Transient simulation of the electrical hysteresis in a metal/polymer/metal nanostructure.

The time-dependent quantum transportation through a metal/polymer/metal system is theoretically investigated on the basis of a Su-Schrieffer-Heeger model combined with the hierarchical equations of motion formalism. Using a non-adiabatic dynamical method, the evolution of the electron subspace and lattice atoms with time can be obtained. It is found that the calculated transient currents vary with time and reach stable values after a response time under the bias voltages. However, the stable current as the system reaches its dynamical steady state exhibits a discrepancy between two sweep directions of the bias voltage, which results in pronounced electrical hysteresis loops in the current-voltage curve. By analyzing the evolution of instantaneous energy eigenstates, the occupation number of the instantaneous eigenstates, and the lattice of the polymer, we show that the formation of excitons and the delay of their annihilation are responsible for the hysteretic current-voltage characteristics, where electron-phonon interactions play the key factor. Furthermore, the hysteresis width and amplitude can also be modulated by the strength of the electron-phonon coupling, level-width broadening function, and temperature. We hope these results about past condition-dependent switching performance at a sweep voltage can provide further insight into some of the basic issues of interest in hysteresis processes in conducting polymers.

Prevotella histicola ameliorates DSS-induced colitis by inhibiting IRE1α-JNK pathway of ER stress and NF-κB signaling.

Inflammatory bowel disease (IBD) is a chronic and recurrent gastrointestinal inflammation regulated by intricate mechanisms. Recently, prebiotics is considered as promising nutritional strategy for the prevention and treatment of IBD. Prevotella histicola (P. histicola), an emerging probiotic, possesses apparently anti-inflammatory bioactivity. However, the role and underlying mechanism of P. histicola on IBD remain unclear. Hence, we probe into the effect of P. histicola on dextran sulfate sodium (DSS)-induced colitis and clarified the potential mechanism. Our results revealed that DSS-induced colonic inflammatory response and damaged epithelial barrier in mice were attenuated by oral administration of P. histicola. Moreover, supplementary P. histicola significantly enriched short-chain fatty acid (SCFA)-producing bacteria (Lactobacillus, and Bacillus) and reduced pathogenic bacteria (Erysipelotrichaceae, Clostridium, Bacteroides) in DSS-induced colitis. Notably, In DSS-treated mice, endoplasmic reticulum stress (ERS) was persistently activated in colonic tissue. Conversely, P. histicola gavage suppressed expansion of endoplasmic reticulum, downregulated PERK-ATF4-CHOP and IRE1α-JNK pathway. In vitro, the P. histicola supernatant eliminated LPS-induced higher production of pro-inflammatory cytokines regulated by NF-κB and impairment of epithelial barrier by inhibiting IRE1α-JNK signaling in Caco-2 cell. In summary, our study indicated that P. histicola mitigated DSS-induced chronic colitis via inhibiting IRE1α-JNK pathway and NF-κB signaling. These findings provide the new insights into the promotion of gut homeostasis and the application potential of P. histicola as a prebiotic for IBD in the future.

Revealing the Role of Dynamic and Static Disorder on Charge-Transfer-State Absorption in Polymer Solar Cells.

In polymer solar cells (PSCs), charge-transfer (CT) state absorption plays an important role in evaluating the CT-state energy and energy loss. However, due to the disordered nature of polymers, a comprehensive understanding of CT absorption properties remains elusive. Especially, the dominant role of dynamic and static disorder in determining CT absorption is frequently debated. Herein, we theoretically constructed an organic donor-acceptor model to investigate the impact of these two types of disorders on CT absorption properties. It is demonstrated that the CT absorption properties depend significantly on the type of disorder. Specifically, it is found that dynamic disorder has a more significant impact on the peak and position of CT absorption as well as the broadening properties, compared to static disorder. The study indicates that minimizing dynamic disorder can lead to a reduction in overall disorder, which is beneficial for improving the performance of PSCs.

The role of SUMO specific peptidase 3 in secondary inflammation of ischemic stroke in mice.

Ischemic stroke is the main cause of death and disability, and microglia play a crucial role in the pathophysiology of hypoxic ischemic brain injury. We found that SENP3 is highly expressed in the early stages of ischemic stroke in both in vivo and in vitro mouse models, and may be related to the deSUMOylation of the key kinase MKK7 in the TLR4/p-JNK signaling pathway. Knocking down SENP3 can inhibit the deSUMOylation of MKK7, thereby inhibiting the activation of the TLR4/p-JNK signaling pathway in an in vitro stroke model. Proteomic analysis showed that SENP3 undergoes phosphorylation at the T429 site after ischemic stroke. Computer simulation predictions show a significant enhancement of the interaction between pT429-SENP3 and MKK7, which has been confirmed through experiments on the interaction of biological macromolecules (SPR). The mitochondrial metabolic abnormalities caused by energy abnormalities in the early stages of stroke provide a good explanation for the phosphorylation of SENP3. Therefore, we used the mitochondrial complex inhibitor TTFA to reverse demonstrate that the phosphorylation of SENP3 comes from the large amount of adenosine triphosphate produced by mitochondrial abnormal metabolism caused by early oxygen glucose deficiency. Finally, proteomic analysis indicates that a significant amount of oxidative phosphorylation does occur in the early stages of stroke. In summary, targeted regulation of SENP3 phosphorylation to affect the deSUMOylation of MKK7 may inhibit secondary inflammation in ischemic stroke.

Cytoplasmic Endonuclease G promotes nonalcoholic fatty liver disease via mTORC2-AKT-ACLY and endoplasmic reticulum stress.

Endonuclease G (ENDOG), a nuclear-encoded mitochondrial intermembrane space protein, is well known to be translocated into the nucleus during apoptosis. Recent studies have shown that ENDOG might enter the mitochondrial matrix to regulate mitochondrial genome cleavage and replication. However, little is known about the role of ENDOG in the cytosol. Our previous work showed that cytoplasmic ENDOG competitively binds with 14-3-3γ, which released TSC2 to repress mTORC1 signaling and induce autophagy. Here, we demonstrate that cytoplasmic ENDOG could also release Rictor from 14-3-3γ to activate the mTORC2-AKT-ACLY axis, resulting in acetyl-CoA production. Importantly, we observe that ENDOG could translocate to the ER, bind with Bip, and release IRE1a/PERK to activate the endoplasmic reticulum stress response, promoting lipid synthesis. Taken together, we demonstrate that loss of ENDOG suppresses acetyl-CoA production and lipid synthesis, along with reducing endoplasmic reticulum stress, which eventually alleviates high-fat diet-induced nonalcoholic fatty liver disease in female mice.

The effect of the intramolecular disorder on hot exciton dynamics in polymer solar cells.

In polymer solar cells (PSCs), the contribution of hot excitons to charge generation is strongly limited by their relatively low yield and ultrafast internal conversion (IC) process. In recent years, different strategies have been proposed to modulate the hot exciton dynamics, but a direct correlation between the microscopic properties of the polymer and hot exciton dynamics is still not completely clear. Here, we theoretically investigate the effect of intramolecular disorder, including the diagonal disorder (DD) and off-diagonal disorder (ODD), on the hot exciton dynamics based on the tight-binding model calculations. We find that the effect of ODD on the hot exciton yield is more significant than that of DD. In addition, we find that the IC relaxation time of hot excitons depends nonmonotonically on the intensity of DD and ODD, indicating that the intramolecular disorder can modulate the competitive relationship between the spontaneous dissociation of hot excitons and the IC process. This work provides a guide for promoting charge generation in PSCs dominated by hot exciton dissociation.

Total alkaloids of Fritillaria unibracteata var. wabuensis bulbus ameliorate chronic asthma via the TRPV1/Ca2+/NFAT pathway.

BACKGROUND: Asthma is a chronic inflammatory disease that is challenging to treat. Fritillaria unibracteata var. wabuensis (FUW) is the plant origin for the famous Chinese antitussive medicine Fritillaria Cirrhosae Bulbus. The total alkaloids of Fritillaria unibracteata var. wabuensis bulbus (TAs-FUW) have anti-inflammatory properties and may be used to treat asthma. PURPOSE: To explore whether TAs-FUW have bioactivity against airway inflammation and a therapeutic effect on chronic asthma. METHODS: The alkaloids were extracted via ultrasonication in a cryogenic chloroform-methanol solution after ammonium-hydroxide percolation of the bulbus. UPLC-Q-TOF/MS was used to characterize the composition of TAs-FUW. An ovalbumin (OVA)-induced asthmatic mouse model was established. We used whole-body plethysmography, ELISA, western blotting, RT-qPCR, and histological analyses to assess the pulmonary pathological changes in these mice after TAs-FUW treatment. Additionally, TNF-α/IL-4-induced inflammation in BEAS-2B cells was used as an in vitro model, whereby the effects of various doses of TAs-FUW on the TRPV1/Ca2+-dependent NFAT-induced expression of TSLP were assessed. Stimulation and inhibition of TRPV1 receptors by capsaicin (CAP) and capsazepine (CPZ), respectively, were used to validate the effect of TAs-FUW. RESULTS: The UPLC-Q-TOF/MS analysis revealed that TAs-FUW mainly contain six compounds (peiminine, peimine, edpetiline, khasianine, peimisine, and sipeimine). TAs-FUW improved airway inflammation and obstruction, mucus secretion, collagen deposition, and leukocyte and macrophage infiltration, and downregulated TSLP by inhibiting the TRPV1/NFAT pathway in asthmatic mice. In vitro, the application of CPZ demonstrated that the TRPV1 channel is involved in TNF-α/IL-4-mediated regulation of TSLP. TAs-FUW suppressed TNF-α/IL-4-induced TSLP generation expression by regulating the TRPV1/Ca2+/NFAT pathway. Furthermore, TAs-FUW reduced CAP-induced TSLP release by inhibiting TRPV1 activation. Notably, sipeimine and edpetiline each were sufficient to block the TRPV1-mediated Ca2+ influx. CONCLUSION: Our study is the first to demonstrate that TNF-α/IL-4 can activate the TRPV1 channel. TAs-FUW can alleviate asthmatic inflammation by suppressing the TRPV1 pathway and thereby preventing the increase in cellular Ca2+ influx and the subsequent NFAT activation. The alkaloids in FUW may be used for complementary or alternative therapies in asthma.

Acetaminophen-induced liver injury: Molecular mechanism and treatments from natural products.

Acetaminophen (APAP) is a widely used analgesic and antipyretic over-the-counter medicine worldwide. Hepatotoxicity caused by APAP overdose is one of the leading causes of acute liver failure (ALF) in the US and in some parts of Europe, limiting its clinical application. Excessive APAP metabolism depletes glutathione and increases N-acetyl-p-benzoquinoneimide (NAPQI) levels, leading to oxidative stress, DNA damage, and cell necrosis in the liver, which in turn leads to liver damage. Studies have shown that natural products such as polyphenols, terpenes, anthraquinones, and sulforaphane can activate the hepatocyte antioxidant defense system with Nrf2 as the core player, reduce oxidative stress damage, and protect the liver. As the key enzyme metabolizing APAP into NAPQI, cytochrome P450 enzymes are also considered to be intriguing target for the treatment of APAP-induced liver injury. Here, we systematically review the hepatoprotective activity and molecular mechanisms of the natural products that are found to counteract the hepatotoxicity caused by APAP, providing reference information for future preclinical and clinical trials of such natural products.

Protocatechuic aldehyde acts synergistically with dacarbazine to augment DNA double-strand breaks and promote apoptosis in cutaneous melanoma cells.

BACKGROUND: Despite rapid developments in immunotherapy and targeted therapy, dacarbazine (DTIC)-based chemotherapy still has been placed at the first-line for advanced melanoma patients who are after failure of immunotherapy or targeted therapy. However, the limited response rate and survival benefit challenge the DTIC-based chemotherapy for advanced melanoma patients. METHODS: Two melanoma cell lines, A375 and SK-MEL-28 were cultured with PA and DTIC over a range of concentrations for 72 h and the cell viabilities were detected by CCK8 assay. The Bliss model and ZIP model were used for calculating the synergistic effect of PA and DTIC. DNA double-strand breaks in the two cell lines were examined by the Comet assay, and cell apoptosis was analyzed by flow cytometry. The short hairpin RNA (shRNA)-mediated knockdown, Real-time polymerase chain reaction (RT-PCR) and Western blot were performed for molecular analysis. RESULTS: In the present study, we report that Protocatechuic aldehyde (PA) synergistically enhances the cytotoxicity of DTIC to two melanoma cell lines, A375 and SK-MEL-28. The combination of PA and DTIC augments DNA double-strand breaks and increases cell apoptosis. Further mechanism study reveals that PA destabilizes MGMT protein (O-6-Methylguanine-DNA Methyltransferase) through the ubiquitin-proteasome process and directly repairs DTIC-induced genetic lesions. Knockdown of MGMT compromises the synergistic effect between PA and DTIC. CONCLUSION: Our study demonstrates that the bioactive compound, Protocatechuic aldehyde, synergistically promotes the cytotoxicity of DTIC to melanoma cells through destabilization of MGMT protein. It could be a potential candidate for melanoma chemotherapy.

Water extract from Herpetospermum pedunculosum attenuates oxidative stress and ferroptosis induced by acetaminophen via regulating Nrf2 and NF-κB pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: The seeds of Herpetospermum pedunculosum seeds is a traditional Tibetan medicine possessing hepatoprotective effect, but their protective effect on APAP-induced liver injury has not yet been explored. AIM OF THE STUDY: This study aimed at exploring the protective effect and mechanism of the water extract from the seeds of Herpetospermum pedunculosum (HPWE) on APAP-induced liver injury in vitro and in vivo. MATERIALS AND METHODS: In vitro and in vivo models of liver injury were established by APAP treatment of BRL-3A cells or mice. The effect and mechanism of action of HPWE were explored by using cell viability assay, ELISA, immunofluorescence assay, RT-qPCR, histological observation and immunohistochemistry staining, western blotting and high-content imaging system. RESULTS: In vitro experiments showed that HPWE treatment significantly promoted the cell viability, decreased ALT/AST level, and inhibited the ROS accumulation induced by APAP. Furthermore, HPWE and Fer-1 alleviated erastin-induced cell ferroptosis, upregulated GPX4 and SLC7A11 expression, and reduced lipid peroxides production. Further study showed that APAP could also downregulate the expression of GPX4 and SLC7A11, causing cell ferroptosis, and HPWE and Fer-1 counteracted this process. Our in vivo experiments showed that pretreatment with HPWE in APAP-treated mice significantly alleviated the serum ALT/AST level, decreased necrotic cells and inflammatory cell infiltration, upregulated the expression of GPX4 and SLC7A11. Further, it was demonstrated that HPWE treatment downregulated Nrf2 and its downstream target genes, i.e. HO-1 and NQO1 expression at the mRNA and protein levels. HPWE treatment also inhibited the activation of NF-κB p65 and downregulated its target genes, i.e. TNF-α and IL-1ß, expression. CONCLUSION: The present study showed that HPWE could relieve oxidative stress and ferroptosis via activating Nrf2 signaling pathway and inhibiting NF-κB mediated pathway.

Integrative analysis of the steroidal alkaloids distribution and biosynthesis of bulbs Fritillariae Cirrhosae through metabolome and transcriptome analyses.

BACKGROUND: Bulbus Fritillariae Cirrhosae (BFC) is an endangered high-altitude medicine and food homology plant with anti-tumor, anti-asthmatic, and antitussive activities as it contains a variety of active ingredients, especially steroidal alkaloids. Bulbus Fritillariae Thunbergia (BFT) is another species of Fritillaria that grows at lower altitude areas. Production of plant-derived active ingredients through a synthetic biology strategy is one of the current hot topics in biological research, which requires a complete understanding of the related molecular pathways. Our knowledge of the steroidal alkaloid biosynthesis in Fritillaria species is still very limited. RESULTS: To promote our understanding of these pathways, we performed non-target metabolomics and transcriptome analysis of BFC and BFT. Metabolomics analysis identified 1288 metabolites in BFC and BFT in total. Steroidal alkaloids, including the proposed active ingredients of Fritillaria species peimine, peimisine, peiminine, etc., were the most abundant alkaloids detected. Our metabolomics data also showed that the contents of the majority of the steroidal alkaloids in BFC were higher than in BFT. Further, our comparative transcriptome analyses between BFC and BFT identified differentially expressed gene sets among these species, which are potentially involved in the alkaloids biosynthesis of BFC. CONCLUSION: These findings promote our understanding of the mechanism of steroidal alkaloids biosynthesis in Fritillaria species.

A phase II open label, single arm study of hypofractionated stereotactic radiotherapy with chemoradiotherapy using intensity-modulated radiotherapy for newly diagnosed glioblastoma after surgery: the HSCK-010 trial protocol.

BACKGROUND: The most frequently diagnosed primary brain tumor is glioblastoma (GBM). Nearly all patients experience tumor recurrence and up to 90% of which is local recurrence. Thus, increasing the therapeutic ratio of radiotherapy using hypofractionated stereotactic radiotherapy (HSRT) can reduce treatment time and may increase tumor control and improve survival. To evaluate the efficacy and toxicity of the combination of HSRT and intensity-modulated radiotherapy (IMRT) with temozolomide after surgery in GBM patients and provide evidence for further randomized controlled trials. METHODS/DESIGN: HSCK-010 is an open-label, single-arm phase II trial (NCT04547621) which includes newly diagnosed GBM patients who underwent gross total resection. Patients will receive the combination of 30 Gy/5fx HSRT, and 20 Gy/10fx IMRT adjuvant therapy with concurrent temozolomide and adjuvant chemotherapy. The primary endpoint is overall survival (OS). Secondary outcomes include progression-free survival (PFS) rate, objective-response rate (ORR), quality of life (Qol) before and after the treatment, cognitive function before and after the treatment, and rate of treatment-related adverse events (AE). The combination of HSRT and IMRT with temozolomide can benefit the patients after surgery with good survival, acceptable toxicity, and reduced treatment time. TRIAL REGISTRATION: NCT04547621 . Registered on 14 September 2020.

GSK3ß mediates the spatiotemporal dynamics of NLRP3 inflammasome activation.

Subcellular machinery of NLRP3 is essential for inflammasome assembly and activation. However, the stepwise process and mechanistic basis of NLRP3 engagement with organelles remain unclear. Herein, we demonstrated glycogen synthase kinase 3ß (GSK3ß) as a molecular determinant for the spatiotemporal dynamics of NLRP3 inflammasome activation. Using live cell multispectral time-lapse tracking acquisition, we observed that upon stimuli NLRP3 was transiently associated with mitochondria and subsequently recruited to the Golgi network (TGN) where it was retained for inflammasome assembly. This occurred in relation to the temporal contact of mitochondria to Golgi apparatus. NLRP3 stimuli initiate GSK3ß activation with subsequent binding to NLRP3, facilitating NLRP3 recruitment to mitochondria and transition to TGN. GSK3ß activation also phosphorylates phosphatidylinositol 4-kinase 2 Α (PI4k2A) in TGN to promote sustained NLRP3 oligomerization. Our study has identified the interplay between GSK3ß signaling and the organelles dynamics of NLRP3 required for inflammasome activation and opens new avenues for therapeutic intervention.

Ingredients with anti-inflammatory effect from medicine food homology plants.

Inflammation occurs when the immune system responses to external harmful stimuli and infection. Chronic inflammation induces various diseases. A variety of foods are prescribed in the traditional medicines of many countries all over the world, which gave birth to the concept of medicine food homology. Over the past few decades, a number of secondary metabolites from medicine food homology plants have been demonstrated to have anti-inflammatory effects. In the present review, the effects and mechanisms of the medicine food homology plants-derived active components on relieving inflammation and inflammation-mediated diseases were summarized and discussed. The information provided in this review is valuable to future studies on anti-inflammatory ingredients derived from medicine food homology plants as drugs or food supplements.

m6A mRNA methylation-directed myeloid cell activation controls progression of NAFLD and obesity.

N6-methyladenosine (m6A) RNA modification is a fundamental determinant of mRNA metabolism, but its role in innate immunity-driven non-alcoholic fatty liver disease (NAFLD) and obesity is not known. Here, we show that myeloid lineage-restricted deletion of the m6A "writer" protein Methyltransferase Like 3 (METTL3) prevents age-related and diet-induced development of NAFLD and obesity in mice with improved inflammatory and metabolic phenotypes. Mechanistically, loss of METTL3 results in the differential expression of multiple mRNA transcripts marked with m6A, with a notable increase of DNA Damage Inducible Transcript 4 (DDIT4) mRNA level. In METTL3-deficient macrophages, there is a significant downregulation of mammalian target of rapamycin (mTOR) and nuclear factor κB (NF-κB) pathway activity in response to cellular stress and cytokine stimulation, which can be restored by knockdown of DDIT4. Taken together, our findings identify the contribution of METTL3-mediated m6A modification of Ddit4 mRNA to macrophage metabolic reprogramming in NAFLD and obesity.

Hopping-Dominated Spin Transport in Unintentionally Doped Organic Semiconductors.

We report a spin diffusion theory to predict unusual pure spin current transport in unintentionally doped organic semiconductors. We demonstrate that the feasibility of pure spin current transport via polaron hopping at a low carrier density. Our theoretical prediction, 40 nm, for spin diffusion length (SDL) in dinaphtho[2,3-b:2,3-f]thieno[3,2-b]thiophene (DNTT) is in very good agreement with experimental data. Interestingly, SDL can be prolonged by restraining molecular geometry structure disorder and reducing the reorganization energy. In comparison with anisotropic organic materials, the SDL in isotropic ones increases up to 60%. Our results open up a new avenue to design organic spintronics devices with long SDL and low carrier density.

The protective effect of Veronica ciliata Fisch. Extracts on relieving oxidative stress-induced liver injury via activating AMPK/p62/Nrf2 pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Veronica ciliata Fisch. existed in various Tibetan medicine prescriptions, which was recorded to treat liver diseases in the Tibetan medicine roll of Chinese materia medica. HYPOTHESIS/PURPOSE: The current study aimed to examine the effect of active constituents from V.ciliata relieving oxidative stress-mediated liver injury and clarify the underlying mechanism. MATERIALS AND METHODS: tert-Butyl hydroperoxide (BHP) induced liver injury in mice model was established to evaluate the hepatoprotective effect of ethyl acetate extract of V. ciliata (EAFVC). Serum and liver indicators, as well as the histopathological change of liver were examined. Next, the constituents of EAFVC were separated and characterized by high-speed countercurrent chromatography (HSCCC) and Ultra performance liquid chromatography-mass spectrometer (UPLC-MS), respectively. Based on the above, the antioxidant activity of EAFVC and two fractions was evaluated using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2, 2'-azino-bis (3-ethylbenzothiazoli- ne-6-sulfonic acid) (ABTS) free radical scavenging assays. The hepatoprotective activity of EAFVC and its fractions/compounds attenuating ethanol-induced hepatocyte damage in BRL-3A cells was evaluated using the MTT method. The effect of the fraction and compounds with the strongest protective activity on ethanol-induced cytotoxicity, reactive oxygen species (ROS) accumulation, and glutathione (GSH) depletion was investigated. mRNA expression of nuclear factor-E2-related factor 2 (Nrf2) and nuclear factor of κB (NF-κB), as well as their downstream target genes, was determined by RT-qPCR. Finally, the potential mechanism of fraction 1 and luteolin on the AMPK/p62/Nrf2 signal pathway was studied using western blotting. RESULTS: Firstly, EAFVC could relieve liver impairment induced by t-BHP in mice. Next, fraction 1 enriched with polyphenolic compounds and luteolin derived from EAFVC were screened to yield the highest hepatoprotective activity against ethanol-induced hepatocyte damage. Further study demonstrated that fraction 1 and luteolin relieved BRL-3A cells damage by decreasing the aspartate aminotransferase (AST), alanine transaminase (ALT) and lactate dehydrogenase (LDH) activities, ROS accumulation, as well as the depletion of GSH. Also, we determined that fraction 1 and luteolin suppressed inflammation and apoptosis of BRL-3A cells. The mechanistic studies indicated that fraction 1 could attenuate oxidative stress, inflammation, and apoptosis by activating AMPK phosphorylation, which promotes autophagy associated protein expression (LC3-B, Beclin1 and p62) as well as promote phosphorylation of p62 -dependent autophagic degradation of Keap1, to induce Nrf2 dissociation from Keap1 and translocate to nuclear. Nrf2 in the nuclear activate cytoprotective related genes to exert hepatoprotective function. Finally, we found that luteolin activated the protein expression of p-AMPK, p-p62, p62, Nrf2, and its downstream target genes. CONCLUSIONS: This study clarified that fraction 1 enriched phenolic compounds could attenuate ethanol-induced liver injury in BRL-3A cells via activating AMPK/p62/Nrf2 pathway. Luteolin could serve as the major bioactive component in the therapeutic effect of fraction 1. These active constituents in V. ciliata could be used as the potential drugs targeted activation of AMPK or p62 for relieving oxidative stress-mediated liver disorders.

Protective effects of n-Butanol extract and iridoid glycosides of Veronica ciliata Fisch. Against ANIT-induced cholestatic liver injury in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Veronica ciliata Fisch. is a traditional medical herb that present in more than 100 types of Tibetan medicine prescriptions, most of which are used for liver disease therapy. Iridoid glycosides have been identified as the major active components of V.ciliata with a variety of biological activities. AIMS OF THE STUDY: The aim of this study is to explore the protective effect and potential mechanism of n-Butanol extract (BE) and iridoid glycosides (IG) from V.ciliata against ɑ-naphthyl isothiocyanate (ANIT)-induced hepatotoxicity and cholestasis in mice. MATERIALS AND METHODS: Mice were intragastrically (i.g.) given BE and IG at different dose or positive control ursodeoxycholic acid (UCDA) once a day for 14 consecutive days, and were treated with ANIT to cause liver injury on day 12th. Serum levels of hepatic injury markers and cholestasis indicators, liver index and liver histopathology were measured to evaluate the effect of BE and IG on liver injury caused by ANIT. The protein levels of tumor necrosis factor-α (TNF-α), nuclear factor kappa B(NF-κB), interleukin-6 (IL-6), Na+/taurocholate cotransporting polypeptide (NTCP), bile salt export pump (BSEP), multidrug resistance-associated protein 2 (MRP2), and the levels of oxidative stress indicators in liver tissue were investigated to reveal the underlying protective mechanisms of BE and IG against ANIT-induced hepatotoxicity and cholestasis. RESULTS: The n-Butanol extract (BE) and iridoid glycosides (IG) isolated from V.ciliata significantly decreased serum level of cholestatic liver injury markers aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), γ-glutamyl transferase (GGT), total bile acid (TBA), total bilirubin (TBIL), and direct bilirubin (DBIL) in ANIT-treated mice. Histopathology of the liver tissue showed that pathological damages were relieved upon BE and IG treatment. Meanwhile, the results indicated BE and IG notably restored relative liver weights, inhibited oxidative stress induced by ANIT through increasing hepatic level of superoxide dismutase (SOD), reduced glutathione (GSH), catalase (CAT) and decreasing hepatic content of malondialdehyde (MDA). Western blot revealed that BE and IG inhibited the expression of pro-inflammatory factors TGF-α, IL-6 and NF-κB. Furthermore, the decreased protein expression of bile acid transporters NTCP, BSEP, MRP2 were upregulated by BE and IG in a dose-dependent manner. CONCLUSION: The results have demonstrated that BE and IG exhibited a dose-dependently protective effect against ANIT-induced liver injury with acute intrahepatic cholestasis in mice, which might be related to the regulation of oxidative stress, inflammatory response and bile acid transport. In addition, these findings pointed out that iridoid glycosides as main active components of V.ciliata play a critical role in hepatoprotective effect of V.ciliata.

Phytochemical characterization and hepatoprotective effect of active fragment from Adhatoda vasica Nees. against tert-butyl hydroperoxide induced oxidative impairment via activating AMPK/p62/Nrf2 pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Adhatoda vasica Nees., which existed in a large; number of Tibetan medicine prescriptions for hepatopathy, used as an adjuvant to treat liver diseases. HYPOTHESIS/PURPOSE: Oxidative stress is the key player in the development and progression of liver pathogenesis. In recent years, research is increasingly being focused on exploitation of the active components from medicinal plants to combat the liver oxidative injury. In our study, we aimed to screen the active principles from A. vasica and clarify whether they could relieve oxidative damage induced by tert-Butyl hydroperoxide (t-BHP) and its potential mechanism via activating AMPK/p62/Nrf2 pathway. MATERIALS AND METHODS: Ultra performance liquid chromatography (UPLC) was adopted for analysis of chemical composition in the extracts. Furthermore, the antioxidant activity of the fractions was evaluated using DPPH, ABTS and reducing power assay. Along with this, the compounds in this fraction with highest antioxidant activity were analyzed using UPLC-MS. Based on this, the condition for extracting flavonoids of this subfraction was optimized via response surface method. CCK-8 assay was used to detect cell viability. Detection kits were used to measure the activity changes of AST, ALT, LDH and CAT as well as MDA and GSH levels induced by t-BHP. Detection of reactive oxygen species (ROS) production was used DCFH-DA probe. DAPI staining and flow cytometry was used to detect cell apoptosis. In terms of the mechanistic studies, the expression of proteins involved in AMPK/p62/Nrf2 pathway was measured using western blotting. RESULTS: Eventually, 70% ethanol extract from leaf of A. vasica was chosen due to its highest active components compared with other extracts. Further, ethyl acetate fraction derived from 70% ethanol extract in A. vasica (AVEA) possess highest ability for scavenging DPPH and ABTS free radicals as well as strongest reducing power than other fractions. Chemical composition analysis showed that AVEA contained 17 compounds, including 1 quinazoline alkaloid, 12 flavonoid-C-glycosides and 4 flavonoid-O-glycosides. In addition, the conditions (ratio of solid-liquid 1:14, the concentration of ethanol 73%, and the temperature 65 °C) were selected to enrich the flavonoids in AVEA. Furthermore, AVEA could attenuate t-BHP induced hepatocyte damage via increasing the cell viability, restoring abnormal the activities of AST, ALT, LDH and CAT as well as the levels of MDA and GSH. ROS fluorescence intensity was reduced by AVEA. Meanwhile, it could inhibit the cell apoptosis of BRL 3 A cells, as evidenced by restoration of cell morphology and decreasing the number of apoptotic cells. Further mechanistic studies indicated AVEA could promote p-AMPK expression to further induce autophagy adaptor-p62 protein expression, which could autophagic degradation of Keap1, leading to Nrf2 release and translocation into nucleus to induce antioxidant genes (HO-1, NQO-1, GCLC and GCLM) expression. CONCLUSION: In our study, AVEA was first to screen as the active fraction in A. vasica with alkaloids and abundant flavones. Moreover, the fraction potentiates its beneficial aspect by displaying the protective role on relieving t-BHP induced oxidative stress and activating AMPK/p62/Nrf2 pathway. AVEA helps maintain the redox homeostasis of hepatic cells and could be considered as an effective candidate against oxidative stress related liver disorders.