Tetramethylpyrazine prevents liver fibrotic injury in mice by targeting hepatocyte-derived and mitochondrial DNA-enriched extracellular vesicles.

Liver fibrosis is the common consequence of almost all liver diseases and has become an urgent clinical problem without efficient therapies. Recent evidence has shown that hepatocytes-derived extracellular vesicles (EVs) play important roles in liver pathophysiology, but little is known about the role of damaged hepatocytes-derived EVs in hepatic stellate cell (HSC) activation and following fibrosis. Tetramethylpyrazine (TMP) from Ligusticum wallichii Franchat exhibits a broad spectrum of biological activities including liver protection. In this study, we investigated whether TMP exerted liver-protective action through regulating EV-dependent intercellular communication between hepatocytes and HSCs. Chronic liver injury was induced in mice by CCl4 (1.6 mg/kg, i.g.) twice a week for 8 weeks. In the last 4 weeks of CCl4 administration, mice were given TMP (40, 80, 160 mg·kg-1·d-1, i.g.). Acute liver injury was induced in mice by injection of a single dose of CCl4 (0.8 mg/kg, i.p.). After injection, mice were treated with TMP (80 mg/kg) every 24 h. We showed that TMP treatment dramatically ameliorated CCl4-induced oxidative stress and hepatic inflammation as well as acute or chronic liver fibrosis. In cultured mouse primary hepatocytes (MPHs), treatment with CCl4 or acetaminophen resulted in mitochondrial dysfunction, release of mitochondrial DNA (mtDNA) from injured hepatocytes to adjacent hepatocytes and HSCs through EVs, mediating hepatocyte damage and fibrogenic responses in activated HSCs; pretreatment of MPHs with TMP (25 µM) prevented all these pathological effects. Transplanted serum EVs from TMP-treated mice prevented both initiation and progression of liver fibrosis caused by CCl4. Taken together, this study unravels the complex mechanisms underlying the protective effects of TMP against mtDNA-containing EV-mediated hepatocyte injury and HSC activation during liver injury, and provides critical evidence inspiring the development of TMP-based innovative therapeutic agents for the treatment of liver fibrosis.

[Determination of concentrations and toxicokinetics of triptolide in plasma and liver of mice by UHPLC-MS/MS].

This study aims to establish an ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS) method for determining the concentrations of triptolide(TP) in plasma and liver, and to explore the toxicokinetics of TP and the relationship between TP exposure and liver injury in C57 BL/6 mice, so as to provide reference for dissecting the toxicity mechanism of TP. The liquid chromatography was conducted with ZORBAX SB-C_(18) column(3.0 mm×100 mm, 3.5 µm) and the mobile phase of methanol-0.05 mmol·L~(-1) ammonium acetate. Electrospray ionization(ESI) and multiple reaction monitoring(MRM) mode were employed for mass spectrometry. After oral administration of TP(toxic dose 600 µg·kg~(-1)), the blood and liver tissues of the C57 BL/6 mice were collected at different time points to measure the TP concentrations in plasma and liver tissues. Furthermore, the blood biochemical indexes, including alkaline phosphatase(ALP), alanine aminotransferase(ALT), aspartate aminotransferase(AST), and total bile acid(TBA), were determined. After being processed by DAS 2.0, the experiment data showed that the TP in mice had the toxicokinetic parameters of T_(max)=5 min, C_(max)=14.38 ng·mL~(-1), t_(1/2)=0.76 h, AUC_(0-t)=5.63 h·ng·mL~(-1), MRT_(0-t)=0.56 h, and CL_(Z/F)=103.19 L·h~(-1)·kg~(-1). The trend of TP concentration in mouse liver tissue was consistent with that in plasma. The concentration of TP peaked at the time point of 5 min and then decreased until TP was completely metabolized. The plasma biochemical indexes(ALT, AST, ALP, and TBA) showed no significant changes within 3 h after TP administration. TP had high clearance rate and short residence time and did not significantly increase the blood biochemical indexes in mice. The results suggested that the exposure amount of free TP in vivo cannot directly cause liver injury, which might be caused by the binding of TP to some substances or the stimulation of inflammation and immune response.

Catalpol counteracts the pathology in a mouse model of Duchenne muscular dystrophy by inhibiting the TGF-ß1/TAK1 signaling pathway.

Duchenne muscular dystrophy (DMD) is a progressive neuromuscular disease caused by a mutation in the gene encoding the dystrophin protein. Catalpol is an iridoid glycoside found in Chinese herbs with anti-inflammatory, anti-oxidant, anti-apoptotic, and hypoglycemic activities that can protect against muscle wasting. In the present study we investigated the effects of catalpol on DMD. Aged Dystrophin-deficient (mdx) mice (12 months old) were treated with catalpol (100, 200 mg·kg-1·d-1, ig) for 6 weeks. At the end of the experiment, the mice were sacrificed, and gastrocnemius (GAS), tibialis anterior (TA), extensor digitorum longus (EDL), soleus (SOL) muscles were collected. We found that catalpol administration dose-dependently increased stride length and decreased stride width in Gait test. Wire grip test showed that the time of wire grip and grip strength were increased. We found that catalpol administration dose-dependently alleviated skeletal muscle damage, evidenced by reduced plasma CK and LDH activity as well as increased the weight of skeletal muscles. Catalpol administration had no effect on dystrophin expression, but exerted anti-inflammatory effects. Furthermore, catalpol administration dose-dependently decreased tibialis anterior (TA) muscle fibrosis, and inhibited the expression of TGF-ß1, TAK1 and α-SMA. In primary myoblasts from mdx mice, knockdown of TAK1 abolished the inhibitory effects of catalpol on the expression levels of TGF-ß1 and α-SMA. In conclusion, catalpol can restore skeletal muscle strength and alleviate skeletal muscle damage in aged mdx mice, thus may provide a novel therapy for DMD. Catalpol attenuates muscle fibrosis by inhibiting the TGF-ß1/TAK1 signaling pathway.

[2,3,5,4'-Tetrahydroxystibane-2-O-ß-D-glucoside induces liver injury by disrupting bile acid homeostasis and phospholipids efflux].

Polygonum multiflorum is a traditional Chinese herbal medicine and has many biological activities such as hair-blacking, anti-atherosclerosis, anti-inflammatory and anti-aging. However, the liver injury induced by P. multiflorum has aroused wide attention in recent years. 2,3,5,4'-tetrahydroxystibane-2-O-ß-D-glucoside(TSG) is a main component of P. multiflorum, but the role of TSG in inducing liver injury is unclear. The aim of present study was to evaluate TSG's potential liver injury and effects on bile acid homeostasis and phospholipids efflux. C57 BL/6 J mice received intraperitoneal administration of 400 mg·kg~(-1) of TSG daily for 15 days, and then biochemical indexes of liver injury and changes of phospholipid content were detected. The changes of bile acid compositions were detected by LC-MS/MS. The results showed TSG 400 mg·kg~(-1) significantly increased the content of serum total bile acid(TBA) and alkaline phosphatase(ALP). Elevated free bile acid levels were observed in TSG-treated groups, including ß-muricholic acid(ß-MCA), ursodeoxycholic acid(UDCA), hyodeoxycholic acid(HDCA), chenodeoxycholic acid(CDCA), deoxcholic acid(DCA) in serum and ß-MCA, CDCA in liver. TSG inhibited the protein expression of farnesoid X receptor(FXR) and down stream bile salt export pump(BSEP), which may result in the accumulation of bile acid. TSG also inhibited the expression of 25-hydroxycholesterol-7 alpha-hydroxylase(CYP7 B1), which may disturb the alternative pathway for bile acid synthesis. In addition, intraperitoneal injection of TSG 400 mg·kg~(-1) significantly decreased the content of phospholipids in bile. The research showed that TSG significantly inhibited the expression of multidrug resistance protein 2(MDR2) and destroyed the regular distribution of MDR2 on the bile duct membrane of liver. In vitro results showed that the IC_(50) of TSG on HepG2 cells was about 1 500 µmol·L~(-1) and TSG at 500 µmol·L~(-1)(for 24 h) could destroy the distribution of MDR2 on the bile duct membrane of liver. In conclusion, TSG induced liver injury by disrupting bile acid homeostasis and phospholipids efflux.

Author Correction: The natural product 4,10-aromadendranediol induces neuritogenesis in neuronal cells in vitro through activation of the ERK pathway.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The hypoglycemic mechanism of catalpol involves increased AMPK-mediated mitochondrial biogenesis.

Mitochondria serve as sensors of energy regulation and glucose levels, which are impaired by diabetes progression. Catalpol is an iridoid glycoside that exerts a hypoglycemic effect by improving mitochondrial function, but the underlying mechanism has not been fully elucidated. In the current study we explored the effects of catalpol on mitochondrial function in db/db mice and C2C12 myotubes in vitro. After oral administration of catalpol (200 mg·kg-1·d-1) for 8 weeks, db/db mice exhibited a decreased fasting blood glucose level and restored mitochondrial function in skeletal muscle. Catalpol increased mitochondrial biogenesis, evidenced by significant elevations in the number of mitochondria, mitochondrial DNA levels, and the expression of three genes associated with mitochondrial biogenesis: peroxisome proliferator-activated receptor gammaco-activator 1 (PGC-1α), mitochondrial transcription factor A (TFAM) and nuclear respiratory factor 1 (NRF1). In C2C12 myotubes, catalpol significantly increased glucose uptake and ATP production. These effects depended on activation of AMP-activated protein kinase (AMPK)-mediated mitochondrial biogenesis. Thus, catalpol improves skeletal muscle mitochondrial function by activating AMPK-mediated mitochondrial biogenesis. These findings may guide the development of a new therapeutic approach for type 2 diabetes.

[Mechanism of psoralen in aggravating hepatotoxicity induced by CCl_4 by delaying liver regeneration].

This study aimed to investigate whether psoralen can aggravate hepatotoxicity induced by carbon tetrachloride(CCl_4) by inducing hepatocyte cycle arrest and delaying liver regeneration. Female C57 BL/6 mice aged 6-8 weeks were randomly divided into control group, model group(CCl_4 group), combined group(CCl_4+PSO group) and psoralen group(PSO group). CCl_4 group and CCl_4+PSO group were given CCl_4 intraperitoneally at a dose of 100 µL·kg~(-1) once; olive oil of the same volume was given to control group and PSO group intraperitoneally; 12 h, 36 h and 60 h after CCl_4 injection, PSO group and CCl_4+PSO group were administrated with PSO intragastrically at a dose of 200 mg·kg~(-1); 0.5% CMC-Na of the same volume was administrated to control group and PSO group intragastrically. The weight of mice was recorded every day. Serum alanine aminotransferase(ALT) and aspartate aminotransferase(AST) were measured at 36 h, 60 h and 84 h after CCl_4 injection. Mice were sacrificed after collection of the last serum samples. Liver samples were collected, and liver weight was recorded. Histopathological and morphological changes of liver were observed by haematoxylin and eosin staining. The mRNA levels of HGF, TGF-ß, TNF-α, p53 and p21 in liver were detected by RT-qPCR. Western blot was used to detect the levels of cell cycle-related proteins. According to the results, significant increase of serum ALT and AST and centrilobular necrosis with massive inflammatory cell infiltration were observed in CCl_4+PSO group. After PSO administration in CCl_4 model, the mRNA levels of HGF(hepatocyte growth factor) and TNF-α were reduced, while the mRNA expressions of TGF-ß, p53 and p21 was up-regulated. The expression of PCNA(proliferating cell nuclear antigen) was significantly increased in CCl_4 and CCl_4+PSO group, while the relative protein level in CCl_4+PSO group was slightly lower than that in CCl_4 group. Compared with control and CCl_4 group, the expression of p27(cyclic dependent kinase inhibitor protein p27) was prominently increased in CCl_4+PSO group. These results indicated that hepatotoxicity induced by CCl_4 could be aggravated by intraperitoneal administration with PSO, and the repair process of liver could be delayed. The preliminary mechanism may be related to the inhibition of PCNA and regulation of some cell cycle-associated protein by psoralen, in which the significant up-regulation of p27, p53 and p21 may play important roles.

Synthesis and Target Identification of Benzoxepane Derivatives as Potential Anti-Neuroinflammatory Agents for Ischemic Stroke.

Benzoxepane derivatives were designed and synthesized, and one hit compound emerged as being effective in vitro with low toxicity. In vivo, this hit compound ameliorated both sickness behavior through anti-inflammation in LPS-induced neuroinflammatory mice model and cerebral ischemic injury through anti-neuroinflammation in rats subjected to transient middle cerebral artery occlusion. Target fishing for the hit compound using photoaffinity probes led to identification of PKM2 as the target protein responsible for anti-inflammatory effect of the hit compound. Furthermore, the hit exhibited an anti-neuroinflammatory effect in vitro and in vivo by inhibiting PKM2-mediated glycolysis and NLRP3 activation, indicating PKM2 as a novel target for neuroinflammation and its related brain disorders. This hit compound has a better safety profile compared to shikonin, a reported PKM2 inhibitor, identifying it as a lead compound in targeting PKM2 for the treatment of inflammation-related diseases.

Toxic effects of triptolide on adrenal steroidogenesis in H295R cells and female rats.

Triptolide (TP), a major active ingredient of Tripterygium wilfordii, exerts potent immunosuppressive effects in the treatment of rheumatoid arthritis but is not widely used in clinical practice due to its multiorgan toxicity, particularly hepatotoxicity, nephrotoxicity, and reproductive toxicity. An LC-MS/MS approach was employed to explore the endocrine-disrupting effects of TP. The endocrine-disrupting effects of various concentrations (0-100 nM) of TP for 48 hour were firstly investigated using an in vitro model (H295R cell line). It was found that TP did not decrease cell viability. The transcriptional levels of steroidogenic enzymes in H295R cells were assessed by quantificational real-time polymerase chain reaction. The possible adrenal and endocrine effects of oral administration of TP (0, 50, and 500 µg/kg) for 28 days on both normal and collagen-induced arthritis (CIA) rats were also explored. The serum and adrenal tissue hormone levels (corticosterone and progesterone) and adrenal histopathology were analyzed, with the results that TP significantly decreased the level of cortisol in H295R cells and the level of plasma corticosterone in both normal and CIA rats. Histological alterations in adrenal cortex were observed at the dose of 500 µg/kg. Exposure to TP for 48 hour had an obvious inhibitory effect on the messenger RNA transcript levels of HSD3B2, CYP21A2, CYP17A1, and CYP11B1, which is essential for the synthesis of corticosteroids. In a word, TP leads to the disorder of corticosteroid synthesis and secretion, and corticosteroid may be a potential biomarker for the treatment of multiorgan toxicity of TP.

[Label-free small molecule probe and target discovery of traditional Chinese medicine].

Target discovery is the core of elucidating the mechanism of traditional Chinese medicine( TCM),and it is also the key to correlate the chemical composition and pharmacological action of TCM. The traditional target screening methods such as the activitybased probe profiling,affinity chromatography,and protein microarray are commonly used in the past,however,which are limited in TCM due to the complexity of small molecules existed in the herbal medicine. The label-free small molecule probe is a recently well-applied technology in the target discovery of natural products,which is characterized by discovering the small molecule-protein ligation without any structural modification at the ligands,and is therefore suitable to the complex chemical constituents in TCM. Furthermore,this method is conducted on the basis of proteome,which is advanced in the discovery of new or multiple target proteins of TCM. Owing to the potential of label-free probe in the target discovery of TCM,its analytical principle,application status,and general protocol were reviewed in this paper. The label-free probe technology is anticipated to accelerate the mechanism-uncovering of TCM.

[Effect of triptolide on Th17/Treg cells in spleen].

Triptolide( TP) is isolated from the traditional Chinese medicine Tripterygium wilfordii,which exhibits notable immuneregulative effect. Th17 cells involve in inflammatory response and Treg cells contribute to immune tolerance. They both play an important role in immune response. Previous studies have investigated that TP induced hepatic Th17/Treg imbalance. However,the effect of TP on spleen Th17/Treg cells remains unclear. Therefore,the aim of present study was to investigate the effect of TP on Th17/Treg cells in spleen. In this study,the effect of TP on the proliferation of splenic lymphocyte was detected by cytotoxicity test in vitro. After different concentrations of TP( 2. 5,5,20,40 nmol·L~(-1)) were given to splenic lymphocyte,cytokines secreted from the supernatant of splenic lymphocyte were detected by cytometric bead array,and the expression of suppressor of cytokine signaling( SOCS) mRNA was detected by qRT-PCR. Female C57 BL/6 mice were continuously observed for 24 h after treatment of 500 µg·kg-1 TP. The effects of TP on the splenic tissue structure and the percentage of Th17/Treg cells were examined. The results showed that the IC50 of TP was19. 6 nmol·L~(-1) in spleen lymphocytes. TP inhibited the secretion of IL-2 and IL-10 and induced the expression of SOCS-1/3 mRNA in spleen lymphocytes at the dosage of 2. 5 and 5 nmol·L~(-1) after 24 h in vitro. Administration of TP at dosage of 500 µg·kg-1 had no significant spleen toxicity in vivo. TP treatment increased the percentage of Th17 cells after 12 h and inhibited the proportion of Treg cells after 12 and 24 h. In conclusion,TP reduced the secretion of IL-2 and IL-10 through SOCS-1/3 signaling pathway,thereby induced the percentage of Th17 cells and inhibited the percentage of Treg cells.

[Progress of effect and mechanisms of Tripterygium wilfordii on immune system].

Traditional Chinese medicine Tripterygium wilfordii Hook.f( TWHF) is a natural botanical drug in China. It has complex chemical compositions and has been used for a long history. TWHF was used as an insecticide to protect crops at early stage,and it was later found to have significant effects in the treatment of rheumatoid arthritis,attaining great concerns. With further researches,it was found that TWHF can treat various diseases in the medical field due to a variety of pharmacological activities such as anti-cancer,neuroprotection,anti-inflammatory and immune-suppressing,particularly. Multiple extracts of TWHF have unique immunosuppressive function,playing an immune role through multi-target and multi-channel,with significant effect in the treatment of autoimmune diseases. As an immune-suppressing drug,TWHF is worthy of in-depth research due to its broad application prospects. While achieving good clinical efficacy,reports about its toxic effects to multiple systems of the body are also increasing,greatly hindering its clinical application. In order to fully understand the immune-suppressing function of TWHF and reduce or avoid the occurrence of toxic and side effects,we summarized recent progress of TWHF on the immune organs,cells and factors in recent years,as well as the pharmacology and toxic effects,hoping to provide a scientific and reasonable reference for its wider use in clinical treatment.

[Study on difference of liver toxicity and its molecular mechanisms caused by Tripterygium wilfordii multiglycoside and equivalent amount of triptolid in rats].

Tripterygium wilfordii multiglycoside( GTW),an extract derived from T. wilfordii,has been used for rheumatoid arthritis and other immune diseases in China. However its potential hepatotoxicity has not been investigated completely. Firstly,the content of triptolid( TP) in GTW was 0. 008% confirmed by a LC method. Then after oral administration of GTW( 100,150 mg·kg-1) and TP( 12 µg·kg-1) in female Wistar rats for 24 h,it was found that 150 mg·kg-1 GTW showed more serious acute liver injury than 12 µg·kg-1 TP,with the significantly increased lever of serum ALT,AST,TBA,TBi L,TG and bile duct hyperplasia even hepatocyte apoptosis. The expression of mRNA and proteins of liver bile acid transporters such as BSEP,MRP2,NTCP and OATP were down-regulated significantly by GTW to inhibit bile acid excretion and absorption,resulting in cholestatic liver injury. Moreover,GTW was considered to be involved in hepatic oxidative stress injury,although it down-regulated SOD1 and GPX-1 mRNA expression without significant difference in MDA and GSH levels. In vitro,we found that TP was the main toxic component in GTW,which could inhibit cell viability up to 80% in Hep G2 and LO2 cells at the dose of 0. 1 µmol·L-1. Next a LC-MS/MS method was used to detect the concentration of triptolid in plasma from rats,interestingly,we found that the content of TP in GTW was always higher than in the same amount of TP,suggesting the other components in GTW may affect the TP metabolism. Finally,we screened the substrate of p-glycoprotein( p-gp) in Caco-2 cells treated with components except TP extrated from GTW,finding that wilforgine,wilforine and wilfordine was the substrate of p-gp. Thus,we speculated that wilforgine,wilforine and wilfordine may competitively inhibit the excretion of TP to bile through p-gp,leading to the enhanced hepatotoxity caused by GTW than the same amount of TP.

Activation of natural killer T cells contributes to triptolide-induced liver injury in mice.

Triptolide (TP) is the main active ingredient of Tripterygium wilfordii Hook.f, which has attracted great interest due to its promising efficacy for autoimmune diseases and tumors. However, severe adverse reactions, especially hepatotoxicity, have restricted its approval in the market. In the present study we explored the role of hepatic natural killer T (NKT) cells in the pathogenesis of TP-induced liver injury in mice. TP (600 µg/kg/day, i.g.) was administered to female mice for 1, 3, or 5 days. We found that administration of TP dose-dependently induced hepatotoxicity, evidenced by the body weight reduction, elevated serum ALT and AST levels, as well as significant histopathological changes in the livers. However, the mice were resistant to the development of TP-induced liver injury when their NKT cells were depleted by injection of anti-NK1.1 mAb (200 µg, i.p.) on days -2 and -1 before TP administration. We further revealed that TP administration activated NKT cells, dominantly releasing Th1 cytokine IFN-γ, recruiting neutrophils and macrophages, and leading to liver damage. After anti-NK1.1 injection, however, the mice mainly secreted Th2 cytokine IL-4 in the livers and exhibited a significantly lower percentage of hepatic infiltrating neutrophils and macrophages upon TP challenge. The activation of NKT cells was associated with the upregulation of Toll-like receptor (TLR) signaling pathway. Collectively, these results demonstrate a novel role of NKT cells contributing to the mechanisms of TP-induced liver injury. More importantly, the regulation of NKT cells may promote effective measures that control drug-induced liver injury.

The natural product 4,10-aromadendranediol induces neuritogenesis in neuronal cells in vitro through activation of the ERK pathway.

Recent studies focus on promoting neurite outgrowth to remodel the central nervous network after brain injury. Currently, however, there are few drugs treating brain diseases in the clinic by enhancing neurite outgrowth. In this study, we established an NGF-induced PC12 differentiation model to screen novel compounds that have the potential to induce neuronal differentiation, and further characterized 4,10-Aromadendranediol (ARDD) isolated from the dried twigs of the Baccharis gaudichaudiana plant, which exhibited the capability of promoting neurite outgrowth in neuronal cells in vitro. ARDD (1, 10 µmol/L) significantly enhanced neurite outgrowth in NGF-treated PC12 cells and N1E115 cells in a time-dependent manner. In cultured primary cortical neurons, ARDD (5, 10 µmol/L) not only significantly increased neurite outgrowth but also increased the number of neurites on the soma and the number of bifurcations. Further analyses showed that ARDD (10 µmol/L) significantly increased the phosphorylation of ERK1/2 and the downstream GSK-3ß, subsequently induced ß-catenin expression and up-regulated the gene expression of the Wnt ligands Fzd1 and Wnt3a in neuronal cells. The neurite outgrowth-promoting effect of ARDD in neuronal cells was abolished by pretreatment with the specific ERK1/2 inhibitor PD98059, but was partially reversed by XAV939, an inhibitor of the Wnt/ß-catenin pathway. ARDD also increased the expression of BDNF, CREB and GAP-43 in N1E115 cells, which was reversed by pretreatment with PD98059. In N1E115 cells subjected to oxygen and glucose deprivation (OGD), pretreatment with ARDD (1-10 µmol/L) significantly enhanced the phosphorylation of ERK1/2 and induced neurite outgrowth. These results demonstrated that the natural product ARDD exhibits neurite outgrowth-inducing activity in neurons via activation of the ERK signaling pathway, which may be beneficial to the treatment of brain diseases.

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.

Triptolide disrupts the actin-based Sertoli-germ cells adherens junctions by inhibiting Rho GTPases expression.

Triptolide (TP), derived from the medicinal plant Triterygium wilfordii Hook. f. (TWHF), is a diterpene triepoxide with variety biological and pharmacological activities. However, TP has been restricted in clinical application due to its narrow therapeutic window especially in reproductive system. During spermatogenesis, Sertoli cell cytoskeleton plays an essential role in facilitating germ cell movement and cell-cell actin-based adherens junctions (AJ). At Sertoli cell-spermatid interface, the anchoring device is a kind of AJ, known as ectoplasmic specializations (ES). In this study, we demonstrate that ß-actin, an important component of cytoskeleton, has been significantly down-regulated after TP treatment. TP can inhibit the expression of Rho GTPase such as, RhoA, RhoB, Cdc42 and Rac1. Downstream of Rho GTPase, Rho-associated protein kinase (ROCKs) gene expressions were also suppressed by TP. F-actin immunofluorescence proved that TP disrupts Sertoli cells cytoskeleton network. As a result of ß-actin down-regulation, TP treatment increased expression of testin, which indicating ES has been disassembled. In summary, this report illustrates that TP induces cytoskeleton dysfunction and disrupts cell-cell adherens junctions via inhibition of Rho GTPases.

A novel GSK-3ß inhibitor YQ138 prevents neuronal injury induced by glutamate and brain ischemia through activation of the Nrf2 signaling pathway.

AIM: To discover neuroprotective compounds and to characterize the discovered active compound YQ138 as a novel GSK-3ß inhibitor. METHODS: Primary rat cerebellar granule cells (CGCs) were treated with glutamate, and cell viability was analyzed with MTT assay, which was used as in vitro model for screening neuroprotective compounds. Active compound was further tested in OGD- or serum deprivation-induced neuronal injury models. The expression levels of GSK-3ß downstream proteins (Nrf2, HO-1, NQO1, Tau and ß-catenin) were detected with Western blotting. For evaluating the neuroprotective effects in vivo, adult male rats were subjected to transient middle cerebral artery occlusion (tMCAO), then treated with YQ138 (10 mg/kg, iv) at 2, 4 and 6 h after ischemia onset. RESULTS: From a compound library consisting of about 2000 potential kinase inhibitors, YQ138 was found to exert neuroprotective effects: pretreatment with YQ138 (0.1-40 µmol/L) dose-dependently inhibited glutamate-induced neuronal death. Furthermore, pretreatment with YQ138 (10 µmol/L) significantly inhibited OGD- or serum deprivation-induced neuronal death. Among a panel of seven kinases tested, YQ138 selectively inhibited the activity of GSK-3ß (IC50=0.52 nmol/L). Furthermore, YQ138 dose-dependently increased the expression of ß-catenin, and decreased the phosphorylation of Tau in CGCs. Moreover, YQ138 significantly increased the expression of GSK-3ß downstream antioxidative proteins Nrf2, HO-1, NQO1, GSH and SOD in CGCs. In rats with tMCAO, administration of YQ138 significantly decreased infarct volume, improved the neurological deficit, and increased the expression of Nrf2 and HO-1 and the activities of SOD and GSH in the cerebral cortex. CONCLUSION: A novel GSK-3ß inhibitor YQ138 effectively suppresses brain ischemic injury in vitro and in vivo.

Antitumor effect of Deoxypodophyllotoxin on human breast cancer xenograft transplanted in BALB/c nude mice model.

Recently, biologically active compounds isolated from plants used in herbal medicine have been the center of interest. Deoxypodophyllotoxin (DPT), structurally closely related to the lignan podophyllotoxin, was found to be a potent antitumor and antiproliferative agent, in several tumor cells, in vitro. However, DPT has not been used clinically yet because of the lack of in vivo studies. This study is the first report demonstrating the antitumor effect of DPT on MDA-MB-231 human breast cancer xenografts in nude mice. DPT, significantly, inhibited the growth of MDA-MB-231 xenograft in BALB/c nude mice. The T/C value (the value of the relative tumor volume of treatment group compared to the control group) of groups treated with 5, 10, and 20 mg/kg of intravenous DPT-HP-ß-CD was 42.87%, 34.04% and 9.63%, respectively, suggesting the positive antitumor activity of DPT. In addition, the antitumor effect of DPT-HP-ß-CD (20 mg/kg) in human breast cancer MDA-MB-231 xenograft was more effective than etoposide (VP-16) (20 mg/kg) and docetaxel (20 mg/kg). These findings suggest that this drug is a promising chemotherapy candidate against human breast carcinoma.

[The effect of zinc on inflammatory reaction in rats with focal cerebral ischemia/reperfusion].

This study was conducted to investigate the effect of N,N-diethyldithiocarbamate (DEDTC) on the changes of inflammatory cytokines after focal cerebral ischemia-reperfusion injury in rats and to explore the potential mechanism. Two hundred Sprague Dawley male rats were randomly divided into sham group, middle cerebral artery occlusion (MCAO) group and DEDTC (Zn chelator) treated group. MCAO model was established by the suture method. Rats were sacrificed at 6, 12 and 24 h after reperfusion. 2,3,5-Triphenyltetrazolium chloride (TTC) was conducted to measure the brain infarct volume. Newport Green was adopted to detect the chelatable zinc in the cerebral penumbra. Enzyme linked immunosorbent assay(ELISA) was performed to determine the release of TNF-α and IL-6. Furthermore Western blot was used to analyze the expression of the PI3K/Akt/NF-κB signaling pathway. The results showed that DEDTC resulted in a significant reduction of brain infarct volume and an obvious improvement of neurological function compared to the model group. DEDTC also decreased the release of inflammatory cytokines such as TNF-α and IL-6. The activation of PI3K/Akt/NF-κB signaling pathway induced by I/R injury was drastically inhibited by the treatment with DEDTC. In conclusion, DEDTC could protect the brain against ischemic injury induced by MCAO, which might be relevant to the inhibition of PI3K/Akt/NF-κB signaling pathway, and the decreased release of inflammatory cytokines.