Quercetin‐mediated regulation of signal transduction cascades and microRNAs: Natural weapon against cancer

Flavonoids as emerging notch signaling pathway modulators in cancer

Notch signaling is an evolutionary conserved pathway important for the developmental processes and implicated in the tumor formation. Notch signaling pathway (NSP) inhibitors have been tested in clinical trials alone or in combination with the chemotherapy but none got clinical approval due to severe toxicity in patients. Flavonoids inhibit NSP by inhibiting notch receptor cleavage and/or inhibiting transcriptional regulation by Notch intracellular domain (NICD). Interestingly, some flavonoids are reported to inhibit NSP by mediating the microRNA expression. NSP inhibitory flavonoid(s) in combination with standard therapy is might be an effective strategy in cancer treatment.

Sea buckthorn, its bioactive constituents, and mechanism of action: potential application in female reproduction

Sea buckthorn (Hippophae rhamnoides L.) is a flowering shrub, and its berries have been utilized for decades as a raw ingredient in cuisines and herbal remedies. This evidence-based study focuses on its key bioactive constituents, and mechanism of protective effects with a focus on female reproductive processes. Parts of the plant contain phenols, carotenoids (lycopene, carotene, lutein, and zeaxanthin), flavonoids (isorhamnetin, quercetin, glycosides, and kaempferol), tocopherols, sterols, polyunsaturated fatty acids, minerals, vitamins, omega 3, 6, 9 and rare omega 7 fatty acids etc. Key polyphenolic flavonoids such as isorhamnetin and quercetin are believed to be mainly responsible behind its health benefits (against cardiovascular diseases, metabolic syndrome, obesity etc.) through properties including anti-cancer, antioxidant, and anti-inflammatory activities. These sea buckthorn constituents appear to mediate healthy ovarian cell proliferation, death, and hormone release, as well as decrease ovarian cancer possibly through apoptosis, and hormonal (estrogen) release. Thus, sea buckthorn and its bioactive ingredients may have potential in the management of gynecological problems such as uterine inflammation, endometriosis, and easing symptoms of vulvovaginal atrophy in postmenopausal women (by targeting inflammatory cytokines and vascular endothelial growth factor - VEGF). Apigenin, myricetin, and luteolin have also been recommended as prospective ovarian cancer preventative and adjuvant therapy options as they can inhibit ovarian cancerogenesis by triggering apoptosis and halting the cell cycle in ovarian tumors. Furthermore, its oil (containing carotenoid, sterol, and hypericin) has been speculated as an alternative to estrogen replacement therapy for postmenopausal women particularly to improve vaginal epithelial integrity. However, it is uncertain whether steroid hormone receptors, reactive oxygen species (ROS), and inflammatory regulators are actually behind sea buckhorn's actions. Sea buckthorn, and its compounds' health promoting potential warrants further validation not just in vitro and in animal research, but also in clinical trials to identify and/or standardize optimal methods of delivery of biologically active molecules.

Phytochemical profile, antioxidant, antiproliferative, and enzyme inhibition-docking analyses of Salvia ekimiana Celep & Doğan

Salvia ekimiana Celep & Doğan is an endemic species of Turkey. To our knowledge, the number of studies on biological activities and phytochemical profiling of this plant is quite limited. Therefore, this study aimed to analyze its activities and phytochemical content in detail. The qualitative-quantitative compositions were determined via spectrophotometric and chromatographic (LC-MS/MS and HPLC) techniques. 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH^•) and 2,2'-Azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS^•+) radical scavenging and ascorbate-iron (III)-catalyzed phospholipid peroxidation experiments were performed to measure antioxidant capacity. Hyaluronidase, collagenase, and elastase enzyme inhibition tests were determined in vitro using a spectrophotometer. Antiproliferative activity was evaluated in human lung cancer (A549) and human breast cancer (MCF7) cells. The murine fibroblast (L929) cell line was used as a normal control cell. While the subextract rich in phenolic compounds was n-butanol extract, rosmarinic acid was defined as the main secondary metabolite. The highest antioxidant activity observed for the n-butanol subextract included the following: DPPH^• EC50: 0.08±0.00 mg/mL, TEAC/ABTS: 2.19±0.09 mmol/L Trolox, MDA EC50: 0.42±0.03 mg/mL. The methanolic extract, the ethyl acetate, and n-butanol subextracts displayed significant inhibitory activity on collagenase, while the other subextracts did not show any inhibitory activity on hyaluronidase and elastase. Due to strong interactions with their active sites, molecular docking showed luteolin 7-glucuronide, apigenin 7-glucuronide, and luteolin 5-glucoside had the highest binding affinity with target enzymes. The chloroform subextract showed significant cytotoxicity in all cell lines. These novel results revealed that S. ekimiana has strong antioxidant, collagenase enzyme inhibitory, and cytotoxic potential.

Riddle of the Sphinx: Emerging Role of Transfer RNAs in Human Cancer

The dysregulation of transfer RNA (tRNA) expression contributes to the diversity of proteomics, heterogeneity of cell populations, and instability of the genome, which may be related to human cancer susceptibility. However, the relationship between tRNA dysregulation and cancer susceptibility remains elusive because the landscape of cancer-associated tRNAs has not been portrayed yet. Furthermore, the molecular mechanisms of tRNAs involved in tumorigenesis and cancer progression have not been systematically understood. In this review, we detail current knowledge of cancer-related tRNAs and comprehensively summarize the basic characteristics and functions of these tRNAs, with a special focus on their role and involvement in human cancer. This review bridges the gap between tRNAs and cancer and broadens our understanding of their relationship, thus providing new insights and strategies to improve the potential clinical applications of tRNAs for cancer diagnosis and therapy.

In vitro pharmacological screening of antioxidant, cytotoxic and enzyme inhibitory activities of Citrus aurantifolia Linn. Dried fruit extract

The Lime Basra (Citrus aurantifolia Linn., Rutaceae) plant also known as dried lime, and Limoo Omani, is used both as a spice in meals and as an herbal tea in the treatment of some diseases in the Middle East. It was aimed to determine the biological activity screening of the 70% methanol, ethanol extracts and infusion which were prepared from dried fruits. 1,1-diphenyl-2-picrylhydrazyl (DPPH^●) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS+^●) radical scavenging activities, ferric reducing activity, cytotoxicity on A 549, MCF 7 and L929 cell lines and α-amylase inhibitory effects were determined. According to the results, 70% methanol extract was more active in antioxidant activity tests and ethanol extract was more active in cytotoxicity tests. Interestingly both 70% methanol and ethanol extracts were found to have potent hypoglycemic activity. The present findings shed light on the fact that it is important to research and scientifically evaluate plants with traditional medicinal use.

The modulatory properties of Astragalus membranaceus treatment on endometrial cancer: an integrated pharmacological method

Astragalus membranaceus is a traditional Chinese medicine and has been used for adjuvant clinical therapy for a variety of cancers. However, the mechanism of its action on endometrial carcinoma is unclear. Based on the Gene Expression Omnibus (GEO) database, the Cancer Genome Atlas (TCGA) database, and the Traditional Chinese Medicine System Pharmacology Database (TCMSP™), the drug and target compounds were initially screened to construct a common network module. Twenty active compounds in Astragalus membranaceus were successfully identified, which hit by 463 potential targets related to endometrial cancer. Eight of the more highly predictive compounds (such as Jaranol, Bifendate, Isorhamnetin, Calycosin, 7-O-methylisomucronulatol, Formononetin, Kaempferol, Quercetin) were involved in DNA integrity checkpoint, cyclin-dependent protein kinase holoenzyme complex, and histone kinase activity. Additionally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway confirmed that Astragalus membranaceus might play a role in the treatment of endometrial cancer through p53 signalling pathway, transcriptional misregulation in cancer, and endometrial cancer signalling pathway. Drug-target-pathway networks were constructed using Cytoscape to provide a visual perspective. In addition, we verified that formononetin inhibited the proliferation of endometrial cancer cells through cell viability tests and clone formation tests. And qPCR and western blot found that formononetin exerts anti-cancer effects by promoting the expression of estrogen receptor beta (ERβ) and p53. Based on a systematic network pharmacology approach, our works successfully predict the active ingredients and potential targets of Astragalus membranaceus for application to endometrial cancer and helps to illustrate mechanism of action on a comprehensive level.

Polyphenols as adjunctive treatments in psychiatric and neurodegenerative disorders: Efficacy, mechanisms of action, and factors influencing inter-individual response

The pathophysiology of psychiatric and neurodegenerative disorders is complex and multifactorial. Polyphenols possess a range of potentially beneficial mechanisms of action that relate to the implicated pathways in psychiatric and neurodegenerative disorders. The aim of this review is to highlight the emerging clinical trial and preclinical efficacy data regarding the role of polyphenols in mental and brain health, elucidate novel mechanisms of action including the gut microbiome and gene expression, and discuss the factors that may be responsible for the mixed clinical results; namely, the role of interindividual differences in treatment response and the potentially pro-oxidant effects of some polyphenols. Further clarification as part of larger, well conducted randomized controlled trials that incorporate precision medicine methods are required to inform clinical efficacy and optimal dosing regimens.

Realizing the Potential of Blueberry as Natural Inhibitor of Metastasis and Powerful Apoptosis Inducer: Tapping the Treasure Trove for Effective Regulation of Cell Signaling Pathways

Blueberries belong to the genus Vaccinium of the family Ericaceae. Rapidly accumulating experimentally verified data is uncovering the tremendous pharmacological properties of biologically active constituents of blueberries against different diseases. Our rapidly evolving knowledge about the multifaceted nature of cancer has opened new horizons to search for different strategies to target multiple effectors of oncogenic networks to effectively inhibit cancer onset and progression. Excitingly, whole blueberry powder and various bioactive constituents (pterostilbene, malvidin-3-galactoside) of blueberries have been shown to efficiently inhibit metastasis in animal models. These results are encouraging and future studies must focus on the identification of cell signaling pathways effectively modulated by blueberries in different cancers. It seems exciting to note that researchers are focusing on metastasis inhibitory effects of blueberry; however, to reap full benefits, it is necessary to take a step back and critically re-interpret the mechanisms used by active components of blueberry to inhibit or prevent metastasis. JAK/STAT, TGF/SMAD, Notch, SHH/GLI, and Wnt/ β-Catenin have been shown to be directly involved in the regulation of metastasis. However, because of limited studies, it is difficult to critically assess the true potential of blueberry. Loss of apoptosis, metastasis and deregulation of signaling pathways are branching trajectories of molecular oncology. Accordingly, we have to emphasize on these essential facets to realistically claim blueberry as "Superfood". Different clinical trials have been conducted to gather clinical evidence about the chemopreventive role of blueberry or its bioactive components in cancer patients. But it seems clear that because of the lack of sufficient proof-of-concept studies, we cannot extract significant information about the transition of blueberry into the next phases of clinical trials. Overview of the existing scientific evidence revealed visible knowledge gaps and a better understanding of the targets of blueberry will be helpful in efficient and meaningful translation of laboratory findings to clinically effective therapeutics.

Quercetin and MicroRNA Interplay in Apoptosis Regulation in Ovarian Cancer

The multifaceted nature of ovarian cancer has severely hampered the development of effective therapeutics over the years. The complicate nature of ovarian cancer makes it therapeutically challenging, therefore, there has been a renewed interest in phytochemistry. Phytochemicals have emerged as a potential therapeutic option due to less side effects. Moreover, the signaling inhibition properties have also been studied extensively in recent times. A growing number of data obtained via high-throughput technologies has started to delineate the complex oncogenic signaling networks, thus broadening the therapeutic opportunities. Within the network, microRNAs (miRNAs) have been shown to play a versatile role in the regulation of cancer. Quercetin has been in the spotlight over the years because of its high pharmacological values and substantial evidence has demonstrated its anti-proliferative effect against various types of cancers. Despite the versatility of quercetin, little is known about its anti-proliferative potential towards ovarian cancer. This review sheds some light on quercetin as an alternative therapeutic approach to cancer. Furthermore, we also addresss the interplay between miRNAs and quercetin in the regulation of apoptosis in ovarian cancer.

Concise review: Coarse cereals exert multiple beneficial effects on human health

Coarse cereals (CC) refer to cereal grains except for rice and wheat which are highly-valued as functional foods with nutritional and pharmacological properties. Owing to their diverse positive effect on chronic diseases, coarse cereals exert a vital role in food industry. CC and the main contents prevent tumor pathogenesis through promoting apoptosis, inducing cell cycle arrest as well as modulating metastasis initiation. Meanwhile, CC ameliorates cardiovascular diseases through affecting multiple pathways, such as CaMKII/p-BFAF-3, NF-κB, MAPK, PI3K/Akt, etc. Besides, CC and the main contents have potential as prebiotics which facilitating the activities and growth of probiotics such as Bifidobacteria and Lactobacillus. However, there's a lack of report on CC' beneficial properties and the underlying mechanisms are not fully understood. Here this article explains in detail, the effect and mechanism of CC on chronic diseases like tumor, inflammation and cardiovascular diseases.

Quercetin inhibits human microvascular endothelial cells viability, migration and tube-formation in vitro through restraining microRNA-216a

Background: Quercetin belongs to the flavonoids family, which has been proven to have extensive pharmacological effects. Nevertheless, the function of quercetin in peripheral arterial disease (PAD) has not yet been reported. In the research, we purposed to disclose the effectiveness of quercetin in the pathogenesis of PAD.Methods: HMEC-1 cells were cultivated in Matrigel for 24 h to observe the tube-formation. Detections of cell viability, migration and apoptosis were through implementing CCK-8, Transwell and flow cytometry methods. Western blot was utilised for measuring angiogenesis-, migration- and apoptosis-correlative factors. MiR-216a expression was examined via qRT-PCR, and its functions in HMEC-1 cells were uncovered after miR-216a mimic transfection. Assessment of JAK2/STAT3 and PI3K/AKT pathways was via implementing western blot.Results: HMEC-1 cells were spontaneously vascularised under Matrigel condition. Quercetin predominantly repressed cell viability, migration, VEGF expression and facilitated apoptosis in HMEC-1 cells. Additionally, suppression of miR-216a was discovered in HMEC-1 cells after quercetin stimulation, meanwhile miR-216a overexpression annulled the functions of quercetin in HMEC-1 cells. Besides, quercetin deactivated PI3K/AKT and JAK/STAT pathways through adjusting miR-216a.Conclusion: The above-mentioned consequences exhibited that quercetin suppressed HMEC-1 cell viability, migration and tube-formation through hindering JAK2/STAT3 and PI3K/AKT pathway via declination of miR-216a.

Effects of quercetin on microRNAs: A mechanistic review

MicroRNA (miRNA)-dependent pathways are one of the newest gene regulation mechanisms in various diseases, particularly in cancers. miRNAs are endogenous noncoding RNAs with about 18 to 25 nucleotide length, which can regulate the expression of at least 60% of human total genome posttranscriptionally. Quercetin is the most abundant flavonoid in a variety of fruits, flowers, and medical herbs, known as a strong free radical scavenger that could show antioxidant, anti-inflammatory, and antitumor activities. Recent studies also reported its strong impact on various miRNA expressions in different abnormalities. In this review, we aimed to summarize the studies focused on the effects of quercetin on different miRNA expressions to more clear the main possible mechanisms of quercetin influences and introduce it as a beneficial agent for regulation of miRNAs in various biological directions.