Aloperine attenuates hydrogen peroxide-induced injury via anti-apoptotic activity and suppression of the nuclear factor-κB signaling pathway

Aloperine Alleviates Myocardial Injury Induced by Myocardial Ischemia and Reperfusion by Activating the ERK1/2/β-catenin Signaling Pathway

OBJECTIVE

Myocardial ischemia/reperfusion (I/R) injury can cause severe cardiac damage. Aloperine is a quinolizidine alkaloid found in the leaves and seeds of Sophora alopecuroides L. It has been recognized that aloperine has organ-protective properties; however, its role in cardioprotection is poorly characterized. This study aimed to evaluate the cardioprotective effects of aloperine against myocardial I/R injury in vivo.

METHODS

Adult male Sprague‒Dawley rats were randomly divided into sham-operated, control, and aloperine groups. All rats except for the sham-operated rats were subjected to 45 min of myocardial ischemia (by left anterior descending ligation) followed by 3 h of reperfusion. Aloperine (10 mg/kg) was given intravenously at the onset of reperfusion. The cardioprotective effects of aloperine were evaluated by determining infarct size, hemodynamics, histological changes, cardiac biomarkers, and cardiac apoptosis.

RESULTS

Aloperine limited infarct size; improved hemodynamics; attenuated myocardial I/R-induced histological deterioration; decreased serum LDH, CK-MB, and α-HBDH levels; and inhibited apoptosis after myocardial I/R injury. Moreover, aloperine stimulated the phosphorylation of ventricular ERK1/2, which is a major module of MAPK signaling pathways. Furthermore, aloperine increased the ventricular expression levels of β-catenin. Pharmacological inhibition of ERK1/2 diminished aloperine-induced cardioprotection and blocked ERK1/2/β-catenin signaling.

CONCLUSIONS

These data support the cardioprotective effect of aloperine against myocardial I/R injury, which is mediated, at least in part, by the ERK1/2/β-catenin signaling pathway.

Beneficial effects of aloperine on inflammation and oxidative stress by suppressing necroptosis in lipopolysaccharide-induced acute lung injury mouse model

RATIONALE

Alveolar epithelial cell death, inflammation, and oxidative stress are typical features of acute lung injury (ALI). Aloperine (Alo), an alkaloid isolated from Sophora alopecuroides, has been reported to display various biological effects, such as anti-inflammatory, immunoregulatory, and anti-oxidant properties. In this study, we investigated the effects and mechanisms of Alo in treating a lipopolysaccharide (LPS)-induced ALI in a murine model.

METHODS

The effects of Alo in LPS-induced ALI were investigated in C57BL/6 mice. The RIPK1 inhibitor (Nec-1) and the RIPK3 inhibitor (GSK'872) were used to evaluate the relationship of necroptosis, NF-κB activation, and PDC subunits in LPS-treated mouse alveolar epithelial cells (MLE-12). Then the effects of Alo on necroptosis, inflammation, and oxidative stress of LPS-stimulated MLE-12 cells were evaluated.

RESULTS

Alo significantly attenuated histopathological lung injuries and reduced lung wet/dry ratio in LPS-induced ALI mice. Alo also remarkedly reduced total protein and neutrophils recruitment in bronchoalveolar lavage fluid of ALI mice. Meanwhile, Alo ameliorated the LPS-induced necroptosis in the lungs of ALI mice. The RIPK3 inhibitor GSK'872, but not the RIPK1 inhibitor Nec-1, reversed LPS-induced p65 phosphorylation and translocation to the nucleus in MLE-12 cells. GSK'872 also reversed the LPS-induced increase in ROS and binding of RIPK3 and PDC subunits in MLE-12 cells. Moreover, Alo down-regulated the levels of p-RIPK1, p-RIPK3, p-MLKL, p-p65, the translocation of p65 to the nucleus, and reduced the expression of IL-6 and IL-8 in LPS-stimulated MLE-12 cells. Alo also inhibited the binding of RIPK3 and PDC-E1α, PDC-E1β, PDC-E2, and PDC-E3 and the ROS production in LPS-treated MLE-12 cells.

CONCLUSION

The present study validated the beneficial effects of Alo on LPS-induced ALI , suggesting Alo may be a new drug candidate against ALI.

Aloperine: A Potent Modulator of Crucial Biological Mechanisms in Multiple Diseases

Aloperine is an alkaloid found in the seeds and leaves of the medicinal plant Sophora alopecuroides L. It has been used as herbal medicine in China for centuries due to its potent anti-inflammatory, antioxidant, antibacterial, and antiviral properties. Recently, aloperine has been widely investigated for its therapeutic activities. Aloperine is proven to be an effective therapeutic agent against many human pathological conditions, including cancer, viral diseases, and cardiovascular and inflammatory disorders. Aloperine is reported to exert therapeutic effects through triggering various biological processes, including cell cycle arrest, apoptosis, autophagy, suppressing cell migration, and invasion. It has also been found to be associated with the modulation of various signaling pathways in different diseases. In this review, we summarize the most recent knowledge on the modulatory effects of aloperine on various critical biological processes and signaling mechanisms, including the PI3K, Akt, NF-κB, Ras, and Nrf2 pathways. These data demonstrate that aloperine is a promising therapeutic candidate. Being a potent modulator of signaling mechanisms, aloperine can be employed in clinical settings to treat various human disorders in the future.

A novel circRNA-miRNA-mRNA network reveals hsa-circ-0040039 as a biomarker for intervertebral disc degeneration

Objective

Alterations in the structure and function of intervertebral discs by multifaceted chronic processes can result in intervertebral disc degeneration (IDD). The mechanisms involved in IDD are still unknown.

Methods

We investigated the possible mechanisms underlying IDD using a bioinformatics analysis of publicly available microarray expression datasets and built a circular RNA–microRNA–mRNA (circRNA–miRNA–mRNA) network based on the results. Datasets GSE67566 and GSE116726 were downloaded from the Gene Expression Omnibus (GEO) and analyzed using the limma package in R. The CircInteractome database was used to detect miRNAs related to circRNA, and TargetScan, miRDB, and miRTarBase were used to predict target mRNAs. Key target genes were annotated using Gene Ontology terms.

Results

The circRNA hsa-circ-0040039 was found to have the top log fold-change score. Analysis using Metascape showed that the associated genes were enriched mainly in the cell cycle. The Cytoscape plugin MCODE predicted that two members of the RAS oncogene family—RAB1A and RAB1B—and multiple coagulation factor deficiency (MCFD2) may play key roles in IDD.

Conclusion

Our results suggested that hsa-circ-0040039 and the related network may be potential biomarkers for IDD.

Research Progress on the Natural Product Aloperine and Its Derivatives

In this review, an effort towards the presentation of an all-around account of the recent progress on the natural product, aloperine is made, and the antivirus structure-activity relationship of its derivatives is also summarized comprehensively. In addition, the principal pharmacological effects and corresponding molecular mechanisms of aloperine are discussed. Some new modification directions of aloperine are given in the end, which might be brief guidance for further investigations on the natural product aloperine.

Establishment of LC-MS/MS method for determination of aloperine in rat plasma and its application in preclinical pharmacokinetics

Aloperine, a novel natural active alkaloid derived from Sophora alopecuroides L., has attracted much attention for its anti-inflammatory, antiviral, anti-tumor, anti-allergy and other pharmacological activities. In this study, we first established and validated an efficient and sensitive high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of aloperine in rat plasma. Cytisine was used as the internal standard (IS). The separation of aloperine and IS was conducted on a Phenomenex Luna Omega Polar C18 column (2.1 × 50 mm, 1.6 μm) with 0.3% (v/v) formic acid aqueous (containing 5 mM ammonium acetate) and 0.3% (v/v) formic acid acetonitrile using isocratic elution condition at a flow rate of 0.20 mL/min. Aloperine and IS were determined under the transitions of m/z 233.2 → 98.1 and m/z 191.2 → 148.2 (positive ionization mode), respectively. The calibration curve of aloperine was established in the range of 5 (LLOQ) to 2000 ng/mL (r2 = 0.994). The well validated method was full compliance with the bioanalytical method validation of FDA, and was applied to the pharmacokinetic study of aloperine in Sprague-Dawley rats after 50 mg/kg oral administration and 5 mg/kg intravenous injection. This study provides valuable references for the further study of Sophora alopecuroides L., especially for the drug development and clinical application of aloperine.

Inhibitory effects of aloperine on voltage-gated Na+ channels in rat ventricular myocytes

Aloperine (ALO), a quinolizidine alkaloid extracted from Sophora alopecuroides L., modulates hypertension, ventricular remodeling, and myocardial ischemia. However, few studies have evaluated the effects of ALO on other cardiovascular parameters. Accordingly, in this study, we used a rat model of aconitine-induced ventricular arrhythmia to assess the effects of ALO. Notably, ALO pretreatment delayed the onset of ventricular premature and ventricular tachycardia and reduced the incidence of fatal ventricular fibrillation. Moreover, whole-cell patch-clamp assays in rats' ventricular myocyte showed that ALO (3, 10, and 30 μM) significantly reduced the peak sodium current density of voltage-gated Na⁺ channel currents (I_Na) in a concentration-dependent manner. The gating kinetics characteristics showed that the steady-state activation and recovery curve were shifted in positive direction along the voltage axis, respectively, and the steady-state inactivation curve was shifted in negative direction along the voltage axis, i.e., which was similar to the inhibitory effects of amiodarone. These results indicated that ALO had anti-arrhythmic effects, partly attributed to I_Na inhibition. ALO may act as a class I sodium channel anti-arrhythmia agent.

Aloperine protects human retinal pigment epithelial cells against hydrogen peroxide-induced oxidative stress and apoptosis through activation of Nrf2/HO-1 pathway

Age-related macular degeneration (AMD) is a complex multifactorial disease associated with the dysfunction of retinal pigment epithelium (RPE). Aloperine is a quinolizidine alkaloid that has been proven to possess broad pharmacological activities. However, the effects of aloperine on AMD remain unclear. In the present study, we used hydrogen peroxide (H₂O₂) to induce oxidative injury in human RPE cells (ARPE-19 cells). ARPE-19 cells were pretreated with different concentrations of aloperine for 2 h, followed by H₂O₂ exposure. Cell cytotoxicity was determined using lactate dehydrogenase (LDH) release assay. Cell viability was measured using Cell Counting Kit-8 (CCK-8) assay. The reactive oxygen species (ROS) generation, malondialdehyde (MDA) level, superoxide dismutase (SOD) activity and glutathione peroxidase (GSH-PX) activity were detected to reflect oxidative status. Western blot was performed to detect the expressions of bcl-2, bax, nuclear factor-erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1). The activity of caspase-3 was also assessed to indicate cell apoptosis. In addition, ARPE-19 cells were transfected with siNrf2 to knock down Nrf2. Our results showed that pretreatment with aloperine elevated the reduced cell viability of H₂O₂-induced ARPE-19 cells in a dose-dependent manner. Aloperine greatly decreased the production of ROS and MDA, and increased the activities of SOD and GSH-PX in H₂O₂-stimulated ARPE-19 cells. H₂O₂-caused a decrease in bcl-2 expression and increases in bax expression and caspase-3 activity were mitigated by aloperine. Moreover, aloperine treatment enhanced the expression levels of Nrf2 in nuclear fraction and the HO-1 expression in lysates. Knockdown of Nrf2 reversed the protective effects of aloperine on H₂O₂-induced ARPE-19 cells. In conclusion, these findings demonstrated that aloperine protected ARPE-19 cells from H₂O₂-induced oxidative stress and apoptosis in part via activating the Nrf2/HO-1 signaling pathway. The findings suggested a therapeutic potential of aloperine for the treatment of ADM.

Aloperine Exerts Antitumor Effects on Bladder Cancer in vitro

Background

Human bladder cancer is the most common malignant tumor of the urinary system and one of the 10 most common tumors of the whole body. Although most patients with bladder cancer exhibit a good prognosis with standard treatment, effective therapies for patients with a recurrent or advanced bladder cancer are unavailable. Therefore, highly effective drugs to treat such patients need to be developed. Aloperine (ALO), a natural compound isolated from Sophora alopecuroides, has antitumor properties. However, the role of ALO in human bladder cancer remains unclear.

Methods

In the present study, MTT was used to detect the cytotoxic effect of ALO on human BC cell line EJ and human urothelium cell line SV-HUC-1cells. Meanwhile, in order to investigate the effects of ALO on the proliferation, apoptosis, migration, and invasion of BC EJ cells and its mechanism by Cell Counting Kit-8 (CCK-8) assay, immunofluorescence, Hoechst 33342 staining, wound scratch assay, transwell migration and invasion assay, Western blot analysis.

Results

ALO can inhibit the proliferation and invasion of human bladder cancer EJ cells, and is low-toxic to human urothelium cells. Moreover, it can promote cellular apoptosis in vitro. Further analysis demonstrated the involvement of Caspase-dependent apoptosis following ALO treatment. ALO also downregulated the protein expression levels of Ras, p-Raf1 and p-Erk1/2.

Conclusion

ALO is a potential drug for human bladder cancer therapy.

Cytochrome P450s regulates aloperine-induced pathological changes in mouse liver and kidney

Aloperine is a major active component in Sophora alopecuroides L that plays diverse pharmacological properties. Recent studies have indicated the potential effect of aloperine against hypertension and cancers. However, possible toxicity of aloperine has not been carefully studied in vivo. The aim of this study was to assess the effect of intraperitoneal aloperine injection on mouse liver and kidney tissues and to investigate the role of CYP450 genes in aloperine-induced toxicity. 72 BALB/c mice were randomly divided into four groups: vehicle control group (normal saline), low-dose group (4 mg/kg), medium-dose group (8 mg/kg), and high-dose group (16 mg/kg). 18 mice in each group were intraperitoneally injected with aloperine daily for 4 weeks, and were then kept for another 1 or 4 weeks without aloperine treatment. Serum was colleted for analysis of serum biochemical indexes including ALT, AST, BUN and CRE. The liver and kidney were collected for analysis of histopathologic changes and CYP450 expression and activity. Vacuolization of cytoplasm in liver cells, swelling in kidney tubular cells, increased levels of ALT, AST, BUN, and CRE, and alteration in the expression and activity of CYP450 were observed in the high-dose group after 4 weeks of treatment. However, all aloperine-induced damages were recovered to a certain degree after maintained without aloperine for 1 week, and fully recovered after maintained without aloperine for 4 weeks. These findings suggested that aloperine regulated the expression of CYP450, which was possibly involved in aloperine-induced reversible toxicity in mouse liver and kidney tissues.

Aloperine suppresses LPS-induced macrophage activation through inhibiting the TLR4/NF-κB pathway

OBJECTIVE

The currently available anti-inflammatory drugs often cause diverse side effects with long-term use. Exploring anti-inflammatory drugs with better efficacy and lower toxicity presents an ongoing challenge. Aloperine is an alkaloid extracted from the leaves and seeds of Sophora alopecuroides L. However, the anti-inflammatory effects of Aloperine have not been fully elucidated. This study aimed to investigate whether Aloperine suppresses lipopolysaccharide (LPS)-induced inflammatory responses in RAW264.7 macrophages.

METHODS

RAW264.7 macrophages were stimulated with LPS (1 μg/mL) in the presence or absence of Aloperine (50 and 100 μM). mRNA expression was measured by real-time PCR, and protein expression was assessed by western blot analysis. The secretion of pro-inflammatory cytokines was measured by ELISA. The levels of nitric oxide (NO) and reactive oxygen species (ROS) were measured by staining. The transcriptional activity of NF-κB was assayed by a luciferase activity assay.

RESULTS

The results proved that Aloperine inhibited the expression of LPS-induced pro-inflammatory cytokines [tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-17A (IL-17A)] in macrophages. Treatment with Aloperine inhibited NO production through suppressing inducible nitric oxide synthase (iNOS) expression and the secretion of prostaglandin E₂ (PGE₂) by inhibiting cyclooxygenase 2 (COX-2) expression. Aloperine prevented LPS-induced oxidative stress by reducing the generation of ROS. Furthermore, aloperine significantly reduced Toll-like receptor 4 (TLR4) and myeloid differentiation factor (Myd-88) levels and prevented the nuclear translocation of nuclear factor-κB (NF-κB) in LPS-treated macrophages.

CONCLUSION

Taken together, our findings show that Aloperine could suppress LPS-induced macrophage activation by inhibiting the TLR4/Myd-88/NF-κB pathway.

Quinolizidine alkaloids derivatives from Sophora alopecuroides Linn: Bioactivities, structure-activity relationships and preliminary molecular mechanisms

Quinolizidine alkaloids, as essential active ingredients extracted from Sophora alopecuroides Linn, have been well concerned in the past several decades owing to the unique structural features and numerous pharmacological activities. Quinolizidine alkaloids consist of matrine, oxymatrine, sophoridine, sophocarpine and aloperine etc. Additionally, quinolizidine alkaloids exert various excellent activities, including anti-cancer, anti-inflammation, anti-fibrosis, anti-virus and anti-arrhythmia regulations. In this review, we comprehensively clarify the pharmacological activities of quinolizidine alkaloids, as well as the relationship between biological function and structure-activity of substituted quinolizidine alkaloids. We believe that biological agents based on the pharmacological functions of quinolizidine alkaloids could be well applied in clinical practice.

Autophagy Modulation in Human Thyroid Cancer Cells following Aloperine Treatment

Aloperine, an alkaloid isolated from Sophoraalopecuroides, exhibits multiple pharmacological activities including anti-inflammatory, antioxidant, antiallergic, antinociceptive, antipathogenic, and antitumor effects. Furthermore, it exerts protective effects against renal and neuronal injuries. Several studies have reported antitumor effects of aloperine against various human cancers, including multiple myeloma; colon, breast, and prostate cancers; and osteosarcoma. Cell cycle arrest, apoptosis induction, and tumorigenesis suppression have been demonstrated following aloperine treatment. In a previous study, we demonstrated antitumor effects of aloperine on human thyroid cancer cells through anti-tumorigenesis and caspase-dependent apoptosis induction via the Akt signaling pathway. In the present study, we demonstrated the modulation of the autophagy mechanism following the incubation of multidrug-resistant papillary and anaplastic human thyroid cancer cells with aloperine; we also illustrate the underlying mechanisms, including AMPK, Erk, JNK, p38, and Akt signaling pathways. Further investigation revealed the involvement of the Akt signaling pathway in aloperine-modulated autophagy in human thyroid cancer cells. These results indicate a previously unappreciated function of aloperine in autophagy modulation in human thyroid cancer cells.

Aloperine suppresses human pulmonary vascular smooth muscle cell proliferation via inhibiting inflammatory response

Abnormal pulmonary arterial vascular smooth muscle cells (PASMCs) proliferation is critical pathological feature of pulmonary vascular remodeling that acts as driving force in the initiation and development of pulmonary arterial hypertension (PAH), ultimately leading to pulmonary hypertension. Aloperine is a main active alkaloid extracted from the traditional Chinese herbal Sophora alopecuroides and possesses outstanding antioxidation and anti-inflammatory effects. Our group found Aloperine has protective effects on monocroline-induced pulmonary hypertension in rats by inhibiting oxidative stress in previous researches. However, the anti-inflammation effects of Aloperine on PAH remain unclear. Therefore, to further explore whether the beneficial role of Aloperine on PAH was connected with its anti-inflammatory effects, we performed experiments in vitro. Aloperine significantly inhibited the proliferation and DNA synthesis of human pulmonary artery smooth muscle cells (HPASMCs) induced by platelet-derived growth factor-BB, blocked progression through G₀/G₁to S phase of the cell cycle and promoted total ratio of apoptosis. In summary, these results suggested that Aloperine negatively regulated nuclear factor-κB signaling pathway activity to exert protective effects on PAH and suppressed HPASMCs proliferation therefore has a potential value in the treatment of pulmonary hypertension by negatively modulating pulmonary vascular remodeling.

Identification of Aloperine as an anti-apoptotic Bcl2 protein inhibitor in glioma cells

Objective

Aloperine (ALO), an alkaloid isolated from the leaves of Sophora alopecuroides, has been suggested to exhibit anti-inflammatory and anti-tumor properties and is traditionally used to treat various human diseases, including cancer. However, limited information is available about the mechanisms that determine the anti-tumor activities of ALO.

Methods

Herein, through comprehensive bioinformatics methods and in vitro functional analyses, we evaluated the detailed anti-tumor mechanisms of ALO.

Results

Using the databases Bioinformatics analysis tool for molecular mechanism of traditional Chinese medicine and PubChem Project, we identified the potential targets of ALO. A protein–protein interaction network was constructed to determine the relationship among these probable targets. Functional enrichment analysis revealed that ALO is potentially involved in the induction of apoptosis. In addition, molecular docking demonstrated that ALO expectedly docks into the active pocket of the Bcl2 protein, suggesting Bcl2 as a direct target of ALO. Moreover, western blot and qPCR analysis showed that ALO downregulated Bcl2 expression in human glioma cell lines, SK-N-AS and U118. Using flow cytometry methods, we further confirmed that ALO significantly promotes apoptosis in SK-N-AS and U118 cell lines, similar to the effect induced by ABT-737, a well-known Bcl2 inhibitor. In addition, Bcl-2 overexpression could rescue ALO-induced Bcl-2 inhibition and suppress pro-apoptotic effects in glioma cells.

Conclusion

Taken together, these findings suggest that the natural agent ALO effectively enhances apoptosis by acting as a potential Bcl2 inhibitor in human glioma cells.

In Vitro Antitumor Activity of Aloperine on Human Thyroid Cancer Cells through Caspase-Dependent Apoptosis

The global incidence of thyroid cancer, one of the most common endocrine malignancies, is especially high among women. Although most patients with thyroid cancers exhibit a good prognosis with standard treatment, there are no effective therapies for patients with anaplastic thyroid cancers or cancers that have reached an advanced or recurrent level. Therefore, it is important to develop highly effective compounds for treating such patients. Aloperine, a natural compound isolated from Sophora alopecuroides, has been reported to possess antioxidant, anti-inflammatory, anti-neuronal injury, anti-renal injury, antitumor, anti-allergic, and antiviral properties. In this study, we show that aloperine can inhibit cell growth in human anaplastic thyroid cancers and multidrug-resistant papillary thyroid cancers. Moreover, it could suppress in vitro tumorigenesis and promote cellular apoptosis. Further analysis demonstrated the involvement of caspase-dependent apoptosis, including intrinsic and/or extrinsic pathways, in aloperine-induced cellular apoptosis. However, cell cycle regulation was not detected with aloperine treatment. This study suggests the potential therapeutic use of aloperine in human anaplastic thyroid cancers and multidrug-resistant papillary thyroid cancers.