Quercetin Alleviates the Progression of Breast Cancer-Related Depression via Inhibiting the Pyroptosis and Promoting the Immune Response

Therapeutic Efficacy of Quercetin and Its Nanoformulation Both the Mono- or Combination Therapies in the Management of Cancer: An Update with Molecular Mechanisms

Quercetin, a major representative of the flavonol subclass found abundantly in almost all edible vegetables and fruits, showed remarkable therapeutic properties and was beneficial in numerous degenerative diseases by preventing lipid peroxidation. Quercetin is beneficial in different diseases, such as atherosclerosis and chronic inflammation. This study aims to find out the anticancer activities of quercetin and to determine different mechanisms and pathways which are responsible for the anticancer effect. It also revealed the biopharmaceutical, toxicological characteristics, and clinical utilization of quercetin to evaluate its suitability for further investigations as a reliable anticancer drug. All of the relevant data concerning this compound with cancer was collected using different scientific search engines, including PubMed, Springer Link, Wiley Online, Web of Science, SciFinder, ScienceDirect, and Google Scholar. This review demonstrated that quercetin showed strong anticancer properties, including apoptosis, inhibition of cell proliferation, autophagy, cell cycle arrest, inhibition of angiogenesis, and inhibition of invasion and migration against various types of cancer. Findings also revealed that quercetin could significantly moderate and regulate different pathways, including PI3K/AKT-mTORC1 pathway, JAK/STAT signaling system, MAPK signaling pathway, MMP signaling pathway, NF-κB pathway, and p-Camk2/p-DRP1 pathway. However, this study found that quercetin showed poor oral bioavailability due to reduced absorption; this limitation is overcome by applying nanotechnology (nanoformulation of quercetin). Moreover, different investigations revealed that quercetin expressed no toxic effect in the investigated subjects. Based on the view of these findings, it is demonstrated that quercetin might be considered a reliable chemotherapeutic drug candidate in the treatment of different cancers. However, more clinical studies are suggested to establish the proper therapeutic efficacy, safety, and human dose.

Quercetin inhibits neuronal Ferroptosis and promotes immune response by targeting lipid metabolism-related gene PTGS2 to alleviate breast cancer-related depression

BACKGROUND

Quercetin, the key ingredient in Xiaoyao Kangai Jieyu Formula, has been previously found to relieve breast cancer-related depression (BCRD).

PURPOSE

We want to explore the potential mechanisms and therapeutic targets of quercetin alleviating BCRD.

METHODS

BALB/c mice were injected subcutaneously with 4T1 cells and corticosterone (CORT) to create a BCRD mice model. The primary hippocampal neurons were co-induced with 10 μg/ml lipopolysaccharide (LPS) and 200 μM CORT for 6 h to establish an in vitro model of BCRD. Quercetin was applied to explore its effect on disease symptoms, gut microbiota, and lipid metabolism of BCRD mice. Lipid metabolism-related genes were screened based on network pharmacology. Molecular docking was employed to prove whether quercetin bound to prostaglandin-endoperoxide synthase 2 (PTGS2). PTGS2 overexpression was carried out to explore the underlying mechanism of quercetin treatment on BCRD.

RESULTS

Quercetin treatment not only altered the composition and abundance of gut microbiota but also alleviated abnormal lipid metabolism in BCRD mice. In particular, quercetin down-regulated BCRD and lipid metabolism-related genes screened by network pharmacology, especially PTGS2. Further, molecular docking verified the stable binding between quercetin and PTGS2. In hippocampal neurons, quercetin promoted proliferation but reduced ferroptosis-related markers (total Fe, Fe2+, MDA, and ROS) levels by targeting PTGS2. In BCRD mice, quercetin reduced the high immobility time and increased the sucrose preference rate and serotonin (5-HT), dopamine (DA), and noradrenaline (NE) levels. Meanwhile, quercetin increased CD4+/CD8+ T cells ratio and IL-2 and IFN-γ levels but reduced CA153 and IL-10 levels to alleviate BCRD development. However, PTGS2 overexpression reversed these effects of quercetin on BCRD.

CONCLUSION

Quercetin inhibited neuronal ferroptosis and promoted immune responses in BCRD mice by targeting the lipid metabolism-related gene PTGS2. This provided a reference for quercetin in the treatment of BCRD.

Unlocking the potential of pyroptosis in tumor immunotherapy: a new horizon in cancer treatment

Background

The interaction between pyroptosis-a form of programmed cell death-and tumor immunity represents a burgeoning field of interest. Pyroptosis exhibits a dual role in cancer: it can both promote tumor development and counteract it by activating immune responses that inhibit tumor evasion and encourage cell death. Current tumor immunotherapy strategies, notably CAR-T cell therapy and immune checkpoint inhibitors (ICIs), alongside the potential of certain traditional Chinese medicinal compounds, highlight the intricate relationship between pyroptosis and cancer immunity. As research delves deeper into pyroptosis mechanisms within tumor therapy, its application in enhancing tumor immune responses emerges as a novel research avenue.

Purpose

This review aims to elucidate the mechanisms underlying pyroptosis, its impact on tumor biology, and the advancements in tumor immunotherapy research.

Methods

A comprehensive literature review was conducted across PubMed, Embase, CNKI, and Wanfang Database from the inception of the study until August 22, 2023. The search employed keywords such as "pyroptosis", "cancer", "tumor", "mechanism", "immunity", "gasdermin", "ICB", "CAR-T", "PD-1", "PD-L1", "herbal medicine", "botanical medicine", "Chinese medicine", "traditional Chinese medicine", "immunotherapy", linked by AND/OR, to capture the latest findings in pyroptosis and tumor immunotherapy.

Results

Pyroptosis is governed by a complex mechanism, with the Gasdermin family playing a pivotal role. While promising for tumor immunotherapy application, research into pyroptosis's effect on tumor immunity is still evolving. Notably, certain traditional Chinese medicine ingredients have been identified as potential pyroptosis inducers, meriting further exploration.

Conclusion

This review consolidates current knowledge on pyroptosis's role in tumor immunotherapy. It reveals pyroptosis as a beneficial factor in the immunotherapeutic landscape, suggesting that leveraging pyroptosis for developing novel cancer treatment strategies, including those involving traditional Chinese medicine, represents a forward-looking approach in oncology.

Therapeutic effects and molecular mechanisms of quercetin in gynecological disorders

Quercetin is a representative flavonoid that is widely present in fruits, herbs, and vegetables. It is also an important active core component in traditional Chinese medicines. As an important flavonoid, quercetin has various properties and exerts antioxidant, anti-inflammatory, and cardioprotective effects. The public interest in quercetin is increasing, and quercetin has been used to prevent or treat numerous of diseases, such as polycystic ovary syndrome (PCOS), cancer, autoimmune diseases and chronic cardiovascular diseases, in clinical experiments and animal studies due to its powerful antioxidant properties and minimal side effects. Quercetin exerts marked pharmacological effects on gynecological disorders; however, there have been no reviews about the potential health benefits of quercetin in the context of gynecological disorders, including PCOS, premature ovary failure (POF), endometriosis (EM), ovarian cancer (OC), cervical cancer (CC) and endometrial carcinoma (EC). Thus, this review aimed to summarize the biological effects of quercetin on gynecological disorders and its mechanisms.

Quercetin inhibits caspase-1-dependent macrophage pyroptosis in experimental folic acid nephropathy

BACKGROUND

The role of pyroptosis in kidney disease is limited and incomplete. Quercetin, a flavonoid compound present in a variety of fruits, vegetables, and plants, has shown antioxidant and anti-inflammatory properties. This study was designed to validate the importance of pyroptosis in an experimental model of folic acid nephropathy and to explore the effect of quercetin in protecting against pyroptosis.

METHODS

Gene set enrichment analysis (GSEA) and weighted gene co-expression network analysis (WGCNA) were used to establish the correlation between pyroptosis and folic acid nephropathy. Immune cell infiltration, network pharmacology and single-cell RNA sequencing analysis were utilized to ascertain the specific target of quercetin in relation to pyroptosis. Finally, quercetin's role was verified in vivo and in vitro.

RESULTS

The GSEA analysis revealed a significant correlation between pyroptosis and folic acid nephropathy (NES = 1.764, P = 0.004). The hub genes identified through WGCNA were closely associated with inflammation. Molecular docking demonstrated a strong binding affinity between quercetin and caspase-1, a protein known to be involved in macrophage function, as confirmed by immune cell infiltration and single-cell analysis. Quercetin demonstrated a significant amelioration of kidney injury and reduction in macrophage infiltration in the animal model. Furthermore, quercetin exhibited a significant inhibition of caspase-1 expression, subsequently leading to the inhibition of pro-inflammatory cytokines expression, such as IL-1β, IL-18, TNF-α, and IL-6. The inhibitory effect of quercetin on macrophage pyroptosis was also confirmed in RAW264.7 cells.

CONCLUSION

This study contributes substantial evidence to support the significant role of pyroptosis in the development of folic acid nephropathy, and highlights the ability of quercetin to downregulate caspase-1 in macrophages as a protective mechanism against pyroptosis.

The Herbal Combination Shu Gan Jie Yu Regulates the SNCG/ER-a/AKT-ERK Pathway in DMBA-Induced Breast Cancer and Breast Cancer Cell Lines Based on RNA-Seq and IPA Analysis

BACKGROUND

Soothing the liver (called Shu Gan Jie Yu in Chinese, SGJY) is a significant therapeutic method for breast cancer in TCM. In this study, 3 liver-soothing herbs, including Cyperus rotundus L., Citrus medica L. var. sarcodactylis Swingle and Rosa rugosa Thunb. were selected and combined to form a SGJY herbal combinatory.

THE AIM OF THE STUDY

To investigate the inhibiting effect of SGJY on breast cancer in vivo and vitro, and to explore the potential mechanisms.

MATERIALS AND METHODS

SGJY herbal combination was extracted using water. A breast cancer rat model was developed by chemical DMBA by gavage, then treated with SGJY for 11 weeks. The tumor tissue was preserved for RNA sequencing and analyzed by IPA software. The inhibition effects of SGJY on MCF-7 and T47D breast cancer cells were investigated by SRB assay and cell apoptosis analysis, and the protein expression levels of SNCG, ER-α, p-AKT and p-ERK were measured by western blotting.

RESULTS

SGJY significantly reduced the tumor weight and volume, and the level of estradiol in serum. The results of IPA analysis reveal SGJY upregulated 7 canonical pathways and downregulated 16 canonical pathways. Estrogen receptor signaling was the key canonical pathway with 9 genes downregulated. The results of upstream regulator analysis reveal beta-estradiol was the central target; the upstream regulator network scheme showed that 86 genes could affect the expression of the beta-estradiol, including SNCG, CCL21 and MB. Additionally, SGJY was verified to significantly alter the expression of SNCG mRNA, CCL21 mRNA and MB mRNA which was consistent with the data of RNA-Seq. The inhibition effects of SGJY exhibited a dose-dependent response. The apoptosis rates of MCF7 and T47D cells were upregulated. The protein expression of SNCG, ER-α, p-AKT and p-ERK were all significantly decreased by SGJY on MCF-7 and T47D cells.

CONCLUSION

The results demonstrate that SGJY may inhibit the growth of breast cancer. The mechanism might involve downregulating the level of serum estradiol, and suppressing the protein expression in the SNCG/ER-α/AKT-ERK pathway.

Uncovering the complex role of interferon-gamma in suppressing type 2 immunity to cancer

Cancer involves cells' abnormal growth and ability to invade or metastasize to different body parts. Cancerous cells can divide uncontrollably and spread to other areas through the lymphatic or circulatory systems. Tumors form when malignant cells clump together in an uncontrolled manner. In this context, the cytokine interferon-gamma (IFN-γ) is crucial in regulating immunological responses, particularly malignancy. While IFN-γ is well-known for its potent anti-tumor effects by activating type 1 immunity, recent research has revealed its ability to suppress type 2 immunity, associated with allergy and inflammatory responses. This review aims to elucidate the intricate function of IFN-γ in inhibiting type 2 immune responses to cancer. We explore how IFN-γ influences the development and function of immune cells involved in type 2 immunity, such as mast cells, eosinophils, and T-helper 2 (Th2) cells. Additionally, we investigate the impact of IFN-mediated reduction of type 2 immunity on tumor development, metastasis, and the response to immunotherapeutic interventions. To develop successful cancer immunotherapies, it is crucial to comprehend the complex interplay between type 2 and type 1 immune response and the regulatory role of IFN-γ. This understanding holds tremendous promise for the development of innovative treatment approaches that harness the abilities of both immune response types to combat cancer. However, unraveling the intricate interplay between IFN-γ and type 2 immunity in the tumor microenvironment will be essential for achieving this goal.

Molecular basis of breast cancer with comorbid depression and the mechanistic insights of Xiaoyaosan in treating breast cancer-associated depression

Depression and breast cancer (BC) have been found to have a shared genetic basis, multiple loci of effect, and a presumed causal relationship. The treatment of BC combined with depression poses significant challenges. This study aims to use bioinformatics and network pharmacology to explore the molecular basis of BC combined with depression and to elucidate the potential mechanisms of Xiaoyaosan (XYS) in treating this disease. The molecular background of BC complicated with depression was discovered via data mining and bioinformatics. The molecular mechanism of XYS in the treatment of BC with depression was investigated by network pharmacology. The binding affinity between targets and active compounds was evaluated by molecular docking. The impact of XYS on the gene and protein expression of matrix metallopeptidase 9 (MMP9) in microglial cells was assessed using RT-quantitative PCR and western blot analysis, respectively. Differential expression analysis was conducted to identify genes associated with BC, revealing that 2958 genes were involved, with 277 of these genes also being related to depression. XYS was found to contain 173 active compounds and 342 targets, with 44 of these targets being involved in regulating the progression of BC and depression. Enrichment analysis was performed to identify pathways associated with these targets, revealing that they were related to cell proliferation, catalytic activity, cell communication, and interleukin-18 signaling and LXR/RXR activation. Network analysis was conducted to identify key targets of Xiaoyaosan in treating BC combined with depression, with EGF, interleukin 6, epidermal growth factor receptor, and peroxisome proliferator activated receptor gamma being identified as important targets. Molecular docking was also performed to assess the binding affinity between key targets and active compounds, with puerarin showing the strongest affinity for MMP9. In microglial cells, XYS significantly enhances the gene and protein expression of MMP9. This study elucidated the pharmacological mechanism of co-treatment for BC patients complicated with depression and the pharmacological mechanism of XYS against BC plus depression.

Effect of tumor-associated macrophages on the pyroptosis of breast cancer tumor cells

Macrophages are immune cells with high plasticity that are widely distributed in all tissues and organs of the body. Under the influence of the immune microenvironment of breast tumors, macrophages differentiate into various germline lineages. They exert pro-tumor or tumor-suppressive effects by secreting various cytokines. Pyroptosis is mediated by Gasdermin family proteins, which form holes in cell membranes and cause a violent inflammatory response and cell death. This is an important way for the body to fight off infections. Tumor cell pyroptosis can activate anti-tumor immunity and inhibit tumor growth. At the same time, it releases inflammatory mediators and recruits tumor-associated macrophages (TAMs) for accumulation. Macrophages act as "mediators" of cytokine interactions and indirectly influence the pyroptosis pathway. This paper describes the mechanism of action on the part of TAM in affecting the pyroptosis process of breast tumor cells, as well as its key role in the tumor microenvironment. Additionally, it provides the basis for in-depth research on how to use immune cells to affect breast tumors and guide anti-tumor trends, with important implications for the prevention and treatment of breast tumors. Video Abstract.

Selected Flavonols in Breast and Gynecological Cancer: A Systematic Review

The consumption of foods that are rich in phenolic compounds has chemopreventive effects on many cancers, including breast cancer, ovarian cancer, and endometrial cancer. A wide spectrum of their health-promoting properties such as antioxidant, anti-inflammatory, and anticancer activities, has been demonstrated. This paper analyzes the mechanisms of the anticancer action of selected common flavonols, including kemferol, myricetin, quercetin, fisetin, galangin, isorhamnetin, and morin, in preclinical studies, with particular emphasis on in vitro studies in gynecological cancers and breast cancer. In the future, these compounds may find applications in the prevention and treatment of gynecological cancers and breast cancer, but this requires further, more advanced research.

Effect of traditional Chinese medicine on postoperative depression of breast cancer: a systematic review and meta-analysis

Background: Depression is one of the common complications in patients with postoperative breast cancer (BC). Conventional therapies for postoperative depression of BC always have modest treatment outcomes and undesirable side effects. Clinical practice and many studies have shown that traditional Chinese medicine (TCM) has a good effect on postoperative depression of BC. This meta-analysis aimed to assess the clinical effect of TCM as an add-on treatment for postoperative depression of BC. Methods: A systematic and thorough search was conducted on eight online electronic databases up to 20 July 2022. The control group received conventional therapies, and intervention groups received what control groups received plus TCM treatment. Review Manager 5.4.1 was used for statistical analysis. Results: Nine RCTs involved 789 participants who met the inclusion standards. The results showed the intervention group was better at decreasing the score of the Hamilton rating scale for depression (HAMD) (mean difference, MD = -4.21, 95% CI -5.54 to -2.88) and the self-rating depression scale (SDS) (MD = -12.03, 95% CI -15.94 to -8.13), improving clinical efficacy (RR = 1.25, 95% CI 1.14-1.37), increasing the levels of 5-hydroxytryptamine (5-HT) (MD = 0.27, 95% CI 0.20-0.34), dopamine (DA) (MD = 26.28, 95% CI 24.18-28.77), and norepinephrine (NE) (MD = 11.05, 95% CI 8.07-14.04), and influencing the immune index, including the levels of CD3⁺ (MD = 15.18, 95% CI 13.61-16.75), CD4⁺ (MD = 8.37, 95% CI 6.00-10.74), and CD4⁺/CD8⁺ (MD = 0.33, 95% CI 0.27-0.39). The level of CD8⁺ (MD = -4.04, 95% CI -11.98 to 3.99) had no obvious difference between the two groups. Conclusion: The meta-analysis stated that a therapeutic regimen involving TCM could better improve the depression status in postoperative BC.

Reactive oxygen species-responsive mitochondria-targeted liposomal quercetin attenuates retinal ischemia-reperfusion injury via regulating SIRT1/FOXO3A and p38 MAPK signaling pathways

Retinal ischemia-reperfusion (RIR) injury is involved in the pathogenesis of various vision-threatening diseases. The overproduction of reactive oxygen species (ROS) is thought to be the main cause of RIR injury. A variety of natural products, including quercetin (Que), exhibit potent antioxidant activity. However, the lack of an efficient delivery system for hydrophobic Que and the presence of various intraocular barriers limit the effective retinal delivery of Que in clinical settings. In this study, we encapsulated Que into ROS-responsive mitochondria-targeted liposomes (abbreviated to Que@TPP-ROS-Lips) to achieve the sustained delivery of Que to the retina. The intracellular uptake, lysosome escape ability, and mitochondria targeting ability of Que@TPP-ROS-Lips were evaluated in R28 retinal cells. Treating R28 cells with Que@TPP-ROS-Lips significantly ameliorated the decrease in ATP content, ROS generation, and increase in the release of lactate dehydrogenase in an in vitro oxygen-glucose deprivation (OGD) model of retinal ischemia. In a rat model, the intravitreal injection of Que@TPP-ROS-Lips 24 h after inducing retinal ischemia significantly enhanced retinal electrophysiological recovery and reduced neuroinflammation, oxidative stress, and apoptosis. Que@TPP-ROS-Lips were taken up by retina for at least 14 days after intravitreal administration. Molecular docking and functional biological experiments revealed that Que targets FOXO3A to inhibit oxidative stress and inflammation. Que@TPP-ROS-Lips also partially inhibited the p38 MAPK signaling pathway, which contributes to oxidative stress and inflammation. In conclusion, our new platform for ROS-responsive and mitochondria-targeted drug release shows promise for the treatment of RIR injury and promotes the clinical application of hydrophobic natural products.

Effectiveness of targeting the NLRP3 inflammasome by using natural polyphenols: A systematic review of implications on health effects

Globally, inflammation and metabolic disorders pose serious public health problems and are major health concerns. It has been shown that natural polyphenols are effective in the treatment of metabolic diseases, including anti-inflammation, anti-diabetes, anti-obesity, neuron-protection, and cardio-protection. NLRP3 inflammasome, which are multiprotein complexes located within the cytosol, play an important role in the innate immune system. However, aberrant activation of the NLRP3 inflammasome were discovered as essential molecular mechanisms in triggering inflammatory processes as well as implicating it in several major metabolic diseases, such as type 2 diabetes mellitus, obesity, atherosclerosis or cardiovascular disease. Recent studies indicate that natural polyphenols can inhibit NLRP3 inflammasome activation. In this review, the progress of natural polyphenols preventing inflammation and metabolic disorders via targeting NLRP3 inflammasome is systemically summarized. From the viewpoint of interfering NLRP3 inflammasome activation, the health effects of natural polyphenols are explained. Recent advances in other beneficial effects, clinical trials, and nano-delivery systems for targeting NLRP3 inflammasome are also reviewed. NLRP3 inflammasome is targeted by natural polyphenols to exert multiple health effects, which broadens the understanding of polyphenol mechanisms and provides valuable guidance to new researchers in this field.

Quercetin and polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a reproductive endocrine disease, and results to opsomenorrhea or amenorrhea, hairy, acne, acanthosis, infertility, abortion. In the long term, PCOS may also increase the risk of endometrial cancer, diabetes, hypertension, dyslipidemia and other diseases. Till now there is no specific drug for PCOS due to the unclearness of the cause and pathogenesis, as current treatments for PCOS only target certain symptoms. Quercetin (QUR) is a flavonoid drug widely found in Chinese herbal medicines, fruits, leaves, vegetables, seeds and plants roots. Studies on other diseases have found that QUR has anti-oxidant, anti-inflammatory, anti-insulin resistance, anti-cancer and other effects. Some studies have shown that serum testosterone (T), luteinizing hormone (LH), the LH/follicule-stimulating hormone (FSH) ratio, fasting glucose, fasting insulin, HOMA-IR and lipid levels are reduced in PCOS patients with QUR treatment. However, the mechanisms of QUR in PCOS patients have not been completely elucidated. In this review, we retrospect the basic characteristics of QUR, and in vitro studies, animal experiments and clinical trials of QUR and plant extracts containing QUR in the treatment of PCOS. We also summarized the effects and mechanism of QUR in ovarian cells in vitro and PCOS model rats, the changes in relevant parameters after QUR administration in PCOS patients, and its potentially therapeutic applications.

Targeting of non-apoptotic cancer cell death mechanisms by quercetin: Implications in cancer therapy

The ultimate goal of cancer treatment is to kill cancer cells, based on the use of various therapeutic agents, such as chemotherapy, radiotherapy, or targeted therapy drugs. Most drugs exert their therapeutic effects on cancer by targeting apoptosis. However, alterations in apoptosis-related molecules and thus assisting cells to evade death, eventually lead to tumor cell resistance to therapeutic drugs. The increased incidence of non-apoptotic cell death modes such as induced autophagy, mitotic catastrophe, senescence, and necrosis is beneficial to overcoming multidrug resistance mediated by apoptosis resistance in tumor cells. Therefore, investigating the function and mechanism of drug-induced non-apoptotic cell death modes has positive implications for the development of new anti-cancer drugs and therapeutic strategies. Phytochemicals show strong potential as an alternative or complementary medicine for alleviating various types of cancer. Quercetin is a flavonoid compound widely found in the daily diet that demonstrates a significant role in inhibiting numerous human cancers. In addition to direct pro-tumor cell apoptosis, both in vivo and in vitro experiments have shown that quercetin exerts anti-tumor properties by triggering diverse non-apoptotic cell death modes. This review summarized the current status of research on the molecular mechanisms and targets through which quercetin-mediated non-apoptotic mode of cancer cell death, including autophagic cell death, senescence, mitotic catastrophe, ferroptosis, necroptosis, etc.

Inflammatory pathophysiological mechanisms implicated in postpartum depression

Postpartum Depression (PPD) is a serious psychiatric disorder of women within the first year after delivery. It grievously damages women's physical and mental health. Inflammatory reaction theory is well-established in depression, and also has been reported associated with PPD. This review summarized the inflammatory pathophysiological mechanisms implicated in PPD, including decreased T cell activation, increased proinflammatory cytokines secretion, active kynurenine pathway, and initiated NLRP3 inflammasome. Clinical and preclinical research are both gathered. Potential therapeutical alternatives targeting the inflammatory mechanisms of PPD were introduced. In addition, this review briefly discussed the differences of inflammatory mechanisms between PPD and depression. The research of inflammation in PPD is limited and seems just embarking, which indicates the direction we can further study. As a variety of risky factors contribute to PPD collectively, therapy for women with PPD should be comprehensive, and clinical heterogeneity should be taken into consideration. As PPD has a predictability, early clinical screening and interventions are also needed. This review aims to help readers better understand the inflammatory pathological mechanisms in PPD, so as to identify biomarkers and potential therapeutic targets in the future.