Intraperitoneal administration of apigenin in liver ischemia/reperfusion injury protective effects

Hepatoprotective effects of natural drugs: Current trends, scope, relevance and future perspectives

BACKGROUND

The liver is a well-known player in the metabolism and removal of drugs. Drug metabolizing enzymes in the liver detoxify drugs and xenobiotics, ultimately leading to the acquisition of homeostasis. However, liver toxicity and cell damage are not only related to the nature and dosage of a particular drug but are also influenced by other factors such as aging, immune status, environmental contaminants, microbial metabolites, gender, obesity, and expression of individual genes Furthermore, factors such as drugs, alcohol, and environmental contaminants could induce oxidative stress, thereby impairing the regenerative potential of the liver and causing several diseases. Persons suffering from other ailments and those with comorbidities are found to be more prone to drug-induced toxicities. Moreover, drug composition and drug-drug interactions could further aggravate the risk of drug-induced hepatotoxicity. A plethora of mechanisms are responsible for initiating liver cell damage and further aggravating liver cell injury, followed by impairment of homeostasis, ultimately leading to the generation of reactive oxygen species, immune-suppression, and oxidative stress.

OBJECTIVE

To summarize the potential of phytochemicals and natural bioactive compounds to treat hepatotoxicity and other liver diseases.

STUDY DESIGN

A deductive qualitative content analysis approach was employed to assess the overall outcomes of the research and review articles pertaining to hepatoprotection induced by natural drugs, along with analysis of the interventions.

METHODS

An extensive literature search of bibliographic databases, including Web of Science, PUBMED, SCOPUS, GOOGLE SCHOLAR, etc., was carried out to understand the role of hepatoprotective effects of natural drugs.

RESULTS

Bioactive natural products, including curcumin, resveratrol, etc., have been seen as neutralizing agents against the side effects induced by the drugs. Moreover, these natural products are dietary and are readily available; thus, could be supplemented along with drugs to reduce toxicity to cells. Probiotics, prebiotics, and synbiotics have shown promise of improving overall liver functioning, and these should be evaluated more extensively for their hepatoprotective potential. Therefore, selecting an appropriate natural product or a bioactive compound that is free of toxicity and offers a reliable solution for drug-induced liver toxicity is quintessential.

CONCLUSIONS

The current review highlights the role of natural bioactive products in neutralizing drug-induced hepatotoxicity. Efforts have been made to delineate the possible underlying mechanism associated with the neutralization process.

Insights into the pharmacological and therapeutic effects of apigenin in liver injuries and diseases

Background

Liver diseases are a spectrum of diseases that include hepatic steatosis, nonalcoholic fatty liver disease, hepatitis, liver fibrosis, cirrhosis, and hepatic cancer. These diseases not only severely decrease the quality of life for patients, but also cause financial burden. Although apigenin (APG) has recently become the primary treatment for liver injuries and diseases (LIADs), there has been no systematic review of its use.

Purpose

To review the existing literature and put forward novel strategies for future APG research on LIADs.

Methods

A search was conducted in PubMed, Science Direct, Research Gate, Web of Science, VIP, Wanfang, and CNKI, and 809 articles were obtained. After applying inclusion and exclusion criteria, 135 articles were included.

Results

APG is promising in treating LIADs via various mechanisms arising from its anti-inflammation, anti-proliferation, anti-infection, anti-oxidation, and anti-cancer properties.

Conclusion

This review summarizes the evidence supporting the use of APG as a treatment for LIADs and provides an insight into the intestinal microbiota, which may have important implications in its future clinical use.

Apigenin protects from hepatorenal damage caused by lead acetate in rats

Exposure to lead (Pb) is associated with serious health problems including hepatorenal toxicity. Apigenin is a natural-sourced flavonoid with promising antioxidant and anti-inflammatory effects. In this research, we investigated the potential protective role of apigenin against lead acetate (PbAc)-induced hepatorenal damage. Thus, this experiment studied the exposure of male Wistar Albino rats to apigenin and/or PbAc and their effects in comparison to the control rats. Apigenin administration decreased the levels of Pb and prevented the histopathological deformations in liver and kidney tissues following PbAc exposure. This was confirmed by the normalized levels of liver and kidney function markers. Additionally, apigenin inhibited significantly oxidative reactions through upregulating Nrf2 and HO-1, and activating their downstreamed antioxidants accompanied by a marked depletion of pro-oxidants. Moreover, apigenin decreased the elevated pro-inflammatory cytokines and inhibited cell loss in liver and kidney tissues in response to PbAc intoxication in both tissues. The obtained results demonstrated that apigenin could be used to attenuate the molecular, biochemical, and histological alterations associated with Pb exposure due to its potent antioxidant, anti-inflammatory, and antiapoptotic effects.

Upregulation of Nrf2/HO-1 Signaling and Attenuation of Oxidative Stress, Inflammation, and Cell Death Mediate the Protective Effect of Apigenin against Cyclophosphamide Hepatotoxicity

Liver injury is among the adverse effects of the chemotherapeutic agent cyclophosphamide (CP). This study investigated the protective role of the flavone apigenin (API) against CP-induced liver damage, pointing to the involvement of Nrf2/HO-1 signaling. Rats were treated with API (20 and 40 mg/kg) for 15 days and received CP (150 mg/kg) on day 16. CP caused liver damage manifested by an elevation of transaminases, alkaline phosphatase (ALP), and lactate dehydrogenase (LDH), and histological alterations, including granular vacuolation, mononuclear cell infiltration, and hydropic changes. Hepatic reactive oxygen species (ROS), malondialdehyde (MDA), and nitric oxide (NO) were increased and glutathione (GSH) and antioxidant enzymes were decreased in CP-administered rats. CP upregulated the inflammatory markers NF-κB p65, TNF-α, IL-6, and iNOS, along with the pro-apoptotic Bax and caspase-3. Pre-treatment with API ameliorated circulating transaminases, ALP, and LDH, and prevented histopathological changes in CP-intoxicated rats. API suppressed ROS, MDA, NO, NF-κB p65, iNOS, inflammatory cytokines, oxidative DNA damage, Bax, and caspase-3 in CP-intoxicated rats. In addition, API enhanced hepatic antioxidants and Bcl-2 and boosted the Nrf2 and HO-1 mRNA abundance and protein. In conclusion, API is effective in preventing CP hepatotoxicity by attenuating oxidative stress, the inflammatory response, and apoptosis. The hepatoprotective efficacy of API was associated with the upregulation of Nrf2/HO-1 signaling.

Bioactives and functional food ingredients with promising potential for the management of cerebral and myocardial ischemia: a comprehensive mechanistic review

Ischemia is a deadly disease featured by restricted perfusion to different organs in the body. An increase in the accumulation of reactive oxygen species and cell debris is the driving force for inducing many oxidative, inflammatory and apoptotic signaling pathways. However, the number of therapeutics existing for ischemic stroke patients is limited and there is insufficient data on their efficiency, which warrants the search for novel therapeutic candidates from natural sources. Herein, a comprehensive survey was done on the reported functional food bioactives (ca. 152 compounds) to manage or protect against health consequences of myocardial and cerebral ischemia. Furthermore, we reviewed the reported mechanistic studies for their anti-ischemic potential. Subsequently, network pharmacology- and in silico-based studies were conducted using the reported myocardial and cerebral ischemia-relevant molecular targets to study their complex interactions and highlight key targets in disease pathogenesis. Subsequently, the most prominent 20 compounds in the literature were used in a comprehensive in silico-based analysis (inverse docking, ΔG calculation and molecular dynamics simulation) to determine other potential targets for these compounds and their probable interactions with different signaling pathways relevant to this disease. Many functional food bioactives, belonging to different chemical classes, i.e., flavonoids, saponins, phenolics, alkaloids, iridoids and carotenoids, were proven to exhibit multifactorial effects in targeting the complex pathophysiology of ischemic conditions. These merits make them valuable therapeutic agents that can outperform the conventional drugs, and hence they can be utilized as add-ons to the conventional therapy for the management of different ischemic conditions; however, their rigorous clinical assessment is necessary.

Apigenin alleviates methotrexate-induced liver and kidney injury in mice

Methotrexate (MTX) is a drug used in the treatment of various types of cancer and inflammatory diseases, but its clinical use has been restricted due to its toxicity. Apigenin (API) is an effective flavonoid with antioxidant and anti-inflammatory properties. The aim of this study was to determine the protective effect of API against MTX-induced liver and kidney toxicity. Four groups with 12 male mice each were used. The control and API groups were received 0.9% saline (ip) and API (3 mg/kg ip) for 4 days, respectively. The MTX group were given a single dose of MTX (20 mg/kg ip) on the fourth day. The MTX + API group were administered API for 7 days and then MTX on fourth day. Blood, liver and kidney were collected to evaluate tissue injury markers, oxidative stress biomarkers, and histopathological and immunohistochemical assessments. In MTX-treated group, significant increases in aminotransferases activities, creatinine and malondialdehyde (MDA) levels and significant decreases in catalase (CAT), glutathione peroxidase (GSH-Px) and superoxide dismutase1 (SOD1) activities and glutathione (GSH) levels were determined compared to the control group. Furthermore, histopathological changes and significant increases in caspase-3, C-reactive protein (CRP), granulocyte colony-stimulating factor (G-CSF), and inducible nitric oxide synthase (iNOS) expressions were detected in both liver and kidney tissues of MTX-treated mice. Pretreatment with API alleviates liver and kidney toxicity by attenuating oxidative stress and tissue injury markers, histopathological alterations, and apoptosis and inflammation. These results suggest that API has a protective effect against oxidative stress and liver-kidney toxicity induced by MTX.

Neuroprotective effects of Apium graveolens against focal cerebral ischemia occur partly via antioxidant, anti-inflammatory, and anti-apoptotic pathways

BACKGROUND

Stroke is a neurological disease caused by a sudden disturbance of cerebral blood flow to the brain, leading to loss of brain function. Recently, accumulating lines of evidence have suggested that dietary enrichment with nutritional antioxidants could reduce brain damage and improve cognitive function. In this study, we investigated the possible protective effects of Apium graveolens, a medicinal plant with putative neuroprotective activity, against oxidative-stress-related brain damage and brain damage due to inflammation induced by focal cerebral ischemia.

METHODS

Male adult Wistar rats were administered with an extract of A. graveolens orally 14 days before permanent occlusion of their right middle cerebral artery. The brain infarct volumes of rats in each group were determined by 2,3,5-triphenyltetrazolium chloride staining, and the density of neurons in the cortex and hippocampus of rats was determined by cresyl violet staining. The levels of malondialdehyde, catalase, glutathione peroxidase, and superoxide dismutase in the cerebral cortex and hippocampus of the rats were also quantified at the end of the study period.

RESULTS

Our results show that A. graveolens extract significantly decreased infarct volume and improved neuronal density in the cortex and hippocampus of rats receiving A. graveolens extract compared with those rats receiving no treatment. This neuroprotective effect was found to occur partly due to antioxidant, anti-inflammatory, and anti-apoptotic effects.

CONCLUSION

Our study demonstrates that A. graveolens helps to reduce the severity of cognitive damage caused by focal cerebral ischemia. © 2020 Society of Chemical Industry.

Use of natural anti-oxidants in experimental animal models of hepatic ischemia-reperfusion injury

Background

Ischemia-reperfusion injury (IRI) remains a clinical challenge in liver surgery, trauma and transplantation, contributing to morbidity and mortality worldwide. Thus, its impact, not only on the liver itself but also on remote tissues, has been studied during the last years. Different natural anti-oxidant substances have been researched in animal models, implementing different times of ischemia, aiming to test new therapeutic interventions.

Objective

A literature review has been conducted with two goals: (1) to identify different natural anti-oxidants studied in experimental models; and (2) to summarize the various times of ischemia employed.

Methods

Scientific papers published in PubMed for the period 2000–2020 were searched and reviewed.

Results

More than 30 natural anti-oxidants have been tested. The time of ischemia ranged from 15 to 90 min with 60 min used most frequently, followed by 45 min. No studies were found with time exceeding 90 min.

Conclusions

A significant number of research has been conducted on the use and protective effect of natural anti-oxidants in experimental animal models. Based on the published papers, 45–60 min seems to be the optimal duration of ischemia.

•

Liver IRI is a multifactorial and complex process, involving many mechanisms, cells and mediators. Even though, most of these mechanisms have not been completely understood, several substances have been tested in experimental models in order to determine their protective or destructive role.

•

Antioxidant therapy is a promising therapeutic pathway that can ameliorate the impact of liver ischemia-reperfusion injury.

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Non-pharmaceutical, natural extracts are increasingly gaining their place into the therapeutic options of physicians, in an attempt to avoid various adverse effects that the chemical drugs can cause.

•

New unexplored research areas may include different strains of rats, more studies in larger mammals of comparable anatomy to humans, experiments on different liver diseases, publishing negative results regarding toxic doses of natural antioxidants, and testing different ischemia times.

Apigenin Attenuates Acetaminophen-Induced Hepatotoxicity by Activating AMP-Activated Protein Kinase/Carnitine Palmitoyltransferase I Pathway

Overuse of acetaminophen (APAP) is a major cause of drug-induced liver failure at the clinics. Apigenin (API) is a natural flavonoid derived from Matricaria chamomilla. The aim of the present study was to investigate the amelioration function of API in APAP-induced hepatotoxicity both in vitro and in vivo and investigate its potential mechanisms. Analysis results of the activities of serum alanine and aspartate aminotransferases (ALT and AST), malondialdehyde, myeloperoxidase (MPO), and reactive oxygen species (ROS) demonstrated therapeutic effects of API. MTT assay results revealed that API attenuated APAP and its metabolic product, N-acetyl-p-benzoquinone imine (NAPQI) induced cytotoxicity in a dose-dependent manner in human liver cells, L-02 cells. Subsequently, metabolomic results of cells and serum analyses demonstrated an aberrant level of carnitine palmitoyltransferase I (CPT1A). We established that API stimulated CPT1A activity in mice liver tissues and L-02 cells. Molecular docking analyses revealed potential interaction of API with CPT1A. Further investigation of the role of CPT1A in L0-2 cells revealed that API reversed cytotoxicity via the AMP-activated protein kinase (AMPK)/GSK-3β signaling pathway and compound C, which is a selective AMPK inhibitor, inhibited activation of CPT1A induced by API. API was bound to the catalytic region of AMPK as indicated by molecular docking results. In addition, compound C suppressed nuclear translocation of nuclear factor erythroid 2–related factor 2 (NRF2) that is enhanced by API and inhibited the antioxidative function of API. In summary, the study demonstrates that API attenuates APAP-induced hepatotoxicity by activating the AMPK/GSK-3β signaling pathway, which subsequently promotes CPT1A activity and activates the NRF2 antioxidant pathway.

Nutraceutical Properties of Polyphenols against Liver Diseases

Current food tendencies, suboptimal dietary habits and a sedentary lifestyle are spreading metabolic disorders worldwide. Consequently, the prevalence of liver pathologies is increasing, as it is the main metabolic organ in the body. Chronic liver diseases, with non-alcoholic fatty liver disease (NAFLD) as the main cause, have an alarming prevalence of around 25% worldwide. Otherwise, the consumption of certain drugs leads to an acute liver failure (ALF), with drug-induced liver injury (DILI) as its main cause, or alcoholic liver disease (ALD). Although programs carried out by authorities are focused on improving dietary habits and lifestyle, the long-term compliance of the patient makes them difficult to follow. Thus, the supplementation with certain substances may represent a more easy-to-follow approach for patients. In this context, the consumption of polyphenol-rich food represents an attractive alternative as these compounds have been characterized to be effective in ameliorating liver pathologies. Despite of their structural diversity, certain similar characteristics allow to classify polyphenols in 5 groups: stilbenes, flavonoids, phenolic acids, lignans and curcuminoids. Herein, we have identified the most relevant compounds in each group and characterized their main sources. By this, authorities should encourage the consumption of polyphenol-rich products, as most of them are available in quotidian life, which might reduce the socioeconomical burden of liver diseases.

Silibinin-hydroxypropyl-β-cyclodextrin (SLB-HP-β-CD) complex prevents apoptosis in liver and kidney after hepatic ischemia-reperfusion injury

BACKGROUND

We investigated the protective effect of silibinin on rat liver and kidney after hepatic inschemia/reperfusion (I/R) injury.

METHODS AND MATERIALS

Sixty three male Wistar-type rats (median age 13 weeks; average weight 314 g) were subjected to I/R injury of the liver. They were randomly divided into three groups: Sham (n = 7), Control (C, n = 28) and Silibinin (Si, n = 28). The last group received intravenously silibinin. The C and Si groups were each subdivided in four subgroups according to euthanasia times (i.e., 60, 120, 180, 240 min). We assessed expression of caspase-3 and TUNEL assay, and biochemical and histological parameters.

RESULTS

At 240 min, expression of caspase-3 and TUNEL assay were statistically significantly lower in the Si compared to the C group for both liver and kidney. SGOT and SGPT were also statistically significantly lower in the Si than in the C group at all time points. Histological parameters of the liver were also improved in the Si group.

CONCLUSION

Silibinin was found to exhibit a protective effect on liver and kidney after hepatic I/R injury. The present results are encouraging for further studies and future clinical application.

Apigenin Prevents Acetaminophen-Induced Liver Injury by Activating the SIRT1 Pathway

Acetaminophen (APAP) overdose is the main cause of acute liver failure. Apigenin (API) is a natural dietary flavonol with high antioxidant capacity. Herein, we investigated protection by API against APAP-induced liver injury in mice, and explored the potential mechanism. Cell viability assays and mice were used to evaluate the effects of API against APAP-induced liver injury. Western blotting, immunofluorescence staining, RT-PCR, and Transmission Electron Microscope were carried out to determine the signalling pathways affected by API. Analysis of mouse serum levels of alanine/aspartate aminotransferase (ALT/AST), malondialdehyde (MDA), liver myeloperoxidase (MPO) activity, glutathione (GSH), and reactive oxygen species (ROS) revealed that API (80 mg/kg) owned protective effect on APAP-induced liver injury. Meanwhile, API ameliorated the decreased cell viability in L-02 cells incubated by APAP with a dose dependent. Furthermore, API promoted SIRT1 expression and deacetylated p53. Western blotting showed that API promoted APAP-induced autophagy, activated the NRF2 pathway, and inhibited the transcriptional activation of nuclear p65 in the presence of APAP. Furthermore, SIRT1 inhibitor EX-527 reduced protection by API against APAP-induced hepatotoxicity. Molecular docking results indicate potential interaction between API and SIRT1. API prevents APAP-induced liver injury by regulating the SIRT1-p53 axis, thereby promoting APAP-induced autophagy and ameliorating APAP-induced inflammatory responses and oxidative stress injury.

Roquin-1 Regulates Macrophage Immune Response and Participates in Hepatic Ischemia-Reperfusion Injury

With the development of liver surgery, ischemia-reperfusion (IR) injury has received increasing attention. Roquin-1 has been shown to play an important role in innate immune and immune balance. We demonstrate that Roquin-1 expression increased at 1 h after IR and then decreased in C57B/L mice. The immunofluorescence double-label showed that Roquin-1 was mainly expressed in macrophages (mø). Furthermore, we used clodronate liposomes to remove mø, and injected the bone marrow-derived mø (BMDM) through the tail vein in 1 h before IR. We found that liver IR injury was aggravated by Roquin-1 interference. The results of PCR and ELISA suggested that after interference with Roquin-1, mø increased toward M1 and decreased toward M2. Then, interference with Roquin-1 promoted the polarization of mø to M1 and inhibited the polarization of M2. By Western blot technology and AMPKα and mTOR inhibitors, we found that Roquin-1 promotes the phosphorylation of mTOR and STAT3 by inhibiting the phosphorylation of AMPKα. We used AICAR to activate AMPKα in mø and found that the level of ubiquitination of AMPKα was decreased after activation of AMPKα. Furthermore, by bioinformatics methods, we identified potential ubiquitination sites on AMPKα. By the point mutation experiments in vitro, we confirmed that the ubiquitination of these sites is regulated by Roquin-1. Meanwhile, Roquin-1 interference inhibited the activation and function of AMPKα. This topic describes the protection of liver IR injury by Roquin-1 and discusses its main mechanism for regulating AMPKα activity through ubiquitination and affecting the polarization of mø.

Role of Natural Phenolics in Hepatoprotection: A Mechanistic Review and Analysis of Regulatory Network of Associated Genes

The liver is not only involved in metabolism and detoxification, but also participate in innate immune function and thus exposed to frequent target Thus, they are the frequent target of physical injury. Interestingly, liver has the unique ability to regenerate and completely recoup from most acute, non-iterative situation. However, multiple conditions, including viral hepatitis, non-alcoholic fatty liver disease, long term alcohol abuse and chronic use of medications can cause persistent injury in which regenerative capacity eventually becomes dysfunctional resulting in hepatic scaring and cirrhosis. Despite the recent therapeutic advances and significant development of modern medicine, hepatic diseases remain a health problem worldwide. Thus, the search for the new therapeutic agents to treat liver disease is still in demand. Many synthetic drugs have been demonstrated to be strong radical scavengers, but they are also carcinogenic and cause liver damage. Present day various hepatic problems are encountered with number of synthetic and plant based drugs. Nexavar (sorafenib) is a chemotherapeutic medication used to treat advanced renal cell carcinoma associated with several side effects. There are a few effective varieties of herbal preparation like Liv-52, silymarin and Stronger neomin phages (SNMC) against hepatic complications. Plants are the huge repository of bioactive secondary metabolites viz; phenol, flavonoid, alkaloid etc. In this review we will try to present exclusive study on phenolics with its mode of action mitigating liver associated complications. And also its future prospects as new drug lead.

Apigenin Alleviates Myocardial Reperfusion Injury in Rats by Downregulating miR-15b

Background

We investigated whether apigenin could mitigate myocardial reperfusion injury in rats, and a possible mechanism was proposed.

Material/Methods

The I-R injury model was established in rats along with a sham group as control, and the expressions of microRNA-15b (miR-15b), JAK2, and p-JAK2 in the myocardia of the 2 groups were detected. Apoptosis and reactive oxygen species (ROS) were also detected. Rats in the I-R injury model were divided into 3 groups in vivo: the 1I-R group, the 2I-R+solvent group, and the 3I-R+apigenin group. Expression of miR-15b, JAK2, p-JAK2, STAT3, and p-STAT3 in the myocardia of the 3 groups were detected. ROS content, apoptosis, MDA content, SOD, and CAT activities were detected. Rat myocardial H9C2 cells were cultured in vitro and divided into 5 treatment groups in vitro; expressions of miR-15b, JAK2, p-JAK2, STAT3, and p-STAT3 in H9C2 cells were detected, and the apoptosis and ROS content were detected by flow cytometry.

Results

We found that the increased miR-15b expression during myocardial I-R injury in rats downregulated the expression of JAK2 and activity of the JAK2-STAT3 pathway, promoted myocardial apoptosis and ROS production, and aggravated myocardial I-R injury. Apigenin treatment can downregulate miR-15b expression, increase the expression of JAK2 and the activity of JAK2-STAT3 pathway, reduce myocardial apoptosis and ROS production, and alleviate myocardial I-R injury.

Conclusions

Api treatment downregulated the expression of miR-15b and upregulated the expression of JAK2 and the activity of the JAK2-STAT3 pathway, thereby alleviating myocardial I-R injury, cardiomyocyte apoptosis, and ROS production in vitro.

Antioxidative and Protective Actions of Apigenin in a Paracetamol-Induced Hepatotoxicity Rat Model

BACKGROUND AND OBJECTIVES

Apigenin is known to have various pharmacological properties without causing significant toxicity; however, hepatoprotective effect of apigenin is not often reported. The aim of our study was to investigate if the alterations in lipid peroxidation and antioxidant status are in favor to prove the efficacy of apigenin against paracetamol-induced hepatotoxicity.

METHODS

The effect of apigenin on paracetamol-induced hepatotoxicity in rats was examined by determining biochemical parameters, histological assessment and oxidative status in liver homogenates.

RESULTS

The treatment of animals with both apigenin and paracetamol attenuates the parameters of hepatotoxicity, especially for ALT and ALP activity which was significantly lower compared to groups of animals treated with saline and paracetamol. Hepatotoxicity induced by toxic dose of paracetamol was revealed also by notable histopathological alterations, which were not observed in the group treated with paracetamol together with apigenin. Apigenin also prevented paracetamol-induced increase in malondialdehyde (MDA) level. The activities of both CAT (catalase) and GR (glutathione reductase) enzymes after the toxic dose of paracetamol were significantly increased in the liver homogenates, compared to control group. Apigenin reversed these parameters near to values of control group.

CONCLUSIONS

The result of our study indicates that apigenin inhibits the level of lipid peroxidation and significantly increases the enzyme antioxidant defense mechanisms in paracetamol-induced hepatotoxicity in rats.

Silibinin Improves TNF-α and M30 Expression and Histological Parameters in Rat Kidneys After Hepatic Ischemia/Reperfusion

BACKGROUND

Remote kidney damage is a sequel of hepatic ischemia-reperfusion (I/R) injury. Silibinin is the main ingredient of the milk thistle plant seed extract with known antioxidant and hepatoprotective activity. Our study investigates the nephroprotective potential of intravenously administered silibinin, as a lyophilized SLB-hydoxypropyl-beta-cyclodextrin product, in hepatic I/R injury.

MATERIAL AND METHODS

63 Wistar rats were divided into three groups: Sham (virtual intervention); Control (45 min ischemia and reperfusion); and Silibinin (200 μL intravenous silibinin administration after 45 min of ischemia). Kidney tissues were collected to determine TNF-α, M30 and histopathological changes at predetermined time intervals.

RESULTS

Comparing Sham vs. Control groups, proved that hepatic I/R injury increased renal TNF-α and M30 expression. Deterioration was observed in hyperemia/filtration of renal parenchyma and tubules, cortical filtration, tubular necrosis and edema (tissue swelling index). Intravenous silibinin administration and comparison of the Control vs. Silibinin groups showed a statistically significant decrease in TNF-α levels at 240 min following I/R (p < 0.0001), and in M30 at 180 min (p = 0.03) and 240 min (p < 0.0001). Renal parameters have significantly decreased in: hyperemia/filtration of renal parenchyma at 120 min (p = 0.003), 180 min (p = 0.0001) and 240 min (p = 0.0002); hyperemia/filtration of renal tubules at 120 min (p = 0.02), 180 min (p = 0.0001) and 240 min (p = 0.0005); cortical filtration (240 min - p = 0.005); tubular necrosis (240 min - p = 0.021); and edema (240 min - p = 0.001).

CONCLUSION

Our study confirms that hepatic I/R injury causes remote renal damage while the intravenous administration of silibinin leads to statistically significant nephroprotective action.

Apigenin promotes TRAIL-mediated apoptosis regardless of ROS generation

Apigenin is a bioactive flavone in several herbs including parsley, thyme, and peppermint. Apigenin possesses anti-cancer and anti-inflammatory properties; however, whether apigenin enhances TRAIL-mediated apoptosis in cancer cells is unknown. In the current study, we found that apigenin enhanced TRAIL-induced apoptosis by promoting caspase activation and death receptor 5 (DR5) expression and a chimeric antibody against DR5 completely blocked the apoptosis. Apigenin also upregulated reactive oxygen species (ROS) generation; however, intriguingly, ROS inhibitors, glutathione (GSH) or N-acetyl-l-cysteine (NAC), moderately increased apigenin/TRAIL-induced apoptosis. Additional results showed that an autophagy inducer, rapamycin, enhanced apigenin/TRAIL-mediated apoptosis by a slight increase of ROS generation. Accordingly, NAC and GSH rather decreased apigenin-induced autophagy formation, suggesting that apigenin-induced ROS generation increased autophagy formation. However, autophagy inhibitors, bafilomycin (BAF) and 3-methyladenine (3-MA), showed different result in apigenin/TRAIL-mediated apoptosis without ROS generation. 3-MA upregulated the apoptosis but remained ROS levels; however, no changes on apoptosis and ROS generation were observed by BAF treatment. Taken together, these findings reveal that apigenin enhances TRAIL-induced apoptosis by activating apoptotic caspases by upregulating DR5 expression regardless of ROS generation, which may be a promising strategy for an adjuvant of TRAIL.