Protective Effect of Eupatilin Pretreatment Against Hepatic Ischemia-Reperfusion Injury in Mice

Eupatilin inhibits pulmonary fibrosis by activating Sestrin2/PI3K/Akt/mTOR dependent autophagy pathway

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive chronic inflammatory disease with poor clinical outcomes and ineffective drug treatment options. Eupatilin is a major component extracted from the traditional herbal medicine Artemisia asiatica Nakai. Notably, it was demonstrated to have an anti-fibrosis effect in endometrial fibrosis, vocal fold, and hepatic fibrosis. Its role and mechanism in IPF remain unclear.

METHODS

This study used the TGF-β1-induced human embryonic lung fibroblasts (MRC-5) activation, IPF lung fibroblasts, and bleomycin-induced lung fibrosis mice model. Western blot, immunofluorescence staining, quantitative real time-PCR, hematoxylin and eosin staining, Masson's trichrome staining, and immunohistochemistry were used to evaluate the effects of eupatilin on fibroblast activation, pulmonary fibrosis, and autophagy. The autophagosomes were observed with a transmission electron microscope (TEM). RNA sequencing was used to determine the signaling pathway and key regulator related to autophagy.

RESULTS

Eupatilin significantly decreased the expression of Col1A1, fibronectin, α-SMA, and SQSTM1/p62. In contrast, it increased the expression of LC3B II/I and the number of autophagosomes in TGF-β1 treated MRC-5, IPF lung fibroblasts, and bleomycin-induced lung fibrosis mice model; it also alleviated bleomycin-induced lung fibrosis. The KEGG pathway mapping displayed that PI3K/Akt and Sestrin2 were associated with the enhanced fibrogenic process. Eupatilin suppressed the phosphorylation of PI3K/Akt/mTOR. Autophagy inhibitor 3-methyladenine (3-MA) and Akt activator SC-79 abrogated the anti-fibrotic effect of eupatilin. Sestrin2 expression was also downregulated in TGF-β1 treated lung fibroblasts and lung tissues of the bleomycin-induced pulmonary fibrosis mice model. Furthermore, eupatilin promoted Sestrin2 expression, and the knockdown of Sestrin2 significantly aggravated the degree of fibrosis, increased the phosphorylation of PI3K/Akt/mTOR, and decreased autophagy.

CONCLUSION

These findings indicate that eupatilin ameliorates pulmonary fibrosis through Sestrin2/PI3K/Akt/mTOR-dependent autophagy pathway.

Effects of iNOS in Hepatic Warm Ischaemia and Reperfusion Models in Mice and Rats: A Systematic Review and Meta-Analysis

Warm ischaemia is usually induced by the Pringle manoeuver (PM) during hepatectomy. Currently, there is no widely accepted standard protocol to minimise ischaemia-related injury, so reducing ischaemia-reperfusion damage is an active area of research. This systematic review and meta-analysis focused on inducible nitric oxide synthase (iNOS) as an early inflammatory response to hepatic ischaemia reperfusion injury (HIRI) in mouse- and rat-liver models. A systematic search of studies was performed within three databases. Studies meeting the inclusion criteria were subjected to qualitative and quantitative synthesis of results. We performed a meta-analysis of studies grouped by different HIRI models and ischaemia times. Additionally, we investigated a possible correlation of endothelial nitric oxide synthase (eNOS) and nitric oxide (NO) regulation with iNOS expression. Of 124 included studies, 49 were eligible for the meta-analysis, revealing that iNOS was upregulated in almost all HIRIs. We were able to show an increase of iNOS regardless of ischemia or reperfusion time. Additionally, we found no direct associations of eNOS or NO with iNOS. A sex gap of primarily male experimental animals used was observed, leading to a higher risk of outcomes not being translatable to humans of all sexes.

New progress in understanding roles of nitric oxide during hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury (HIRI) is a major clinical cause of morbidity and mortality in liver surgery and transplantation. Many studies have found that nitric oxide (NO) plays an important role in the HIRI and its increase or decrease can affect the progression and outcome of HIRI. However, the role of NO in HIRI is controversial and complicated. NO derived by endothelial NO synthase (eNOS) shows a protective role in HIRI, while excessive NO derived by inducible NO synthase (iNOS) accelerates inflammation and increases oxidative stress, further aggravating HIRI. Nevertheless, the overexpression of eNOS may exacerbate HIRI and iNOS-derived NO in some cases reduces HIRI. Here we review the new progress in the understanding of the roles of NO during HIRI: (1) NO possesses different roles in HIRI by increasing NO bioavailability, down-regulating leukotriene C4 synthase, inhibiting the activation of the nuclear factorκB (NFκB) pathway, enhancing cell autophagy, and reducing inflammatory cytokines and reactive oxygen species (ROS). And NO has both protective and deleterious effects by regulating apoptotic factors; (2) eNOS promotes NO production and suppresses its own overexpression, exerting a hepatoprotective effect reversely. Its activation is regulated by the PI3K/Akt and KLF2/AMPK pathways; and (3) iNOS derived NO mainly has deteriorating effects on HIRI, while it may have a protective function under some conditions. Their expression should reach a balance to reduce the adverse side and make NO protective in the treatment of HIRI. Thus, it can be inferred that NO modulating drugs may be a new direction in the treatment of HIRI or may be used as an adjunct to mitigate HIRI for the purpose of protecting the liver.

Eupatilin prevents behavioral deficits and dopaminergic neuron degeneration in a Parkinson's disease mouse model

AIMS

Neuroinflammation and apoptosis play a crucial role in Parkinson's disease (PD) pathogenesis. Eupatilin is a lipophilic flavonoid isolated from Artemisia species and exerts anti-apoptotic and anti-inflammatory activities. In this study, we investigated the effects of Eupatilin on a mouse model of PD induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP).

MAIN METHODS

The rotarod test and traction test were constructed to examine the motor function. Immunofluorescent staining was performed to detect the expression of TH, Iba-1 and GFAP. Apoptosis was examined by the TUNEL assay. Real-time PCR was used to determine the mRNA expression and Western blot and ELISA were used to determine the protein expression.

KEY FINDINGS

Eupatilin improved behavioral impairment caused by MPTP. A loss of TH positive neurons was observed in the substantia nigra pars compacta of MPTP-lesioned brain, while it was rescued by Eupatilin. Moreover, MPTP administration increased the cell number of microglia and astrocytes and the expression of inflammatory factors TNF-α, IL-1β, and IL-6. Whereas Eupatilin suppressed the activation of neuroinflammation. Eupatilin also decreased cell apoptosis enhanced by MPTP/MPP⁺ exposure in vivo and in vitro. We further revealed that Eupatilin abolished MPTP-induced downregulation of IκBα expression and accumulation of p65 in the nuclear compartment. Besides, MPTP administration led to dephosphorylation of Akt and GSK-3β, but it was restored by Eupatilin.

SIGNIFICANCE

We demonstrate that Eupatilin alleviates behavioral impairment and dopaminergic neuron loss induced by MPTP through inhibition of neuroinflammation and apoptosis. Our research provides more evidence for Eupatilin as a potential preventative drug for PD.

Eupatilin: a natural pharmacologically active flavone compound with its wide range applications

Eupatilin (5,7-dihydroxy-3',4',6-trimethoxyflavone) is a pharmacologically active flavone which has been isolated from a variety of medicinal plants. Eupatilin is known to possess various pharmacological properties such as anti-cancer, anti-oxidant, and anti-inflammatory. It is speculated that eupatilin could be subjected to structural optimization for the synthesis of derivative analogs to reinforce its efficacy, to minimize toxicity, and to optimize absorption profiles, which will ultimately lead towards potent drug candidates. Although, reported data acclaim multiple pharmacological activities of eupatilin but further experimentations on its molecular mechanism of action are yet mandatory to elucidate full spectrum of its pharmacological activities.

Eupatilin Inhibits Renal Cancer Growth by Downregulating MicroRNA-21 through the Activation of YAP1

Renal cell carcinoma (RCC) is the second most common human urinary tumor. Eupatilin is the main active ingredient of the traditional Chinese medicine Artemisia asiatica. The effect of Eupatilin on RCC and the underlying mechanism remain unknown. Here, we investigated the anticancer effects and mechanisms of Eupatilin in RCC in vivo and in vitro, laying an experimental foundation for the clinical application of Eupatilin in the treatment of RCC. The results showed that Eupatilin significantly inhibited 786-O cell viability and migration and promoted apoptosis. Eupatilin inhibited the expression of miR-21 in 786-O cells, and overexpression of miR-21 suppressed the effect of Eupatilin on viability, apoptosis, and migration in 786-O cells. Eupatilin inhibited the growth of renal tumors in nude mice by downregulating miR-21. YAP1, which was identified as a target of miR-21, showed significantly lower expression in RCC tissues than in healthy tissues. miR-21 significantly inhibited YAP1 protein expression in 786-O cells and tumor tissues isolated from nude mice, and YAP1 attenuated the effect of miR-21 on the viability, apoptosis, and migration of 786-O cells. In conclusion, Eupatilin inhibited the expression of miR-21, which mediated the proapoptotic and antimigratory effects of Eupatilin by suppressing YAP1 in renal cancer cells. These results suggested that Eupatilin could be a potent agent for the treatment of RCC.

Identification and Comparison of Constituents of Aurantii Fructus and Aurantii Fructus Immaturus by UFLC-DAD-Triple TOF-MS/MS

Although Aurantii Fructus (AF) and Aurantii Fructus Immaturus (AFI) are both the fruits of the same rutaceae plant at different stages of growth, they exert similar yet distinct clinical effects. The chemical composition is crucial for quality control as well as therapeutic application. To address this concern, it is significant to evaluate the similarities and differences of the constituents in both AF and AFI. The extract of AF and AFI were comprehensively analyzed by ultra fast liquid chromatography-photodiode array detector-triple-time of flight-tandem mass spectrometry (UFLC-DAD-Triple TOF-MS/MS). Among the 40 compounds detected, 19 metabolites were detected in both the AF and AFI; whereas 13 compounds were only detected in AF and five constituents were exclusively detected in AFI. In particular, even in AFI, three compounds were only identified in AFI (Citrus aurantium' L. and its cultivar). Among the 18 compounds confirmed by standard database, 13 compounds were reported in AF and AFI for the first time. Furthermore, the distinction was also revealed by the content of naringin, hesperidin, neohesperidin, and synephrine. The study directly contributed to the similarities and differences of AF and AFI. Herein, similarities and the differences in chemical profiles of AF and AFI could explain the current clinical applications.

Hydrogen protects against liver injury during CO2 pneumoperitoneum in rats

The aim of the current study was to identify the protective effect of hydrogen gas against liver injury during CO₂ pneumoperitoneum. Rats were randomly divided into three groups: control group (C group), pneumoperitoneum group (P15 group) and hydrogen group (H₂ group). Rats in the C group were subjected to anesthesia for 90 min. Rats in the P15 group received an abdominal insufflation of CO₂ for 90 min at an intra-abdominal pressure of 15 mmHg. Rats in the H₂ group received a hypodermic injection of hydrogen gas (0.2 mL/kg) and after 10 min they received an abdominal insufflation of CO₂ for 90 min at an intra-abdominal pressure of 15 mmHg. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured to evaluate liver function. Malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) content were measured to evaluate oxidative stress. Nuclear factor E2-related factor 2 (Nrf2) and Nrf2 downstream target genes, apoptosis-related genes and inflammatory cytokine mRNA and protein expression were detected. Liver injury was detected under the microscope. Our results revealed that liver function, antioxidants content, inflammation and liver injury were improved after hydrogen preconditioning in H₂ group compared with P15 group. Overall, our results revealed that subcutaneous hydrogen injection could exert a protective effect against liver injury during CO₂ pneumoperitoneum through reducing oxidative stress, cell apoptosis and inflammatory cytokines release.

Pre-conditions for eliminating mitochondrial dysfunction and maintaining liver function after hepatic ischaemia reperfusion

The liver, the largest organ with multiple synthesis and secretion functions in mammals, consists of hepatocytes and Kupffer, stem, endothelial, stellate and other parenchymal cells. Because of early and extensive contact with the external environment, hepatic ischaemia reperfusion (IR) may result in mitochondrial dysfunction, autophagy and apoptosis of cells and tissues under various pathological conditions. Because the liver requires a high oxygen supply to maintain normal detoxification and synthesis functions, it is extremely susceptible to ischaemia and subsequent reperfusion with blood. Consequently, hepatic IR leads to acute or chronic liver failure and significantly increases the total rate of morbidity and mortality through multiple regulatory mechanisms. An increasing number of studies indicate that mitochondrial structure and function are impaired after hepatic IR, but that the health of liver tissues or liver grafts can be effectively rescued by attenuation of mitochondrial dysfunction. In this review, we mainly focus on the subsequent therapeutic interventions related to the conservation of mitochondrial function involved in mitigating hepatic IR injury and the potential mechanisms of protection. Because mitochondria are abundant in liver tissue, clarification of the regulatory mechanisms between mitochondrial dysfunction and hepatic IR should shed light on clinical therapies for alleviating hepatic IR‐induced injury.