Peimine Inhibits the Production of Proinflammatory Cytokines Through Regulation of the Phosphorylation of NF-κB and MAPKs in HMC-1 Cells

Peimine promotes microglial polarization to the M2 phenotype to attenuate drug-resistant epilepsy through suppressing the TLR4/NF-κB/HIF-1α signaling pathway in a rat model and in BV-2 microglia

Epilepsy is a chronic neurological disorder. Drug-resistant epilepsy (DRE) accounts for about one-third of epilepsy patients worldwide. Peimine, a main active component of Fritillaria, has been reported to show anti-inflammatory effects. However, its potential therapeutic role in DRE is not yet fully understood. In this work, a DRE rat model was established by injecting 1 μg kainic acid (KA), followed by a 250 mg/kg administration of valproic acid (VPA) from day 4-31. Rats were treated with different doses of peimine (2.5 mg/kg, 5 mg/kg and 10 mg/kg) daily from day 32-62. In vitro, BV-2 microglia were exposed to different doses of peimine (7.5 μg/ml, 15 μg/ml, and 30 μg/ml) in presence of LPS. The aim of this study was to investigate the potential therapeutic effects of peimine on DRE. The results showed that peimine efficiently suppressed the KA-induced epileptic behaviors of rats in a dose-dependent manner, as recorded by electroencephalography. Furthermore, peimine ameliorated hippocampal neuron injury in DRE rats, and promoted an M1-to-M2 microglial phenotype shift in a dose-dependent manner. Mechanistically, peimine inhibited the TLR4/NF-κB/HIF-1α signaling pathway both in vivo and in vitro. Additionally, peimine suppressed the apoptosis of primary neurons induced by LPS-treated microglia. In conclusion, peimine augments the microglial polarization towards an M2 phenotype by inhibiting the TLR4/NF-κB/HIF-1α signaling pathway, thereby attenuating DRE.

Advantages of Chinese herbal medicine in treating rheumatoid arthritis: a focus on its anti-inflammatory and anti-oxidative effects

Oxidative stress is a condition characterized by an imbalance between the oxidative and antioxidant processes within the human body. Rheumatoid arthritis (RA) is significantly influenced by the presence of oxidative stress, which acts as a pivotal factor in its pathogenesis. Elevated levels of mitochondrial reactive oxygen species (ROS) and inflammation have been found to be closely associated in the plasma of patients with RA. The clinical treatment strategies for this disease are mainly chemical drugs, such as nonsteroidal anti-inflammatory drugs (NSAIDs), disease-modifying anti-rheumatic drugs (DMARDs), glucocorticoids (GCs) and biological agents, but it is difficult for patients to accept long-term drug treatment and its side effects. In the theory of traditional Chinese medicine (TCM), RA is thought to be caused by the attack of "wind, cold, damp humor," and herbs with the effect of removing wind and dampness are used to relieve pain. Chinese herbal medicine boasts a rich heritage in effectively attenuating the symptoms of RA, and its global recognition continues to ascend. In particular, RA-relevant anti-inflammatory/anti-oxidative effects of TCM herbs/herbal compounds. The main aim of this review is to make a valuable contribution to the expanding pool of evidence that advocates for the incorporation of Chinese herbal medicine in conventional treatment plans for RA.

Advances in Neuropathic Pain Research: Selected Intracellular Factors as Potential Targets for Multidirectional Analgesics

Neuropathic pain is a complex and debilitating condition that affects millions of people worldwide. Unlike acute pain, which is short-term and starts suddenly in response to an injury, neuropathic pain arises from somatosensory nervous system damage or disease, is usually chronic, and makes every day functioning difficult, substantially reducing quality of life. The main reason for the lack of effective pharmacotherapies for neuropathic pain is its diverse etiology and the complex, still poorly understood, pathophysiological mechanism of its progression. Numerous experimental studies, including ours, conducted over the last several decades have shown that the development of neuropathic pain is based on disturbances in cell activity, imbalances in the production of pronociceptive factors, and changes in signaling pathways such as p38MAPK, ERK, JNK, NF-κB, PI3K, and NRF2, which could become important targets for pharmacotherapy in the future. Despite the availability of many different analgesics, relieving neuropathic pain is still extremely difficult and requires a multidirectional, individual approach. We would like to point out that an increasing amount of data indicates that nonselective compounds directed at more than one molecular target exert promising analgesic effects. In our review, we characterize four substances (minocycline, astaxanthin, fisetin, and peimine) with analgesic properties that result from a wide spectrum of actions, including the modulation of MAPKs and other factors. We would like to draw attention to these selected substances since, in preclinical studies, they show suitable analgesic properties in models of neuropathy of various etiologies, and, importantly, some are already used as dietary supplements; for example, astaxanthin and fisetin protect against oxidative stress and have anti-inflammatory properties. It is worth emphasizing that the results of behavioral tests also indicate their usefulness when combined with opioids, the effectiveness of which decreases when neuropathy develops. Moreover, these substances appear to have additional, beneficial properties for the treatment of diseases that frequently co-occur with neuropathic pain. Therefore, these substances provide hope for the development of modern pharmacological tools to not only treat symptoms but also restore the proper functioning of the human body.

Efficacy, chemical composition, and pharmacological effects of herbal drugs derived from Fritillaria cirrhosa D. Don and Fritillaria thunbergii Miq

Fritillaria cirrhosa D. Don and F. thunbergii Miq. belong to the genus Fritillaria within the Liliaceae family. They are used in traditional Chinese medicines that are often administered in clinical settings as they have notable effects on cough, bronchitis, pneumonia, lung injury, cancer, and other diseases. In this review, we focus on the history, origin, similarities, and differences in efficacy, chemical composition, and pharmacological outcomes of the drugs obtained from F. cirrhosa (FRC) and F. thunbergii (FRT). We list various valuable pharmacological effects of FRC and FRT, including antitussive, expectorant, anti-inflammatory, antioxidant, and anticancer effects. Thus, this review offers a basis for the medical application of and further research into the pharmacological impacts of these two drugs. We believe that new drugs derived from the phytoconstituents of F. cirrhosa and F. thunbergii that have specific therapeutic properties can be developed in the future.

Peimine-induced apoptosis and inhibition of migration by regulating reactive oxygen species-mediated MAPK/STAT3/NF-κB and Wnt/β-catenin signaling pathways in gastric cancer MKN-45 cells

Peimine (PM), a natural product extracted from Fritillaria, has anti-inflammatory, drug resistance reversal, and other pharmacological effects. The purpose of this study was to investigate the antitumor effects and the molecular mechanisms of PM using gastric cancer MKN-45 cells. Cell counting kit-8 assays were used to evaluate the viability of gastric cancer cells after treatment with PM. The results showed that PM significantly reduced the activity of gastric cancer cells, and the effect was most obvious in MKN-45 cells. Annexin V-FITC/propidium iodide staining and flow cytometry were used to assess apoptosis of MKN-45 cells after PM treatment. Our results showed that PM-induced apoptosis of MKN-45 cells. Flow cytometry was also used to determine the mitochondrial membrane potential and reactive oxygen species (ROS) levels, and to assess PM-induced cell-cycle arrest. Additionally, Western blot was used to analyze the expression of signaling pathway proteins and the relationship between apoptosis and ROS accumulation. Our findings showed that PM destroyed the mitochondria by diminishing the mitochondrial membrane potential. In addition, PM regulated the mitogen-activated protein kinase (MAPK), signal transducer and activator of transcription 3, and nuclear factor kappa-B signaling pathways by promoting the accumulation of ROS in MKN-45 cells. PM also caused cell-cycle arrest in the G2/M phase by increasing ROS accumulation. Furthermore, PM inhibited cell migration by regulating the Wnt/β-catenin pathway. In conclusion, PM plays an anticancer role through endogenous apoptosis pathways and by inhibiting cell migration, and it has the potential to be a useful treatment for gastric cancers.

Peimine suppresses collagen-induced arthritis, activated fibroblast-like synoviocytes and TNFα-induced MAPK pathways

BACKGROUND AND PURPOSE

Peimine (PM), a main isosterol alkaloid component isolated from the bulbs of traditional Chinese herb Fritillaria cirrhosa D. Don, has been demonstrated to exhibit multiple pharmacological properties, including anti-inflammation, anti-cancer and pain suppression. However, its effect on rheumatoid arthritis (RA) remains unknown. In the present study, we investigated the effect of PM on collagen-induced arthritis (CIA) rats in vivo and its inhibition on destructive behaviors of arthritic fibroblast-like synoviocytes (FLSs) in vitro.

METHODS

Arthritis was induced in rats by chicken type II collagen. Arthritis score, radiological evaluation, and histopathological assessment were used to evaluate the therapeutic effects of PM on CIA rats. EdU assay, wound healing assay and real-time PCR were used to examine the inhibitory effect of PM on proliferation, migration, and over-expression of pro-inflammatory cytokines in TNFα-induced arthritic FLSs. TRAP staining and scanning electron microscopy were used to analyze the effect of PM on osteoclastogensis and bone resorption. Western blot was used to reveal PM's molecular mechanism of action on RA.

RESULTS

PM significantly suppressed synovitis and bone destruction in CIA rats. In vitro experiments showed that PM treatment significantly inhibited TNFα-induced destructive behaviors of arthritic FLSs, including over-proliferation, migration and over-expression of pro-inflammatory cytokines. Additionally, RANKL-induced osteoclast formation and bone-resorpting function were also inhibited by PM. Further molecular mechanism studies revealed that PM treatment significantly suppressed TNFα-induced activations of MAPKs (ERK, JNK and p38) in arthritic FLSs.

CONCLUSION

Our findings provide strong evidence that PM has the potential to be developed as a therapeutic agent for patients with RA.

Anti-Allergic Effect of 3,4-Dihydroxybenzaldehyde Isolated from Polysiphonia morrowii in IgE/BSA-Stimulated Mast Cells and a Passive Cutaneous Anaphylaxis Mouse Model

In this study, we investigated the anti-allergic effects of 3,4-dihydroxybenzaldehyde (DHB) isolated from the marine red alga, Polysiphonia morrowii, in mouse bone-marrow-derived cultured mast cells (BMCMCs) and passive cutaneous anaphylaxis (PCA) in anti-dinitrophenyl (DNP) immunoglobulin E (IgE)-sensitized mice. DHB inhibited IgE/bovine serum albumin (BSA)-induced BMCMCs degranulation by reducing the release of β-hexosaminidase without inducing cytotoxicity. Further, DHB dose-dependently decreased the IgE binding and high-affinity IgE receptor (FcεRI) expression and FcεRI-IgE binding on the surface of BMCMCs. Moreover, DHB suppressed the secretion and/or the expression of the allergic cytokines, interleukin (IL)-4, IL-5, IL-6, IL-13, and tumor necrosis factor (TNF)-α, and the chemokine, thymus activation-regulated chemokine (TARC), by regulating the phosphorylation of IκBα and the translocation of cytoplasmic NF-κB into the nucleus. Furthermore, DHB attenuated the passive cutaneous anaphylactic (PCA) reaction reducing the exuded Evans blue amount in the mouse ear stimulated by IgE/BSA. These results suggest that DHB is a potential therapeutic candidate for the prevention and treatment of type I allergic disorders.

Bulbus Fritillariae Cirrhosae as a Respiratory Medicine: Is There a Potential Drug in the Treatment of COVID-19?

Bulbus fritillariae cirrhosae (BFC) is one of the most used Chinese medicines for lung disease, and exerts antitussive, expectorant, anti-inflammatory, anti-asthmatic, and antioxidant effects, which is an ideal therapeutic drug for respiratory diseases such as ARDS, COPD, asthma, lung cancer, and pulmonary tuberculosis. Through this review, it is found that the therapeutic mechanism of BFC on respiratory diseases exhibits the characteristics of multi-components, multi-targets, and multi-signaling pathways. In particular, the therapeutic potential of BFC in terms of intervention of “cytokine storm”, STAT, NF-κB, and MAPK signaling pathways, as well as the renin-angiotensin system (RAS) that ACE is involved in. In the “cytokine storm” of SARS-CoV-2 infection there is an intense inflammatory response. ACE2 regulates the RAS by degradation of Ang II produced by ACE, which is associated with SARS-CoV-2. For COVID-19, may it be a potential drug? This review summarized the research progress of BFC in the respiratory diseases, discussed the development potentiality of BFC for the treatment of COVID-19, explained the chemical diversity and biological significance of the alkaloids in BFC, and clarified the material basis, molecular targets, and signaling pathways of BFC for the respiratory diseases. We hope this review can provide insights on the drug discovery of anti-COVID-19.

Effects of chloroform fraction of Fritillariae Thunbergii Bulbus on atopic symptoms in a DNCB-induced atopic dermatitis-like skin lesion model and in vitro models

ETHNOPHARMACOLOGICAL RELEVANCE

Fritillariae thunbergii Bulbus (FT), knowns as "Jeolpaemo ()" in Korean traditional medicine, is a perennial plant belonging to the Liliaceae family and has been used to treat symptoms such as cough, sputum formation, and purulent pneumonia. Owing to its effects of lowering heat, removing sputum, and reducing swelling, the plant has also been used as an external prescription medicine to treat inflammation.

AIM OF THE STUDY

To analyze the anti-inflammatory effects of FT-ethanol extract (FT-Et) and FT-chloroform fraction extract (FT-Cl) on 1-chloro-2,4-dinitrobenzene (DNCB)-induced atopic dermatitis (AD) in vivo and in vitro.

MATERIALS AND METHODS

The effect of FT-Et and FT-Cl on AD was observed using an AD-like skin lesion model induced by DNCB in vivo. HaCaT and RBL2H3 cells were used to determine the effects of FT-Et and FT-Cl in vitro. After inducing AD-like skin lesions in vivo, FT was topically applied to the skin lesion for 35 days. Epidermal thickness, dermal thickness, scratching behavior, infiltration of inflammatory cells, and expression of skin barrier proteins were measured. TARC, MDC, and IL-4 levels were analyzed using ELISA in HaCaT cells. Beta-hexosaminidase and IL-4 levels were measured in RBL2H3 cells. The expression of filaggrin (FLG), loricrin (LOR), involucrin (INV), and aquaporin-3(AQP-3) was measured by PCR. Phosphorylation of MAPKs was analyzed using Western blot technique.

RESULTS

FT-Cl significantly reduced ear swelling, scratching behavior, SCORAD index, epidermal thickness, infiltration of inflammatory cells, and loss of skin barrier proteins. FT-Et inhibited the infiltration of mast cells and CD8⁺ cells and decreased the loss of skin barrier proteins. In TNF-α/IFN-γ-stimulated HaCaT cells, FT-Cl inhibited TRAC, MDC, and IL-4 expression and upregulated the expression of FLG, INV, and AQP-3, whereas FT-Et inhibited the expression of TRAC and MDC and increased the expression of FLG, INV, and AQP-3 at high concentrations. In RBL2H3, FT-Cl downregulated β-hexosaminidase and IL-4 expression. In addition, FT-Cl inhibited the phosphorylation of ERK and p-38 in HaCaT and RBL2H3 cells.

CONCLUSIONS

Collectively, FT-Cl showed better effect than FT-Et in vivo and in vitro. These results suggest that a specific component present in FT-Cl acted against AD. Future research should focus on the analysis of components contained in FT-Cl and the anti-inflammatory effects of the active ingredient.

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 C_max (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 t_1/2 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 t_1/2 (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.

Anti-inflammatory effects of Fritillaria thunbergii Miquel extracts in LPS-stimulated murine macrophage RAW 264.7 cells

The aim of the present study was to demonstrate that Fritillaria thunbergii Miquel extract exerts anti-inflammatory and antioxidant effects on lipopolysaccharide-stimulated RAW 264.7 cells. To confirm the inhibitory effect of ethyl acetate fraction of FTM (EAFM) on inflammation, the expression of nitric oxide (NO) and inflammatory cytokines was assessed by performing ELISA. Expression of intracellular mRNA and protein was confirmed by reverse transcription PCR and western blotting. In addition, the anti-inflammatory and anti-oxidant mechanisms of NF-κB, MAPK and heme oxygenase-1 (HO-1) were also investigated. EAFM significantly inhibited the expression of inflammatory factors including NO, IL-6 and TNF-α at non-toxic concentrations. EAFM also inhibited the mRNA and protein expression of inducible nitric oxide synthase in a concentration-dependent manner, but did not alter the expression of cyclooxygenase-2. Pre-treatment with EAFM inhibited the nuclear translocation of NF-κB, and suppressed the phosphorylation of ERK and JNK. In addition, EAFM induced 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity and an increase in the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and HO-1. The results indicated that EAFM inhibited the expression of pro-inflammatory cytokines by inhibiting ERK/JNK phosphorylation and NF-κB translocation. EAFM also exerted antioxidant effects via Nrf2/HO-1 stimulation. Collectively, the results of the present study indicated that EAFM may be a valuable alternative for the treatment of a variety of inflammatory diseases.

gga-miR-21 modulates Mycoplasma gallisepticum (HS strain)-Induced inflammation via targeting MAP3K1 and activating MAPKs and NF-κB pathways

Mycoplasma gallisepticum (MG) can target host cells and cause chronic respiratory disease (CRD) in chickens that is characterized by pMGA and concomitant. Although microRNAs (miRNAs) have been manifested are crucial regulatory noncoding RNAs with important effects on microbial pathogenesis and inflammatory response, how miRNAs regulate MG-induced inflammation remains to be discovered. The results showed that gga-miR-21 was up-regulated in MG-infected chicken embryonic lungs and MG infection of chicken embryo fibroblast cells (DF-1) compared with the control group. Overexpression of gga-miR-21 increased the inflammatory cytokines production, including tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and interleukin-8 (IL-8) after MG infection, knockdown of gga-miR-21 had thoroughly inverse effects. Gene expression data combined with bioinformatics analysis and luciferase reporter assays demonstrated that mitogen-activated protein kinase kinase kinase 1(MAP3K1) was a novel target of gga-miR-21. The inhibition of MAP3K1 by gga-miR-21 resulted in the accumulation of NF-κB in the nucleus, which in turn generate higher inflammatory cytokines. Furthermore, upregulation of gga-miR-21 significantly inhibited MG propagation and promoted MG-infected DF-1 cells proliferation by increasing the cell cycle progression and suppressing cell apoptosis. Our study provides evidence for proinflammatory effects of gga-miR-21 which is mediated at least in part by targeting MAP3K1 in the MG-infected DF-1 cells. gga-miR-21 activates MAPKs and NF-κB signaling pathways via targeting MAP3K1, and then promotes the production of inflammatory cytokines and cell proliferation by increasing the cell cycle progression and suppressing cell apoptosis to defend against MG infection.

Avenanthramide C from germinated oats exhibits anti-allergic inflammatory effects in mast cells

Mast cells play a crucial role in allergic diseases via the release of inflammatory mediators, particularly histamine and pro-inflammatory cytokines. Avenanthramide (Avn) C, a polyphenol found mainly in oats, is known to exhibit various biological properties. In this study, we aimed to evaluate the effectiveness of Avn C from germinated oats against mast cell-mediated allergic inflammation. For the in vitro study, RBL-2H3, mouse bone marrow-derived mast cells and rat peritoneal mast cells were used. Avn C (1–100 nM) inhibited the immunoglobulin (Ig)E-stimulated mast cells degranulation by suppressing phosphorylation of phosphoinositide 3-kinase and phospholipase Cγ1 and decreasing intracellular calcium levels. It inhibited IgE-stimulated secretion of inflammatory cytokines via suppression of FcεRI-mediated signaling proteins Lyn, Syk, Akt, and nuclear factor-κB. To verify the effects of Avn C in vivo, ovalbumin-induced active systemic anaphylaxis (ASA) and IgE-mediated passive cutaneous anaphylaxis (PCA) models were used. Oral administration of Avn C dose-dependently attenuated the ASA reactions, as evidenced by the inhibition of hypothermia and reduction of elevated serum histamine, IgE, and interleukin-4 levels. Avn C also inhibited the PCA reactions, such as ear swelling and plasma extravasation. Our results suggested that Avn C from germinated oats might be a possible therapeutic candidate for mast cell-mediated allergic inflammation.

Peimine suppresses interleukin‑1β‑induced inflammation via MAPK downregulation in chondrocytes

Osteoarthritis (OA) is the most common type of degenerative joint disease and secreted inflammatory molecules serve a pivotal role in it. Peimine has been reported to have anti‑inflammatory activity. In order to investigate the potential therapeutic role of Peimine in OA, mouse articular chondrocytes were treated with IL‑1β and different doses of Peimine in vitro. The data revealed that Peimine not only suppressed IL‑1β‑induced production of nitric oxide (NO) and prostaglandin E2, but also reduced the protein levels of inducible NO synthase (iNOS) and cyclooxygenase‑2 (COX‑2). In addition, Peimine inhibited the IL‑1β‑induced mRNA expression of matrix metalloproteinase (MMP)‑1, MMP‑3, MMP‑9, MMP‑13, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)‑4 and ADAMTS‑5. Furthermore, Peimine inhibited IL‑1β‑induced activation of the mitogen‑activated protein kinase (MAPK) pathway. The protective effect of Peimine on IL‑1β‑treated chondrocytes was attenuated following activation of the MAPK pathway, as demonstrated by the increased expression levels of MMP‑3, MMP‑13, ADAMTS‑5, iNOS and COX‑2 compared with the Peimine group. The in vivo data suggested that Peimine limited the development of OA in the mouse model. In general, the data indicate that Peimine suppresses IL‑1β‑induced inflammation in mouse chondrocytes by inhibiting the MAPK pathway, suggesting a promising therapeutic role for Peimine in the treatment of OA.

Pharmacological Effects of Verticine: Current Status

Verticine is the major bioactive constituent of Fritillaria as a kind of Traditional Chinese Medicine. Pharmacological researches have reported various benefits of verticine, including anticancer, anti-inflammatory, protecting against acute lung injury, tracheobronchial relaxation, antitussive, expectorant, sedative, and analgesic activities, in addition to inhibiting proliferation of cultured orbital fibroblast, angiotensin converting enzyme (ACE), and acetylcholinesterase (AChE) and inhibiting hERG potassium channels. The underlying mechanisms of verticine are still under investigation. This review will comprehensively summarize the metabolism, biological activities, and possible mechanism of verticine.

Simultaneous Determination and Pharmacokinetics of Peimine and Peiminine in Beagle Dog Plasma by UPLC-MS/MS after the Oral Administration of Fritillariae ussuriensis Maxim and Fritillariae thunbergii Miq Powder

A simple and high sensitive ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the simultaneous determination of peimine and peiminine in beagle dog plasma after the oral administration of Fritillariae ussuriensis Maxim and Fritillariae thunbergii Miq powder. Chromatographic separation was achieved on an ACQUIT UPLC^® BEH C₁₈ column (1.7 μm, 2.1 × 100 mm) in a gradient elution way with a mobile phase consisting of acetonitrile and water containing 0.1% formic acid at a flow rate of 0.4 mL/min. The plasma samples were prepared by a liquid–liquid extraction (LLE) method with ethyl acetate. The analytes were detected with a triple quadrupole tandem mass spectrometry (MS) in multiple reaction monitoring (MRM) mode and a positive ion electrospray ionization (ESI) of the transitions at m/z 432.4→414.4 for peimine and m/z 430.3→412.3 for peiminine. The method was linear for two analytes over the investigated range with all determined correlation coefficients exceeding 0.9900. The lower limit of quantification (LLOQ) was 0.988 ng/mL for peimine and 0.980 ng/mL for peiminine. The mean extraction recoveries of peimine and peiminine at three quality control samples (QC) levels were ranged from 82.56 to 88.71%, and matrix effects ranged from 92.06 to 101.2%. The intra-day and inter-day precision and accuracy were within the acceptable limits at LLOQ and QC levels. The method was effectively and successfully applied to the pharmacokinetics of peimine and peiminine after oral administration of powder to beagle dogs. The obtained results may be help to guide the clinical application of Fritillaria ussuriensis Maxim and Fritillaria thunbergii Miq.

Cryptotanshinone inhibits IgE‑mediated degranulation through inhibition of spleen tyrosine kinase and tyrosine‑protein kinase phosphorylation in mast cells

Atopic dermatitis (AD) is a type of chronic skin inflammation and one of the most common relapsing allergic diseases, which presents with a severe rash and itchy skin lesions. The pathogenesis of AD is primarily associated with hyper‑activated mast cells, which makes them an effective treatment target. After cross‑linking the antigen/immunoglobulin (Ig) E complex binds to its high affinity receptor FcεRl on the surface of mast cells. The cells subsequently secrete excessive pro‑inflammatory mediators, including histamine and cytokines, which lead to pruritus and immune cell infiltration in the skin lesions. The present study screened natural compounds that have an inhibitory effect on IgE/antigen‑mediated secretory activity. It was revealed that cryptotanshinone (CRT), a natural compound extracted from Salvia miltiorrhiza Bunge, had inhibitory effects on the IgE/antigen complex. The underlying mechanism by which CRT exerted an anti‑allergy/inflammatory function was investigated using rat basophilic leukaemia (RBL) cells for degranulation assays and a 1‑chloro‑2,4‑dinitrobenzene (DNCB)‑induced AD Balb/c mouse model for in vivo study. CRT effectively mitigated the secretion of pro‑inflammatory cytokines, including tumor necrosis factor‑α and interleukin 1β, as well as immune cell infiltration into skin lesions in a mouse model of AD‑like skin disease induced by dinitrochlorobenzene. The inhibitory effect of CRT on IgE‑mediated mast cell degranulation was mediated by the inhibition of tyrosine kinase‑dependent degranulation signalling pathways involving spleen tyrosine kinase and Lyn. The present study revealed CRT as an inhibitor of mast cell degranulation. Therefore, CRT may be considered for development as a therapeutic drug to treat IgE‑mediated skin diseases.