Evaluation of hepatotoxicity and cholestasis in rats treated with EtOH extract of Fructus Psoraleae

Taurocholic acid represents an earlier and more sensitive biomarker and promotes cholestatic hepatotoxicity in ANIT-treated rats

Bile acid homeostasis is crucial for the normal physiological functioning of the liver. Disruptions in bile acid profiles are closely linked to the occurrence of cholestatic liver injury. As part of our diagnostic and therapeutic approach, we aimed to investigate the disturbance in bile acid profiles during cholestasis and its correlation with cholestatic liver injury. Before the occurrence of liver injury, alterations in bile acid profiles were detected in both plasma and liver between 8 and 16 h, persisting up to 96 h. TCA, TCDCA, and TUDCA in the plasma, as well as TCA, TUDCA, TCDCA, TDCA, TLCA, and THDCA in the liver, emerged as early sensitive and potential markers for diagnosing ANIT-induced cholestasis at 8-16 h. The distinguishing features of ANIT-induced liver injury were as follows: T-BAs exceeding G-BAs and serum biochemical indicators surpassing free bile acids. Notably, plasma T-BAs, particularly TCA, exhibited higher sensitivity to cholestatic hepatotoxicity compared with serum enzyme activity and liver histopathology. Further investigation revealed that TCA exacerbated ANIT-induced liver injury by elevating liver function enzyme activity, inflammation, and bile duct proliferation and promoting the migration of bile duct epithelial cell. Nevertheless, no morphological changes or alterations in transaminase activity indicative of liver damage were observed in the rats treated with TCA alone. Additionally, there were no changes in bile acid profiles or inflammatory responses under physiological conditions with maintained bile acid homeostasis. In summary, our findings suggest that taurine-conjugated bile acids in both plasma and liver, particularly TCA, can serve as early and sensitive markers for predicting intrahepatic cholestatic drugs and can act as potent exacerbators of cholestatic liver injury progression. However, exogenous TCA does not induce liver injury under physiological conditions where bile acid homeostasis is maintained.

Bavachinin, a main compound of Psoraleae Fructus, facilitates GSDMD-mediated pyroptosis and causes hepatotoxicity in mice

Psoraleae Fructus (PF, Psoralea corylifolia L.), a traditional medicine with a long history of application, is widely used clinically for the treatment of various diseases. However, the reports of PF-related adverse reactions, such as hepatotoxicity, phototoxic dermatitis, and allergy, are increasing year by year, with liver injury being the mostly common. Our previous studies have demonstrated that PF and its preparations can cause liver injury in lipopolysaccharide (LPS)-mediated susceptibility mouse model, but the mechanism of PF-related liver injury is unclear. In this study, we showed that PF and bavachinin, a major component of PF, can directly induce the expression of caspase-1 and interleukin-1β (IL-1β), indicating that PF and bavachinin can directly triggered the activation of inflammasome. Furthermore, pretreatment with NLR family pyrin domain-containing 3 (NLRP3), NLR family CARD domain containing 4 (NLRC4) or absent in melanoma 2 (AIM2) inflammasome inhibitors, containing MCC950, ODN TTAGGG (ODN) and carnosol, all significantly reversed bavachinin-induced inflammasome activation. Mechanistically, bavachinin dose-dependently promote Gasdermin D (GSDMD) post-shear activation and then induce mitochondrial reactive oxygen species (mtROS) production and this effect is markedly inhibited by pretreatment with N-Acetylcysteine amide (NAC). In addition, combination treatment of LPS and bavachinin significantly induced liver injury in mice, but not LPS or bavachinin alone, and transcriptome analysis further validated these results. Thus, PF and bavachinin can induce the activation of inflammasome by promoting GSDMD cleavage and cause hepatotoxicity in mice. Therefore, PF, bavachinin, and PF-related preparations should be avoided in patients with inflammasome activation-associated diseases.

Evaluation of the hepatotoxicity of Psoralea corylifolia L. based on a zebrafish model

Objective: Psoralea corylifolia L. (FP) has received increasing attention due to its potential hepatotoxicity. Methods: In this study, zebrafish were treated with different concentrations of an aqueous extract of FP (AEFP; 40, 50, or 60 μg/mL), and the hepatotoxic effects of tonicity were determined by the mortality rate, liver morphology, fluorescence area and intensity of the liver, biochemical indices, and pathological tissue staining. The mRNA expression of target genes in the bile acid metabolic signaling pathway and lipid metabolic pathway was detected by qPCR, and the mechanism of toxicity was initially investigated. AEFP (50 μg/mL) was administered in combination with FXR or a peroxisome proliferator-activated receptor α (PPARα) agonist/inhibitor to further define the target of toxicity. Results: Experiments on toxic effects showed that, compared with no treatment, AEFP administration resulted in liver atrophy, a smaller fluorescence area in the liver, and a lower fluorescence intensity (p < 0.05); alanine transaminase (ALT), aspartate transaminase (AST), and γ-GT levels were significantly elevated in zebrafish (p < 0.01), and TBA, TBIL, total cholesterol (TC), TG, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels were elevated to different degrees (p < 0.05); and increased lipid droplets in the liver appeared as fatty deposits. Molecular biological validation revealed that AEFP inhibited the expression of the FXR gene, causing an increase in the expression of the downstream genes SHP, CYP7A1, CYP8B1, BSEP, MRP2, NTCP, peroxisome proliferator-activated receptor γ (PPARγ), ME-1, SCD-1, lipoprotein lipase (LPL), CPT-1, and CPT-2 and a decrease in the expression of PPARα (p < 0.05). Conclusion: This study demonstrated that tonic acid extracts are hepatotoxic to zebrafish through the inhibition of FXR and PPARα expression, thereby causing bile acid and lipid metabolism disorders.

Exploring the mechanism and phytochemicals in Psoraleae Fructus-induced hepatotoxicity based on RNA-seq, in vitro screening and molecular docking

Psoraleae Fructus (PF) is a widely-used herb with diverse pharmacological activities, while its related hepatic injuries have aroused public concerns. In this work, a systematic approach based on RNA sequencing (RNA-seq), high-content screening (HCS) and molecular docking was developed to investigate the potential mechanism and identify major phytochemicals contributed to PF-induced hepatotoxicity. Animal experiments proved oral administration of PF water extracts disturbed lipid metabolism and promoted hepatic injuries by suppressing fatty acid and cholesterol catabolism. RNA-seq combined with KEGG enrichment analysis identified mitochondrial oxidative phosphorylation (OXPHOS) as the potential key pathway. Further experiments validated PF caused mitochondrial structure damage, mtDNA depletion and inhibited expressions of genes engaged in OXPHOS. By detecting mitochondrial membrane potential and mitochondrial superoxide, HCS identified bavachin, isobavachalcone, bakuchiol and psoralidin as most potent mitotoxic compounds in PF. Moreover, molecular docking confirmed the potential binding patterns and strong binding affinity of the critical compounds with mitochondrial respiratory complex. This study unveiled the underlying mechanism and phytochemicals in PF-induced liver injuries from the view of mitochondrial dysfunction.

Development and validation of a sensitive liquid chromatography-tandem mass spectrometry method for the assay of 12 substances in rat plasma and its application to rat pharmacokinetics of Epimedium and Psoraleae Fructus herb pair after oral administration

Epimedium (EM) and Psoraleae Fructus (PF) are a traditional herb combination often used as a fixed form to treat osteoporosis disease in the clinic. However, the intricate interactions of this pair remain unknown. In our study, we undertook a comprehensive examination of their compatibility behaviors. Concurrently, a precise and sensitive quantitation method was successfully developed and validated using liquid chromatography-tandem mass spectrometry for the determination of 12 components. This method was applied in analyzing herbal extracts and biological samples (both in the portal vein and systemic plasma), which was also used to study the pharmacokinetics of the herb pair. The results indicated that the combination of EM and PF enhanced the dissolution of chemical components from PF in extracts, but it had a negligible influence on the contents of the components from EM. On the contrary, the in vivo exposure of the lowly exposed EM flavonoids significantly increased following the combination of EM and PF, whereas the highly exposed psoralen and isopsoralen were greatly reduced. These interactions might be crucial for the synergy and toxicity reduction of the herbal pair in disease treatment, which pave the way for further exploration into the clinical application and pharmacological mechanisms of EM and PF.

Cytochrome P450-mediated herb-drug interaction (HDI) of Polygonum multiflorum Thunb. based on pharmacokinetic studies and in vitro inhibition assays

BACKGROUND

Polygonum multiflorum Thunb. (PM) is well known both in China and other countries of the world for its tonic properties, however, it has lost its former glory due to liver toxicity incidents in recent years.

PURPOSE

The purpose of this study is to determine whether the occurrence of herb-drug interaction (HDI) caused by PM is associated with cytochrome P450 (CYP450) based on pharmacokinetic studies and in vitro inhibition assays. The objective was to provide a reference for the rational and safe use of drugs in clinical practice.

METHODS

In this study, raw PM (R), together with its two processed products which included PM by Chinese Pharmacopoeia (M) and PM by "nine cycles of steaming and sunning (NCSS)" ("9"), were prepared as the main research objects. A method based on fluorescence technology was used to evaluate the inhibition levels of raw and processed PMs, as well as corresponding characteristic compounds on seven recombinant human cytochrome P450s (rhCYP450s). The pharmacokinetics of sulindac (a representative of commonly used nonsteroidal anti-inflammatory drugs) and psoralen (a major compound of Psoralea in combination with PM) in rat plasma were studied when combined with raw and different processed products of PM.

RESULTS

The inhibitory level order of the three extracts on major different subtypes of CYP450 (CYP1A2, CYP2B6, CYP2C8, CYP2C19, CYP2D6, and CYP3A4) was: R > M > "9". However, the inhibition level of R and "9" is higher than that of M on CYP2C9. Further studies showed that trans-THSG and emodin could selectively inhibit CYP3A4 and CYP1A2, respectively. Epicatechin gallate mainly inhibited CYP3A4 and CYP1A2, followed by CYP2C8 and CYP2C9. Genistein mainly inhibited CYP3A4, followed by CYP2C9 and CYP2C8. CYP3A4 and CYP2C9 were also inhibited by daidzein. The inhibitory effects of all the PM extracts were associated with their characteristic compounds. The results of HDI showed that R increased sulindac exposure to rat blood, and R and M increased psoralen exposure to rat blood, which were consistent with corresponding metabolic enzymes. Overall, the in vitro and in vivo results indicated that PM, especially R, would be at high risk to cause toxicity and drug interactions via CYP450 inhibition.

CONCLUSION

This study not only elucidates the scientific connotation of "efficiency enhancement and toxicity reduction" of PM by NCSS from the perspective of metabolic inhibition but also contributes to HDI prediction and appropriate clinical medication of PM.

Psoralen induces liver injury and affects hepatic bile acids metabolism in female and male C57BL/6J mice

Psoralen is a major component of Fructus Psoraleae that could induce liver injury. In this study, C57BL/6J mice were administered with psoralen at doses of 80 mg/kg for 3, 7 and 14 days. Blood and liver samples were collected for serum biochemistry and histopathology examinations, respectively. Psoralen led to liver injury with significantly increased liver weight and liver coefficient and up regulated serum ALT, AST and TG but down regulated serum TC and TP. The expression of bile acid-associated transporters and enzymes was detected by western blot, and the results showed that psoralen significantly down-regulates the expressions of CYP7A1, CYP27A1, BSEP and OSTα protein while up-regulates the expressions of HMGCR and FASN, resulting in the obstacles of bile acid efflux in the liver. The contents of 24 kinds of bile acids in the liver were measured by LC-MS/MS, and the results showed that psoralen led to the accumulation of unconjugated bile acids in the liver, such as ALCA and CA, which were more severe in male mice than female mice. It was indicated that psoralen may disrupt the balance of bile acid metabolism by inhibiting the expression of the efflux transporter, which then leads to liver damage.

The changes of hepatic bile acid synthesis and transport and bile acids profiles in isopsoralen-induced liver injury C57BL/6J mice

CONTEST

Isopsoralen, one of the main active and quality-control compounds in Psoralea corylifolia L. (Fabaceae), has antitumor and oestrogen-like effects. Previous studies demonstrated that isopsoralen induced hepatotoxicity and its long-term exposure led to cholestatic liver injury.

OBJECTIVE

This study investigates the effect of three- or seven-day exposure of low dose isopsoralen (80 mg/kg) on bile acid homeostasis in C57BL/6J mice.

MATERIALS AND METHODS

Forty-two C57BL/6J mice were randomly divided into control, three- and seven-day groups (n = 14 per group, half female and half male). Isopsoralen suspension was administrated intragastrically at 80 mg/kg once a day. Blood and liver samples were collected to measure biochemical indices and transport of BAs. The histopathology of the liver was also observed. HPLC-MS/MS was also used to measure the BAs profiles and transport activity.

RESULTS

In the study, isopsoralen increased the levels of serum AST, ALT in three- and seven-day groups, and caused vacuolar degeneration and swelling in the liver. Canalicular efflux transporters BSEP, OSTα, MRP2, MRP3, and basolateral uptake transporters NTCP, OATP4 were inhibited after seven-day-administration. Moreover, amino acid binding enzymes (BAAT and BACS) were also inhibited after seven-day-administration. The composition of BAs changed greatly and the concentration of some unconjugated-BAs which have stronger hydrophobicity, such as CA, CDCA, was significantly increased.

CONCLUSIONS

Isopsoralen (80 mg/kg) caused hepatotoxicity after short-term exposure by inhibiting the expression of efflux transporters, amino acid binding enzymes, and disrupting BAs spectrum.

Psoralen induces hepatotoxicity by covalently binding to glutathione-S-transferases and the hepatic cytochrome P450

BACKGROUND

Psoraleae Fructus has been widely used in China and its surroundings; however, Psoraleae Fructus and its compound preparation have been reported recently to cause liver injury in clinics. Thus, its safe use has attracted increasing attention. The possible mechanism is related to the metabolism of psoralen, but it still needs further clarification.

PURPOSE

The present study was designed to evaluate the toxicity of psoralen and investigate the potentially related molecular mechanisms using chemical biology methods combined with animal experiments to provide evidence for the rational clinical use of psoralen.

METHODS

An in vivo experiment was conducted with a time series of 20-80 mg/kg psoralen to verify its toxic performance. Target capture and click reactions were used to investigate direct targets of psoralen. Selectivity for different glutathione-S-transferase (GST) subtypes in the liver and inhibition of cytochrome P450 (CYP450) were also detected.

RESULTS

Psoralen build-up in the liver is the primary cause of liver damage. Our study revealed the mechanism by which psoralen induces liver injury. Psoralen can bind directly to CYP2D6, CYP3A4, GST-α, and GST-μ and inhibit their activities, causing the depletion of glutathione (GSH) in vivo, which in turn induces hepatic damage. The special structure of α,β-unsaturated lactones in psoralen facilitates its attachment to its target; therefore, complementing psoralen with GSH can efficiently protect the liver from damage.

CONCLUSIONS

Psoralen causes a disorder in drug metabolism by inhibiting the activity of CYPs and GSTs, causing exhaustion of GSH, and subsequently leading to liver damage. The co-administration of GSH and psoralen is an effective way to avoid liver injury in clinical settings.

Combination of molecular docking and liver transcription sequencing analysis for the evaluation of salt-processed psoraleae fructus-induced hepatotoxicity in ovariectomized mice

ETHNOPHARMACOLOGICAL RELEVANCE

Salt-processed Psoraleae fructus (SPF) is widely used as a phytoestrogen-like agent in the treatment of osteoporosis. However, SPF-associated hepatotoxicity is a known health hazard. Cholestasis is often associated with SPF-induced hepatotoxicity. Notably, clinical liver injury is a common side effect of SPF in the treatment of osteoporosis; however, the exact mechanism underlying this phenomenon is unclear.

AIM OF THE STUDY

To evaluate SPF-induced hepatotoxicity in an ovariectomized murine model of estrogen deficiency and examine the mechanisms underlying this process.

MATERIALS AND METHODS

To explore the molecular mechanism of SPF-induced cholestatic liver injury, different concentrations of SPF (5 and 10 g/kg) were intragastrically administered to ovariectomized and non-ovariectomized female ICR mice for 30 days.

RESULTS

SPF-treated mice showed noticeably swollen hepatocytes, dilated bile ducts, and elevated levels of serum biochemical markers. Compared to ovariectomized mice, these changes were more prominent in non-ovariectomized mice. According to the sequence data, a total of 6689 mRNAs were identified. Compared with the control group, 1814 differentially expressed mRNAs were identified in the group treated with high SPF doses (SPHD), including 939 upregulated and 875 downregulated mRNAs. Molecular docking and Western blot experiments showed that liver injury was closely related to the estrogen levels. Compared with the negative control group, the expression levels of FXR, Mrp2, CYP7a1, BSEP, SULT1E1, HNF4a, and Nrf2 decreased in the estradiol-treated (E2), low-dose SPF-treated (SPLD), and SPHD groups. Interestingly, the expression levels of FXR, CYP7a1, SULT1E1, and HNF4α were significantly higher in the ovariectomized groups than in the non-ovariectomized groups (#P < 0.05; ###P < 0.001).

CONCLUSIONS

Overall, this study demonstrates that SPF downregulates key enzymes involved in cholesterol and bile acid biosyntheses, posing a risk for cholestatic liver injury. SPF also regulates the FXR-SULT1E signaling pathway via HNF4α, which is an important causative factor of cholestasis. Moreover, the severity of liver damage was significantly lower in the ovariectomized groups than in the non-ovariectomized group. These results suggest that the estrogen level is the most critical factor determining liver injury.

Five Constituents Contributed to the Psoraleae Fructus-Induced Hepatotoxicity via Mitochondrial Dysfunction and Apoptosis

Backgrounds: Psoraleae Fructus (PF)-induced hepatotoxicity has been reported in clinical and animal experiments. However, the hepatotoxic constituents and mechanisms underlying PF-induced toxicity have remained unclear. Therefore, this study explored the potentially toxic PF components and revealed their relative mechanisms.

Methods: The hepatotoxicity of PF water (PFW) and ethanol (PFE) extracts was compared using Kunming mice. The different compositions between PFW and PFE, which were considered toxic compositions, were identified using the UHPLC-Q-Exactive MS method. Then, L02 and HepG2 cell lines were used to evaluate the toxicity of these compositions. Cell viability and apoptosis were determined through the Cell Counting Kit-8 (CCK-8) assay and flow cytometry, respectively. An automatic biochemical analyzer detected the aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). Lastly, we used high-content screening (HCS) to determine the levels of reactive oxygen species (ROS), lipid, and mitochondrial membrane potential (MMP).

Results: The ethanol extraction process aggravated the hepatotoxicity of PF, causing more severe injuries. The content of psoralen, isopsoralen, bavachin, psoralidin, bavachinin, neobavaisoflavone, and bakuchiol was higher in the PFE than PFW. Bavachin, psoralidin, bavachinin, neobavaisoflavone, and bakuchiol induced cell apoptosis and the AST, ALT, and ALP leakages. Furthermore, these five constituents increased intracellular lipid accumulation and ROS levels but decreased the MMP level.

Conclusion: The ethanol extraction process could induce severe PF hepatotoxicity. Bavachin, psoralidin, bavachinin, neobavaisoflavone, and bakuchiol are the main hepatotoxic ingredients. This mechanism could be associated with oxidative stress and mitochondrial damage-mediated apoptosis. Taken together, this study provides a basis for the clinical application of PF that formulates and improves its herbal standards.

Landscape of Hepatobiliary Adverse Drug Reactions Related to Preparations Containing Psoraleae Fructus and Its Application in Pharmacovigilance

OBJECTIVE

To analyze clinical feature and information of medication to explore the risk signals of preparations containing Psoraleae Fructus (BGZP) related with hepatobiliary adverse drug reactions (ADR), in order to reinforce pharmacovigilance.

METHODS

A retrospective study was conducted based on hepatobiliary ADR related with BGZP from the China Adverse Drug Reaction Monitoring System in years from January 2012 to December 2016. Serious and general ADRs were analyzed and assessed.

RESULTS

There were 355 cases of hepatobiliary ADR related to BGZP. Both the amount of cases and the proportion of serious ADR showed an increasing growth by years (P<0.05). It was found that 10.43% of 355 cases may be involved with irrational drug use, including overdose, repeated medication, and combination of multiple drugs. There were 190 cases which used BGZP (non-combination), and they were mainly for common in diseases caused by abnormal immune activation (accounting for 40.53% of the total cases). Especially at the age group with the most cases with age of 41-50 years, the cases associated with immunological diseases of female were obviously more than that of male (P<0.05). The latency of hepatobiliary ADR related to BGZP ranged from 1 to 386 days, and the median latency was 27.5 days, along with the range of cumulative dose (0.45-520.02 g) as well as the daily dose (0.09-2.64 g/d) after the conversion.

CONCLUSIONS

Cases of hepatobiliary ADR related to BGZP showed significant individual differences, and there was no correlation between drug usage duration and dosage and the occurrence of hepatobiliary ADR. It may be similar with idiosyncratic drug-induced liver injury, and recommended that BGZP should be used with more caution under monitoring liver function, especially in female patients with immunological diseases.

Research on the Species Difference of the Hepatotoxicity of Medicine Based on Transcriptome

In recent years, several drugs have been withdrawn from use by regulatory bodies owing to hepatotoxicity; therefore, studies on drug-induced liver injury (DILI) are being actively pursued. Most studies evaluating DILI use rats or mice as animal models to determine drug toxicity; however, the toxicity of a drug can vary between rats or mice. These inconsistencies in in vivo studies among different animal models affect the extrapolation of experimental results to humans. Thus, it is particularly important to choose the most suitable animal model to determine drug hepatotoxicity owing to the genomic differences between rats and mice resulting from evolution. In this study, genome-wide transcriptome analysis was used to explore hepatotoxicity caused by differences in species. Our findings provide the preclinical basis to further study the mechanisms of drug hepatotoxicity and aid in the selection of animal models to determine drug safety. We used murine models (Sprague-Dawley and Wistar rats, ICR and Kunming mice) in this study and by using transcriptome sequencing with the differentially expressed genes in rat and mouse livers as the entry point, we explored the mechanism of oxidative stress and the difference in gene expression in the lipid-metabolism pathway between rats and mice. The clinically established hepatotoxic drugs, fructus psoraleae and acetaminophen were used to validate our study. Using pathological studies, we confirmed that oxidative stress in mice was more serious than that in rats, and that Kunming mice were more suited for the study of oxidative stress-related DILI. The validity of our findings was further verified based on gene expression. Thus, our study could serve as a valuable reference for the evaluation of potential preclinical hepatotoxicity. Moreover, it could be used in the prediction and early diagnosis of drug-induced liver injury caused by traditional Chinese medicine or synthetic drugs, thereby providing a new avenue for drug-toxicity studies.

Potential Determinants for Metabolic Fates and Inhibitory Effects of Isobavachalcone Involving in Human Cytochrome P450, UDP-Glucuronosyltransferase Enzymes, and Efflux Transporters

Isobavachalcone, a naturally occurring chalcone in Psoralea corylifolia, posses many biological properties including anticancer, antiplatelet, and antifungal. However, its glucuronidation, glucuronides excretion, and drug-drug interaction (DDI) involving in human cytochrome P450 (CYP), UDP-glucuronosyltransferase (UGT) enzymes, and efflux transporters (BCRP and MRPs) remains unclear so far. After incubation, three glucuronides were produced by HLM and HIM with total intrinsic clearance (CL_int) of 236.71 and 323.40 μL/min/mg, respectively. Reaction phenotyping proved UGT1A1, 1A3, 1A7, 1A8, and 1A9 played important roles in glucuronidation with total CL_int values of 62.69-143.00 μL/min/mg. Activity correlation analysis indicated UGT1A1 and UGT1A3 participated more in the glucuronidation. In addition, the glucuronidation showed marked species differences, and rabbits and dogs were probably appropriate model animals to investigate the in vivo glucuronidation. Furthermore, BCRP, MRP1, and MRP4 transporters were identified as the most important contributors to glucuronides excretion in HeLa1A1 cells based on gene silencing method. Moreover, isobavachalcone demonstrated broad-spectrum inhibitory effects against CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, UGT1A1, UGT1A9, UGT2B7 with IC₅₀ values of 1.08-9.78 μM. Except CYP2B6 and CYP2D6, the calculated [I]/K_i values for other enzymes were all greater than 0.1, indicating the inhibition of systemic metabolism or elimination for these enzyme substrates seems likely. Taken together, we summarized metabolic fates of isobavachalcone including glucuronidation and efflux transport as well as inhibitory effects involving in human CYP and UGT enzymes.

Hepatotoxicity and nephrotoxicity assessment on ethanol extract of Fructus Psoraleae in Sprague Dawley rats using a UPLC-Q-TOF-MS analysis of serum metabolomics

Fructus Psoraleae (FP) is commonly used in the treatment of vitiligo, osteoporosis, and other diseases in clinic. As a result, the toxicity caused by FP is frequently encountered in clinical practice; however, the underlying toxicity mechanism remains unclear. The purpose of this study was to investigate the toxic effect of the ethanol extract of FP (EEFP) in rats and to explore the underlying toxic mechanisms using a metabolomics approach. The toxicity was evaluated by hematological indicators, biochemical indicators, and histological changes. In addition, a serum metabolomic method based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight MS (UPLC-Q-TOF-MS) had been established to investigate the hepatorenal toxicity of FP. Multivariate statistical approaches, such as partial least squares discriminant analysis and orthogonal partial least squares discriminant analysis, were built to evaluate the toxic effects of FP and find potential biomarkers and metabolic pathways. Ten endogenous metabolites had been identified and the related metabolic pathways were involved in phospholipid metabolism, amino acid metabolism, purine metabolism, and antioxidant system activities. The results showed that long-term exposure to high-dose EEFP may cause hepatorenal toxicity in rats. Therefore, serum metabolomics can improve the diagnostic efficiency of FP toxicity and make it more accurate and comprehensive.

Psoralidin, a major component of Psoraleae Fructus, induces inflammasome activation and idiosyncratic liver injury

Idiosyncratic drug-induced liver injury (IDILI) is a rare but potentially fatal disease that is unpredictable and independent of the dose of the drug. Increasing evidence suggests that the majority of IDILI cases are immune-mediated, and the aberrant activation of inflammasome plays a vital role in progression. Psoraleae Fructus (PF), a tonic Chinese medicine, has been able to cause IDILI, but the precise mechanism of hepatotoxicity remains unclear. In this study, eight bioactive compounds involved in PF-induced inflammasome activation were investigated. The results demonstrated that psoralidin activated the inflammasomes followed by secreting caspase-1 and interleukin 1β (IL-1β) in a dose-dependent manner. Interestingly, MCC950, a potent inhibitor of the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, could not entirely suppress the psoralidin-induced inflammasome activation. Moreover, psoralidin significantly induced IL-1β maturation and caspase-1 activation in NLRP3-knockout bone marrow-derived macrophages (BMDMs), suggesting that psoralidin not only activates the NLRP3 inflammasome but also activates other types of inflammasomes. The results also demonstrated that psoralidin activated the inflammasomes by promoting the C-terminal caspase recruitment domain (ASC) oligomerization, and the production of mitochondrial reactive oxygen species (mtROS) is a decisive factor in psoralidin-induced inflammasome activation. Importantly, in vivo data revealed that psoralidin induced hepatic inflammation, increased aminotransferase activity and increased the production of IL-1β and tumor necrosis factor(TNF-α) in a susceptible mouse model of lipopolysaccharide (LPS)-mediated IDILI. In summary, these results confirmed that psoralidin causes IDILI by inducing inflammasome activation. The study suggests that psoralidin is a possible risk factor and is responsible for PF-induced IDILI.

Effects of psoralen on hepatic bile acid transporters in rats

Fructus Psoraleae (FP), widely used in traditional medicine, is increasingly reported to cause serious hepatotoxicity in recent years. However, the main toxic constituents responsible for hepatotoxicity and the underlying mechanisms are poorly understood. In the present study, psoralen, a main and quality-control constituent of FP, was intragastrically administered to Sprague-Dawley rats at a dose of 60 mg/kg for 1, 3 and 7 days. Blood and selected tissue samples were collected and analyzed for biochemistry and histopathology to evaluate hepatotoxicity. The results showed that psoralen could induce hepatotoxicity by enhanced liver-to-body weight ratio and alterations of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total cholesterol after administration for 3 days. In addition, histopathological examinations also indicated the hepatotoxicity induced by psoralen. Furthermore, the mRNA and protein levels of hepatic bile acid transporters were significantly changed, in which MRP4, ABCG5 and ABCG8 were repressed, while the protein level of NTCP tended to increase in the rat liver. Taken together, psoralen caused liver injury possibly through affecting bile acid transporters, leading to the disorder of bile acid transport and accumulation in hepatocytes.

The Accumulation of Psoralen Contributes to Its Hepatotoxicity Revealed by Pharmacokinetic and Toxicokinetic Study after Repeated Administration

Psoralen is a furanocoumarin compound found in many herb medicines and is claimed to contribute to the hepatotoxicity caused by lots of traditional Chinese medicine. So far, there has been no research on the differences in pharmacokinetics of single and repeated dosing of psoralen. Moreover, the research on the cumulative toxicity of low concentration and long-term administration on cells has not been reported. Therefore, this study investigated the pharmacokinetic differences and the accumulated cytotoxicity of psoralen from repeated administration. The study found that after single or repeated administration of psoralen for 3 months at various dosages (14, 28, and 56 mg/kg), the pharmacokinetic parameters of female rats between single dose and repeated dose administration are totally different. Compared with a single administration, multiple administrations increased psoralen's in vivo exposure, prolonged the peak time, prolonged the half-life of the drug, reduced the drug clearance rate, and prolonged the drug's stay in the body. HepG2 cells were exposed to low doses (5, 10, 20, or 40 μM) of psoralen for 1, 2, 3, or 4 days. A 20 and 40 μM dose of psoralen did not induced cell death in the 1st day but significantly decreased the cell viability at the 3rd and 4th day of repeated administration, respectively. In addition, multiple administrations of psoralen decreased cell viability due to G2 arrest.

Metabolism and disposition of corylifol A from Psoralea corylifolia: metabolite mapping, isozyme contribution, species differences and identification of efflux transporters for corylifol A-O-glucuronide in HeLa1A1 cells

Corylifol A (CA), a phenolic compound from Psoralea corylifolia, possessed several biological properties but poor bioavailability. Here we aimed to investigate the roles of cytochromes P450s (CYPs), UDP-glucuronosyltransferases (UGTs) and efflux transporters in metabolism and disposition of CA.Metabolism of CA was evaluated in HLM, expressed CYPs and UGTs. Chemical inhibitors and shRNA-mediated gene silencing of multidrug resistance-associated proteins (MRPs) and breast cancer resistance protein (BCRP) were performed to assess the roles of transporters in CA disposition.Three oxidated metabolites (M1-M3) and two glucuronides (M4-M5) were detected. The intrinsic clearances (CL_int) values of M1 and M4 in HLM were 48.10 and 184.03 μL/min/mg, respectively. Additionally, CYP1A1, 2C8 and 2C19 were identified as main contributors with CL_int values of 13.01-49.36 μL/min/mg, while UGT1A1, 1A7, 1A8 and 1A9 were with CL_int values ranging from 85.01 to 284.07 μL/min/mg. Furthermore, activity correlation analysis proved CYP2C8, UGT1A1 and 1A9 were the main active hepatic isozymes. Besides, rats and monkeys were appropriate model animals. Moreover, dipyridamole and MK571 both could significantly inhibit M4 efflux. Gene silencing results also indicated MRP4 and BCRP were major contributors in HeLa1A1 cells.Taken together, CYPs, UGTs, MRP4 and BCRP were important determinants of CA pharmacokinetics.

Similar hepatotoxicity response induced by Rhizoma Paridis in zebrafish larvae, cell and rat

Rhizoma Paridis, as a Traditional Chinese Medicine (TCM), has been used in clinic for thousands of years. Recently, the hepatic toxicity was reported in some published articles while its hepatotoxicity mechanisms have not been well established. Therefore, the present study was performed to determine the effect of Rhizoma Paridis treatment on the lipid deposition and metabolism, oxidative stress and mitochondrial dysfunction, and explore the underlying molecular mechanism through L02 cell, rat and zebrafish larvae. Rhizoma Paridis could diminish cell activity and cell proliferation, brought on cell apoptosis and elevated the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) compared with the control group, as evaluated in cell cultures. Rhizoma Paridis could result in the change of the liver structure and the liver function in the rat model and zebrafish larvae. Our results showed that Rhizoma Paridis could increase hepatic lipid accumulation, which was similar to the previous study and probably exerted toxic effect through intensive fatty acid lipogenesis, inhibition of fat degradation. Meanwhile, this experiment highlighted the importance of the oxidative stress, mitochondrial dysfunction, ER function, and the inflammation response in Rhizoma Paridis-induced disorder of hepatic lipid metabolism, which proposed a novel mechanism for interpretation of Rhizoma Paridis exposure inducing the disorder of lipid metabolism in vertebrates. Furthermore, the result of this experiment suggested that the toxicity response of zebrafish larvae was similar to the conventional model with a significant advantage.

Quantitative proteomics analysis of Fructus Psoraleae-induced hepatotoxicity in rats

Fructus Psoraleae, which is commonly consumed for the treatment of osteoporosis, bone fracture, and leucoderma, induces liver injury. This study investigated the pathogenesis of the ethanol extract of Fructus Psoraleae (EEFP)-induced liver injury in rats. EEFP (1.35, 1.80, and 2.25 g·kg^-1) was administrated to Sprague Dawley (SD) rats for 30 d. We measured liver chemistries, histopathology, and quantitative isobaric tags for relative and absolute quantitation (iTRAQ)-based protein profiling. EEFP demonstrated parameters suggestive of liver injury with changes in bile secretion, bile flow rate, and liver histopathology. iTRAQ analysis showed that a total of 4042 proteins were expressed in liver tissues of EEFP-treated and untreated rats. Among these proteins, 81 were upregulated and 32 were downregulated in the treatment group. KEGG pathway analysis showed that the drug metabolic pathways of cytochrome P450, glutathione metabolism, glycerolipid metabolism, and bile secretion were enriched with differentially expressed proteins. The expression of key proteins related to the farnesoid X receptor (FXR), i.e., the peroxisome proliferators-activated receptor alpha (PPAR-α), were downregulated, and multidrug resistance-associated protein 3 (MRP3) was upregulated in the EEFP-treated rats. Our results provide evidence that EEFP may induce hepatotoxicity through various pathways. Furthermore, our study demonstrates changes in protein regulation using iTRAQ quantitative proteomics analysis.

Cholestatic liver injury induced by food additives, dietary supplements and parenteral nutrition

Cholestasis refers to the accumulation of toxic levels of bile acids in the liver due to defective bile secretion. This pathological situation can be triggered by drugs, but also by ingredients contained in food, food supplements and parenteral nutrition. This paper provides an overview of the current knowledge on cholestatic injury associated with such ingredients, with particular emphasis on the underlying mechanisms of toxicity.

Fructus Psoraleae-Induced Severe Liver Injury and Treatment With Two Artificial Liver Support Systems: A Case Series Study

To describe the clinical features and outcomes of patients with suspected Fructus Psoraleae (FP)-induced severe liver injury who underwent treatment with two artificial liver support systems (ALSSs). The cases of 12 patients with severe liver injury by FP were enrolled. We evaluated the tolerability of, and changes in biochemical parameters after treatment with plasma exchange combined with hemofiltration and double plasma molecular absorption system, and 6-month follow-up information were collected. The median age of the 12 patients was 60 years and nine (75%) patients were females. All patients had jaundice as the initial symptom. Two ALSS types were used to treat the patients. The group that underwent plasma exchange combined with hemofiltration showed remarkable improvements in ALT, AST, total bilirubin (TB), GGT and international normalized ratio levels (AST, TB, international normalized ratio, P < 0.01; ALT, GGT, P < 0.05), and the levels of AST, ALP, TB, and total bile acid decreased significantly in the double plasma molecular absorption system group after treatment (TB, P < 0.01; AST, ALP, total bile acid P < 0.05). During 6 months of follow-up, two patients died, two became chronic, and eight recovered to normal. FP can cause clinically severe liver injury, characterized by gastrointestinal symptoms and jaundice, which can lead to death or become chronic. Both ALSSs were safe and well tolerated in drug-induced liver injury patients. After ALSS treatment, the levels of biochemical indicators of liver function improved significantly, indicating that ALSS might be beneficial for patients with severe drug-induced liver injury.

The mechanism of Psoralen and Isopsoralen hepatotoxicity as revealed by hepatic gene expression profiling in SD rats

BACKGROUND

The main bioactive components of Fructus psoraleae, such as psoralen and isopsoralen, are known to be hepatotoxic. However, its underlying mechanism is to be elucidated.

METHODS

To address this, SD rats were randomly divided into control group, 60 mg/kg psoralen group and 60 mg/kg isopsoralen group. Blood was collected to detect serum biochemical indices. RNA was extracted from liver samples, and then, cDNA gene expression profiles were analysed.

RESULTS

Psoralen administration significantly up-regulated serum AST (aspartate aminotransferase) while addition of isopsoralen increased serum ALT (alanine aminotransferase), AST, TBA (total bile acid) and TG (total triglyceride) levels. A total of 172 differentially expressed genes (DEGs) were acquired between psoralen group and control group while 884 DEGs were screened between isopsoralen group and control group. Chemical Carcinogenesis and Metabolism of Xenobiotics by Cytochrome P450 were the two most significantly enriched pathways as revealed by DEGs. Liver was the most impacted organ, and endoplasmic reticulum was the most impacted organelle in subcellular level. Finally, some kinds of cancers and cytochrome p450 oxidoreductase deficiency were predicted. Taken together, psoralen and isopsoralen might cause hepatotoxicity mainly through cytochrome P450 metabolism of xenobiotics. Furthermore, Cyp1a1, Cyp1a2, Gstm1 and Akr7a3 worked as key genes in hepatotoxicity. Moreover, endoplasmic reticulum was the main target subcellular structure in hepatotoxicity induced by psoralen and isopsoralen.

Multiorgan toxicity induced by EtOH extract of Fructus Psoraleae in Wistar rats

BACKGROUND

The fruits of Psoralea corylifolia L. (Fructus Psoraleae, FP) has a long history and a wide range of applications in the treatment of osteoporosis and leukoderma. Although it is well known that FP could cause hepatotoxicity and reproductive toxicity, less is known about its potential toxicity on multiple organs.

PURPOSE

This study aims to determine the multiorgan toxicity of EtOH extract of FP (EEFP) and to investigate the underlying mechanisms through a systematic evaluation in Wistar rats.

STUDY DESIGN AND METHODS

Wistar rats were orally administered with the EEFP at doses of 1.5, 1.0 and 0.5 g/kg for 28 days. Histopathologic and clinicopathologic analyses were performed, and the hormone levels in serum and the mRNA levels of enzymes related to the production of steroid hormones in adrenal glands were detected. The area of each band of adrenal glands and the steroid levels in the adrenal glands were also measured.

RESULTS

After the treatment, both the histopathologic and clinicopathologic examination showed that EEFP caused liver, prostate, seminal vesicle and adrenal gland damage. Among the enzymes involved in the regulation of adrenal steroid hormone production, NET, VMAT2, and CYP11B1 were upregulated, while CYP17A1 was downregulated. Among the adrenal steroid hormones, COR and NE were upregulated, while levels of DHT and serum ACRH and CRH decreased.

CONCLUSION

Our results indicated that adrenal gland, prostate, and seminal vesicles could also be the target organs of FP-induced toxicity. Abnormal enzyme and hormone production related to the hypothalamic pituitary adrenal (HPA) axis caused by the EEFP may be the potential toxic mechanism for changes in the adrenal gland and secondary sex organs of male rats.

Isopsoralen induces different subchronic toxicities and metabolomic outcomes between male and female Wistar rats

Isopsoralen is a major active and quality-control component of Fructus Psoraleae, but lacks a full safety evaluation. We evaluated the oral toxicity of isopsoralen in Wistar rats treated for 3 months at doses of 0, 3.5, 7.0, and 14 mg/kg. Additionally, the plasma metabolomics of isopsoralen in male and female rats treated for 3 months at doses of 0 and 14 mg/kg were investigated by gas chromatography-mass spectrometry. Many abnormalities were observed in the isopsoralen-treated rats, including suppression of body weight gain, and changes in serum biochemical parameters and visceral coefficients. Histopathological changes in liver, pancreatic, and reproductive system tissues were also observed in the isopsoralen-treated rats. The metabolomic analyses showed alterations in many metabolites (19 in female rats; 28 in male rats) after isopsoralen administration. The significant changes in these metabolites revealed metabolomic alterations in the isopsoralen-treated rats, especially in amino acid metabolism regardless of sex, including phenylalanine, tyrosine, and tryptophan biosynthesis and glycine, serine, and threonine metabolism. Furthermore, fatty acid metabolism comprised the main affected pathways in female rats, while lipid metabolism and energy metabolism were the main affected pathways in male rats.

Psoralen Induced Liver Injury by Attenuating Liver Regenerative Capability

Psoralen is a major component of the common traditional Chinese medicine Fructus Psoraleae (FP). In this study, we focused on psoralen to explore FP-induced hepatotoxicity and the underlying mechanisms. The acute oral median lethal dose of psoralen in ICR mice was determined to be 1,673 mg/kg. C57BL/6 mice were administered psoralen intragastrically at doses of 400 mg/kg or 800 mg/kg, and were sacrificed 24 h after treatment. Changes in various hepatotoxicity indicators demonstrated that psoralen can cause mild liver injury in mice. Psoralen inhibited the viability of normal human liver L02 cells in vitro by inducing S-phase arrest. In addition, psoralen in both the mouse livers and L02 cells upregulated cyclin E1 and p27 protein levels. The 2/3 partial hepatectomy mouse model was used to further explore the effects of psoralen on the liver regeneration and hepatocellular cycle arrest in vivo. The results showed that the decrease of liver regenerative and self-healing capabilities induced by hepatocellular cycle arrest may play an important role in the hepatotoxicity of psoralen. The further mechanism researches indicated that psoralen-induced hepatotoxicity was associated with inhibition of mTOR signalling pathway and mitochondrial injury; furthermore, MHY, an mTOR activator, partly alleviated the inhibition of mTOR and S-phase cycle arrest induced by psoralen in L02 cells. In conclusion, in this study we showed for the first time, that psoralen significantly induced liver injury in mice; the decrease of liver regenerative and compensatory capabilities induced by hepatocellular cycle arrest may play an important role in the progression of hepatotoxicity associated with the upregulation of cyclin E1 and p27, as well as the inhibition of mTOR signalling and mitochondrial injury. Our findings may contribute to the reduction of hepatotoxicity risk induced by Fructus Psoraleae.

The Evaluation of Toxicity Induced by Psoraleae Fructus in Rats Using Untargeted Metabonomic Method Based on UPLC-Q-TOF/MS

Psoraleae Fructus is the dry and mature fruit of leguminous plant Psoralea corylifolia L., with the activity of warming kidney and enhancing yang, warming spleen, and other effects. However, large doses can cause liver and kidney toxicity. Therefore, it is necessary to evaluate the toxicity of Psoraleae Fructus systematically. Although traditional biochemical indicators and pathological tests have been used to evaluate the safety of drug, these methods lack sensitivity and specificity, so a fast and sensitive analytical method is urgently needed. In this study, an ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) method was used to analyze the metabolic profiles of rat plasma. The changes of metabolites in plasma samples were detected by partial least squares-discriminant analysis (PLS-DA). Compared with the control group, after 7 days of administration, the pathological sections showed liver and kidney toxicity, and the metabolic trend was changed. Finally, 13 potential biomarkers related to the toxicity of Psoraleae Fructus were screened. The metabolic pathways involved were glycerol phospholipids metabolism, amino acid metabolism, energy metabolism, and so forth. The discovery of these biomarkers laid a foundation for better explaining the hepatotoxicity and nephrotoxicity of Psoraleae Fructus and provided a guarantee for its safety evaluation.

Hepatotoxicity Induced by Sophora flavescens and Hepatic Accumulation of Kurarinone, a Major Hepatotoxic Constituent of Sophora flavescens in Rats

Our previous study showed that kurarinone was the main hepatotoxic ingredient of Sophora flavescens, accumulating in the liver. This study characterized the mechanism of Sophora flavescens extract (ESF) hepatotoxicity and hepatic accumulation of kurarinone. ESF impaired hepatic function and caused fat accumulation in the liver after oral administration (1.25 and 2.5 g/kg for 14 days in rats). Serum metabolomics evaluation based on high-resolution mass spectrometry was conducted and real-time PCR was used to determine the expression levels of CPT-1, CPT-2, PPAR-α, and LCAD genes. Effects of kurarinone on triglyceride levels were evaluated in HL-7702 cells. Tissue distribution of kurarinone and kurarinone glucuronides was analyzed in rats receiving ESF (2.5 g/kg). Active uptake of kurarinone and kurarinone glucuronides was studied in OAT2-, OATP1B1-, OATP2B1-, and OATP1B3-transfected HEK293 cells. Our results revealed that after oral administration of ESF in rats, kurarinone glucuronides were actively transported into hepatocytes by OATP1B3 and hydrolyzed into kurarinone, which inhibited fatty acid β-oxidation through the reduction of l-carnitine and the inhibition of PPAR-α pathway, ultimately leading to lipid accumulation and liver injury. These findings contribute to understanding hepatotoxicity of kurarinone after oral administration of ESF.

Early indications of ANIT-induced cholestatic liver injury: Alteration of hepatocyte polarization and bile acid homeostasis

Hepatocyte polarization is essential for biliary secretion, and loss of polarity causes bile secretory failure and hepatotoxicity. Here, we showed that alpha-naphthyl isothiocyanate (ANIT)-induced liver injury was accompanied by the dynamic interruption of bile acid homeostasis in rat plasma, liver and bile, which was characterized by the redistribution of bile acids in plasma and bile and a small range of fluctuations in the liver. Molecular mechanism studies indicated that these factors are dynamically mediated by the disruption of bile acid transporters and hepatic tight junctions. Dynamic changes in tight junction (TJ) permeability were observed by hepatobiliary barrier function assessment. Hepatocyte polarization was disrupted by ANIT before the development of cholestatic hepatotoxicity and alteration of bile acid metabolic profiles, which were assayed by high-performance liquid chromatography-tandem mass spectrometry, further verifying TJ deficiency. S1PR1 activation with SEW2871 reduced ANIT-induced liver injury by reducing the total serum bile acid concentration, liver functional enzyme activity and inflammation. Our data suggest that hepatocyte polarization plays an important role in maintaining bile acid homeostasis before the development of cholestatic hepatotoxicity and that TJs were more prominent in the early stage of cholestasis. S1PR1 may be a potential target for the prevention of drug-induced cholestatic liver injury.

Bakuchiol Contributes to the Hepatotoxicity of Psoralea corylifolia in Rats

Psoralea corylifolia L. (Fructus Psoraleae) is widely used in Asia, but there are concerns about hepatotoxicity caused by constituents such as psoralens and bakukiol. Bakuchiol (BAK) has antiinflammatory, antipyretic, antibacterial antiviral, anticancer, and estrogenic activity but appears to be hepatotoxic in in vitro tests. This study investigated the hepatotoxicity in vivo in rats. Using intragastrically administered bakuchiol at doses of 52.5 and 262.5 mg/kg for 6 weeks. Bodyweight, relative liver weight, biochemical indicators, histopathology, mRNA expression of CYP7A1, HMG-CoA reductase, BSEP, PPARα, SREBP-2, and MRP3 were measured. Many abnormalities were observed in the bakuchiol-treated groups including suppression of weight gain and food intake, change of some parameters in serum biochemistry, and increased weight of liver. The mRNA expression of CYP7A1, HMG-CoA reductase, PPARα, and SREBP-2 decreased in bakuchiol-treated group, the expression of BSEP increased in bakuchiol-treated low dosage, and the expression of BSEP decreased in bakuchiol-treated high dosage. In conclusion, we provide evidence for the first time that bakuchiol can induce cholestatic hepatotoxicity, suggesting potential hepatotoxicity. The mechanism may be related to effects on liver lipid metabolism, but further investigation is necessary. Copyright © 2017 John Wiley & Sons, Ltd.

8-Methoxypsoralen disrupts MDR3-mediated phospholipids efflux and bile acid homeostasis and its relevance to hepatotoxicity

Since its discovery in 1987, multidrug resistance 3 P-glycoprotein (MDR3) had recognized to play a crucial role in the translocation of phospholipids from the inner to outer leaflets of bile canalicular membranes. An increasing number of reports suggest that drug-mediated functional disruption of MDR3 is responsible for drug-induced cholestasis. 8-Methoxypsoralen (8-MOP) is used clinically to treat psoriasis, vitiligo and other skin disorders. However, psoralens safety for long-term use is a concern. In the current study, we evaluate 8-MOP's potential hepatotoxicity and effects on bile formation. Sprague Dawley (SD) rats were treated daily 200mg/kg or 400mg/kg of 8-MOP orally for 28 days. The result showed a prominent decrease in biliary phospholipids output, which associated with the down-regulation of MDR3. Elevated bile acid serum level and increased biliary bile acid outputs were observed in 8-MOP-treated groups. The disturbance of bile acid homeostasis was associated with changes in enzymes and proteins involved in bile acid synthesis, regulation and transport. Human liver cell line L02 was used to determine on the mRNA and protein levels of MDR3. Cells treated with 8-MOP reveled a decrease in fluorescent PC (phosphatidylcholine) secretion into the pseudocanaliculi (formed between adjacent cells) compared with untreated cells. Our investigation represent the first evidence that 8-MOP can induce cholestatic liver injury by disturbing MDR3-mediated phospholipids efflux and bile acid homeostasis.

Studies on the metabolites difference of psoralen/isopsoralen in human and six mammalian liver microsomes in vitro by UHPLC-MS/MS

Psoralen and isopsoralen are found in many fruits, vegetables and traditional Chinese medicines (TCM), such as Ficus carica L., Celery, Fructus Psoraleae etc. Modern pharmacological studies found that psoralen and isopsoralen can show estrogen-like activity, antitumor, and antibacterial activities etc. However, some research results also show some liver damage associated with the use of psoralen/isopsoralen or related medicines in human. Many studies focus on the pharmacological activities of psoralen/isopsoralen, while it is important to choose the suitable pharmacological models which are relevant to human in drug metabolism and pharmacokinetic process. The aim of this study is to identify the metabolites of psoralen/isopsoralen by human and six mammalian liver microsomes, and compare the metabolites difference of different species. Psoralen/isopsoralen are metabolized by liver microsomes of different animals to form five and seven metabolites, respectively. The metabolism of psoralen/isopsoralen undergoes hydroxylation, hydrogenation and hydrolysis, and oxidation of the furan ring to generate a furanoepoxide or γ-ketoenal intermediate. Furanoepoxide then forms a dihydrodiol, while γ-ketoenal forms 6-(7-hydroxycoumaryl)-acetic acid (in psoralen)/8-(7-hydroxycoumaryl)-acetic acid (in isopsoralen). By comparing the types of metabolites in the seven liver microsomes, it shows that the metabolic behaviors of psoralen by Beagle dog is most relevant to human, while the metabolic behaviors of isopsoralen by Sprague-Dawley rat is most similar to human. By comparing the relative amounts of the main metabolites, it shows that the metabolic capabilities of Sprague-Dawley rat and Rhesus monkey for psoralen are most similar to human, while the metabolic capabilities of Mouse, Dunkin-Hartley guinea pig, Sprague-Dawley rat, and human for isopsoralen are similar. Furthermore, the results show that the metabolic capability of human for psoralen and isopsoralen are weaker than other mammal species. The results of this work are useful for studying the metabolism mechanism of psoralen/isopsolaren, and choosing the most relevant animal species for investigation of psoralen/isopsolaren from experimental animals to human.

Characterization of human UDP-glucuronosyltransferases responsible for glucuronidation and inhibition of norbakuchinic acid, a primary metabolite of hepatotoxicity and nephrotoxicity component bakuchiol inPsoralea corylifolia L

Norbakuchinic acid (NBKA) is the most abundant metabolite of bakuchiol (a hepatotoxicity and nephrotoxicity component inPsoralea corylifoliaL.) in plasma and urine.

Mechanism-based pharmacokinetic-pharmacodynamic modeling of salvianolic acid A effects on plasma xanthine oxidase activity and uric acid levels in acute myocardial infarction rats

1. Salvianolic acid A (SalA) was found to attenuate plasma uric acid (UA) concentration and xanthine oxidase (XO) activity in acute myocardial infraction (AMI) rats, which was characterized with developed mechanism-based pharmacokinetic-pharmacodynamic (PK-PD) model. 2. AMI was induced in rats by coronary artery ligation. Surviving AMI rats received a single intravenous dose of 5 mg/kg of SalA and normal saline. The plasma SalA concentrations were determined by HPLC-MS/MS method. The plasma UA concentrations were determined by HPLC method and plasma XO activity were measured spectrophotometrically. An integrated mathematical model characterized the relationship between plasma UA and SalA. 3. Pharmacokinetics was described using two-compartment model for SalA with linear metabolic process. In post-AMI rats, XO activity and UA concentrations were increased, while SalA dosing palliated this increase. These effects were well captured by using two series of transduction models, simulating the delay of inhibition on XO driven by SalA and UA elevation resulted from the multiple factors, respectively. 4. The effect was well described by the developed PK-PD model, indicating that SalA can exert cardiovascular protective effects by decreasing elevated plasma UA levels induced by AMI.

Multitargeted combination effects of a triherbal formulation containing ELP against osteoporosis: in vitro evidence

OBJECTIVES

An anti-osteoporotic herbal formula ELP containing Epimedii Herba (E), Ligustri Lucidi Fructus (L) and Psoraleae Fructus (P) was studied to investigate the herb-herb interaction (or the possible synergistic effect) among each component and to identify the principal herbs in different modes of action.

METHODS

Rat osteoblast-like UMR-106 cells proliferation, rat MSCs-derived osteoblastogenesis and RANKL-induced RAW 264.7 osteoclastogenesis were adopted to investigate the bone-forming activity and bone-degrading activity of the herbal extracts. In the statistical aspect, a modified Tallarida's approach was employed to assess the synergistic effects in herbal combinations.

KEY FINDINGS

Psoraleae Fructus is the active herb for stimulating osteoblast proliferation, and mild synergy was detected in the pairwise combinations EL, LP and formula ELP. In osteoblastogenesis assay, E and L are the principal herbs for promoting osteoblast differentiation and significant synergy was detected in the pairwise combination EL. For inhibiting osteoclast formation, L is the active herb and significant synergy was detected in the 3-way combination ELP.

CONCLUSIONS

The presence of E, L and P is essential for ELP formula as a whole to act against osteoporosis via enhancing bone formation and reducing bone reabsorption. An optimal dosage at 150 μg/ml was proposed for ELP based on our findings.

Investigations of the total flavonoids extracted from flowers of Abelmoschus manihot (L.) Medic against α-naphthylisothiocyanate-induced cholestatic liver injury in rats

ETHNOPHARMACOLOGY RELEVANCE

The decoction of the flowers of Abelmoschus manihot (L.) Medic was traditionally used for the treatment of jaundice and various types of chronic and acute hepatitis in Anhui and Jiangsu Provinces of China for hundreds of years. Phytochemical studies have indicated that total flavonoids extracted from flowers of A. manihot (L.) Medic (TFA) were the major constituents of the flowers. Our previous studies have investigated the hepatoprotective effects of the TFA against carbon tetrachloride (CCl4) induced hepatocyte damage in vitro and liver injury in vivo. This study aimed to investigate the protective effects and mechanisms of TFA on α-naphthylisothiocyanate (ANIT)-induced cholestatic liver injury in rats.

MATERIAL AND METHODS

The hepatoprotective activities of TFA (125, 250 and 500mg/kg) were investigated on ANIT-induced cholestatic liver injury in rats. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) were used as indices of hepatic cell damage and measured. Meanwhile, the serum levels of alkaline phosphatase (ALP), gamma-glutamyltransferase (GGT), total bilirubin (TBIL), direct bilirubin (DBIL), and total bile acid (TBA) were used as indices of biliary cell damage and cholestasis and evaluated. Hepatic malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), glutathione transferase (GST), tumor necrosis factor-α (TNF-α) and nitric oxide (NO) were measured in the liver homogenates. The bile flow in 4h was estimated and the histopathology of the liver tissue was evaluated. Furthermore, the expression of transporters, bile salt export pump (BSEP), multidrug resistance-associated protein 2 (MRP2), and Na(+)-taurocholate cotransporting polypeptide (NTCP) were studied by western blot and reverse transcription-quantitative real-time polymerase chain reaction (RT-PCR) to elucidate the protective mechanisms of TFA against ANIT-induced cholestasis.

RESULTS

The oral administration of TFA to ANIT-treated rats could reduce the increases in serum levels of ALT, AST, LDH, ALP, GGT, TBIL, DBIL and TBA. Decreased bile flow by ANIT was restored with TFA treatment. Concurrent administration of TFA reduced the severity of polymorphonuclear neutrophil infiltration and other histological damages, which were consistent with the serological tests. Hepatic MDA and GSH contents in liver tissue were reduced, while SOD and GST activities, which had been suppressed by ANIT, were elevated in the groups pretreated with TFA. With TFA intervention, levels of TNF-α and NO in liver were decreased. Additionally, TFA was found to increase the expression of liver BSEP, MRP2, and NTCP in both protein and mRNA levels in ANIT-induced liver injury with cholestasis.

CONCLUSION

TFA exerted protective effects against ANIT-induced liver injury. The possible mechanisms could be related to anti-oxidative damage, anti-inflammation and regulating the expression of hepatic transporters. It layed the foundation for the further research on the mechanisms of cholestasis as well as the therapeutic effects of A. manihot (L.) Medic for the treatment of jaundice.

Resveratrol effectively attenuates α-naphthyl-isothiocyanate-induced acute cholestasis and liver injury through choleretic and anti-inflammatory mechanisms

AIM

α-Naphthylisothiocyanate (ANIT) is a well-characterized cholestatic agent for rats. The aim of this study was to examine whether resveratrol could attenuate ANIT-induced acute cholestasis and liver injury in rats.

METHODS

SD rats were treated with resveratrol (15 or 30 mg/kg, ip) or a positive control drug ursodeoxycholic acid (100 mg/kg, po) for 5 consecutive days followed by a single dose of ANIT (60 mg/kg, po). Bile flow, and serum biochemical markers and bile constituents were measured 48 h after ANIT administration. Hepatic levels of oxidative repair enzymes (glutathione peroxidase, catalase and MnSOD), myeloperoxidase activity, TNF-α, IL-6 and ATP content, as well as the expression of liver transporter genes and proteins were assayed.

RESULTS

ANIT exposure resulted in serious cholestasis and liver injury, as shown by marked neutrophil infiltration in liver, dramatically increased serum levels of ALT, AST, GGT, ALP, TBA, TBIL, IBIL and DBIL, and significantly decreased bile excretion and biliary output of GSH and HCO3(-). ANIT significantly increased TNF-α and IL-6 release and myeloperoxidase activity, decreased mitochondrial biogenesis in liver, but had little effect on hepatic oxidative repair enzymes and ATP content. Furthermore, ANIT significantly decreased the expression of Mrp2, FXR and Cyp7a1, markedly increased Mrp3 expression in liver. Pretreatment with resveratrol attenuated ANIT-induced acute cholestasis and liver injury, and other pathological changes. Pretreatment with ursodeoxycholic acid was less effective.

CONCLUSION

Resveratrol effectively attenuates ANIT-induced acute cholestasis and liver injury in rats, possibly through suppression of neutrophil infiltration, as well as upregulation of expression of hepatic transporters and enzymes, thus decreasing accumulation of bile acids.