, liver iron quantitation, and Perls stain. Compared with the control group, the serum of iron-overload mice exhibited low levels of urea nitrogen and high-density lipoprotein (HDL), and high concentrations of total bile acid, low-density lipoprotein (LDL), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH), suggestive of liver injury. Moreover, iron overload disrupted liver morphology, induced reactive oxygen species (ROS) production, reduced superoxide dismutase (SOD) activity, caused lipid peroxidation, and led to DNA fragmentation. Iron overload altered the overall composition of lipid ions in the liver, with significant changes in over 100 unique lipid ions. Notably, iron overload selectively increased the overall abundance of glycerolipids and changed the composition of glycerophospholipids and sphingolipids. This study, one of the first to report iron-overload induced lipid alterations on a global lipidomics scale, provides early insight into lipid ions that may be involved in iron overload-induced pathology.

Ameliorative effects and mechanisms of salvianic acid A on retinal iron overload in vivo and in vitro

Excessive iron can be accumulated in the retina and lead to retinal iron overload. Salvianic acid A (SAA) has a variety of pharmacologic effects, but there is only a limited understanding of its benefits for retinal iron overload. The aim of this study was to examine the protective effects and latent mechanisms of SAA on retinal iron overload. SAA reduced iron in the serum and retina, attenuated pathophysiological changes, and reduced retinal iron deposition in the retinas of iron-overloaded mice. It also reduced intracellular iron in ARPE-19 cells by regulating iron-handling proteins and chelating with iron. It also significantly inhibited cellular oxidative and inflammatory damage by increasing the nuclear translocation of nuclear erythroid 2-related factor 2 (Nrf2) while decreasing nuclear factor-kappa B (NF-κB), protecting the ARPE-19 cells from apoptosis by suppressing the Bax/Bcl-2 ratio, cytochrome c release, caspase activation, and poly ADP-ribose polymerase cleavage. The ability of SAA to inhibit apoptosis, increase nuclear Nrf2 expression, and decrease nuclear NF-κB expression was further confirmed in the retinas of iron-overloaded mice. This study demonstrates that SAA shows significant protective effects against retinal iron overload; its mechanisms might be associated with iron chelation; regulation of iron-handling proteins; and inhibition of oxidative stress, inflammation and apoptosis.

Salvia miltiorrhiza (SM) Injection Ameliorates Iron Overload-Associated Cardiac Dysfunction by Regulating the Expression of DMT1, TfR1, and FP1 in Rats

Previous studies have found that Salvia miltiorrhiza (SM) injection have a protective effect on the iron overloaded (IO) heart. However, the mechanisms are not completely known. In the present study, we investigated the underlying mechanisms based on the iron transport-related proteins. The rats were randomly divided into five groups: control, IO group, low-dose SM group, high-dose SM group, and deferoxamine control group. Iron dextran was injected to establish the IO model. After 14 days of treatment, cardiac histological changes were observed by hematoxylin and eosin (H&E) staining. Iron uptake-related proteins divalent metal transporter-1 (DMT-1), transferrin receptor-1 (TfR-1), and iron export-related proteins ferroportin1 (FP1) in the heart were detected by Western blotting. The results showed that SM injection decreased cardiac iron deposition, ameliorated cardiac function, and inhibited cardiac oxidation. Most important of all, SM injection downregulated the expression of DMT-1 and TfR-1 and upregulated FP1 protein levels compared with the IO group. Our results indicated that reducing cardiac iron uptake and increasing iron excretion may be one of the important mechanisms of SM injection reducing cardiac iron deposition and improving cardiac function under the conditions of IO.

The protective mechanism of resveratrol against hepatic injury induced by iron overload in mice

Excessive iron deposition can produce toxicity. Liver, as the main storage site of iron, is more vulnerable to excessive iron than other organs. Many studies have found that Resveratrol (RES) can effectively eliminate oxygen free radicals and resist lipid peroxide damage. However, studies investigating the mechanism of how RES prevents liver injury induced by iron overload are few. This study aims to observe the protective effect of RES on liver injury induced by iron overload in mice. Mice, except for the control group, received an intraperitoneal injection of iron dextran (50 mg/kg) every morning. The L-RES and H-RES groups received intragastric administration of low- and high-concentration RES solutions (20 or 50 mg/kg). The deferoxamine (DFO) group was intraperitoneally injected with DFO (50 mg/kg), while the control and iron overload groups were intraperitoneally injected with the same amount of normal saline every afternoon. Two weeks after continuous administration, iron-overloaded mice treated with high and low doses of RES significantly improved liver injury (GOT and GPT) and decreased LDH activity and MDA content and increased SOD and GSH activities (P < 0.01). Morphological tests showed that RES treatment can reduce liver iron deposition and improve liver pathological changes in iron-overloaded mice. Furthermore, RES treatment caused a significant decrease in Ft expression (P < 0.01). In conclusion, RES can alleviate liver injury in iron-overloaded mice. The mechanism may be related to improve the antioxidant capacity and reduce excess iron in the liver.

Puerarin protects against iron overload-induced retinal injury through regulation of iron-handling proteins

Excess iron content can build up in the retina and lead to iron-mediated retinal injury. An important isoflavone C-glucoside, puerarin, has been reported to be involved in retinal protection. In this experiment, we studied the effects and potential mechanisms of puerarin on retinal injury in vivo and in vitro. We found that puerarin reduced serum and retinal iron content, attenuated the pathophysiological changes and retinal iron deposition, and partially prevented the decrease of rhodopsin and retinal pigment epithelium-specific 65 kDa protein expression in retinas of iron-overload mice. Puerarin rescued the abnormal expression of iron-handling proteins in the mouse retina and suppressed the oxidative stress induced by iron overload, as evident from the enhanced activity of superoxide dismutase, catalase, and glutathione peroxidase and decreased content of malondialdehyde. Moreover, puerarin inhibited the phosphorylation of p38 and ERK mitogen-activated protein kinases (MAPKs) and signal transducer and activator of transcription 3 (STAT3), thereby protecting the retinal cells from apoptosis by suppressing cytochrome c release, caspase activation, and poly (ADP-ribose) polymerase cleavage in vivo. Also, the ability of puerarin to regulate iron-handling proteins, decrease intracellular Fe²⁺, and inhibit cell apoptosis was further confirmed in ARPE-19 cells. The experimental data verify the protective role of puerarin in the treatment of retinal injury caused by iron overload; its possible mechanisms might be associated with regulation of iron-handling proteins, enhancement of the antioxidant capacity, and the inhibition of MAPK and STAT3 activation and the apoptotic pathways under iron overload conditions.

The mycma_1113 Gene from Mycobacterium abscessus subsp. massiliense is Related to Siderophore Synthesis

Iron (Fe) homeostasis control is important for both pathogen and the host. During infection, the host reduces the access of microorganisms to iron, however, studies have shown that virulent pathogens are capable to sequester Fe from host proteins, and establish the infection. M. abscessus subsp. massiliense (Mycma), that is resistant to most drugs used against tuberculosis, was responsible for outbreaks around the world showing increased virulence when compared to other rapidly growing mycobacteria. The goal of this study was to determine whether Mycma produce siderophores and if the mycma_1113 gene expression, a putative homolog of M. tuberculosis mbtB gene located in the mbt gene cluster, is related to the synthesis of these molecules. For that, the effect of different iron concentrations on the growth of Mycma, the expression of mycma_1113 gene, and the production of siderophores was evaluated in vitro and in vivo. It is shown that Mycma produce siderophores under iron deprivation conditions and mycma_1113 gene expression was influenced by iron availability. The mycma_1113 gene expression was also increased after macrophage or in vivo infection indicating that mycobactin synthesis by Mycma could participate in the Fe sequestration from the host during infection. In conclusion, we show that Mycma produces siderophores under iron deprivation conditions and that the mycma_1113 gene is involved in this process, furthermore, this gene expression is induced during infection.

Green synthesis of safe zero valent iron nanoparticles by Myrtus communis leaf extract as an effective agent for reducing excessive iron in iron-overloaded mice, a thalassemia model

Green synthesis of Myrtus communis-Zero Valent Iron Nanoparticles (MC-ZVINs) was carried out in an alkaline environment.

A composite mouse model of aplastic anemia complicated with iron overload

Iron overload is commonly encountered during the course of aplastic anemia (AA), but no composite animal model has been developed yet, which hinders drug research. In the present study, the optimal dosage and duration of intraperitoneal iron dextran injection for the development of an iron overload model in mice were explored. A composite model of AA was successfully established on the principle of immune-mediated bone marrow failure. Liver volume, peripheral hemogram, bone marrow pathology, serum iron, serum ferritin, pathological iron deposition in multiple organs (liver, bone marrow, spleen), liver hepcidin, and bone morphogenetic protein 6 (BMP6), SMAD family member 4 (SMAD4) and transferrin receptor 2 (TfR2) mRNA expression levels were compared among the normal control, AA, iron overload and composite model groups to validate the composite model, and explore the pathogenesis and features of iron overload in this model. The results indicated marked increases in iron deposits, with significantly increased liver/body weight ratios as well as serum iron and ferritin in the iron overload and composite model groups as compared with the normal control and AA groups (P<0.05). There were marked abnormalities in iron regulation gene expression between the AA and composite model groups, as seen by the significant decrease of hepcidin expression in the liver (P<0.01) that paralleled the changes in BMP6, SMAD4, and TfR2. In summary, a composite mouse model with iron overload and AA was successfully established, and AA was indicated to possibly have a critical role in abnormal iron metabolism, which promoted the development of iron deposits.

Iron mediated toxicity and programmed cell death: A review and a re-examination of existing paradigms

Iron is an essential micronutrient that is problematic for biological systems since it is toxic as it generates free radicals by interconverting between ferrous (Fe²⁺) and ferric (Fe³⁺) forms. Additionally, even though iron is abundant, it is largely insoluble so cells must treat biologically available iron as a valuable commodity. Thus elaborate mechanisms have evolved to absorb, re-cycle and store iron while minimizing toxicity. Focusing on rarely encountered situations, most of the existing literature suggests that iron toxicity is common. A more nuanced examination clearly demonstrates that existing regulatory processes are more than adequate to limit the toxicity of iron even in response to iron overload. Only under pathological or artificially harsh situations of exposure to excess iron does it become problematic. Here we review iron metabolism and its toxicity as well as the literature demonstrating that intracellular iron is not toxic but a stress responsive programmed cell death-inducing second messenger.

Anti-fibro-hepatocarcinogenic Chinese herbal medicines: A mechanistic overview

Chinese herbal medicine (CHM) is an integral component of complementary/alternative medicine and it is increasingly becoming the preferred therapeutic modality for the treatment of liver fibrosis and hepatocellular carcinoma (HCC) worldwide. Accordingly, the World Health Organization (WHO) has attested to the popularity and efficacy of indigenous herbal therapies including CHM as a first line of treatment for some diseases including liver disorders. However, the WHO and drug discovery experts have always recommended that use of indigenous herbal remedies must go hand-in-hand with the requisite mechanistic elucidation so as to constitute a system of verification of efficacy within the ethnobotanical context of use. Although many CHM experts have advanced knowledge on CHM, nonetheless, more enlightenment is needed, particularly mechanisms of action of CHMs on fibro-hepato-carcinogenesis. We, herein, provide in-depth mechanisms of the action of CHMs which have demonstrated anti-fibro-hepatocarcinogenic effects, in pre-clinical and clinical studies as published in PubMed and other major scientific databases. Specifically, the review brings out the important signaling pathways, and their downstream targets which are modulated at multi-level by various anti-fibro-hepatocarcinogenic CHMs.

The Acute Effect of Humic Acid on Iron Accumulation in Rats

Free iron leads to the formation of pro-oxidant reactive oxygen species (ROS). Humic acids (HAs) enhance permeability of cellular wall and act as a chelator through electron transferring. This study was designed to test chelator effect of HA on iron as well as its anti-oxidant effect against the iron-induced hepatotoxicity and cardiotoxicity. The rats used were randomly divided into four groups (n = 8/group): group I (the control group); group II (the HA group), humic acid (562 mg/kg) was given over 10 days by oral gavage; group III (the iron group), iron III hydroxide polymaltose (250 mg/kg) was given over 10 days by intraperitoneal route; and group IV (the HA plus iron group), received the iron (similar to group II) plus humic acid (similar to those in groups II and III) group. Blood and two tissue samples both from liver and heart were obtained for biochemical and histopathological evaluations. Iron deposition, the iron-induced hepatotoxicity, and cardiotoxicity were demonstrated by histopathological and biochemical manner. However, no significant differences were observed in the serum biochemical values and the histopathological results among the iron and the HA plus iron groups in the liver tissue but not in the heart tissue. The protective effects of humic acid against iron-induced cardiotoxicity were shown but not against hepatotoxicity in our study.

Calcium channel blockers ameliorate iron overload-associated hepatic fibrosis by altering iron transport and stellate cell apoptosis

Liver fibrosis is the principal cause of morbidity and mortality in patients with iron overload. Calcium channel blockers (CCBs) can antagonize divalent cation entry into renal and myocardial cells and inhibit fibrogenic gene expression. We investigated the potential of CCBs to resolve iron overload-associated hepatic fibrosis. Kunming mice were assigned to nine groups (n=8 per group): control, iron overload, deferoxamine, high and low dose verapamil, high and low dose nimodipine, and high and low dose diltiazem. Iron deposition and hepatic fibrosis were measured in mouse livers. Expression levels of molecules associated with transmembrane iron transport were determined by molecular biology approaches. In vitro HSC-T6 cells were randomized into nine groups (the same groups as the mice). Changes in proliferation, apoptosis, and metalloproteinase expression in cells were detected to assess the anti-fibrotic effects of CCBs during iron overload conditions. We found that CCBs reduced hepatic iron content, intracellular iron deposition, the number of hepatic fibrotic areas, collagen expression levels, and hydroxyproline content. CCBs rescued abnormal expression of α1C protein in L-type voltage-dependent calcium channel (LVDCC) and down-regulated divalent metal transporter-1 (DMT-1) expression in mouse livers. In iron-overloaded HSC-T6 cells, CCBs reduced iron deposition, inhibited proliferation, induced apoptosis, and elevated expression of matrix metalloproteinase-13 (MMP-13) and tissue inhibitor of metalloproteinase-1 (TIMP-1). CCBs are potential therapeutic agents that can be used to address hepatic fibrosis during iron overload. They resolve hepatic fibrosis probably correlated with regulating transmembrane iron transport and inhibiting HSC growth.

Effects of iron overload condition on liver toxicity and hepcidin/ferroportin expression in thalassemic mice

AIMS

Although iron-overload conditions can be found in β-thalassemic patients, resulting in cellular damage, particularly in the liver, the mechanism for this iron-mediated hepatic injury specifically in β-thalassemic (HT) mice is unclear. This study aimed to investigate the roles of L-type calcium channels (LTCC), T-type calcium channels (TTCC) and divalent metal transporter1 (DMT1) in iron-mediated hepatic injury in HT mice.

MAIN METHODS

Iron chelator deferoxamine (DFO), LTCC blocker, TTCC blocker and DMT1 blocker were used to determine the roles of these channels regarding liver iron accumulation, apoptosis and iron regulatory protein expression in HT mice.

KEY FINDINGS

TTCC and DMT1 blockers and DFO decreased liver iron and malondialdehyde (MDA) in HT mice indicating their antioxidant effects, whereas LTCC blocker produced no decrease in liver iron or MDA. However, only DFO decreased liver apoptosis through the reduced Bax/Bcl-2 ratio in wild type (WT) mice. The levels of iron regulatory hormone hepcidin were markedly higher in HT mice even before iron loading while ferroportin levels did not alter. Each of the pharmacological interventions increased ferroportin protein back to normal levels only in WT while HT mice showed no difference.

SIGNIFICANCE

Thalassemic mice have different hepcidin/ferroportin and apoptotic protein expression as a defense mechanism to iron-overload compared with those in WT mice. DFO was the most effective intervention in preventing liver apoptosis under iron-overload conditions in WT but did not have the same effect in HT mice.

Acute iron overload leads to hypothalamic-pituitary-gonadal axis abnormalities in female rats

Iron plays a critical role in a mammal's physiological processes. However, iron tissue deposits have been shown to act as endocrine disrupters. Studies that evaluate the effect of acute iron overload on hypothalamic-pituitary-gonadal (HPG) axis health are particularly sparse. This study demonstrates that acute iron overload leads to HPG axis abnormalities, including iron accumulation and impairment in reproductive tract morphology. Female rats were treated with iron-dextran (Fe rats) to assess their HPG morphophysiology. The increasing serum iron levels due to iron-dextran treatment were positively correlated with higher iron accumulation in the HPG axis and uterus of Fe rats than in control rats. An increase in the production of superoxide anions was observed in the pituitary, uterus and ovary of Fe rats. Morphophysiological reproductive tract abnormalities, such as abnormal ovarian follicular development and the reduction of serum estrogen levels, were observed in Fe rats. In addition, a significant negative correlation was obtained between ovary superoxide anion and serum estrogen levels. Together, these data provide in vivo evidence that acute iron overload is toxic for the HPG axis, a finding that may be associated with the subsequent development of the risk of reproductive dysfunction.

Tanshinone I selectively suppresses pro-inflammatory genes expression in activated microglia and prevents nigrostriatal dopaminergic neurodegeneration in a mouse model of Parkinson's disease

ETHNOPHARMACOLOGICAL RELEVANCE

Radix Salviae Miltiorrhizae, known as Danshen, is a well-known traditional Chinese herb which has been used extensively for the treatment of various diseases, including cardiovascular and cerebrovascular disease and neurodegenerative diseases for thousands of years. Tanshinone I is one of major bioactive flavonoids of Radix Salviae Miltiorrhizae. Modulation of microglial over-reaction may represent a therapeutic target to alleviate the progression of neurodegenerative diseases. Here, we tested the effect of Tanshinone I on neuro-inflammation and whether it can provide neuroprotection through inhibition of neuro-inflammation.

MATERIALS AND METHODS

The effects of Tanshinone I on the production and/or mRNA expression of pro-inflammatory and anti-inflammatory factors in lipopolysaccharide(LPS)-induced BV-2 microglia cells were tested by Griess reaction, enzyme-linked immunosorbent assay (Elisa) or real time polymerase chain reaction. Activation of nuclear factor κ B (NF-κB) was measured by the nuclear translocation p65 and DNA binding activity. A model of Parkinson׳s disease was established by treatment of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in C57BL/6 mice. The effect of Tanshinone I on the behavioral changes, dopamine and its metabolites levels, expression of tyrosine hydroxylase (TH) and IBA-1, production of cytokines in the midbrain were investigated by the rotarod test, high-performance liquid chromatography (HPLC)-ECD, immunohistochemistry and Elisa. 1-methyl-4-phenylpyridinium (MPP+) concentration was tested by HPLC. Liver toxicity was determined by biochemical assay and histochemistry.

RESULTS

We found that the productions and/or expressions of several pro-inflammatory M1 factors such as nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 were highly suppressed by Tanshinone I in LPS-induced microglia. Interestingly, it did not affect the enhancement of expression of some anti-inflammatory M2 microglia markers, including IL-10, IL-1 receptor antagonist (IL-1Ra) and Cox-2. But it could significantly inhibit LPS-induced granulocyte colony-stimulating factor (G-CSF) expression. Tanshinone I could also inhibit LPS-induced NF-κB activation in microglia. Furthermore, it improved motor functions, normalized striatal neurotransmitters, and provided dopaminergic neuronal protection in MPTP-intoxicated mice. In vivo results also indicated that Tanshinone I could modulate MPTP-induced microglial activation, attenuated the increase of TNF-α, reserved the increase of IL-10 concentrain of MPTP-intoxicated mice. Tanshinone I does not alter MPTP toxic metabolite (MPP+) concentration. Oral administration of Tanshinone I at 10mg/kg daily for 2 weeks did not show liver toxicity.

CONCLUSIONS

Tanshinone I selectively suppressed pro-inflammatory M1 genes expression in activated microglia, interestingly, partially reserved anti-inflammatory M2 genes expression. It also could provide neuroprotection in a mouse model of Parkinson׳s disease. These data indicated that Tanshinone I could make the most of the beneficial side and minimize the detrimental side of activated microglia simultaneously, and provide neuroprotection by modulating the immune response of microglia.

Continuing treatment with Salvia miltiorrhiza injection attenuates myocardial fibrosis in chronic iron-overloaded mice

Iron overload cardiomyopathy results from iron accumulation in the myocardium that is closely linked to iron-mediated myocardial fibrosis. Salvia miltiorrhiza (SM, also known as Danshen), a traditional Chinese medicinal herb, has been widely used for hundreds of years to treat cardiovascular diseases. Here, we investigated the effect and potential mechanism of SM on myocardial fibrosis induced by chronic iron overload (CIO) in mice. Kunming male mice (8 weeks old) were randomized to six groups of 10 animals each: control (CONT), CIO, low-dose SM (L-SM), high-dose SM (H-SM), verapamil (VRP) and deferoxamine (DFO) groups. Normal saline was injected in the CONT group. Mice in the other five groups were treated with iron dextran at 50 mg/kg per day intraperitoneally for 7 weeks, and those in the latter four groups also received corresponding daily treatments, including 3 g/kg or 6 g/kg of SM, 100 mg/kg of VRP, or 100 mg/kg of DFO. The iron deposition was estimated histologically using Prussian blue staining. Myocardial fibrosis was determined by Masson's trichrome staining and hydroxyproline (Hyp) quantitative assay. Superoxide dismutase (SOD) activity, malondialdehyde (MDA) content and protein expression levels of type I collagen (COL I), type I collagen (COL III), transforming growth factor-β1 (TGF-β1) and matrix metalloproteinase-9 (MMP-9) were analyzed to investigate the mechanisms underlying the effects of SM against iron-overloaded fibrosis. Treatment of chronic iron-overloaded mice with SM dose-dependently reduced iron deposition levels, fibrotic area percentage, Hyp content, expression levels of COL I and COL III, as well as upregulated the expression of TGF- β1 and MMP-9 proteins in the heart. Moreover, SM treatment decreased MDA content and increased SOD activity. In conclusion, SM exerted activities against cardiac fibrosis induced by CIO, which may be attributed to its inhibition of iron deposition, as well as collagen metabolism and oxidative stress.

Iron chelation and liver disease healing activity of edible mushroom (Cantharellus cibarius), in vitro and in vivo assays

Methanolic and ethyl acetate extracts ofCantharellus cibariusshow significant iron chelation activities bothin vitroandin vivo. The methanolic extract is more efficient in chelation of excessive iron from plasma and liver.

Salvia miltiorrhiza (Danshen) inhibits L-type calcium current and attenuates calcium transient and contractility in rat ventricular myocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza (SM, Danshen), a traditional Chinese herbal drug, has been widely used for hundreds of years to treat coronary artery disease.

MATERIALS AND METHODS

We studied the effects of SM on the L-type Ca(2+) current (ICa-L) with whole-cell patch-clamp technique in rat ventricular myocytes, and its influence on Ca(2+) transient and contractility using video-based edge detection and dual excitation fluorescence photomultiplier systems as well.

RESULTS

Exposure to SM solution caused a concentration- and voltage-dependent blockade of ICa-L, and the dose of SM solution (10g/l) decreased the maximal inhibitory effect of 35.2±1.2%. However, SM solution did not significantly change the current-voltage relationship or reversal potential of ICa-L, nor did it altered the activation and inactivation gating properties of cardiac Ca(2+) channels. Meanwhile, SM decreased the amplitude of myocyte shortening and the peak value of Ca(2+) transient with a significant decrease in the time to 90% of the baseline (Tr), but the time to 10% of the peak (Tp) was not dramatically prolonged.

CONCLUSIONS

The results indicated that SM significantly inhibited L-type Ca(2+) channels, decreased [Ca(2+)]i and contractility in adult rat cardiac myocytes. These findings may be relevant to the cardioprotective efficacy of SM.

Liver fibrosis and protection mechanisms action of medicinal plants targeting apoptosis of hepatocytes and hepatic stellate cells

Following chronic liver injury, hepatocytes undergo apoptosis leading to activation of hepatic stellate cells (HSC). Consequently, activated HSC proliferate and produce excessive extracellular matrix, responsible for the scar formation. The pandemic trend of obesity, combined with the high incidence of alcohol intake and viral hepatitis infections, highlights the urgent need to find accessible antifibrotic therapies. Treatment strategies should take into account the versatility of its pathogenesis and act on all the cell lines involved to reduce liver fibrosis. Medicinal plants are achieving popularity as antifibrotic agents, supported by their safety, cost-effectiveness, and versatility. This review will describe the role of hepatocytes and HSC in the pathogenesis of liver fibrosis and detail the mechanisms of modulation of apoptosis of both cell lines by twelve known hepatoprotective plants in order to reduce liver fibrosis.

Salvia miltiorrhiza injection ameliorates renal damage induced by lead exposure in mice

Exposure to lead (Pb) can induce kidney injury and our recent studies have found that Salvia miltiorrhiza (SM) injection, a traditional Chinese medicine, could protect against the organ injury induced by iron overload. This study was designed to investigate the protective effects of SM injection on nephrotoxicity induced by Pb acetate in mice and to elucidate the potential mechanism(s). Healthy male mice were randomly divided into four groups: control, Pb, low-dose Salvia miltiorrhiza (L-SM), and high-dose Salvia miltiorrhiza (H-SM). SM injection dose dependently reduced the Pb accumulation in the kidney, decreased kidney coefficients, and ameliorated renal structure and function from the morphology analysis. Meanwhile, SM administration downregulated serum levels of blood urea nitrogen (BUN) and creatinine (CR), decreased malondialdehyde (MAD) content, and increased activities of super oxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the kidney homogenate. Moreover, SM injection reduced the level of renal apoptosis by immunohistochemical staining analysis. Our findings implicate the therapeutic potential of SM injection for Pb-induced nephrotoxicity, which were at least partly due to the decrease of Pb accumulation, inhibition of lipid peroxidation, and suppression of renal apoptosis. These results provided preliminary experimental support for Danshen as a therapeutic drug for Pb poisoning diseases.

Combined therapy of iron chelator and antioxidant completely restores brain dysfunction induced by iron toxicity

Background

Excessive iron accumulation leads to iron toxicity in the brain; however the underlying mechanism is unclear. We investigated the effects of iron overload induced by high iron-diet consumption on brain mitochondrial function, brain synaptic plasticity and learning and memory. Iron chelator (deferiprone) and antioxidant (n-acetyl cysteine) effects on iron-overload brains were also studied.

Methodology

Male Wistar rats were fed either normal diet or high iron-diet consumption for 12 weeks, after which rats in each diet group were treated with vehicle or deferiprone (50 mg/kg) or n-acetyl cysteine (100 mg/kg) or both for another 4 weeks. High iron-diet consumption caused brain iron accumulation, brain mitochondrial dysfunction, impaired brain synaptic plasticity and cognition, blood-brain-barrier breakdown, and brain apoptosis. Although both iron chelator and antioxidant attenuated these deleterious effects, combined therapy provided more robust results.

Conclusion

In conclusion, this is the first study demonstrating that combined iron chelator and anti-oxidant therapy completely restored brain function impaired by iron overload.

Danshen (Salvia miltiorrhiza) injection suppresses kidney injury induced by iron overload in mice

Objectives

Excessive iron can accumulate in the kidney and induce tissue damage. Danshen (Salvia miltiorrhiza) injection is a traditional Chinese medicinal preparation used for preventing and treating chronic renal failure. The aim of the present study was to evaluate the effects of treatment with Danshen injection on iron overload-induced kidney damage.

Methods

Mice were mock-treated with saline (control group) or given a single dose of iron dextran without treatment (iron overload group, 50 mg/kg/day for 2 weeks) or with daily treatments of low-dose Danshen (3 g/kg/day), high-dose Danshen (6 g/kg/day) or deferoxamine (100 mg/kg/day).

Results

Treatment of iron-overloaded mice with Danshen injection led to significant improvements of body weight and decreased iron levels in the kidney. Danshen injection treatment also reduced concentrations of blood urea nitrogen, creatinine and malondialdehyde and enhanced glutathione peroxidase and superoxide dismutase activities. Histopathological examinations showed that Danshen injection ameliorated pathological changes and reduced iron deposition in kidneys of iron overloaded mice. Furthermore, the treatment was demonstrated to suppress apoptosis in nephrocytes.

Conclusions

These results indicated that Danshen injection exerted significant renal protective effects in iron-overloaded mice, which were closely associated with the decrease of iron deposition and suppression of lipid peroxidation and apoptosis in the kidney.

Multitargeted inhibition of hepatic fibrosis in chronic iron-overloaded mice by Salvia miltiorrhiza

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza (SM, also known as Danshen) is a well-known Chinese medicinal herb, which has shown hepatoprotective effects with anti-fibrotic, anti-oxidative, anti-inflammatory and anti-apoptotic properties. To explore the effects and potential mechanism of SM against hepatic fibrosis induced by chronic iron overload in mice.

MATERIALS AND METHODS

Sixty male mice were randomized into five groups (n=12 in each group): control (saline), iron overload, iron overload with low-dose SM (3g/kg/day), iron overload with high-dose SM (6g/kg/day) and iron overload with deferoxamine (100mg/kg/day) groups. The iron overload model was established by intraperitoneal injection with iron dextran at 50mg/kg body weight/day, and the entire course lasted for 7 weeks. The major constituents of SM injection were quantified by high performance liquid chromatography. Changes of hepatic iron, hydroxyproline (Hyp), glutathione (GSH), superoxide dismutase (SOD) and malondialdehyde (MDA) were assayed by standard procedures. Protein expression levels of type I collagen, type III collagen, tumor necrosis factor-α (TNF-α) and interleukin-1α (IL-1α) were analyzed by immunohistochemistry, and mRNA levels of transforming growth factor-β (TGF-β), matrix metal proteinase-9 (MMP-9) and caspase-3 were detected by RT-PCR. Morphological changes were observed with Prussian blue, Masson's trichrome and hematoxylin-eosin staining.

RESULTS

Treatment of chronic iron-overloaded mice with SM dose-dependently ameliorated changes in hepatic morphology and coefficient, reduced iron deposition and Hyp content, suppressed overexpression of type I collagen and type III collagen, downregulated expression of TGF-β mRNA, and upregulated expression of MMP-9 mRNA in the liver. Moreover, SM treatment contributed to decreased MDA content, increased SOD activity and GSH content, while it reduced expression of TNF-α, IL-1α and caspase-3.

CONCLUSIONS

SM displayed anti-fibrotic activity in the liver induced by chronic iron overload, which may be attributed to multitargeted inhibition of iron deposition and collagen accumulation, as well as oxidative stress, inflammation and apoptosis.