Anti-Proliferation and Pro-Apoptotic Effects of Diosmetin via Modulating Cell Cycle Arrest and Mitochondria-Mediated Intrinsic Apoptotic Pathway in MDA-MB-231 Cells

Diosmetin: A dietary flavone as modulator of signaling pathways in cancer progression

Flavonoids, constituting the most extensive category of polyphenols, founds in a variety of plants and comprise over 9000 compounds. Diosmetin, O-methylated flavone (3',5,7-trihydroxy-4'-methoxyflavone) of flavonoid aglycone diosmin have witnessed a significant surge in recent years. Many studies showed that flavonoids induced cytotoxicity in different organ specific cancer types. Thus, current review evaluates the anticancer potential of diosmetin and shed light on its mechanism of action such as cell cycle regulation, apoptosis via both intrinsic and extrinsic pathway, autophagy and tumour progression and metastasis. It also provides comprehensive analysis of different cancer targets and their role in breast, colon, hepatic, gliomas, leukemia, lung, prostate and skin cancer. Combination studies of diosmetin to improve drug sensitivity and reduce toxicity towards normal cells has been also discussed. Besides, in vitro studies, present review also discuss the anticancer potential of diosmetin on xenograft mice model. Different natural sources of diosmetin, limitations, pharmacokinetic analysis and toxicity study also summarized in current review. The emphasis on enhancing solubility and permeability for clinical utility has been thoroughly highlighted with particular attention given to the utilization of nano formulations to overcome existing barriers. At last, in-depth analysis of current challenges and a forward-looking perspective deliberated to address the existing gaps and position it as a promising lead compound for clinical applications in cancer treatment. This discussion is boosted by diosmetin's potential anticancer properties on different cancers, makes valuable candidates in the ongoing quest for effective therapeutic interventions against cancer.

The Antioxidative Effects of Flavones in Hypertensive Disease

Hypertension is the leading remediable risk factor for cardiovascular morbidity and mortality in the United States. Excess dietary salt consumption, which is a catalyst of hypertension, initiates an inflammatory cascade via activation of antigen-presenting cells (APCs). This pro-inflammatory response is driven primarily by sodium ions (Na+) transporting into APCs by the epithelial sodium channel (ENaC) and subsequent NADPH oxidase activation, leading to high levels of oxidative stress. Oxidative stress, a well-known catalyst for hypertension-related illness development, disturbs redox homeostasis, which ultimately promotes lipid peroxidation, isolevuglandin production and an inflammatory response. Natural medicinal compounds derived from organic materials that are characterized by their anti-inflammatory, anti-oxidative, and anti-mutagenic properties have recently gained traction amongst the pharmacology community due to their therapeutic effects. Flavonoids, a natural phenolic compound, have these therapeutic benefits and can potentially serve as anti-hypertensives. Flavones are a type of flavonoid that have increased anti-inflammatory effects that may allow them to act as therapeutic agents for hypertension, including diosmetin, which is able to induce significant arterial vasodilation in several different animal models. This review will focus on the activity of flavones to illuminate potential preventative and potential therapeutic mechanisms against hypertension.

Diosmetin induces apoptosis and protective autophagy in human gastric cancer HGC-27 cells via the PI3K/Akt/FoxO1 and MAPK/JNK pathways

Gastric cancer represents a significant global health concern, necessitating the exploration of novel therapeutic options. Diosmetin, a natural flavonoid derived from citrus and vegetables, has demonstrated promising anti-tumor activity against various tumor cells. However, the potential anticancer effect of diosmetin in gastric cancer and its underlying mechanism have yet to be elucidated. In this study, we aimed to investigate the impact of diosmetin on cell proliferation, migration, cell cycle progression and apoptosis in human gastric cancer HGC-27 cells. Our findings revealed that diosmetin effectively suppressed cell proliferation, induced G2/M phase cell cycle arrest, and triggered cell apoptosis. Mechanistically, diosmetin downregulated the expression of antiapoptotic proteins Bcl-2 and Bcl-xL, while upregulated the level of proapoptotic proteins such as Bax, cleaved PARP and cleaved caspase-3. Additionally, diosmetin inhibited Akt and FoxO1 phosphorylation, while activated the MAPK signaling pathway. Notably, pretreatment of IGF-1, an Akt activator, attenuated the diosmetin-induced apoptosis. Furthermore, pretreatment with SP600125, a JNK inhibitor, significantly reduced the protein level of LC3B, while promoted the expression of cleaved caspase-3 and cleaved PARP. Collectively, our results suggest that diosmetin holds promise as an effective therapeutic agent against gastric cancer by inducing apoptosis through inhibition of the Akt/FoxO1 pathway and promoting protective autophagy via the MAPK/JNK signaling pathway.

Fenofibrate and Diosmetin in a rat model of testicular toxicity: New insight on their protective mechanism through PPAR-α/NRF-2/HO-1 signaling pathway

One of the most significant chemotherapeutic side effects of cisplatin (Cis) that limits its use and efficacy is testicular toxicity. Thus, the objective of the present study was to investigate the possible ameliorative effect of Fenofibrate (Fen), Diosmetin (D), and their combination against cis-mediated testicular damage. Fifty-four adult male albino rats were randomly allocated into nine groups (6 rats each): Control group, Fen (100 mg/kg), D20 (20 mg/kg), D40 (40 mg/kg), Cis group (7 mg/kg), Cis +Fen group (7 mg/kg+100 mg/kg), Cis+D20 group (7 mg/kg+20 mg/kg), Cis+D40 group (7 mg/kg+40 mg/kg), Cis+Fen+D40 treated group (7 mg/kg+100 mg/kg+40 mg/kg). Relative testicular weight, epididymal sperm count and viability, serum testosterone level, testicular oxidative stress indices, mRNA expression of peroxisome proliferator-activated receptor alpha (PPAR-α), nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1), histopathological, and immunohistochemical alterations were assessed. Our results revealed that cis administration induced testicular oxidative and inflammatory damage as indicated by a substantial reduction in relative testicular weight, sperm parameters, serum testosterone levels, the antioxidant enzyme activity of catalase, and Johnson's histopathological score, PPAR-α/NRF-2/HO-1 and proliferating cell nuclear antigen (PCNA) immunoexpression with marked increment in malondialdehyde (MDA), Cosentino's score, nuclear factor kappa B (NF-κβ p65), interleukin (IL)- 1β and caspase 3 in testicular tissue. Interestingly, Fen and D diminished the harmful effects of cis on testes via upregulation of the antioxidant activities and downregulation of lipid peroxidation, apoptosis, and inflammation. Moreover, the combination therapy Fen/D40 also exhibited a more pronounced enhancement of previous markers than either treatment alone. In conclusion, because of their antioxidant, anti-inflammatory, and anti-apoptotic properties, cotreatment with Fen or D or their combination could be beneficial in reducing the harmful impacts of cis on testicular tissue, particularly in patients that receive cis chemotherapy.

Crosstalk between xanthine oxidase (XO) inhibiting and cancer chemotherapeutic properties of comestible flavonoids- a comprehensive update

Gout is an inflammatory disease caused by metabolic disorder or genetic inheritance. People throughout the world are strongly dependent on ethnomedicine for the treatment of gout and some receive satisfactory curative treatment. The natural remedies as well as established drugs derived from natural sources or synthetically made exert their action by mechanisms that are closely associated with anticancer treatment mechanisms regarding inhibition of xanthine oxidase, feedback inhibition of de novo purine synthesis, depolymerization and disappearance of microtubule, inhibition of NF-ĸB activation, induction of TRAIL, promotion of apoptosis, and caspase activation and proteasome inhibition. Some anti-gout and anticancer novel compounds interact with same receptors for their action, e.g., colchicine and colchicine analogues. Dietary flavonoids, i.e., chrysin, kaempferol, quercetin, fisetin, pelargonidin, apigenin, luteolin, myricetin, isorhamnetin, phloretinetc etc. have comparable IC₅₀ values with established anti-gout drug and effective against both cancer and gout. Moreover, a noticeable number of newer anticancer compounds have already been isolated from plants that have been using by local traditional healers and herbal practitioners to treat gout. Therefore, the anti-gout plants might have greater potentiality to become selective candidates for screening of newer anticancer leads.

Diosmetin Affects Gene Expression on Human Lung Adenocarcinoma Cells

Objective

This study was aimed at investigating the effects of diosmetin (a natural flavonoid) on the gene expression of human lung adenocarcinoma (LUAD) cells.

Methods

HCC827 and A549 cells were used. MTT and colony formation assay were used to investigate the effects of diosmetin on cell proliferation and colony forming activity. The expression of mRNA, microRNA, and lncRNA in HCC827 and A549 cell lines after diosmetin treatment was measured using DNA microarray, microRNA chromatin immunoprecipitation assay (ChIP), and long noncoding RNA (lncRNA) ChIP. Part of the results were cross-validated by quantitative reverse transcription PCR (RT-qPCR), while some others were analyzed using bioinformatic tools.

Results

Diosmetin inhibited proliferation and colony formation of HCC827 and A549 cells. Investigation on gene expression profiles of A549 and HCC827 cells revealed that compared with the control group, diosmetin can up- or downregulated the expression of mRNAs, microRNAs, and lncRNAs. The top three candidates in each RNA category were cross-validated by RT-qPCR, from which single peaks were observed in the melt curves, showing a great specificity. After a comprehensive selection of the results from the mRNA ChIP, we performed GO and KEGG functional clustering analyses on the differentially expressed genes.

Conclusion

Diosmetin treatment induced gene expression of A549 and HCC827 cells. Our results will provide guidance for development of new diagnostic and therapeutic targets.

Qualitative and Quantitative Analysis of Phenolic Compounds in Spray-Dried Olive Mill Wastewater

The processing of olives for oil production generates the most abundant agro-industrial by-products in the Mediterranean area. The three-phase olive oil extraction process requires the addition of a large amount of water to the system, which is difficult to dispose of for its load of toxic pollutants. On the other hand, olive mill wastewater is a rich source of bioactive substances with various biological properties that can be used as ingredients in the food industry for obtaining functional and nutraceutical foods as well as in the pharmaceutical industry. In this study, we present the results relative to the phenolic compounds detected in dried olive mill wastewaters obtained using a spray dryer. Qualitative and quantitative analyses were obtained by high-pressure liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). In particular, the compounds here discussed are: apigenin (9.55 mg/kg dry weight), caffeic acid (2.89 mg/kg dry weight), catecol (6.12 mg/kg dry weight), p-cumaric acid (5.01 mg/kg dry weight), diosmetin (3.58 mg/kg dry weight), hydroxytyrosol (1.481 mg/kg dry weight), hydroxytyrosyl oleate (564 mg/kg dry weight), luteolin (62.38 mg/kg dry weight), luteolin-7-O-glucoside (88.55 mg/kg dry weight), luteolin-4-O-glucoside (11.48 mg/kg dry weight), oleuropein (103 mg/kg dry weight), rutin (48.52 mg/kg dry weight), tyrosol (2043 mg/kg dry weight), vanillin (27.70 mg/kg dry weight), and verbascoside (700 mg/kg dry weight). The results obtained highlighted that the use of dehumidified air as a drying medium, with the addition of maltodextrin, appears to be an effective way to produce a phenol-rich powder to be included in food formulations as well as in pharmaceutical preparations having different biological properties.

Anticancer Action of Xiaoxianxiong Tang in Non-Small Cell Lung Cancer by Pharmacological Analysis and Experimental Validation

Xiaoxianxiong Tang (XXXT) is a well-known traditional Chinese medicine formula. Evidence is emerging supporting the benefits of XXXT in ameliorating therapy for non-small cell lung cancer (NSCLC). The purpose of this study aimed to explore the effects and mechanisms of XXXT through network pharmacological analysis and biological validation. TCMSP database was used to identify potentially active compounds in XXXT with absorption, distribution, metabolism, excretion screening, and their potential targets. The disease targets related to NSCLC were predicted by searching for Therapeutic Target database, GeneCards database, DrugBank database, and DisGeNET database. Of the 4385 NSCLC-related targets, 156 targets were also the targets of compounds present in XXXT. Subsequently, GO function and KEGG pathway enrichment and PPI network analyses revealed that, of the 95 targets and 20 pathways influenced by 20 ingredients in XXXT, 20 targets were associated with patient survival, and XXXT could exert an inhibitory action on the PI3K-AKT signaling pathway. Moreover, XXXT restrained the proliferation of A549 and H460 cells in a concentration-dependent manner and suppressed the mRNA and protein levels of key targets CCNA2, FOSL2, and BIRC5 closely linked to the PI3K-AKT pathway. Hence, XXXT has the potential to improve therapy for NSCLC by targeting the PI3K-AKT signaling pathway.

Diosmetin induces apoptosis in ovarian cancer cells by activating reactive oxygen species and inhibiting the Nrf2 pathway

The fatality rate of ovarian cancer ranks first among gynecological tumors, and the prognosis is poor. Diosmetin (Dio), a natural flavonoid obtained from citrus fruits, has been shown to have anti-tumor effects in lung, liver, and skin cancers. We aimed to investigate the effects of Dio on ovarian cancer A2780 and SKOV3 cells along with the underlying mechanisms. Our data showed that Dio inhibited the proliferation, migration, and invasion of these cells and induced their apoptosis. Moreover, Dio upregulated the levels of Bax and cleaved Caspase-3 and PARP while downregulating the level of Bcl2. Mechanistically, our results revealed that Dio inhibited Nrf2 and induced the production of reactive oxygen species (ROS). The ROS scavenger N-acetyl-L-cysteine (NAC) suppressed the inhibitory effect of Dio on the proliferation of the ovarian cancer cells. Additionally, overexpression of Nrf2 partially suppressed the Dio-induced apoptosis and proliferation inhibition in these cells. These findings indicate that Dio exerts an anti-tumor activity by upregulating ROS levels and inhibiting Nrf2, indicating that Dio is a promising chemotherapeutic candidate for the treatment of ovarian cancer.

Novel Small Molecular Compound AE-848 Potently Induces Human Multiple Myeloma Cell Apoptosis by Modulating the NF-κB and PI3K/Akt/mTOR Signaling Pathways

Background

We aimed to investigate the anti-multiple myeloma (MM) activity of the new small molecular compound AE-848 (5-bromo-2-hydroxyisophthalaldehyde bis[(1-methyl-1H-benzimidazol-2-yl)hydrazone]) and its underlying anti-MM mechanism.

Methods

Cell viability and apoptosis were detected and quantified by using MTT and flow cytometry, respectively. JC-1 dye-related techniques were used to assess mitochondrial membrane potential (MMP). Western blotting was applied to detect the expression of NF-κB and PI3K/Akt/mTOR pathway-associated proteins. The in vivo activity of AE-848 against MM was evaluated in a MM mouse model.

Results

Application of AE-848 into the in vitro cell culture system significantly reduced the viability and induced apoptosis of the MM cell lines, RPMI-8226 and U266, in a dose- and time-dependent manner, respectively. JC-1 dye and Western blotting analysis revealed that AE-848 induced the cleavage of caspase-8, caspase-3, and poly ADP-ribose polymerase (PARP), resulting in loss of mitochondrial membrane potential (MMP). Both the NF-κB and PI3K/AKT/mTOR signaling pathways were involved in AE-848-induced apoptosis of U266 and RPMI8226 cells. Moreover, AE-848 leads to cell cycle arrest of MM cells. Its anti-MM efficacy was further confirmed in a xenograft model of MM. AE-848 administration significantly inhibited MM tumor progression and prolonged the survival of MM-bearing mice. More importantly, our results demonstrated that AE-848 markedly induced primary MM cell apoptosis.

Conclusion

Our results for the first time showed that the small compound AE-848 had potent in vitro and in vivo anti-myeloma activity, indicating that AE-848 may have great potential to be developed as a drug for MM treatment.

Diosmetin Induces Apoptosis by Downregulating AKT Phosphorylation via P53 Activation in Human Renal Carcinoma ACHN Cells

Background:

Diosmetin (DIOS) is the aglycone of the flavonoid glycoside, diosmin, derived naturally from the leaves of the legume, Olea europaea, and Acacia farnesiana. It has potent anticancer activity against multiple forms of cancers. However, the role of DIOS in renal carcinoma and its mechanism of action remain unclear.

Objective:

The purpose of this study is to investigate the effect of DIOS on cell viability and apoptosis in renal carcinoma cells and explore the possible mechanism of action.

Methods:

Cell viability, cytotoxicity, caspase activity, apoptosis, and expression of apoptotic related proteins were analyzed in renal carcinoma ACHN cells.

Results:

The results showed that DIOS inhibited the cell viability, and induced cytotoxicity and apoptosis in ACHN cells. Furthermore, DIOS increased expression of p53 mRNA and proteins, and downregulated phosphorylation of the phosphoinositide 3-kinase and protein B kinase (PI3K/AKT). In addition, it was observed that the anticancer effect of DIOS was significantly enhanced by the p53 activator, but inhibited by the p53 inhibitor.

Conclusion:

Our data suggested that DIOS induced apoptosis in renal carcinoma ACHN cells by reducing AKT phosphorylation through p53 upregulation.

Diosmetin enhances the sensitivity of radiotherapy by suppressing homologous recombination in endometrial cancer

Radiotherapy is an essential treatment for endometrial cancer (EC), especially in advanced, metastatic, and recurrent cases. Combining radiotherapy, which mainly causes DNA double-strand breaks (DSBs), with small molecules targeting aberrantly activated homologous recombination (HR) repair pathways holds great potential for treating ECs in advanced stages. Here, we demonstrate that diosmetin (DIO), a natural flavonoid, suppresses HR, therefore inhibiting cell proliferation and enhancing the sensitivity of EC to radiotherapy. Clonogenic experiments revealed that combining DIO and X-ray significantly inhibited the viability of EC cells compared to cells treated with diosmetin or X-ray alone. The survival fraction of EC cells decreased to 40% when combining 0.4 Gy X-ray and 4 μM DIO; however, each treatment alone only caused death in approximately 15% and 22% of cancer cells, respectively. Further mechanistic studies showed that diosmetin inhibited the recruitment of RPA2 and RAD51, two critical factors involved in the HR repair pathway, upon the occurrence of DSBs. Thus, we propose that a combination of diosmetin and irradiation is a promising therapeutic strategy for treating endometrial cancer.

Diosmetin exerts cardioprotective effect on myocardial ischaemia injury in neonatal rats by decreasing oxidative stress and myocardial apoptosis

Myocardial injury caused by the myocardial ischaemia (MI) is still a troublesome condition in the clinic, including apoptosis, oxidative stress and inflammation. Diosmetin inhibits the cellular apoptosis and inflammatory response and enhances antioxidant activity. So, this study was designed to investigate the cardioprotective effects of diosmetin on MI model neonatal rats. Forty Sprague Dawley (SD) rats 7 days old were randomly divided into five groups. Four groups of rats received diosmetin (50, 100, and 200 mg/kg) or vehicle (MI group) after ischaemia. Another group received vehicle without ischaemia to serve as a control group. Rats were pretreated with diosmetin intraperitoneally for 7 days and intoxicated with isoproterenol (ISO, 85 mg/kg, sc) on the last 2 days. The expression of apoptotic molecules, myocardial systolic function index, antioxidant enzymes and myocardial enzyme was analyzed. Compared with the control group, the proliferation marker proteins of Ki67 were increased significantly (P < .05), the MI group significantly increased the cardiac apoptosis, oxidative stress and myocardial enzymes, and weakened myocardial contractility. The levels of p‐P65/P65 were increased significantly (P < .05) with decreased p‐AKT/AKT and p‐Nrf2/Nrf2 (P < .05). Nevertheless, pretreatment with diosmetin reversed these changes, especially high‐dose group. In summary, diosmetin has significant potential as a therapeutic intervention to ameliorate myocardial injury after MI and provides the rationale for further clinical studies.

Citrus Flavones: An Update on Sources, Biological Functions, and Health Promoting Properties

Citrus spp. are among the most widespread plants cultivated worldwide and every year millions of tons of fruit, juices, or processed compounds are produced and consumed, representing one of the main sources of nutrients in human diet. Among these, the flavonoids play a key role in providing a wide range of health beneficial effects. Apigenin, diosmetin, luteolin, acacetin, chrysoeriol, and their respective glycosides, that occur in concentrations up to 60 mg/L, are the most common flavones found in Citrus fruits and juices. The unique characteristics of their basic skeleton and the nature and position of the substituents have attracted and stimulated vigorous investigations as a consequence of an enormous biological potential, that manifests itself as (among other properties) antioxidant, anti-inflammatory, antiviral, antimicrobial, and anticancer activities. This review analyzes the biochemical, pharmacological, and biological properties of Citrus flavones, emphasizing their occurrence in Citrus spp. fruits and juices, on their bioavailability, and their ability to modulate signal cascades and key metabolic enzymes both in vitro and in vivo. Electronic databases including PubMed, Scopus, Web of Science, and SciFinder were used to investigate recent published articles on Citrus spp. in terms of components and bioactivity potentials.

Diosmin induces caspase-dependent apoptosis in human glioblastoma cells

Diosmin is a flavone glycoside clinically used as the main component of Daflon for the treatment of venous diseases. Several studies demonstrated that this natural compound can induce apoptosis in different tumors. However, isolated diosmin has not been studied regarding its effects on glioblastoma so far. Since glioblastoma is a highly lethal and fast-growing brain tumor, new therapeutic strategies are urgently needed. Herein, we evaluated the role of this flavonoid against glioblastoma cells using in vitro assays. Diosmin significantly reduced the viability of GBM95, GBM02, and U87MG glioblastoma cells, but not of healthy human astrocytes, as verified by MTT assay. Vimentin immunostaining showed that diosmin induced morphological changes in GBM95 and GBM02 cells, making them smaller and more polygonal. Diosmin did not inhibit GBM95 and GBM02 cell proliferation, but it caused DNA fragmentation, as verified by the TUNEL assay, and increased cleaved caspase-3 expression in these cells. In summary, diosmin is able to induce caspase-dependent apoptosis specifically in tumor cells and, therefore, could be considered a promising therapeutic compound against glioblastoma.