Aronia melanocarpa L. fruit peels show anti-cancer effects in preclinical models of breast carcinoma: The perspectives in the chemoprevention and therapy modulation.

Introduction: Within oncology research, there is a high effort for new approaches to prevent and treat cancer as a life-threatening disease. Specific plant species that adapt to harsh conditions may possess unique properties that may be utilized in the management of cancer. Hypothesis: Chokeberry fruit is rich in secondary metabolites with anti-cancer activities potentially useful in cancer prevention and treatment. Aims of the study and Methods: Based on mentioned hypothesis, the main goal of our study was to evaluate the antitumor effects of dietary administered Aronia melanocarpa L. fruit peels (in two concentrations of 0.3 and 3% [w/w]) in the therapeutic syngeneic 4T1 mouse adenocarcinoma model, the chemopreventive model of chemically induced mammary carcinogenesis in rats, a cell antioxidant assay, and robust in vitro analyses using MCF-7 and MDA-MB-231 cancer cells. Results: The dominant metabolites in the A. melanocarpa fruit peel extract tested were phenolic derivatives classified as anthocyanins and procyanidins. In a therapeutic model, aronia significantly reduced the volume of 4T1 tumors at both higher and lower doses. In the same tumors, we noted a significant dose-dependent decrease in the mitotic activity index compared to the control. In the chemopreventive model, the expression of Bax was significantly increased by aronia at both doses. Additionally, aronia decreased Bcl-2 and VEGF levels, increasing the Bax/Bcl-2 ratio compared to the control group. The cytoplasmic expression of caspase-3 was significantly enhanced when aronia was administered at a higher dosage, in contrast to both the control group and the aronia group treated with a lower dosage. Furthermore, the higher dosage of aronia exhibited a significant reduction in the expression of the tumor stem cell marker CD133 compared to the control group. In addition, the examination of aronia`s epigenetic impact on tumor tissue through in vivo analyses revealed significant alterations in histone chemical modifications, specifically H3K4m3 and H3K9m3, miRNAs expression (miR155, miR210, and miR34a) and methylation status of tumor suppressor genes (PTEN and TIMP3). In vitro studies utilizing a methanolic extract of A.melanocarpa demonstrated significant anti-cancer properties in the MCF-7 and MDA-MB-231 cell lines. Various analyses, including Resazurin, cell cycle, annexin V/PI, caspase-3/7, Bcl-2, PARP, and mitochondrial membrane potential, were conducted in this regard. Additionally, the aronia extract enhanced the responsiveness to epirubicin in both cancer cell lines. Conclusion: This study is the first to analyze the antitumor effect of A. melanocarpa in selected models of experimental breast carcinoma in vivo and in vitro. The utilization of the antitumor effects of aronia in clinical practice is still minimal and requires precise and long-term clinical evaluations. Individualized cancer-type profiling and patient stratification are crucial for effectively implementing plant nutraceuticals within targeted anti-cancer strategies in clinical oncology.

Prognostic value of nucleotide excision repair and translesion DNA synthesis proteins in muscle-infiltrating bladder carcinoma.

BACKGROUND: Cisplatin (CDDP) remains a key agent in the treatment of muscle-infiltrating bladder carcinoma (MIBC). However, a proportion of MIBC patients do not respond to chemotherapy, which may be caused by the increased repair of CDDP-induced DNA damage. The purpose of this study was to explore the prognostic value of proteins involved in nucleotide excision repair (NER) and translesion DNA synthesis (TLS) in MIBC patients. METHODS: This is a retrospective analysis of 86 MIBC patients. The XPA, XPF, XPG, ERCC1, POLI, POLH and REV3L proteins were stained in primary bladder tumors and their levels were analyzed both in the total cohort and in a subgroup with metastatic urothelial carcinoma (mUC) that received gemcitabine and CDDP as a first-line therapy. Both cohorts were divided by percentage of cancer cells stained positive for each protein into subgroups with high and low expression. In the same manner, the combined expression of NER (XPA + ERCC1 + XPF + XPG) and TLS (POLI + POLH + REV3L), as the whole pathways, was analyzed. RESULTS: Mortality was 89.5% at the median follow-up of 120.2 months. In the total cohort, patients with tumors stained positive for XPA, XPG and POLI had significantly worse overall survival (OS) compared to those with negative staining [hazard ratio (HR) = 0.60, 0.62 and 0.53, respectively]. Both XPG and POLI were independent prognostic factors in multivariate analyses (MVA). In addition, an increase in NER and TLS pathway expression was significantly associated with worse OS in the total cohort (HR = 0.54 and 0.60, respectively). In the mUC subgroup, high POLI expression was associated with significant deterioration of OS (HR = 0.56) in univariate analyses, and its independent prognostic value was shown in MVA. CONCLUSIONS: Our study showed significant correlations between the tumor expression of XPG and POLI, as well as NER and TLS as the whole pathways, and inferior OS. Hence, they could constitute prognostic biomarkers and potentially promising therapeutic targets in MIBC. However, a prospective trial is required for further validation, thereby overcoming the limitations of this study.

Hamman's Syndrome after Vaginal Delivery: A Case of Postpartum Spontaneous Pneumomediastinum with Subcutaneous Emphysema and Review of the Literature.

Hamman's syndrome is a rare condition that mostly affects young males, often with a predisposition to asthma. It includes the presence of free air in the mediastinum and subcutaneous emphysema with no other underlying cause such as trauma, infection, or administration of any sort of mask support with hyperpressure. It occurs spontaneously and often in association with a prolonged Valsalva maneuver. This might explain why there are some cases of Hamman's syndrome among young females giving birth. Here, we present a case report of a 24-year-old non-smoker primigravida with Hamman's syndrome. She presented with symptoms a few hours after an uncomplicated vaginal delivery at 40 + 1 weeks of pregnancy where the active phase of labor lasted for three hours with normal progress. The second stage lasted for 30 min, with no signs of distress on CTG. The symptoms (pain in the right ear, swelling and pain in the neck, chest tightness, shortness of breath, dysphagia, odynophagia, and pain in the upper thorax on the right side) and objective findings as subcutaneous crepitations in the neck, parasternal region, right axillary fossa, clavicle and over the chest resolved spontaneously after a few days of observation and conservative management. We also give a systemic review of reported cases since 2000 to provide an overview of the pathomechanism, symptoms, diagnostics, treatment, and management of this condition. Hamman's syndrome is a rare, usually benign, but potentially serious complication that can occur during the second stage of labor. Diagnostics include inquiring about typical symptoms, clinical examination, and chest x-ray or CT scan. Treatment is usually conservative with oxygen, bronchodilators, and pain relief. The recurrence rate is low and there is no contraindication to vaginal delivery in future pregnancies. However, it is suggested that physicians and midwives be cautious and consider a low threshold for instrumental delivery or cesarean section to avoid excessive Valsalva maneuvers.

Salvia officinalis L. exerts oncostatic effects in rodent and in vitro models of breast carcinoma.

Introduction: Based on extensive data from oncology research, the use of phytochemicals or plant-based nutraceuticals is considered an innovative tool for cancer management. This research aimed to analyze the oncostatic properties of Salvia officinalis L. [Lamiaceae; Salviae officinalis herba] using animal and in vitro models of breast carcinoma (BC). Methods: The effects of dietary administered S. officinalis in two concentrations (0.1%/SAL 0.1/and 1%/SAL 1/) were assessed in both syngeneic 4T1 mouse and chemically induced rat models of BC. The histopathological and molecular evaluations of rodent carcinoma specimens were performed after the autopsy. Besides, numerous in vitro analyses using two human cancer cell lines were performed. Results and Conclusion: The dominant metabolites found in S. officinalis propylene glycol extract (SPGE) were representatives of phenolics, specifically rosmarinic, protocatechuic, and salicylic acids. Furthermore, the occurrence of triterpenoids ursolic and oleanolic acid was proved in SPGE. In a mouse model, a non-significant tumor volume decrease after S. officinalis treatment was associated with a significant reduction in the mitotic activity index of 4T1 tumors by 37.5% (SAL 0.1) and 31.5% (SAL 1) vs. controls (set as a blank group with not applied salvia in the diet). In addition, salvia at higher doses significantly decreased necrosis/whole tumor area ratio by 46% when compared to control tumor samples. In a rat chemoprevention study, S. officinalis at a higher dose significantly lengthened the latency of tumors by 8.5 days and significantly improved the high/low-grade carcinomas ratio vs. controls in both doses. Analyses of the mechanisms of anticancer activities of S. officinalis included well-validated prognostic, predictive, and diagnostic biomarkers that are applied in both oncology practice and preclinical investigation. Our assessment in vivo revealed numerous significant changes after a comparison of treated vs. untreated cancer cells. In this regard, we found an overexpression in caspase-3, an increased Bax/Bcl-2 ratio, and a decrease in MDA, ALDH1, and EpCam expression. In addition, salvia reduced TGF-ß serum levels in rats (decrease in IL-6 and TNF-α levels were with borderline significance). Evaluation of epigenetic modifications in rat cancer specimens in vivo revealed a decline in the lysine methylations of H3K4m3 and an increase in lysine acetylation in H4K16ac levels in treated groups. Salvia decreased the relative levels of oncogenic miR21 and tumor-suppressive miR145 (miR210, miR22, miR34a, and miR155 were not significantly altered). The methylation of ATM and PTEN promoters was decreased after S. officinalis treatment (PITX2, RASSF1, and TIMP3 promoters were not altered). Analyzing plasma metabolomics profile in tumor-bearing rats, we found reduced levels of ketoacids derived from BCAAs after salvia treatment. In vitro analyses revealed significant anti-cancer effects of SPGE extract in MCF-7 and MDA-MB-231 cell lines (cytotoxicity, caspase-3/-7, Bcl-2, Annexin V/PI, cell cycle, BrdU, and mitochondrial membrane potential). Our study demonstrates the significant chemopreventive and treatment effects of salvia haulm using animal or in vitro BC models.

Desmoid Fibromatosis of the Anterior Abdominal Wall in Pregnancy: A Case Report and Review of the Literature.

A desmoid tumor (DT) is a rare benign neoplasm arising from muscle aponeurosis, associated mostly with trauma or pregnancy. DT has an infiltrative and locally aggressive growth pattern and usually does not metastasize. However, it has a high recurrence and complication rate. When it occurs in pregnancy, the pregnancy and delivery is taken as an individual case for optimal management by physicians and midwifes, who need to be cautious in finding the optimal delivery mode for the patient, which depends on the tumor size, location, behavior, and past history. The authors report a case of 29-year-old pregnant woman who previously underwent systemic oncological treatment for a large abdominal wall desmoid tumor and became pregnant afterwards. The history of DT presented a follow-up and delivery challenge. Observational management was chosen with an elective cesarean section at week 38 + 4 of pregnancy with uncomplicated postpartum follow-up. The authors detail the clinical management and chosen therapeutic approach; chemotherapy can be a choice in the treatment options for patients with DTs, although the majority of DTs are treated surgically with subsequent mesh plastic. Moreover, the authors provide a systematic review of the literature focused on the treatment management of DTs in pregnant women during pregnancy and the postpartum period, as pregnancy-associated desmoid tumors are a specific condition, where the optimal management is not well established, despite some guidelines for non-pregnant patients.

Histopathology and indicators of borderline ovarian tumours with microinvasion in bitches.

The authors present two cases of borderline ovarian tumours with microinvasion in bitches with variable clinical significance. The first case documents a four-year-old female Weimaraner diagnosed with a tumour on the right ovary during a veterinary check-up, using ultrasound (USG) examination, which was then surgically removed. Histological examination revealed a clear cell borderline tumour of the ovary with microinvasion. The second case is represented by a necropsy sample from a 52-month-old female German Shepherd who died a day before the planned hysterectomy due to undertreated pyometra. During necropsy, a developed bilateral ovarian tumour was found. An additional histological examination revealed a serous borderline tumour with microinvasion of both ovaries. This paper discusses the histopathological and clinical aspects involved in the prognosis of borderline ovarian tumours in bitches. This concerns the possibility of a change for a more aggressive behaviour of these tumours and their immunohistochemical profile, then the risk of implant metastases and, finally, the time point of diagnosis, intervention, and therapy. Even histologically verified well-differentiated forms of borderline ovarian tumours with microinvasion in bitches can show the variable clinical significance and, therefore, in similar cases, only a good or only a bad prognosis of the disease should not be expected.

Tall cell carcinoma of the breast with reversed polarity - a report of three cases with a review of the literature.

Tall cell carcinoma with reverse polarity (TCCRP) is a rare special type of breast epithelial neoplasm presented by columnar cells with opposite nuclear polarity, solid and solid-papillary architecture, and frequent IDH2 gene alterations. Hereby, the authors present three cases of TCCRP in women aged 56, 66 and 67 years with maximum tumour sizes of 29 mm, 10 mm and 8 mm. Tumours showed histomorphological characteristics of TCCRP supported by immunohistochemical profile of tumour cells, in which positive expression of CK7, CK5/6, GCDFP15, mammaglobin, GATA3 and calretinin and negativity of CK14, p63, TTF1, thyroglobulin and neuroendocrine markers were demonstrated. Two tumours were triple negative, and in one tumour, only weak focal ER expression was noted along with PR and HER2 negativity. Pathogenic somatic variants in mutational hotspot region p.R172 in IDH2 gene were detected using NGS technology in all three tumours. Moreover, in two of these tumours, the most common pathogenic variants p.E545A and p.H1047R of PIK3CA were identified. TCCRP represents a rare breast neoplasm of low malignant potential, the incidence of which will probably increase due to the more clearly defined histomorphological, immunohistochemical and molecular-genetic characteristics, which were all responsible for including this entity into the 5th edition of WHO classification breast tumours.

Cystic trophoblastic tumour of the testis: Case report.

Cystic trophoblastic tumor (CTT) is a rare non-aggressive germinative neoplasm from the group of non-choriocarcinomatous trophoblastic tumors, which is presented by cystic spaces lined with mononuclear degenerative-looking trophoblastic cells. CTT has been most often described as a residual disease in dissected retroperitoneal lymph nodes of patients with metastatic germ cell testicular tumours after chemotherapy. There were published only sporadic cases of primary testicular mixed germ cell tumour with CTT component. Hereby, the authors present a case of a 22-year-old man with a mixed germ cell tumour composed of postpubertal teratoma, embryonal carcinoma and CTT. Immunohistochemically, the CTT tumour cells were positive for cytokeratins (AE1/AE3, CK8/18), GATA3, p63 and focally also for beta-hCG and alpha-inhibin. CTT may be presented as a rare component of primary testicular mixed germ cell tumour and it represents very likely an evolutionary intermediate stage of transition from choriocarcinoma into teratoma during the process of regression.

Pathological Diagnosis, Work-Up and Reporting of Breast Cancer 1st Central-Eastern European Professional Consensus Statement on Breast Cancer.

This text is based on the recommendations accepted by the 4th Hungarian Consensus Conference on Breast Cancer, modified on the basis of the international consultation and conference within the frames of the Central-Eastern European Academy of Oncology. The recommendations cover non-operative, intraoperative and postoperative diagnostics, determination of prognostic and predictive markers and the content of cytology and histology reports. Furthermore, they address some specific issues such as the current status of multigene molecular markers, the role of pathologists in clinical trials and prerequisites for their involvement, and some remarks about the future.

5-Fluorouracil Treatment of CT26 Colon Cancer Is Compromised by Combined Therapy with IMMODIN.

Due to the physiological complexity of the tumour, a single drug therapeutic strategy may not be sufficient for effective treatment. Emerging evidence suggests that combination strategies may be important to achieve more efficient tumour responses. Different immunomodulators are frequently tested to reverse the situation for the purpose of improving immune response and minimizing chemotherapy side effects. Immodin (IM) represents an attractive alternative to complement chemotherapy, which can be used to enhance the immune system after disturbances resulting from the side effects of chemotherapy. In the presented study, a model of CT26 tumor-bearing mice was used to investigate the effect of single IM or its combination with 5-fluorouracil (5-FU) on colon cancer cells. Our results highlight that the beneficial role of IM claimed in previous studies cannot be generalised to all chemotherapeutic drugs, as 5-FU toxicity was not increased. On the contrary, the chemotherapeutic anti-cancer efficacy of 5-FU was greatly compromised when combined with IM. Indeed, the combined treatment was significantly less effective regarding the tumour growth and animal survival, most probably due to the increased number of tumour-associated macrophages, and increased 5-FU cytotoxic effect related to kidneys and the liver.

Anti-breast cancer effects of phytochemicals: primary, secondary, and tertiary care.

Breast cancer incidence is actually the highest one among all cancers. Overall breast cancer management is associated with challenges considering risk assessment and predictive diagnostics, targeted prevention of metastatic disease, appropriate treatment options, and cost-effectiveness of approaches applied. Accumulated research evidence indicates promising anti-cancer effects of phytochemicals protecting cells against malignant transformation, inhibiting carcinogenesis and metastatic spread, supporting immune system and increasing effectiveness of conventional anti-cancer therapies, among others. Molecular and sub-/cellular mechanisms are highly complex affecting several pathways considered potent targets for advanced diagnostics and cost-effective treatments. Demonstrated anti-cancer affects, therefore, are clinically relevant for improving individual outcomes and might be applicable to the primary (protection against initial cancer development), secondary (protection against potential metastatic disease development), and tertiary (towards cascading complications) care. However, a detailed data analysis is essential to adapt treatment algorithms to individuals' and patients' needs. Consequently, advanced concepts of patient stratification, predictive diagnostics, targeted prevention, and treatments tailored to the individualized patient profile are instrumental for the cost-effective application of natural anti-cancer substances to improve overall breast cancer management benefiting affected individuals and the society at large.

A case report of a patient with inoperable primary diffuse leptomeningeal melanomatosis treated with whole-brain radiotherapy and pembrolizumab.

RATIONALE: Primary diffuse leptomeningeal melanomatosis (PDLM) is a rare disease that affects melanocytes in the leptomeninges. There is very limited data on the efficacy of immunotherapy in this setting. PATIENT CONCERNS: A patient (23 years old) was diagnosed with PDLM. Histologically, atypical melanocytic cells were also observed. DIAGNOSIS: Immunohistochemistry showed positivity for S100 protein, NKiC3, and vimentin, and negativity for Melan-A and HMB-45, with a proliferation index of 30%. Extracranial disease was excluded using dermatological and other examinations, including positron emission tomography/computed tomography with 18F-fluorodeoxyglucose. INTERVENTIONS: The patient was treated with whole-brain radiotherapy (10 fractions to a total dose of 30 Gy) concomitantly with pembrolizumab and then continued with immunotherapy until disease progression with a maximum effect of partial remission on magnetic resonance imaging scans. OUTCOMES: Progression-free survival was 6.0 months and overall survival 6.5 months. LESSONS: This is one of the few case reports of an adult patient with this rare malignancy being treated with a programmed death-1 inhibitor with partial response. Immunotherapy in metastatic PDLM may be a reasonable therapeutic option.

Expression of fascin in association with p16 and Ki-67 in cervical lesions: immunohistochemical study.

Annual gynecological examination with cervical cancer screening and HPV vaccination ensures the appropriate prevention of the onset and progression of cervical cancer. Currently, efforts are being made to find new diagnostic and prognostic biomarkers. Fascin, an actin-bundling protein, promotes cellular migration. Its overexpression has been observed in many types of squamous carcinomas and was usually correlated with a worse prognosis and metastasis. However, the data on fascin expression in cervical lesions are limited. This study focuses on the quantitative evaluation of fascin expression, the immunoreaction intensity and subcellular localization of fascin expression in low-grade squamous intraepithelial lesions (LSIL), high-grade squamous intraepithelial lesions (HSIL) and squamous cell carcinomas (SCC). Fascin expression was also correlated with the routinely used diagnostic markers p16 and Ki-67. Biopsy specimens (n = 67) of LSIL, HSIL and SCC were taken from adult women in the age range 20-86 years. Fascin expression was detected by immunohistochemical analysis and quantified using morphometric software. Analysis of variance confirmed statistically significant differences in the percentage of fascin-positive cells between the LSIL, HSIL and SCC groups. Finally, the results showed a significant positive correlation between fascin expression and p16 and Ki-67 expression.

Flavonoids against non-physiologic inflammation attributed to cancer initiation, development, and progression-3PM pathways.

Inflammation is an essential pillar of the immune defense. On the other hand, chronic inflammation is considered a hallmark of cancer initiation and progression. Chronic inflammation demonstrates a potential to induce complex changes at molecular, cellular, and organ levels including but not restricted to the stagnation and impairment of healing processes, uncontrolled production of aggressive ROS/RNS, triggered DNA mutations and damage, compromised efficacy of the DNA repair machinery, significantly upregulated cytokine/chemokine release and associated patho-physiologic protein synthesis, activated signaling pathways involved in carcinogenesis and tumor progression, abnormal tissue remodeling, and created pre-metastatic niches, among others. The anti-inflammatory activities of flavonoids demonstrate clinically relevant potential as preventive and therapeutic agents to improve individual outcomes in diseases linked to the low-grade systemic and chronic inflammation, including cancers. To this end, flavonoids are potent modulators of pro-inflammatory gene expression being, therefore, of great interest as agents selectively suppressing molecular targets within pro-inflammatory pathways. This paper provides in-depth analysis of anti-inflammatory properties of flavonoids, highlights corresponding mechanisms and targeted molecular pathways, and proposes potential treatment models for multi-level cancer prevention in the framework of predictive, preventive, and personalized medicine (PPPM / 3PM). To this end, individualized profiling and patient stratification are essential for implementing targeted anti-inflammatory approaches. Most prominent examples are presented for the proposed application of flavonoid-conducted anti-inflammatory treatments in overall cancer management. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13167-021-00257-y.

Recurrent Giant Malignant Phyllodes Tumor of the Breast.

Phyllodes tumors (PTs) are rare fibroepithelial neoplasms of the breast. They have a proliferating stromal component that can be graded as benign, borderline, and malignant. In addition, they are associated with an increased risk of local recurrence and distant metastasis. The authors hereby present a case report of a 34-year-old woman with recurrent malignant PT with an increasing aggressiveness. There were two recurrences of giant tumors that consumed the entire right breast, which developed over a three-year period. The final surgical treatment was a total extirpation of the tumor with subsequent plastic reconstruction using a cutaneous flap from the region of the latissimus dorsi muscle. The patient died three months after the last recurrence due to multiorgan failure.

Metabolic Anti-Cancer Effects of Melatonin: Clinically Relevant Prospects.

Metabolic reprogramming characterized by alterations in nutrient uptake and critical molecular pathways associated with cancer cell metabolism represents a fundamental process of malignant transformation. Melatonin (N-acetyl-5-methoxytryptamine) is a hormone secreted by the pineal gland. Melatonin primarily regulates circadian rhythms but also exerts anti-inflammatory, anti-depressant, antioxidant and anti-tumor activities. Concerning cancer metabolism, melatonin displays significant anticancer effects via the regulation of key components of aerobic glycolysis, gluconeogenesis, the pentose phosphate pathway (PPP) and lipid metabolism. Melatonin treatment affects glucose transporter (GLUT) expression, glucose-6-phosphate dehydrogenase (G6PDH) activity, lactate production and other metabolic contributors. Moreover, melatonin modulates critical players in cancer development, such as HIF-1 and p53. Taken together, melatonin has notable anti-cancer effects at malignancy initiation, progression and metastasing. Further investigations of melatonin impacts relevant for cancer metabolism are expected to create innovative approaches supportive for the effective prevention and targeted therapy of cancers.

Phenotypical modifications of immune cells are enhanced by extracellular matrix.

Immune cells not only constitute tumour microenvironment but they may even affect disease prognosis as a result of dual functional roles that they may play in tumour tissues. Two frequently used established immune cell lines (lymphocytic Jurkat and monocytic THP-1) were used to test whether microenvironmental factors, especially molecular components of extracellular matrix, can shape the phenotype of immune cells. Proliferation, morphological and phenotypical analyses were applied to compare behaviour of the immune cells, typically cultured as suspensions in culture medium, with their behaviour in collagen type I-based and Matrigel-based 3D cultures. Density of both immune cell types in routine suspension cultures affected their subsequent proliferation in extracellular matrices. THP-1 cells appeared to be more sensitive to their surrounding microenvironment as judged from extracellular matrix type-dependent changes in their cell doubling times and from slight increase in their diameters in both extracellular matrix-containing cell cultures. Moreover, even chemically uninduced monocytic THP-1 cells were present in a minor fraction as CD68 positive cell population in collagen type I matrix indicating their partial differentiation to macrophages. Observed modifications of immune cells by microenvironmental factors may have profound implications for their roles in healthy and pathological tissues.

Flavonoids against the SARS-CoV-2 induced inflammatory storm.

The disease severity of COVID-19, especially in the elderly and patients with co-morbidities, is characterized by hypercytokinemia, an exaggerated immune response associated with an uncontrolled and excessive release of proinflammatory cytokine mediators (cytokine storm). Flavonoids, important secondary metabolites of plants, have long been studied as therapeutic interventions in inflammatory diseases due to their cytokine-modulatory effects. In this review, we discuss the potential role of flavonoids in the modulation of signaling pathways that are crucial for COVID-19 disease, particularly those related to inflammation and immunity. The immunomodulatory ability of flavonoids, carried out by the regulation of inflammatory mediators, the inhibition of endothelial activation, NLRP3 inflammasome, toll-like receptors (TLRs) or bromodomain containing protein 4 (BRD4), and the activation of the nuclear factor erythroid-derived 2-related factor 2 (Nrf2), might be beneficial in regulating the cytokine storm during SARS-CoV-2 infection. Moreover, the ability of flavonoids to inhibit dipeptidyl peptidase 4 (DPP4), neutralize 3-chymotrypsin-like protease (3CLpro) or to affect gut microbiota to maintain immune response, and the dual action of angiotensin-converting enzyme 2 (ACE-2) may potentially also be applied to the exaggerated inflammatory responses induced by SARS-CoV-2. Based on the previously proven effects of flavonoids in other diseases or on the basis of newly published studies associated with COVID-19 (bioinformatics, molecular docking), it is reasonable to assume positive effects of flavonoids on inflammatory changes associated with COVID-19. This review highlights the current state of knowledge of the utility of flavonoids in the management of COVID-19 and also points to the multiple biological effects of flavonoids on signaling pathways associated with the inflammation processes that are deregulated in the pathology induced by SARS-CoV-2. The identification of agents, including naturally occurring substances such as flavonoids, represents great approach potentially utilizable in the management of COVID-19. Although not clinically investigated yet, the applicability of flavonoids against COVID-19 could be a promising strategy due to a broad spectrum of their biological activities.