Sipeimine ameliorates PM2.5-induced lung injury by inhibiting ferroptosis via the PI3K/Akt/Nrf2 pathway: A network pharmacology approach.

Fine particulate matter (PM2.5) exposure can cause lung injury and a large number of respiratory diseases. Sipeimine is a steroidal alkaloid isolated from Fritillaria roylei which has been associated with anti-inflammatory, antitussive and antiasthmatic properties. In this study, we explored the potential effects of sipeimine against PM2.5-induced lung injury in Sprague Dawley rats. Sipeimine alleviated lung injury caused by PM2.5 and decreased pulmonary edema, inflammation and the levels of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) in the bronchoalveolar lavage fluid. In addition, sipeimine upregulated the glutathione (GSH) expression and downregulated the expression of 4-hydroxynonenal (4-HNE), tissue iron and malondialdehyde (MDA). The downregulation of proteins involved in ferroptosis, including nuclear factor E2-related factor 2 (Nrf2), glutathione peroxidase 4 (GPX4), heme oxygenase-1 (HO-1) and solute carrier family 7 member 11 (SLC7A11) was reversed by sipeimine. The administration of RSL3, a potent ferroptosis-triggering agent, blocked the effects of sipeimine. Using network pharmacology, we found that the effects of sipeimine were presumably mediated through the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway. A PI3K inhibitor (LY294002) blocked the PI3K/Akt signaling pathway and reversed the effects of sipeimine. Overall, this study suggested that the protective effect of sipeimine against PM2.5-induced lung injury was mainly mediated through the PI3K/Akt pathway, ultimately leading to a reduction in ferroptosis.

Peiminine inhibits the progression of colorectal cancer through up-regulating miR-760 via declining the expression of long noncoding RNA LINC00659.

Colorectal cancer (CRC) is a commonly diagnosed type of cancer globally. The molecular mechanism by which peiminine suppressed the progression of CRC is not fully addressed. The viability was assessed through cell counting kit 8 assay. Colony formation assay was used to analyze the colony formation ability. The metastasis was evaluated by transwell migration and invasion assays. Quantitative real-time PCR was performed to measure the expression of LINC00659 and miR-760 in CRC cells. The binding sites between miR-760 and LINC00659 were predicted by Starbase software and verified by dual-luciferase reporter assay, RNA immunoprecipitation assay and RNA-pull down assay. The in-vivo function of peiminine in CRC progression was confirmed by murine xenograft model. Peiminine inhibited the viability, colony formation and metastasis of CRC cells. Peiminine notably down-regulated the expression of LINC00659, while the expression of miR-760 was up-regulated by peiminine treatment. MiR-760 was a direct target of LINC00659 in CRC cells. The depletion of miR-760 attenuated the inhibitory effects of LINC00659 intervention on the viability, colony formation and metastasis of CRC cells. Peiminine restrained the progression of CRC through LINC00659 and miR-760. LINC00659 inhibited the growth of CRC tumors through LINC00659/miR-760 axis in vivo. Peiminine suppressed the development of CRC through inhibiting the viability, colony formation and metastasis of CRC cells via LINC00659/miR-760 axis. LINC00659/miR-760 axis might be an underlying target for CRC therapy.

Peiminine Reduces ARTS-Mediated Degradation of XIAP by Modulating the PINK1/Parkin Pathway to Ameliorate 6-Hydroxydopamine Toxicity and α-Synuclein Accumulation in Parkinson's Disease Models In Vivo and In Vitro.

Parkinson's disease (PD) is a degenerative disease that can cause motor, cognitive, and behavioral disorders. The treatment strategies being developed are based on the typical pathologic features of PD, including the death of dopaminergic (DA) neurons in the substantia nigra of the midbrain and the accumulation of α-synuclein in neurons. Peiminine (PMN) is an extract of Fritillaria thunbergii Miq that has antioxidant and anti-neuroinflammatory effects. We used Caenorhabditis elegans and SH-SY5Y cell models of PD to evaluate the neuroprotective potential of PMN and address its corresponding mechanism of action. We found that pretreatment with PMN reduced reactive oxygen species production and DA neuron degeneration caused by exposure to 6-hydroxydopamine (6-OHDA), and therefore significantly improved the DA-mediated food-sensing behavior of 6-OHDA-exposed worms and prolonged their lifespan. PMN also diminished the accumulation of α-synuclein in transgenic worms and transfected cells. In our study of the mechanism of action, we found that PMN lessened ARTS-mediated degradation of X-linked inhibitor of apoptosis (XIAP) by enhancing the expression of PINK1/parkin. This led to reduced 6-OHDA-induced apoptosis, enhanced activity of the ubiquitin-proteasome system, and increased autophagy, which diminished the accumulation of α-synuclein. The use of small interfering RNA to down-regulate parkin reversed the benefits of PMN in the PD models. Our findings suggest PMN as a candidate compound worthy of further evaluation for the treatment of PD.

Peimine, an Anti-Inflammatory Compound from Chinese Herbal Extracts, Modulates Muscle-Type Nicotinic Receptors.

Fritillaria bulbs are used in Traditional Chinese Medicine to treat several illnesses. Peimine (Pm), an anti-inflammatory compound from Fritillaria, is known to inhibit some voltage-dependent ion channels and muscarinic receptors, but its interaction with ligand-gated ion channels remains unexplored. We have studied if Pm affects nicotinic acetylcholine receptors (nAChRs), since they play broad functional roles, both in the nervous system and non-neuronal tissues. Muscle-type nAChRs were incorporated to Xenopus oocytes and the action of Pm on the membrane currents elicited by ACh (IAChs) was assessed. Functional studies were combined with virtual docking and molecular dynamics assays. Co-application of ACh and Pm reversibly blocked IACh, with an IC50 in the low micromolar range. Pm inhibited nAChR by: (i) open-channel blockade, evidenced by the voltage-dependent inhibition of IAch, (ii) enhancement of nAChR desensitization, revealed by both an accelerated IACh decay and a decelerated IACh deactivation, and (iii) resting-nAChR blockade, deduced from the IACh inhibition elicited by Pm when applied before ACh superfusion. In good concordance, virtual docking and molecular dynamics assays demonstrated that Pm binds to different sites at the nAChR, mostly at the transmembrane domain. Thus, Pm from Fritillaria bulbs, considered therapeutic herbs, targets nAChRs with high affinity, which might account for its anti-inflammatory actions.

Pharmacokinetic interaction between peimine and paeoniflorin in rats and its potential mechanism.

CONTEXT: Peimine and paeoniflorin can be combined for the treatment of cough in paediatrics. The interaction during the co-administration could dramatically affect the bioavailability of drugs. OBJECTIVE: The interaction between peimine and paeoniflorin was investigated in this study. MATERIALS AND METHODS: The pharmacokinetics of paeoniflorin (20 mg/kg) with or without the coadministration of peimine (5 mg/kg for 10 days before paeoniflorin) was orally investigated in Sprague-Dawley rats (n = 6). The group without the peimine was set as the control group. The metabolic stability of paeoniflorin was studied in rat liver with microsomes. The effect of peimine on the absorption of paeoniflorin was investigated with Caco-2 cell monolayers. RESULTS: The Cmax (244.98 ± 10.95 vs. 139.18 ± 15.14 µg/L) and AUC(0-t) (3295.92 ± 263.02 vs. 139.18 ± 15.14 h·µg/L) of paeoniflorin was increased by peimine. The t1/2 was prolonged from 5.33 ± 1.65 to 14.21 ± 4.97 h and the clearance was decreased from 15.43 ± 1.75 to 4.12 ± 0.57 L/h/kg. Consistently, peimine increased the metabolic stability of paeoniflorin with rat liver microsomes with the increased t1/2 (56.78 ± 2.62 vs. 26.33 ± 3.15 min) and the decreased intrinsic clearance (24.42 ± 3.78 vs. 52.64 ± 4.47 µL/min/mg protein). Moreover, the transportation of paeoniflorin was also inhibited by peimine as the efflux ratio decreased from 3.06 to 1.63. DISCUSSION AND CONCLUSIONS: Peimine increased the systemic exposure of paeoniflorin through inhibiting the activity of CYP3A4 and P-gp. These results provide a reference for further in vivo studies in a broader population.

Peimine inhibits the growth and motility of prostate cancer cells and induces apoptosis by disruption of intracellular calcium homeostasis through Ca2+ /CaMKII/JNK pathway.

Prostate cancer (PC) is one of the most common malignant tumors in man. Peimine (PM) is a bioactive substance isolated from Fritillaria. Previous studies have shown that PM could inhibit the occurrence of a variety of cancers. However, the roles of PM in PC and its related mechanism have not been elucidated. Calcium (Ca2+ ) is an important intracellular messenger involved in a variety of cell processes. In this study, we found that the appropriate doses of PM (2.5, 5, and 10 µM) significantly inhibited the growth of PC cells (DU-145, LNCap, and PC-3), but has no significant effect on normal prostate cells (RWPE-1). In addition, PM treatment inhibited the invasion and migration of PC-3 cells and blocked the epithelial-mesenchymal transition process. These effects were exhibited a dose-dependent manner. Furthermore, the current results also showed that PM treatment significantly increased the Ca2+ concentration, the increased Ca2+ promoted the phosphorylation of Ca2+ /calmodulin-dependent protein kinase II (CaMKII) and c-Jun N-terminal kinase (JNK), further inhibited the growth and invasion of PC-3 cells, and induced its apoptosis. Ca2+ chelator BAPTA-AM (1 µM) could counteract the increase of intracellular Ca2+ concentration. Similarly, JNK pathway inhibitor SP600125 (10 µM) also inhibited cell growth and invasion and induced apoptosis. In addition, experiments in nude mice showed that PM inhibited tumor formation through Ca2+ /CaMKII/JNK signaling pathway. In conclusion, our results show that PM inhibits the growth and motility of prostate cancer cells and induces apoptosis by disruption of intracellular calcium homeostasis through Ca2+ /CaMKII/JNK pathway.

In vitro effects of peimine on the activity of cytochrome P450 enzymes.

Peimine is a major component of Fritillaria ussuriensis, which is a widely used herb in pediatric. It is very common in Chinese traditional medicine to combine with two or more herbs in the clinic. To investigate the effect of peimine on the activity of cytochrome P450 enzymes (CYP450) is necessary for the clinical application of peimine.The effects of peimine on eight human liver CYP isoforms (i.e., 1A2, 3A4, 2A6, 2E1, 2D6, 2C9, 2C19 and 2C8) were investigated in vitro in human liver microsomes (HLMs) with the specific inhibitors as positive control and without peimine or inhibitors as negative control. The enzyme kinetic parameters were calculated.It was found that peimine inhibited the activity of CYP3A4, 2E1, and 2D6 in a concentration-dependent manner with the IC50 values of 13.43, 21.93, and 22.46 µM, respectively. The inhibition of CYP3A4 was performed in a non-competitive manner with the Ki value of 6.49 µM, and the inhibition of CYP2E1 and 2D6 was performed in a competitive manner with Ki values of 10.76 and 11.95 µM. Additionally, peimine inhibited the activity of CYP3A4 in a time-dependent manner with the KI/Kinact value of 6.17/0.049 min-1 µM-1.Peimine inhibited the activity of CYP3A4, 2E1, and 2D6, which indicated the potential interaction between peimine and drugs metabolized by CYP3A4, 2E1, and 2D6. Further studies are needed to verify the drug-drug interaction and the in vivo effects.

Peiminine Inhibits Glioblastoma in Vitro and in Vivo Through Cell Cycle Arrest and Autophagic Flux Blocking.

BACKGROUND/AIMS: Glioblastoma multiforme (GBM) is the most devastating and widespread primary central nervous system tumour in adults, with poor survival rate and high mortality rates. Existing treatments do not provide substantial benefits to patients; therefore, novel treatment strategies are required. Peiminine, a natural bioactive compound extracted from the traditional Chinese medicine Fritillaria thunbergii, has many pharmacological effects, especially anticancer activities. However, its anticancer effects on GBM and the underlying mechanism have not been demonstrated. This study was conducted to investigate the potential antitumour effects of peiminine in human GBM cells and to explore the related molecular signalling mechanisms in vitro and in vivo Methods: Cell viability and proliferation were detected with MTT and colony formation assays. Morphological changes associated with autophagy were assessed by transmission electron microscopy (TEM). The cell cycle rate was measured by flow cytometry. To detect changes in related genes and signalling pathways in vitro and in vivo, RNA-seq, Western blotting and immunohistochemical analyses were employed. RESULTS: Peiminine significantly inhibited the proliferation and colony formation of GBM cells and resulted in changes in many tumour-related genes and transcriptional products. The potential anti-GBM role of peiminine might involve cell cycle arrest and autophagic flux blocking via changes in expression of the cyclin D1/CDK network, p62 and LC3. Changes in Changes in flow cytometry results and TEM findings were also observed. Molecular alterations included downregulation of the expression of not only phospho-Akt and phospho-GSK3ß but also phospho-AMPK and phospho-ULK1. Furthermore, overexpression of AKT and inhibition of AKT reversed and augmented peiminine-induced cell cycle arrest in GBM cells, respectively. The cellular activation of AMPK reversed the changes in the levels of protein markers of autophagic flux. These results demonstrated that peiminine mediates cell cycle arrest by suppressing AktGSk3ß signalling and blocks autophagic flux by depressing AMPK-ULK1 signalling in GBM cells. Finally, peiminine inhibited the growth of U251 gliomas in vivo. CONCLUSION: Peiminine inhibits glioblastoma in vitro and in vivo via arresting the cell cycle and blocking autophagic flux, suggesting new avenues for GBM therapy.

Peiminine Protects Dopaminergic Neurons from Inflammation-Induced Cell Death by Inhibiting the ERK1/2 and NF-κB Signalling Pathways.

Neuroinflammation, characterized marked by microglial activation, plays a very important role in the pathogenesis of Parkinson's disease (PD). Upon activation, pro-inflammatory mediators are produced by microglia, triggering excessive inflammatory responses and ultimately damaging dopaminergic neurons. Therefore, the identification of agents that inhibit neuroinflammation may be an effective approach for developing novel treatments for PD. In this study, we sought to investigate whether peiminine protects dopaminergic neurons by inhibiting neuroinflammation. We evaluated the effects of peiminine on behavioural dysfunction, microglial activation and the loss of dopaminergic neurons in a rat model of lipopolysaccharide (LPS)-induced PD. BV-2 cells were pretreated with peiminine for 1 h and then stimulated with LPS for different times. Then, inflammatory responses and the related signalling pathways were analysed. Peiminine markedly attenuated behavioural dysfunction and inhibited the loss of dopaminergic neurons and microglial activation in the LPS-induced PD rat model. In BV-2 cells, peiminine significantly decreased LPS-induced expression of the pro-inflammatory mediators TNF-α, IL-6 and IL-1ß, COX-2 and iNOS by inhibiting the phosphorylation of ERK1/2, AKT and NF-κB p65. Based on these results demonstrated that peiminine has a role in protecting dopaminergic neurons in the LPS-induced PD rat model by inhibiting neuroinflammation.

Peiminine Protects against Lipopolysaccharide-Induced Mastitis by Inhibiting the AKT/NF-κB, ERK1/2 and p38 Signaling Pathways.

Peiminine, an alkaloid extracted from Fritillaria plants, has been reported to have potent anti-inflammatory properties. However, the anti-inflammatory effect of peiminine on a mouse lipopolysaccharide (LPS)-induced mastitis model remains to be elucidated. The purpose of this experiment was to investigate the effect of peiminine on LPS-induced mastitis in mice. LPS was injected through the canals of the mammary gland to generate the mouse LPS-induced mastitis model. Peiminine was administered intraperitoneally 1 h before and 12 h after the LPS injection. In vitro, mouse mammary epithelial cells (mMECs) were pretreated with different concentrations of peiminine for 1 h and were then stimulated with LPS. The mechanism of peiminine on mastitis was studied by hematoxylin-eosin staining (H&E) staining, western blotting, and enzyme-linked immunosorbent assay (ELISA). The results showed that peiminine significantly decreased the histopathological impairment of the mammary gland in vivo and reduced the production of pro-inflammatory mediators in vivo and in vitro. Furthermore, peiminine inhibited the phosphorylation of the protein kinase B (AKT)/ nuclear factor-κB (NF-κB), extracellular regulated protein kinase (ERK1/2), and p38 signaling pathways both in vivo and in vitro. All the results suggested that peiminine exerted potent anti-inflammatory effects on LPS-induced mastitis in mice. Therefore, peiminine might be a potential therapeutic agent for mastitis.

The natural product peiminine represses colorectal carcinoma tumor growth by inducing autophagic cell death.

Autophagy is evolutionarily conservative in eukaryotic cells that engulf cellular long-lived proteins and organelles, and it degrades the contents through fusion with lysosomes, via which the cell acquires recycled building blocks for the synthesis of new molecules. In this study, we revealed that peiminine induces cell death and enhances autophagic flux in colorectal carcinoma HCT-116 cells. We determined that peiminine enhances the autophagic flux by repressing the phosphorylation of mTOR through inhibiting upstream signals. Knocking down ATG5 greatly reduced the peiminine-induced cell death in wild-type HCT-116 cells, while treating Bax/Bak-deficient cells with peiminine resulted in significant cell death. In summary, our discoveries demonstrated that peiminine represses colorectal carcinoma cell proliferation and cell growth by inducing autophagic cell death.

Intestinal absorption characteristics of imperialine: in vitro and in situ assessments.

AIM: Imperialine is an effective compound in the traditional Chinese medicine chuanbeimu (Bulbus Fritillariae Cirrhosae) that has been used as antitussive/expectorant in a clinical setting. In this study we investigated the absorption characteristics of imperialine in intestinal segments based on an evaluation of its physicochemical properties. METHODS: Caco-2 cells were used to examine uptake and transport of imperialine in vitro, and a rat in situ intestinal perfusion model was used to characterize the absorption of imperialine. The amount of imperialine in the samples was quantified using LC-MS/MS. RESULTS: The aqueous solubility and oil/water partition coefficient of imperialine were determined. This compound demonstrated a relatively weak alkalinity with a pKa of 8.467±0.028. In Caco-2 cells, the uptake of imperialine was increased with increasing pH in medium, but not affected by temperature. The apparent absorptive and secretive coefficient was (8.39±0.12)×10(-6) cm/s and (7.78±0.09)×10(-6) cm/s, respectively. Furthermore, neither the P-glycoprotein inhibitor verapamil nor Niemann-Pick C1-Like 1 transporter inhibitor ezetimibe affected the absorption and secretion of imperialine in vitro. The in situ intestinal perfusion study showed that the absorption parameters of imperialine varied in 4 intestinal segments (duodenum, jejunum, ileum and colon) with the highest ones in the colon, where a greater number of non-ionized form of imperialine was present. CONCLUSION: The intestinal absorptive characteristics of imperialine are closely related to its physicochemical properties. The passive membrane diffusion dominates the intestinal absorption of imperialine.

Imperialine and Verticinone from Bulbs of Fritillaria wabuensis Inhibit Pro-inflammatory Mediators in LPS-stimulated RAW 264.7 Macrophages.

The bulbs of plants belonging to the Fritillaria cirrhosa-group have been used as antitussive and expectorant herbs in traditional Chinese medicine for thousands of years. In this study, we isolated two isomers of verticinone and imperialine, steroidal alkaloids belonging to the cevanine group, from bulbs of Fritillaria wabuensis, which is a part of the Fritillaria cirrhosa group, and investigated their anti-inflammatory effects and relative mechanisms on lipopolysaccharide-stimulated RAW 264.7 macrophages. Our results clearly demonstrate that verticinone or imperialine could dose-dependently inhibit nitric oxide production and also suppress inducible nitric oxide synthase and cyclooxygenase-2 expressions. In addition, verticinone or imperialine suppress the production of pro-inflammatory cytokines in a dose dependent manner, such as tumor necrosis factor-α and interleukin-1ß. The effect of verticinone and imperialine on the activation of nuclear factor-kappaB was also evaluated. The phosphorylation of nuclear factor-kappaB stimulated with LPS is also down-regulated by verticinone or imperialine in a concentration dependent manner, which coincided with the inhibition of phosphorylation forms of inhibitory kappaB-α, a crucial inhibitory factor of nuclear factor-kappaB. Generally, the anti-inflammatory effects and mechanisms of verticinone and imperialine are mediated by the inhibition of the nuclear factor-kappaB activation signaling pathway. According to the results of our researches, verticinone and imperialine may present great potentials to be developed as therapeutics for inflammatory diseases.

Antiallergic effects of peiminine through the regulation of inflammatory mediators in HMC-1 cells.

Peiminine is the main biologically active component derived from Fritillaria ussuriensis. Peiminine was investigated in various pulmonary diseases, but its antiallergic effect and the related mechanism have not been reported yet. The present study aimed to evaluate the effect of peiminine on mast cell-mediated allergic inflammation in HMC-1 cells. The pro-inflammatory cytokine production was measured using ELISA, reverse transcription-polymerase chain reaction and nuclear factor-kappaB (NF-κB), mitogen-activated protein kinases (MAPKs) pathway activation, as determined by Western blot analysis. Peiminine inhibits the production of the pro-inflammatory cytokine, such as interleukin (IL)-6, IL-8, tumor necrosis factor-alpha (TNF-α) and IL-1beta (IL-1ß). It was shown to have inhibitory effects on MAPKs phosphorylation and NF-B expression in human mast cells (HMC)-1 using Western blot. HMC-1 cells were observed for confirmation of histamine release. Passive cutaneous anaphylaxis (PCA) reactions were evaluated using an animal model and peiminine demonstrated inhibitory effects on IgE-dependent anaphylaxis. These results suggest that peiminine has regulatory potential for allergic inflammatory reactions mediated by HMC-1 cells.

[Effect of Peimine on ERCC1 mRNA and LRP Expressions of A549/DDP Multidrug Resistance Cell Line].

OBJECTIVE: To explore the effect of peimine on excision repair cross-complementation 1 (ERCC1) mRNA and lung resistant protein (LRP) expressions in A549/cisplatin (DDP) multidrug resistance (MDR) cell line. METHODS: Lung cancer A549/DDP cells were cultured in vitro.Cells at logarithmic growth phase were divided into 4 groups, i.e., the blank control group, the DDP group, the ligustrazine group (DDP+ligustrazine), the peimine group (DDP + peimine). After 48-h drug action, ERCC1 mRNA expression was detected by RT-PCR and LRP expression detected by cell immunofluorescence. RESULTS: There was no statistical difference in expression levels of ERCC1 mRNA and LRP between the DDP group and the blank control group (P > 0.05). Compared with the DDP group, expression levels of ERCC1 mRNA and LRP obviously decreased in the ligustrazine group and the peimine group (P < 0.05). They were obviously lower in the peimine group than in the ligustrazine group (P < 0.05). CONCLUSIONS: Peimine could reverse MDR of A549/DDP cell line. Its mechanism might be associated with down-regulating ERCC1 mRNA and LRP expression levels.

Unveiling the therapeutic potential of plant steroid peimine: A study on apoptotic induction in MRMT-1 cell line-induced breast cancer in rats.

BACKGROUND: Breast cancer stands as a leading contributor to global cancer-related mortality. Progressing Research and Medical Innovations Elevate Treatment Choices and Results for Breast Cancer. Among these, Peimine, a natural steroid inherent in plants, notably within the Fritillaria species, demonstrates the capability to trigger apoptosis in breast cancer cells through the mitochondrial membrane permeation pathway. Nevertheless, its impact on an appropriate cancer model remains an area necessitating further exploration. AIM: This study explored the in vivo anticancer effects of peimine on MRMT-1 Cell-line induced breast cancer in rats. METHOD: Cancer was induced by the administration of MRMT-1 (6 x 106 cells) cells in the mammary pads of SD rats. The daily drug treatmentcommenced on day 14 and continued till 39 days. Peimine was administered in two doses (0.24 mg/kg and 0.48 mg/kg p.o) to examine its efficacy in curing breast cancer while tamoxifen was used as standard. RESULTS: A reduction in tumour size was observed in the peimine-treated groups. Peimine can correct the changed blood cell count in addition to its anti-tumour activity. In peimine-treated rats, imbalanced immune marker IgE, serum oxidative marker, and tissue apoptotic markers like cytochrome c and calcium level were shown to be restored significantly. CONCLUSION: Our findings imply that quinine has beneficial effects as an anti-neoplastic medication for breast cancer, most likely through its apoptotic activity. More research is necessary to thoroughly understand their mechanisms of action, ideal dose, and potential side effects.

Cevanine-type steroidal alkaloids from the bulbs of Fritillaria cirrhosa D. Don.

Eight previously undescribed cevanine-type steroidal alkaloids, cirrhosinones I-N and cirrhosinols A-B, along with five known analogs, were isolated from the bulbs of Fritillaria cirrhosa D. Don. Their structures were elucidated on the basis of comprehensive analysis of HRESIMS, 1D and 2D NMR spectroscopic data, and single-crystal X-ray diffraction analyses. All compounds revealed weak NO inhibitory activities in the LPS-stimulated NR8383 cells at the concentration of 20 µM, with inhibition ratios ranging from 5.1% to 14.3%.

Peimine impairs pro-inflammatory cytokine secretion through the inhibition of the activation of NF-κB and MAPK in LPS-induced RAW264.7 macrophages.

In the previous study, we found that peimine has good anti-inflammatory effects in vivo. However, the anti-inflammatory mechanism of peimine remains unclear. We, therefore, assessed the effects of peimine on inflammatory cytokines in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. We found that peimine (0-25 mg/L) significantly inhibited tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1ß, and increased IL-10 production. Furthermore, peimine significantly inhibited the phosphorylation of p38, ERK and c-jun N-terminal kinase (JNK) as well as decreased p65 and IκB. The present results indicate that peimine inhibits the production of inflammatory cytokines induced by LPS through blocking MAPKs and NF-κB signaling pathways.

Interaction of a Novel Alternatively Spliced Variant of HSD11B1L with Parkin Enhances the Carcinogenesis Potential of Glioblastoma: Peiminine Interferes with This Interaction.

Glioblastoma (GBM) is a primary brain tumor of unknown etiology. It is extremely aggressive, incurable and has a short average survival time for patients. Therefore, understanding the precise molecular mechanisms of this diseases is essential to establish effective treatments. In this study, we cloned and sequenced a splice variant of the hydroxysteroid 11-ß dehydrogenase 1 like gene (HSD11B1L) and named it HSD11B1L-181. HSD11 B1L-181 was specifically expressed only in GBM cells. Overexpression of this variant can significantly promote the proliferation, migration and invasion of GBM cells. Knockdown of HSD11B1L-181 expression inhibited the oncogenic potential of GBM cells. Furthermore, we identified the direct interaction of parkin with HSD11B1L-181 by screening the GBM cDNA expression library via yeast two-hybrid. Parkin is an RBR E3 ubiquitin ligase whose mutations are associated with tumorigenesis. Small interfering RNA treatment of parkin enhanced the proliferative, migratory and invasive abilities of GBM. Finally, we found that the alkaloid peiminine from the bulbs of Fritillaria thunbergii Miq blocks the interaction between HSD11B1L-181 and parkin, thereby lessening carcinogenesis of GBM. We further confirmed the potential of peiminine to prevent GBM in cellular, ectopic and orthotopic xenograft mouse models. Taken together, these findings not only provide insight into GBM, but also present an opportunity for future GBM treatment.

Steroidal alkaloids from the bulbs of Fritillaria unibracteata.

Two new steroidal alkaloids peimisine-3-O-ß-D-glucopyranoside (1) and puqiedinone-3-O-ß-D-glucopyranoside (3), together with three known compounds peimisine (2), puqiedinone (4), and puqiedine (5), were isolated and characterized from the bulbs of Fritillaria unibracteata. Their structures were fully elucidated by spectroscopic and chemical methods. Compound 1 showed moderate protection effect on neurotoxicity of PC12 cell lines induced by rotenone.