Paeoniflorin protects spiral ganglion neurons from cisplatin-induced ototoxicity: Possible relation to PINK1/BAD pathway

Antioxidant effects of Paeoniflorin and relevant molecular mechanisms as related to a variety of diseases: A review

Paeoniflorin (PF), which is the main component of the Paeonia lactiflora Pall extract, is one of the traditional Chinese medicines. The pharmacological effects associated with PF include antioxidant, immunomodulatory, anti-inflammatory, anticancer, antidepressant-like and neuroprotective effects. Our previous studies had revealed that PF protected melanocytes and inhibited photodamage through the suppression of oxidative stress (OS). As OS plays a vital role in the progression of a variety of diseases, the capacity for PF to suppress OS may exert important effects upon them. However, no review exists on these antioxidant effects of PF as related to various diseases. Therefore, in this review we summarized studies involved with examining the antioxidant effects and molecular mechanisms of PF. Through its capacity to inhibit OS, PF has been shown to exert beneficial effects upon several systems including nervous, cardiac/vascular, digestive, and respiratory as well as specific diseases such as diabetes, autoimmune, pregnancy related, ocular, kidney, dermatology, along with suppression of distal flap necrosis, postoperative adhesions, and hearing loss. Such findings provide new insights and directions for future research directed at the development of PF as a natural antioxidant for the treatment of clinical diseases.

Nuciferine Protects Cochlear Hair Cells from Ferroptosis through Inhibiting NCOA4-Mediated Ferritinophagy

Cisplatin is a widely used antineoplastic drug for treating various types of cancers. However, it can cause severe side effects, such as bilateral and irreversible hearing loss, which significantly impacts quality of life. Ferroptosis, an iron-dependent form of programmed cell death, has been implicated in the pathogenesis of cisplatin-induced ototoxicity. Here, we investigated the effects of nuciferine, a natural active ingredient isolated from lotus species, on the ferroptosis of cochlear hair cells. Firstly, our results demonstrated that nuciferine can protect hair cells against RSL3-induced and cisplatin-induced damage. Secondly, nuciferine treatment reduced ferrous iron (Fe2+) overload in cochlear hair cells via inhibiting NCOA4-mediated ferritinophagy. Inhibition of ferritinophagy by knocking down Ncoa4 alleviated cisplatin-induced ototoxicity. Importantly, nuciferine treatment mitigated cochlear hair cell loss and damage to ribbon synapse, and improved mouse hearing function in an acute cisplatin-induced hearing loss model. Our findings highlight the role of NCOA4-mediated ferritinophagy in the pathogenesis of cisplatin-induced ototoxicity and provide evidence for nuciferine as a promising protective agent for treating cisplatin-induced hearing loss.

Genus Paeonia monoterpene glycosides: A systematic review on their pharmacological activities and molecular mechanisms

BACKGROUND

Genus Paeonia, which is the main source of Traditional Chinese Medicine (TCM) Paeoniae Radix Rubra (Chishao in Chinese), Paeoniae Radix Alba (Baishao in Chinese) and Moutan Cortex (Mudanpi in Chinese), is rich in active pharmaceutical ingredient such as monoterpenoid glycosides (MPGs). MPGs from Paeonia have extensive pharmacological effects, but the pharmacological effects and molecular mechanisms of MPGs has not been comprehensively reviewed.

PURPOSE

MPGs compounds are one of the main chemical components of the genus Paeonia, with a wide variety of compounds and strong pharmacological activities, and the structure of the mother nucleus-pinane skeleton is similar to that of a cage. The purpose of this review is to summarize the pharmacological activity and mechanism of action of MPGs from 2012 to 2023, providing reference direction for the development and utilization of Paeonia resources and preclinical research.

METHODS

Keywords and phrases are widely used in database searches, such as PubMed, Web of Science, Google Scholar and X-Mol to search for citations related to the new compounds, extensive pharmacological research and molecular mechanisms of MPGs compounds of genus Paeonia.

RESULTS

Modern research confirms that MPGs are the main compounds in Paeonia that exert pharmacological effects. MPGs with extensive pharmacological characteristics are mainly concentrated in two categories: paeoniflorin derivatives and albiflflorin derivatives among MPGs, which contains 32 compounds. Among them, 5 components including paeoniflorin, albiflorin, oxypaeoniflorin, 6'-O-galloylpaeoniflorin and paeoniflorigenone have been extensively studied, while the other 28 components have only been confirmed to have a certain degree of anti-inflammatory and anticomplementary effects. Studies of pharmacological effects are widely involved in nervous system, endocrine system, digestive system, immune system, etc., and some studies have identified clear mechanisms. MPGs exert pharmacological activity through multilateral mechanisms, including anti-inflammatory, antioxidant, inhibition of cell apoptosis, regulation of brain gut axis, regulation of gut microbiota and downregulation of mitochondrial apoptosis, etc. CONCLUSION: This systematic review delved into the pharmacological effects and related molecular mechanisms of MPGs. However, there are still some compounds in MPGs whose pharmacological effects and pharmacological mechanisms have not been clarified. In addition, extensive clinical randomized trials are needed to verify the efficacy and dosage of MPGs.

4-octyl itaconate alleviates cisplatin-induced ferroptosis possibly via activating the NRF2/HO-1 signalling pathway

Ferroptosis, characterized by iron-dependent lipid reactive oxygen species (ROS) accumulation, plays a pivotal role in cisplatin-induced ototoxicity. Existing research has suggested that in cisplatin-mediated damage to auditory cells and hearing loss, ferroptosis is partially implicated. 4-Octyl itaconate (4-OI), derived from itaconic acid, effectively permeates cell membranes, showcasing potent anti-inflammatory as well as antioxidant effects in several disease models. Our study aimed to investigate the effect of 4-OI on cisplatin-induced ferroptosis and the underlying molecular mechanisms. The survival rates of HEI-OC1 cells and mice cochlea hair cells were measured by CCK8 and immunofluorescence, respectively. The auditory brainstem response (ABR) audiometry was used to detect changes in hearing thresholds in mice before and after treatment. Levels of ROS were evaluated by DCFH-DA. Real-time PCR quantified inflammatory cytokines TNF-α, IL-6 and IL-1β. Network Pharmacology and RNA sequencing (RNA-seq) analysis of the potential mechanism of 4-OI resistance to cisplatin-induced ferroptosis. The expressions of ferroptosis-related factors (GPX4, SLC7A11 and PTGS2) and important antioxidant factors (NRF2, HO-1, GCLC and NQO1) were tested by real-time PCR, Western blot and immunofluorescence. Results demonstrated cisplatin-induced significant ROS and inflammatory factor release, reduced NRF2 expression, hindered nuclear translocation and activated ferroptosis. Pretreatment with 4-OI exhibited anti-inflammatory and antioxidant effects, along with resistance to ferroptosis, ultimately mitigating cisplatin-induced cell loss. In the present study, we show that 4-OI inhibits cisplatin-induced ferroptosis possibly through activation of the NRF2/HO-1 signalling pathway, thereby exerting a protective effect against cisplatin-induced damage to auditory cells, and providing a new therapeutic strategy for cisplatin-induced hearing loss.

AdipoRon reduces cisplatin-induced ototoxicity in hair cells:possible relation to the regulation of mitochondrial biogenesis

AdipoRon (AR) can exert antidiabetic and anti-inflammatory effects by maintaining mitochondrial structure and function. The present study was designed to explore whether AR protects the auditory cells from cisplatin-induced damage and, if so, to probe the possible mechanisms underlying its action on this type of cells. Cell viability and apoptosis in House Ear Institute-Organization of Corti 1 (HEI-OC1 cells) and mouse cochlea hair cells (HCs) were detected by CCK8 and immunofluorescence. The expressions of apoptosis-related proteins (cleaved caspase-3 and Bcl-2), adiponectin receptor 1 (AdipoR 1) and the key factors relevant to mitochondrial biogenesis（SIRT1 and TFAM）were determined by Western blot and immunofluorescence. Changes in apoptotic rate and expression of SIRT1 and TFAM after silencing of AdipoR 1 (AdipoR 1-siRNA) in HEI-OC1 cells were measured by flow cytometry and Western blot. The levels of reactive oxygen species (ROS) were evaluated by MitoSox red staining. We found that 30 μM cisplatin exposure induced severe cellular damage, which resulted from activation of the mitochondrial apoptotic pathway. Cisplatin decreased the expression of AdipoR 1, SIRT1, and TFAM proteins, leading to impaired mitochondrial biogenesis and increased mitochondrial ROS production. 10 μM AR pre-treatment enhanced mitochondrial biogenesis, decreased mitochondrial ROS levels, alleviated imbalances in the mitochondrial apoptotic pathway, thus reducing cisplatin-induced apoptosis. Taken together, this work reveals that AR exerts anti-apoptotic effects, possibly via regulating mitochondrial biogenesis and function. Interestingly, AR might possess the promising potential to be a novel drug for the prevention and/ or treatment of cisplatin-induced ototoxicity.

Chemerin/CMKLR1 pathway exacerbates cisplatin-induced spiral ganglion neuron injury

This study investigated whether chemerin/chemokine-like receptor 1 (CMKLR1) pathway participate in cisplatin-induced spiral ganglion neuron (SGN) damage. Middle cochlear turn was collected from C57BL/6 mice and the SGNs were cultured. Cisplatin, 2-(anaphthoyl) ethyltrimethylammonium iodide (α-NETA), or recombinant mouse chemerin was added into the medium for the treatment. Relative mRNA and protein expression was determined by RT-PCR, ELISA and Western blot, respectively. In cultured mouse cochlear SGNs, the treatment of cisplatin enhanced the secretion of chemerin and CMKLR1. Recombinant chemerin promoted but α-NETA inhibited chemerin/CMKLR1 pathway in cisplatin stimulated SGNs. Cisplatin-induced apoptosis and inflammation response in SGNs were enhanced by recombinant chemerin while inhibited by α-NETA. Recombinant chemerin promoted but α-NETA inhibited NF-κB signal in cisplatin stimulated SGNs. In conclusion, chemerin/CMKLR1 pathway regulated apoptosis and inflammation response in cisplatin-induced SGN injury through NF-κB signaling pathway.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43188-023-00205-0.

Sustained delivery of triamcinolone acetonide from a thermosensitive microemulsion gel system for the treatment of sensorineural hearing loss

Intratympanic administration for the delivery of steroids has been extensively studied but limited because of low permeability of the drug through the row window membrane. Here, to effectively deliver poorly soluble triamcinolone acetonide (TA), microemulsions (ME) were prepared from Capmul MCM (oil), Cremophor RH40 (surfactant), and tetraglycol (cosurfactant) based on solubility studies, emulsifying ability test, and pseudoternary phase diagrams. Microemulsion gel (MEG) was prepared by mixing TA-ME with a poloxamer hydrogel base. The physicochemical properties of ME and MEG formulations were characterized, and the toxicity and oto-protective effectiveness were evaluated in vitro and in vivo. The ME-3 formulation showed a small droplet size (16.5 ± 0.2 nm), narrow PDI (0.067 ± 0.041), and enhanced TA solubility (2619.7 ± 57.6 μg/g). The optimized MEG demonstrated temperature-dependent gelation with a gelation time of 208 ± 10 sec at 37 °C. Slow degradation of the gel matrix sustained release of TA from MEG compared to the ME formulation. Both TA-ME and TA-MEG were found to be nontoxic to NIH3T3 cells at the test concentrations (0 to 5 µg/mL), and biocompatible after intratympanic administration to mice. The incorporation of ME into thermosensitive hydrogels prolonged retention of TA at the site of administration until 6 days. As a consequence, the enhanced drug absorption into the cochlea in TA-MEG group (approximately 2 times higher than other groups) protected hair cells, spiral ganglion neurons, and stria vascular cells from cisplatin-induced damage. Therefore, this injectable TA-loaded MEG is an effective and safe vehicle for the sustained delivery of triamcinolone acetonide into the inner ear.

Natural products modulate NLRP3 in ulcerative colitis

Ulcerative colitis (UC) is a clinically common, progressive, devastating, chronic inflammatory disease of the intestine that is recurrent and difficult to treat. Nod-like receptor protein 3 (NLRP3) is a protein complex composed of multiple proteins whose formation activates cysteine aspartate protease-1 (caspase-1) to induce the maturation and secretion of inflammatory mediators such as interleukin (IL)-1β and IL-18, promoting the development of inflammatory responses. Recent studies have shown that NLRP3 is associated with UC susceptibility, and that it maintains a stable intestinal environment by responding to a wide range of pathogenic microorganisms. The mainstay of treatment for UC is to control inflammation and relieve symptoms. Despite a certain curative effect, there are problems such as easy recurrence after drug withdrawal and many side effects associated with long-term medication. NLRP3 serves as a core link in the inflammatory response. If the relationship between NLRP3 and gut microbes and inflammation-associated factors can be analyzed concerning its related inflammatory signaling pathways, its expression status as well as specific mechanism in the course of IBD can be elucidated and further considered for clinical diagnosis and treatment of IBD, it is expected that the development of lead compounds targeting the NLRP3 inflammasome can be developed for the treatment of IBD. Research into the prevention and treatment of UC, which has become a hotbed of research in recent years, has shown that natural products are rich in therapeutic means, and multi-targets, with fewer adverse effects. Natural products have shown promise in treating UC in numerous basic and clinical trials over the past few years. This paper describes the regulatory role of the NLRP3 inflammasome in UC and the mechanism of recent natural products targeting NLRP3 against UC, which provides a reference for the clinical treatment of this disease.

Recent advances in the treatment and prevention of peripheral neuropathy after multiple myeloma treatment

The incidence of multiple myeloma (MM) is increasing year by year, requiring chemotherapy drugs to control the condition. With the advent of new proteasome inhibitors, immunomodulators, and monoclonal antibodies, the prognosis of patients has improved significantly. However, peripheral neuropathy caused by drugs limits the dose and duration of treatment, which seriously affects patients' quality of life and treatment outcome. Although the neuropathies induced by chemotherapy drugs have attracted much attention, their mechanism and effective prevention and treatment measures are not clear. Therefore, how to alleviate peripheral neuropathy caused by drugs for treatment of MM is a key issue in improving patients' quality of life and prolonging their survival time, which have some clinical value. In this paper, we review the current research on the pathogenesis, pharmacological and nonpharmacological treatment, and prevention, which expects to present instruction for peripheral neuropathy after treatment of MM.

Apelin-13 protects against cisplatin-induced ototoxicity by inhibiting apoptosis and regulating STAT1 and STAT3

The ototoxic side effect of cisplatin is a main cause of sensorineural hearing loss. This side effect limits the clinical application of cisplatin and affects patients' quality of life. This study was designed to investigate the effect of apelin-13 on cisplatin-induced C57BL/6 mice hearing loss model and explore the potential underlying molecular mechanisms. Mice were intraperitoneally injected with 100 μg/kg apelin-13 2 h before 3 mg/kg cisplatin injection for 7 consecutive days. Cochlear explants cultured in vitro were pretreated with 10 nM apelin-13 2 h prior to 30 μM cisplatin treatment for another 24 h. Hearing test and morphology results showed that apelin-13 attenuated cisplatin-induced mice hearing loss and protected cochlear hair cells and spiral ganglion neurons from damage. In vivo and in vitro experimental results showed that apelin-3 reduced cisplatin-induced apoptosis of hair cells and spiral ganglion neurons. In addition, apelin-3 preserved mitochondrial membrane potential and inhibited ROS production in cultured cochlear explants. Mechanistic studies showed that apelin-3 decreased cisplatin-induced cleaved caspase 3 expression but increased Bcl-2; inhibited the expression of pro-inflammatory factors TNF-a and IL-6; and increased STAT1 phosphorylation but decreased STAT3 phosphorylation. In conclusion, our results indicate that apelin-13 could be a potential otoprotective agent to prevent cisplatin-induced ototoxicity by inhibiting apoptosis, ROS production, TNF-α and IL-6 expression, and regulating phosphorylation of STAT1 and STAT3 transcription factors.

20(S)-Ginsenoside Rh1 inhibits cisplatin-induced hearing loss by inhibiting the MAPK signaling pathway and suppressing apoptosis in vitro

As an anticancer drug, cisplatin is widely used, but its clinical application is restricted due to its severe side effects of ototoxicity. Therefore, this study was dedicated to assessing the benefit of ginsenoside extract, 20(S)-Ginsenoside Rh1 (Rh1), on cisplatin-induced ototoxicity. HEI-OC1 cells and neonatal cochlear explants were cultured. Cleaved caspase-3, TUNEL, and MitoSOX Red were observed in vitro by immunofluorescence staining. CCK8 and LDH cytotoxicity assays were detected to measure cell viability and cytotoxicity. Our results showed that Rh1 significantly increased cell viability, reduced cytotoxicity, and alleviated cisplatin-induced apoptosis. In addition, Rh1 pretreatment decreased the excessive accumulation of intracellular reactive oxygen species. Mechanistic studies indicated that Rh1 pretreatment reversed the increase of apoptotic protein expression, accumulation of mitochondrial ROS, and activation of the MAPK signaling pathway. These results suggested that Rh1 can act as an antioxidant and anti-apoptotic agent against cisplatin-induced hearing loss by suppressing the excessive accumulation of mitochondrial ROS, activation of MAPK signaling pathway and apoptosis.

Degranulation of Murine Resident Cochlear Mast Cells: A Possible Factor Contributing to Cisplatin-Induced Ototoxicity and Neurotoxicity

Permanent hearing loss is one of cisplatin's adverse effects, affecting 30-60% of cancer patients treated with that drug. Our research group recently identified resident mast cells in rodents' cochleae and observed that the number of mast cells changed upon adding cisplatin to cochlear explants. Here, we followed that observation and found that the murine cochlear mast cells degranulate in response to cisplatin and that the mast cell stabilizer cromoglicic acid (cromolyn) inhibits this process. Additionally, cromolyn significantly prevented cisplatin-induced loss of auditory hair cells and spiral ganglion neurons. Our study provides the first evidence for the possible mast cell participation in cisplatin-induced damage to the inner ear.

Paeoniflorin Ameliorates BiPN by Reducing IL6 Levels and Regulating PARKIN-Mediated Mitochondrial Autophagy

Background

Bortezomib-induced peripheral neuropathy (BiPN) is a common complication of multiple myeloma (MM) treatment that seriously affects the quality of life of patients. The purpose of the present study was to explore the therapeutic effect of paeoniflorin on BiPN and its possible mechanism.

Methods

ELISA was used to measure the level of interleukin-6 (IL6) in the plasma of MM patients, and bioinformatics analysis was used to predict the mechanism underlying the effect of paeoniflorin on peripheral neuropathy. Cell and animal models of BiPN were constructed to evaluate mitochondrial function by measuring cell viability and mitochondrial quality and labeling mitochondria with MitoTracker Green. Nerve injury in mice with BiPN was assessed by behavioral tests, evaluation of motor nerve conduction velocity, hematoxylin-eosin (HE) staining, electron microscopy and analysis of the levels of reactive oxygen species (ROS). Western blotting and immunohistochemistry (IHC) were used to assess the expression of autophagy-related proteins.

Results

In MM patients, IL6 levels were positively correlated with the degree of PN. The results of bioinformatics analysis suggested that paeoniflorin ameliorated PN by altering inflammation levels and mitochondrial autophagy. Paeoniflorin increased PC12 cell viability and mitochondrial autophagy levels, alleviated mitochondrial damage, and reduced IL6 levels. In addition, paeoniflorin effectively improved the behavior of mice with BiPN, relieved sciatic nerve injury in mice, increased the expression of LC3II/I, beclin-1, and Parkin in sciatic nerve cells, and increased the expression of LC3B and Parkin in the nerve tissue.

Conclusion

The present study confirmed that paeoniflorin significantly ameliorated peripheral neuropathy (PN) caused by bortezomib, possibly by reducing IL6 levels to regulate PARKIN-mediated mitochondrial autophagy and mitochondrial damage.

Efficacy of paeoniflorin on models of depression: A systematic review and meta-analysis of rodent studies

ETHNOPHARMACOLOGICAL RELEVANCE

Paeoniflorin, a bioactive compound extracted from the traditional Chinese herb, Paeonia lactiflora Pall, has been demonstrated to possess efficient antidepressant activity in previous studies.

AIM OF THE STUDY

Our systematic review and meta-analysis aimed to assess the effectiveness of paeoniflorin in relieving depressive-like behaviors in animal models.

MATERIALS AND METHODS

We searched for in vivo studies on the antidepressant effects of paeoniflorin in rodents using electronic databases from their inception to April 2021. The measurements of animal behavioral tests, including the sucrose consumption, forced swimming, tail suspension, and open field tests, were regarded as the outcomes.

RESULTS

Fourteen studies involving 416 animals met the inclusion criteria and were included in the meta-analysis. Statistical analysis revealed remarkable differences between the paeoniflorin and control groups. Furthermore, the paeoniflorin group showed great efficiency in improving depressive-like symptoms of animals in the sucrose consumption, forced swimming, tail suspension, and open field tests.

CONCLUSIONS

Our meta-analysis demonstrates that paeoniflorin can significantly improve depressive-like symptoms in animals and suggests that it can be a potential therapy for patients with depression in the future.

The Protective Effect of Natural Compounds on Doxorubicin-Induced Cardiotoxicity via Nicotinamide Adenine Dinucleotide Phosphate Oxidase Inhibition

OBJECTIVES

Doxorubicin (DOX) is widely prescribed for the treatment of several human cancers. Unfortunately, cumulative doses of DOX are the main cause of myocardial dysfunction. Although preclinical and pharmaceutical studies were performed to investigate the potential of natural compounds in minimizing DOX toxicity, a comprehensive review of them is not available. This review can help the researchers for an effective search strategy.

KEY FINDINGS

Oxidative stress and p53 play an important role in DOX-associated cardiotoxicity. DOX activates nicotinamide adenine dinucleotide phosphate NADPH oxidase (NOX) in the heart, resulting in excessive reactive oxygen species that can induce cardiomyocyte apoptosis through phosphorylation of p53, DNA damage and/or mitogen-activated protein kinases-mediated cardiomyocyte apoptosis. Although a few chemical drugs with high efficacy are administered along with DOX to prevent or more likely to reduce cardiovascular toxicity, their use is often limited by additional side effects. Recently, attention has been drawn to natural compounds that prevent DOX cardiotoxicity. This review focuses on some of the natural bioactive compounds with potential therapeutic efficacy against DOX-induced cardiotoxicity (DIC).

SUMMARY

Some natural compounds, especially flavonols, flavonoids and proanthocyanidins, have the most protective effects against DIC by forming stable radicals and preventing the assembly of the NOX subunits.

Paeoniflorin: A neuroprotective monoterpenoid glycoside with promising anti-depressive properties

BACKGROUND

Depression, as a prevalent and debilitating psychiatric disease, severely decreases the life quality of individuals and brings heavy burdens to the whole society. Currently, some antidepressants are applied in the treatment of severe depressive symptoms, while there are still some undesirable drawbacks. Paeoniflorin is a monoterpenoid glycoside that was firstly extracted from Paeonia lactiflora Pall, a traditional Chinese herb that is widely used in the Chinese herbal formulas for treating depression.

PURPOSE

This review summarized the previous pre-clinical studies of paeoniflorin in treating depression and further discussed the potential anti-depressive mechanisms for that paeoniflorin to be further explored and utilized in the treatment of depression clinically.

METHODS

Some electronic databases, e.g., PubMed and China National Knowledge Infrastructure, were searched from inception until April 2021.

RESULTS

This review summarized the effective anti-depressive properties of paeoniflorin, which is related to its functions in the upregulation of the levels of monoaminergic neurotransmitters, inhibition of the hypothalamic-pituitary-adrenal axis hyperfunction, promotion of neuroprotection, promotion of hippocampus neurogenesis, and upregulation of brain-derived neurotrophic factor level, inhibition of inflammatory reaction, downregulation of nitric oxide level, etc. CONCLUSION: This review focused on the pre-clinical studies of paeoniflorin in depression and summarized the recent development of the anti-depressive mechanisms of paeoniflorin, which approves the role of paeoniflorin plays in anti-depression. However, more high-quality pre-clinical and clinical studies are expected to be conducted in the future.

Paeoniflorin protects against dextran sulfate sodium (DSS)-induced colitis in mice through inhibition of inflammation and eosinophil infiltration

Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) that causes inflammation and ulcers in the digestive tract. The treatment commonly includes anti-inflammatory agents like 5-aminosalicylic acid or corticosteroids or biologics for people with UC who are no longer responding to corticosteroids. The radices of Paeonia lactiflora Pall. or similar plants of the Paeonia genus have been used in Chinese medicine to treat certain diseases that resemble the symptoms of UC. Paeoniflorin, a terpenoid glycoside, is a major active component for the anti-inflammatory and antitumor activity. In this study, we evaluated the therapeutic effect of paeoniflorin (PF) against dextran sulfate sodium (DSS)-induced colitis in mice and found that PF exhibited protective activity against colitis. PF treatment suppressed NF-κB pathway activation, resulting down regulation of pro-inflammatory factor expression. In addition, we detected reduction in eosinophil-related chemokine gene expression and eosinophil infiltration. The treatment also reversed Treg cell population suppression. Although PF treatment did not block COX2 induction, the compound weakly inhibited COX2 activity in an enzymatic assay. Taken together, PF exerts its therapeutic activity against UC through inhibition of inflammation and eosinophil infiltration.

Protective effect of paeoniflorin on H2O2 induced Schwann cells injury based on network pharmacology and experimental validation

This study was to investigate the protective effect of paeoniflorin (PF) on hydrogen peroxide-induced injury. Firstly, "SMILES" of PF was searched in Pubchem and further was used for reverse molecular docking in Swiss Target Prediction database to obtain potential targets. Injury-related molecules were obtained from GeenCards database, and the predicted targets of PF for injury treatment were selected by Wayne diagram. For mechanism analysis, the protein-protein interactions were constructed by String, and the KEGG analysis was conducted in Webgestalt. Then, cell viability and cytotoxicity assay were established by CCK8 assay. Also, the experimental cells were allocated to control, model (200 μmol·L^-1 H₂O₂), SB203580 10 μmol·L^-1 (200 μmol·L^-1 H₂O₂+ SB203580 10 μmol·L^-1), PF 50 μmol·L^-1 (200 μmol·L^-1 H₂O₂+ PF 50 μmol·L^-1), and PF 100 μmol·L^-1 (200 μmol·L^-1 H₂O₂+ PF 100 μmol·L^-1) groups. We measured the intracellular ROS, Hoechst 33258 staining, cell apoptosis, the levels of Bcl-xl, Bcl-2, Caspase-3, Cleaved-caspase3, Cleaved-caspase7, TRPA1, TRPV1, and the phosphorylation expression of p38MAPK. There are 96 potential targets that may be associated with PF for injury treatment. Then, we chose the "Inflammatory mediator regulation of TRP channels" pathway for the experimental verification from the first 10 KEGG pathway. In experimental verification, H₂O₂ decreased the cell viability moderately (P < 0.05), and 100 μmol·L ^-1 PF increased the cell viability significantly (P < 0.05). Depending on the difference of intracellular ROS fluorescence intensity, PF inhibited H ₂O₂-induced reactive oxygen species production in Schwann cells. In Hoechst 33258 staining, PF reversed the condensed chromatin and apoptotic nuclei following H₂O₂ treatment. Moreover, Flow cytometry results showed that PF could substantially inhibit H₂O₂ induced apoptosis (P < 0.05). Pretreatment with PF obviously reduced the levels of Caspase3, Cleaved-caspase3, Cleaved-caspase7, TRPA1, TRPV1, and the phosphorylation expression of p38MAPK after H ₂O₂ treatment (P < 0.05), increased the levels of Bcl-2, and Bcl-xl ( P < 0.05). PF inhibited Schwann cell injury and apoptosis induced by hydrogen peroxide, which mechanism was linked to the inhibition of phosphorylation of p38MAPK.

BRAF inhibition protects against hearing loss in mice

Hearing loss caused by noise, aging, antibiotics, and chemotherapy affects 10% of the world population, yet there are no Food and Drug Administration (FDA)-approved drugs to prevent it. Here, we screened 162 small-molecule kinase-specific inhibitors for reduction of cisplatin toxicity in an inner ear cell line and identified dabrafenib (TAFINLAR), a BRAF kinase inhibitor FDA-approved for cancer treatment. Dabrafenib and six additional kinase inhibitors in the BRAF/MEK/ERK cellular pathway mitigated cisplatin-induced hair cell death in the cell line and mouse cochlear explants. In adult mice, oral delivery of dabrafenib repressed ERK phosphorylation in cochlear cells, and protected from cisplatin- and noise-induced hearing loss. Full protection was achieved in mice with co-treatment with oral AZD5438, a CDK2 kinase inhibitor. Our study explores a previously unidentified cellular pathway and molecular target BRAF kinase for otoprotection and may advance dabrafenib into clinics to benefit patients with cisplatin- and noise-induced ototoxicity.

Mitochondrial Dysfunction and Therapeutic Targets in Auditory Neuropathy

Sensorineural hearing loss (SNHL) becomes an inevitable worldwide public health issue, and deafness treatment is urgently imperative; yet their current curative therapy is limited. Auditory neuropathies (AN) were proved to play a substantial role in SNHL recently, and spiral ganglion neuron (SGN) dysfunction is a dominant pathogenesis of AN. Auditory pathway is a high energy consumption system, and SGNs required sufficient mitochondria. Mitochondria are known treatment target of SNHL, but mitochondrion mechanism and pathology in SGNs are not valued. Mitochondrial dysfunction and pharmacological therapy were studied in neurodegeneration, providing new insights in mitochondrion-targeted treatment of AN. In this review, we summarized mitochondrial biological functions related to SGNs and discussed interaction between mitochondrial dysfunction and AN, as well as existing mitochondrion treatment for SNHL. Pharmaceutical exploration to protect mitochondrion dysfunction is a feasible and effective therapeutics for AN.

Current Strategies to Combat Cisplatin-Induced Ototoxicity

Cisplatin is widely used for the treatment of a number of solid malignant tumors. However, ototoxicity induced by cisplatin is an obstacle to effective treatment of tumors. The basis for this toxicity has not been fully elucidated. It is generally accepted that hearing loss is due to excessive production of reactive oxygen species by cells of the cochlea. In addition, recent data suggest that inflammation may trigger inner ear cell death through endoplasmic reticulum stress, autophagy, and necroptosis, which induce apoptosis. Strategies have been extensively explored by which to prevent, alleviate, and treat cisplatin-induced ototoxicity, which minimize interference with antitumor activity. Of these strategies, none have been approved by the Federal Drug Administration, although several preclinical studies have been promising. This review highlights recent strategies that reduce cisplatin-induced ototoxicity. The focus of this review is to identify candidate agents as novel molecular targets, drug administration routes, delivery systems, and dosage schedules. Animal models of cisplatin ototoxicity are described that have been used to evaluate drug efficacy and side effect prevention. Finally, clinical reports of otoprotection in patients treated with cisplatin are highlighted. For the future, high-quality studies are required to provide reliable data regarding the safety and effectiveness of pharmacological interventions that reduce cisplatin-induced ototoxicity.

Paeoniflorin protects spiral ganglion neurons from cisplatin-induced ototoxicity: Possible relation to PINK1/BAD pathway

The objective of this study was to elucidate whether paeoniflorin (PF) exerted an effect on cisplatin‐induced spiral ganglion neuron (SGN) damage, with special attention given to the role of PINK1/BAD pathway in this process. Middle cochlear turn culture and C57BL/6 mice were utilized to identify the character of PF in vitro and in vivo. We found that cisplatin treatment led to SGN damage, in which reactive oxygen species (ROS) generation increased, PINK1 expression decreased, BAD accumulation on mitochondria raised and mitochondrial apoptotic pathway activated. Conversely, we demonstrated that PF pre‐treatment obviously mitigated cisplatin‐induced SGN damage. Mechanistic studies showed that PF could reduce ROS levels, increase PINK1 expression, decrease the BAD accumulation on mitochondria and, thus, alleviate the activated mitochondrial apoptosis in SGNs caused by cisplatin. Overall, the findings from this work reveal the important role of PF and provide another strategy against cisplatin‐induced ototoxicity.