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Saikosaponin D inhibits the inflammatory response of secretory otitis media through FTO-mediated N6-methyladenosine modification of TLR4 mRNA

BMC Pharmacology and Toxicology volume 26, Article number: 79 (2025) Cite this article

Abstract

Secretory Otitis Media (SOM) is a non-suppurative inflammatory disease of the middle ear. Saikosaponin D (SSD), a compound with significant anti-inflammatory and immunomodulatory properties, was investigated for its preventive effects and underlying mechanisms against SOM. A rat model of SOM was established through intraperitoneal ovalbumin injection. Middle ear lavage fluid (MELF) and tissue samples were collected for comprehensive analysis, including bacterial load quantification, neutrophil enumeration, and inflammatory factor assessment. HEK293T cells were utilized for mechanistic validation. Our findings demonstrated that SSD preventive treatment significantly reduced colony-forming units (CFUs) in SOM-induced rats, attenuated middle ear mucosal thickening, and suppressed pro-inflammatory cytokine levels (TNF-α, IL-6, and INF-γ). Mechanistically, SSD treatment counteracted SOM-induced m6A level elevation and reversed the downregulation of FTO expression. Functional studies revealed that FTO inhibition exacerbated inflammatory responses, while SSD treatment mitigated these effects. Further investigation demonstrated that SSD decreased TLR4 mRNA stability through FTO-mediated m6A modification. In conclusion, SSD alleviates SOM progression by reducing bacterial load and neutrophil infiltration. The therapeutic effects are mediated through FTO upregulation and subsequent m6A-dependent TLR4 mRNA degradation. This study elucidates a novel molecular mechanism underlying SSD’s preventive action against SOM development.

Peer Review reports

Introduction

Secretory Otitis Media (SOM), a prevalent non-suppurative inflammatory disorder of the middle ear, is characterized by persistent fluid accumulation, conductive hearing loss, and an intact tympanic membrane [1]. Current therapeutic strategies primarily rely on antibiotics and glucocorticoids; however, these approaches are often associated with the development of drug resistance and potential dependency issues [2]. Although myringotomy demonstrates efficacy in short-term management, its application for long-term treatment remains controversial due to potential complications [3]. These limitations underscore the urgent need for developing novel therapeutic agents and elucidating their underlying mechanisms for SOM treatment.

Saikosaponin D (SSD), a bioactive triterpenoid saponin derived from Radix Bupleuri, has garnered significant attention due to its potent anti-inflammatory and immunomodulatory properties. Emerging evidence indicates that SSD modulates inflammatory responses through multiple mechanisms, including the suppression of pro-inflammatory mediators such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) [4, 5]. Furthermore, SSD has been shown to inhibit critical inflammatory signaling pathways by regulating the expression and phosphorylation status of key proteins, including Toll-like receptor 4 (TLR4) and nuclear factor κB (NF-κB) [6]. These multifaceted anti-inflammatory properties position SSD as a promising candidate for SOM intervention.

The emerging role of N6-methyladenosine (m6A) modification, a prevalent epigenetic modification in eukaryotic mRNAs, has recently been highlighted in inflammatory pathogenesis. This reversible RNA modification regulates various aspects of RNA metabolism, including splicing, transport, stability, and translation [7]. Accumulating evidence suggests that m6A modification plays a pivotal role in the pathogenesis and progression of diverse inflammatory disorders [8,9,10]. Notably, recent studies have demonstrated that SSD exerts anti-leukemic effects through modulation of the fat mass and obesity-associated protein (FTO)/m6A signaling pathway [11], suggesting a potential link between SSD’s therapeutic effects and m6A modification regulation.

In the present study, we established a rat model of SOM to investigate the therapeutic potential of SSD, with particular focus on its effects on bacterial colonization, cytokine profiles, and middle ear tissue morphology. Furthermore, we explored the regulatory effects of SSD on m6A modification-related genes, aiming to elucidate the molecular mechanisms underlying SSD’s therapeutic effects. Our findings provided novel insights into the potential of m6A-related genes as therapeutic targets for SOM treatment, mediated through SSD intervention.

Materials and methods

Animal grouping

Eight-week-old specific pathogen-free (SPF) Sprague-Dawley rats (body weight: 160–190 g) were obtained from Beijing Vital River Laboratories (Beijing, China). All animal experiments were approved by the Institutional Animal Care and Use Committee (IACUC) of the Animal Science (Approval Number: MDKN-2024-186) and conducted in accordance with the National Institutes of Health Guide for the Care and Use of Laboratory Animals. All animals exhibited patent bilateral external auditory canals, intact tympanic membranes without congestion, clearly visible tympanic landmarks, and normal auricular reflexes. The rats were randomly allocated into nine experimental groups (n = 10 per group):

Control group: Rats were intraperitoneally injected with 1.0 mL 0.9% NaCl twice a day for 16 days starting from day 1 of the experiment.

SOM model group: Animals were intraperitoneally administered 1.2 mg ovalbumin (A5503, Sigma-Aldrich) on day 1 and day 8 following a 7-day acclimatization period. On days 15 and 16, 0.1 mg ovalbumin was injected into the bilateral middle ear cavity through the posteroinferior or anteroinferior quadrant of the tympanic membrane [12].

SSD treatment groups: Three dosage groups were established using SSD (ultrasonically dissolved in sterile water):

Three SSD treatment group: Three concentrations of SSD (ultrasonic dissolved in water) were configured. The doses of SSD were low dose (LD, 0.75 mg/kg) medium dose (MD, 1.50 mg/kg) and high dose (HD, 3.00 mg/kg), which were administered by intraperitoneal injection twice a day for 16 days starting from day 1 of the experiment [13].

FTO inhibition groups: Lentiviral vectors carrying shFTO (LV-shFTO) and negative control (LV-shNC) were constructed and packaged by HanBio Technology Co., Ltd. (Shanghai, China). Rats received 100 µL of lentivirus suspension (1 × 109 TU/mL) via tail vein injection on day 1.

Sample collection

On day 18 of the experiment, euthanasia was performed by inhalation of isoflurane (5% for induction, followed by maintenance at 2–3%) in a sealed chamber until cessation of breathing and heartbeat. Tympanic membranes were examined under a surgical microscope (Leica M651). Middle ear tissues were carefully dissected and lavaged with phosphate-buffered saline (PBS) containing 1% fetal bovine serum (FBS; Gibco). Each ear was irrigated six times with 10 µL of PBS per lavage, and approximately 50 µL of MELF was collected from each ear and labeled accordingly. A 5 µL aliquot of MELF from each ear was serially diluted for bacterial quantification. The remaining MELF was centrifuged at 4 °C for 5 min (3000 × g), and the supernatant was stored at -80 °C for subsequent cytokine analysis.

Calculation of the amount of bacteria in the MELF

MELF samples from each ear were serially diluted and plated onto Columbia Blood Agar Plates (CP0160, Huankai Microbial). Plates were incubated at 37 °C in a 5% CO₂ atmosphere overnight. After 48 h of incubation, colony growth was observed, and colony-forming units (CFUs) were counted. The bacterial load in the middle ear was quantified by calculating the number of CFUs per milliliter of MELF.

HE staining

Middle ear tissues from each group were collected and immersed in 10% formaldehyde solution for fixation. After complete fixation for 12 h, tissues were decalcified in 10% neutral EDTA solution for approximately 20 days. Following dehydration, tissues were embedded in paraffin and sectioned using standard protocols. HE staining was performed to evaluate pathological changes in the middle ear and Eustachian tube, as well as to assess eosinophil infiltration.

Determination of inflammatory factors in MELF

The levels of TNF-α, IL-6, and IFN-γ in MELF were quantified using commercial enzyme-linked immunosorbent assay (ELISA) kits specific for rat cytokines: TNF-α (PT516, Beyotime), IL-6 (PI328, Beyotime), and IFN-γ (PI510, Beyotime). All assays were performed according to the manufacturer’s protocols.

Flow cytometry analysis

Neutrophils in MELF were identified and quantified using flow cytometry. Total cells were collected by centrifugation and washed twice with pre-cooled PBS. Cell density was adjusted to 1 × 10⁶ cells/mL. Neutrophils were stained with fluorescence-labeled antibodies against Ly-6G (RB6-8C5, GeneTex) and CD11b (PA5-79532, Invitrogen) for 15 min at room temperature in the dark. Stained cells were analyzed by flow cytometry within one hour of staining.

m6A Dot blot assay

The m6A dot blot assay was performed to detect RNA m6A modification levels. Total RNA was extracted from rat middle ear tissues using the Trizol method (Invitrogen Life Technologies), followed by genomic DNA removal using DNase treatment. RNA concentration and purity were assessed using a NanoDrop spectrophotometer. RNA samples were diluted and immobilized onto a nylon membrane. After washing with TBST, the membrane was incubated with an anti-m6A primary antibody (ab284130, 1:5000 dilution, Abcam) overnight at 4 °C. The following day, the membrane was incubated with an HRP-labeled secondary antibody (RGAM001, 1:3000 dilution, Proteintech) for 1 h at room temperature. Signal detection was performed using a chemiluminescence imaging system (Bio-Rad).

Reverse transcription quantitative PCR

RT-qPCR was performed to quantify mRNA expression levels. Total RNA extracted from middle ear tissues was reverse-transcribed into cDNA using the TaKaRa PrimeScript™ RT Reagent Kit. PCR amplification was conducted using gene-specific primers, Takara SYBR Premix Ex Taq™ II reagent, and a Real-time Thermal Cycler. Gene expression levels were normalized to β-actin and calculated using the 2−ΔΔCT method. The primer sequences used were as follows:

  • METTL3: forward 5′-CTGGGCACTTGGACTTAA-3′, reverse 5′-GAGGTGGTGTAGCAACTTCT-3′

  • METTL14: forward 5′-CAGCACCTCGGTCATTTA-3′, reverse 5′-TTCCAGGATTGTTCTTATTG-3′

  • WTAP: forward 5′-TAGAGTAGATGTGGGCTTAG-3′, reverse 5′-CAGATGTATGGTGGAAAA-3′

  • FTO: forward 5′-GACACTTGGCTTCCTTACC-3′, reverse 5′-CGGCACAGCGTCTTCATT-3′

  • ALKBH5: forward 5′-CTTTAGCGACTCGGCACTT-3′, reverse 5′-CTCATCAGCAGCATACCCAC-3′

  • TLR4: forward 5′-CCTTTCCTGCCTGAGACC-3′, reverse 5′-GATTATGAGCCACATTTAGT-3′

Western blot assay

Protein samples were extracted from middle ear tissues, and protein concentrations were determined using the BCA method. Equal amounts of protein were separated by 10–12% SDS-PAGE and transferred onto PVDF membranes at a constant current of 100 mA for 1–2 h. Membranes were washed three times with TBST (TBS containing 0.1% Tween-20) for 5 min each. Subsequently, membranes were incubated overnight at 4 °C with primary antibodies against FTO (ab280081, 1:1000 dilution, Abcam) and β-actin (ab8227, 1:1000 dilution, Abcam). After three additional TBST washes (10 min each), membranes were incubated with an HRP-labeled secondary antibody (ab6721, 1:5000 dilution, Abcam) for 1 h at room temperature. Protein bands were visualized using ECL chemiluminescence reagent (1–2 min) and quantified by scanning densitometry (Bio-Rad).

Cell culture and treatment

HEK293T cells were obtained from the Chinese Academy of Sciences and used for exogenous gene expression studies [14]. Cells were cultured in DMEM (Gibco) supplemented with 10% FBS, 100 U/mL penicillin, and 100 U/mL streptomycin at 37 °C in a 5% CO₂ atmosphere. To establish HEK293T cells with low FTO expression, LV-shNC or LV-shFTO plasmids were transfected into cells using Lipofectamine 2000 according to the manufacturer’s instructions. For specific experiments, HEK293T cells were treated with 10 µM SSD for 24 h.

Methylated RNA Immunoprecipitation (meRIP)

The m6A modification level of TLR4 mRNA in HEK293T cells was assessed using the MeRIP m6A kit (17-10499, Millipore). Purified RNA was immunoprecipitated with an anti-m6A antibody (ab208577, Abcam) for 2 h at 4 °C. RNA was then extracted, and TLR4 expression levels were quantified by RT-qPCR.

mRNA stability evaluation

HEK293T cells were treated with Actinomycin D (5 µg/mL, ab291108, Abcam) to inhibit transcription. TLR4 mRNA levels were measured at 0, 3, 6, and 12 h post-treatment using RT-qPCR to assess mRNA stability.

Statistical analysis

All statistical analyses were performed using SPSS 25 software. Differences between two groups were analyzed using Student’s t-test. For comparisons among multiple groups, one-way ANOVA followed by Tukey’s post hoc test was applied. A p-value < 0.05 was considered statistically significant. Data are presented as mean ± standard deviation (SD).

Results

SSD promotes bacterial clearance in SOM

SSD, a bioactive monomer derived from the dried root of Bupleurum (Umbelliferae family), exhibits significant pharmacological activity. Its chemical structure is characterized as an epoxy-ether pentacyclic triterpene oleanane derivative, with a molecular formula of C₄₂H₆₈O₁₃ and a molecular weight of 780.99 (Fig. 1A).

Fig. 1
figure 1

SSD promotes bacterial clearance in SOM. (A) The molecular formula of SSD is C42H68O13 and molecular weight is 780.99. (B) CFUs per milliliter in the MELF collected from rats in control, SOM model, and three SSD treated groups. (C) Flow cytometry analysis was performed to identify and count neutrophils in MELF collected from rats in control, SOM model, and three SSD treated groups. (D) HE staining images of middle ears collected from rats in control, SOM model, and three SSD treated groups, scalr bars: 200 μm. (E) ELISA was performed to evaluate TNF-α, IL-6 and INF-γ levels in MELF collected from rats in control, SOM model, and three SSD treated groups. *p < 0.05, **p < 0.01, ***p < 0.001

Full size image

To evaluate the therapeutic effects of SSD on SOM, we collected MELF from rats in each experimental group and quantified bacterial load. The results demonstrated that CFUs in the MELF of SOM model rats were significantly higher than those in the control group, approximately 7-fold greater. SSD treatment markedly reduced CFUs in a dose-dependent manner, with the high-dose SSD group showing a reduction of approximately 50% compared to the untreated SOM group (Fig. 1B).

Neutrophil counts in the MELF of SOM model rats were significantly elevated compared to the control group. SSD treatment effectively reduced neutrophil infiltration in a concentration-dependent manner (Fig. 1C). Histopathological analysis using HE staining revealed significant thickening of the middle ear mucosa, increased capillary density, and elevated neutrophil infiltration in the SOM model group. These pathological changes were attenuated in SSD-treated groups, with the high-dose SSD group showing the most pronounced reduction in mucosal thickness (Fig. 1D).

Furthermore, ELISA analysis of inflammatory cytokines in MELF demonstrated that TNF-α, IL-6, and IFN-γ levels were significantly upregulated in the SOM group compared to the control group. However, SSD treatment dose-dependently suppressed the expression of these pro-inflammatory factors (Fig. 1E).

SSD inhibits FTO mediated m6A modification in SOM

Total m6A levels in each experimental group were evaluated to investigate the role of m6A modification in SOM. The results revealed that m6A levels in the middle ear tissues of SOM model rats were significantly elevated compared to the control group. Notably, high-dose SSD treatment effectively suppressed the SOM-induced upregulation of m6A levels (Fig. 2A).

Fig. 2
figure 2

SSD inhibits FTO mediated m6A modification in SOM. A Representative images of m6A dot blot and quantitative analysis to indicate m6A levels in middle ears of SOM model rats and SSD treated SOM model rats. B qPCR analysis of m6A writers levels in middle ears of SOM model rats and SSD treated SOM model rats. *p < 0.05, ***p < 0.001

Full size image

We further examined the mRNA expression levels of five m6A-related writers in middle ear tissues. qPCR analysis demonstrated that SOM modeling significantly upregulated METTL3 and downregulated FTO expression. In contrast, high-dose SSD treatment markedly reduced METTL3 levels and increased FTO expression (Fig. 2B). Given the pronounced regulatory effect of SSD on FTO expression, FTO was selected as the focus for subsequent investigations.

SSD suppresses effects of FTO knockdown on bacterial clearance

To elucidate the regulatory role of FTO in SOM pathogenesis and the impact of SSD on FTO modulation, we established rat models with stable FTO knockdown. qPCR analysis confirmed that FTO mRNA levels were significantly lower in the LV-shFTO group compared to the LV-shNC group. High-dose SSD treatment significantly increased FTO expression in both LV-shNC and LV-shFTO groups (Fig. 3A). Western blot analysis corroborated these findings, demonstrating that SSD treatment elevated FTO protein levels (Fig. 3B and C).

Fig. 3
figure 3

SSD suppresses effects of FTO knockdown on bacterial clearance. A qPCR analysis of FTO levels in middle ears of rats injected with LV-shNC or LV-shFTO, and two SSD treated rats injected with LV-shNC or LV-shFTO. B&C Western blot analysis of FTO levels in middle ears of rats injected with LV-shNC or LV-shFTO, and two SSD treated rats injected with LV-shNC or LV-shFTO. D HE staining images of middle ears of rats injected with LV-shNC or LV-shFTO, and two SSD treated rats injected with LV-shNC or LV-shFTO, scalr bars: 200 μm. E ELISA was performed to evaluate TNF-α, IL-6 and INF-γ levels in MELF collected from rats injected with LV-shNC or LV-shFTO, and two SSD treated rats injected with LV-shNC or LV-shFTO. F CFUs per milliliter, and neutrophils number in the MELF collected from rats injected with LV-shNC or LV-shFTO, and two SSD treated rats injected with LV-shNC or LV-shFTO. *p < 0.05, **p < 0.01, ***p < 0.001

Full size image

Histopathological examination using HE staining revealed that FTO inhibition led to thickening of the middle ear mucosa, increased capillary density, and elevated neutrophil infiltration. SSD treatment significantly mitigated these FTO knockdown-induced pathological changes (Fig. 3D).

Furthermore, FTO inhibition resulted in elevated levels of pro-inflammatory cytokines (TNF-α, IL-6, and IFN-γ), which were effectively reduced by SSD treatment (Fig. 3E). Additionally, FTO knockdown increased CFUs and neutrophil counts in MELF, while SSD treatment significantly reduced these parameters (Fig. 3F).

SSD decreases TLR4 mRNA stability by suppressing FTO mediated m6A modification

TLR4 activation is a critical mediator of neutrophil-driven inflammation [15]. To investigate the interaction between FTO and TLR4, we conducted experiments in HEK293T cells. Our findings demonstrated that TLR4 mRNA levels were significantly upregulated following FTO inhibition (Fig. 4A). Concurrently, m6A enrichment of TLR4 mRNA was increased in FTO-silenced cells (Fig. 4B). FTO knockdown also markedly delayed TLR4 mRNA degradation (Fig. 4C).

Fig. 4
figure 4

FTO effects on TLR4 mRNA levels. A qPCR analysis of TLR4 levels in HEK293T cells transfected with LV-shNC or LV-shFTO. B MeRIP-qPCR analysis of m6A modification of TLR4 levels in HEK293T cells transfected with LV-shNC or LV-shFTO. C mRNA levels of TLR4 in HEK293T cells treated with Actinomycin D were monitored at different time points. ***p < 0.001

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Furthermore, SSD treatment significantly restored FTO expression in HEK293T cells transfected with LV-shFTO, as confirmed by both mRNA and protein level analyses (Fig. 5A-C). In these cells, SSD treatment reduced TLR4 mRNA levels and enhanced m6A enrichment of TLR4 (Fig. 5D and E). Importantly, SSD treatment accelerated TLR4 mRNA degradation in vitro (Fig. 5F).

Fig. 5
figure 5

SSD decreases TLR4 mRNA stability by suppressing FTO mediated m6A modification. A qPCR analysis of FTO levels in HEK293T cells transfected with LV-shFTO before and after SSD treatment. B&C Western blot analysis of FTO levels in HEK293T cells transfected with LV-shFTO before and after SSD treatment. D qPCR analysis of TLR4 levels in HEK293T cells transfected with LV-shFTO before and after SSD treatment. E MeRIP-qPCR analysis of m6A modification of TLR4 levels in HEK293T cells transfected with LV-shFTO before and after SSD treatment. F mRNA levels of TLR4 in HEK293T cells treated with Actinomycin D were monitored at different time points. **p < 0.01, ***p < 0.001

Full size image

Discussion

SOM is a prevalent otological disorder characterized by the accumulation of non-suppurative fluid in the middle ear cavity. The pathogenesis of SOM is closely associated with infections and immune responses [16]. Studies have demonstrated that approximately 30–50% of middle ear effusions yield positive bacterial cultures, with Haemophilus influenzae and Streptococcus pneumoniae being the predominant pathogens [17, 18].

Neutrophils, as primary effector cells in inflammatory responses, play a critical defensive role during the initial stages of inflammation [19]. Emerging evidence highlights the importance of neutrophil extracellular traps (NETs), a novel mechanism of neutrophil function, in host defense. NETs utilize their unique three-dimensional network structures to combat pathogenic microorganisms, including bacteria, fungi, viruses, and parasites. Furthermore, NETs have been implicated in various pathological conditions, such as cardiovascular diseases, autoimmune disorders, systemic lupus erythematosus, and asthma [20]. In the context of SOM, NETs have been identified in the middle ear mucosa and effusions of both patients and animal models. The presence of NET components and their distinctive reticular structures suggest a significant role in SOM-related inflammatory responses [21,22,23,24]. In this study, we demonstrated that SSD treatment significantly reduced bacterial load and neutrophil infiltration in SOM model rats. Additionally, SSD alleviated inflammatory responses, as evidenced by decreased levels of pro-inflammatory cytokines and improved histopathological outcomes. These findings suggested that SSD may exert its therapeutic effects by modulating neutrophil activity and NET formation, thereby attenuating the inflammatory cascade in SOM.

TLR4, a pivotal pattern recognition receptor in the innate immune system, plays a crucial role in neutrophil activation. TLR4 signaling promotes neutrophil release and activation, thereby regulating inflammatory and immune responses [25]. Emerging evidence indicates that METTL3-mediated m6A mRNA methylation modulates neutrophil activation through the TLR4 signaling pathway in endotoxemia [26]. Additionally, HNRNPA2B1, which is enriched at m6A sites of TLR4, has been shown to drive multiple myeloma progression [27]. Furthermore, m6A modification has been implicated in immune regulation, with FTO-mediated m6A modification attenuating autoimmune uveitis by modulating microglial phenotypes via TLR4-related signaling pathways [28]. Consistent with these findings, our study demonstrated that FTO is enriched at the m6A sites of TLR4. In FTO-knockdown cells, both m6A modification and transcriptional levels of TLR4 were significantly upregulated. These results suggest that FTO-mediated m6A modification plays a critical role in regulating TLR4 expression and function. Therefore, our findings highlight FTO as a potential therapeutic target for SOM, offering new insights into the molecular mechanisms underlying SOM pathogenesis and treatment.

Based on our findings, SSD demonstrates potential as a preventive intervention for populations at high risk of developing SOM. However, we acknowledge several limitations in this study. First, our research was conducted using animal models, and the translational applicability of these results to human SOM requires further validation through clinical studies. While we observed that SSD reduces TLR4 mRNA stability in the SOM model, the direct involvement of FTO-mediated m6A modification in this process remains to be conclusively demonstrated. Future studies should employ more targeted molecular approaches, such as FTO-specific inhibitors or FTO gene knockout models, to elucidate the precise mechanism by which SSD modulates TLR4 mRNA stability. Additionally, the development of FTO overexpression models would provide a more comprehensive understanding of FTO’s role in SOM pathogenesis. It is also important to note that SSD exhibits acute toxicity, particularly hepatotoxicity, as reported in previous studies [29]. Therefore, careful evaluation of dosage optimization and potential side effects is essential before considering SSD as a therapeutic agent for SOM. Further pharmacological and toxicological studies are warranted to establish a safe and effective therapeutic window for SSD in clinical applications.

Conclusions

In summary, our findings demonstrate that SSD alleviates SOM progression by reducing bacterial load and neutrophil infiltration. Mechanistically, SSD upregulates FTO expression and enhances m6A modification of TLR4 mRNA, thereby promoting TLR4 mRNA degradation. This study elucidates a potential mechanism underlying the preventive effects of SSD on SOM, highlighting its therapeutic potential through modulation of the FTO/m6A/TLR4 axis.

Data availability

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.

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Acknowledgements

Not applicable.

Funding

This work was supported by Project of Shandong Provincial Administration of Traditional Chinese Medicine (2020-03).

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Authors and Affiliations

  1. Department of Otolaryngology, The Guang’anmen Hospital, of the China Academy of Chinese Medical Sciences in Jinan, Jinan City Traditional Chinese Medicine Hospital, Jinan, 250000, China

    Minjing Yin

  2. Department of Otolaryngology, First Clinical School of Shandong, University of Traditional Chinese Medicine, No.42 Wenhua West Road, Jinan, Shandong, 250011, China

    Xiuli Han

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All authors participated in the design, interpretation of the studies and analysis of the data and review of the manuscript. M Y drafted the work and revised it critically for important intellectual content; X H was responsible for the acquisition, analysis and interpretation of data for the work; M Y made substantial contributions to the conception or design of the work. All authors read and approved the final manuscript.

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Correspondence to Xiuli Han.

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This study was approved by the Ethics Committee of The Guang’anmen Hospital, of the China Academy of Chinese Medical Sciences in Jinan, Jinan City Traditional Chinese Medicine Hospital. All animal experiments should comply with the ARRIVE guidelines. All methods were carried out in accordance with relevant guidelines and regulations.

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Yin, M., Han, X. Saikosaponin D inhibits the inflammatory response of secretory otitis media through FTO-mediated N6-methyladenosine modification of TLR4 mRNA. BMC Pharmacol Toxicol 26, 79 (2025). https://doiorg.publicaciones.saludcastillayleon.es/10.1186/s40360-025-00910-6

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  • DOI: https://doiorg.publicaciones.saludcastillayleon.es/10.1186/s40360-025-00910-6

Keywords

BMC Pharmacology and Toxicology

ISSN: 2050-6511

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