다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Resveratrol, a phytoalexin found in grapes and other food products, was purified and shown to have cancer chemopreventive activity in assays representing three major stages of carcinogenesis. Resveratrol was found to act as an antioxidant and antimutagen and to induce phase II drug-metabolizing enzymes (anti-initiation activity); it mediated anti-inflammatory effects and inhibited cyclooxygenase and hydroperoxidase functions (antipromotion activity); and it induced human promyelocytic leukemia cell differentiation (antiprogression activity). In addition, it inhibited the development of preneoplastic lesions in carcinogen-treated mouse mammary glands in culture and inhibited tumorigenesis in a mouse skin cancer model. These data suggest that resveratrol, a common constituent of the human diet, merits investigation as a potential cancer chemopreventive agent in humans.

https://science.sciencemag.org/content/sci/275/5297/218.full.pdf

Cancer Chemopreventive Activity of Resveratrol, a Natural Product Derived from Grapes

Flavonoids are nearly ubiquitous in plants and are recognized as the pigments responsible for the colors of leaves, especially in autumn. They are rich in seeds, citrus fruits, olive oil, tea, and red wine. They are low molecular weight compounds composed of a three-ring structure with various substitutions. This basic structure is shared by tocopherols (vitamin E). Flavonoids can be subdivided according to the presence of an oxy group at position 4, a double bond between carbon atoms 2 and 3, or a hydroxyl group in position 3 of the C (middle) ring. These characteristics appear to also be required for best activity, especially antioxidant and antiproliferative, in the systems studied. The particular hydroxylation pattern of the B ring of the flavonoles increases their activities, especially in inhibition of mast cell secretion. Certain plants and spices containing flavonoids have been used for thousands of years in traditional Eastern medicine. In spite of the voluminous literature available, however, Western medicine has not yet used flavonoids therapeutically, even though their safety record is exceptional. Suggestions are made where such possibilities may be worth pursuing.

The Effects of Plant Flavonoids on Mammalian Cells:Implications for Inflammation, Heart Disease, and Cancer

https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

Curcumin (diferuloylmethane) is a polyphenol derived from the plant Curcuma longa, commonly called turmeric. Extensive research over the last 50 years has indicated this polyphenol can both prevent and treat cancer. The anticancer potential of curcumin stems from its ability to suppress proliferation of a wide variety of tumor cells, down-regulate transcription factors NF- κB, AP-1 and Egr-1; down-regulate the expression of COX2, LOX, NOS, MMP-9, uPA, TNF, chemokines, cell surface adhesion molecules and cyclin D1; down-regulate growth factor receptors (such as EGFR and HER2); and inhibit the activity of c-Jun N-terminal kinase, protein tyrosine kinases and protein serine/threonine kinases. In several systems, curcumin has been described as a potent antioxidant and anti-inflammatory agent. Evidence has also been presented to suggest that curcumin can suppress tumor initiation, promotion and metastasis. Pharmacologically, curcumin has been found to be safe. Human clinical trials indicated no dose-limiting toxicity when administered at doses up to 10 g/day. All of these studies suggest that curcumin has enormous potential in the prevention and therapy of cancer. The current review describes in detail the data supporting these studies. Curcumin, derived from turmeric (vernacular name: Haldi), is a rhizome of the plant Curcuma longa. The medicinal use of this plant has been documented in Ayurveda (the Indian

Anticancer potential of curcumin: preclinical and clinical studies.

Since reactive oxygen radicals play an important role in carcinogenesis and other human disease states, antioxidants present in consumable fruits, vegetables, and beverages have received considerable attention as cancer chemopreventive agents Thus, in order to identify antioxidants in plant extracts, test materials were assessed for potential to scavenge stable 1,2-diphenyl-2-picrylhydrazyl (DPPH) free radicals, reduce TPA-induced free radical formation in cultured HL-60 human leukemia cells, and inhibit responses observed with a xanthine/xanthine oxidase assay system Approximately 700 plant extracts were evaluated, and 28 were found to be active in the DPPH free radical scavenging assay Based on secondary analyses performed to assess inhibition of 7,12-dimethylbenz(a)anthracene-induced preneoplastic lesion formation with a mouse mammary organ culture model, Chorizanthe diffusa Benth (Polygonaceae), Mezoneuron cucullatum Roxb (Leguminosae), Cerbera manghas L (Apocynaceae) and Daphniphyllum calycinum Benth (Daphniphyllaceae) were selected and subjected to bioassay-guided fractionation 5,7,3',5'-Tetrahydroxy-8,4'-dimethoxyflavonol, 5,8,4'-trihydroxy-7,3'-dimethoxyflavonol, 5,3',4'-trihydroxy-7-methoxyflavonol, and 6,3',4'-trihydroxy-7-methoxyflavonol were identified as active principles from C diffusa Piceatannol, trans-resveratrol, apigenin and scirpusin A were found as the active principles of M cucullatum, olivil, (-)-carinol, and (+)-cycloolivil were active principles from C manghas, and 5,6,7,4'-tetrahydroxyflavone 3-O-rutinoside and kaempferol 3-O-neohesperidoside were active principles from D calycinum Of these substances, the hydroxystilbenes piceatannol and transresveratrol have thus far been shown to inhibit carcinogen-induced preneoplastic lesion formation in the mouse mammary gland organ culture model

Evaluation of the antioxidant potential of natural products.

Circular RNAs (circRNAs) are a class of single-stranded closed RNA molecules that are formed by precursor mRNA back-splicing or skipping events of thousands of genes in eukaryotes as covalently closed continuous loops. High-throughput sequencing and bioinformatics approaches have uncovered the broad expression of circRNAs across species. Their high stability, abundance, and evolutionary conservation among species points to their distinct properties and diverse cellular functions as efficient microRNAs and protein sponges; they also play important roles in modulating transcription and splicing. Additionally, most circRNAs are aberrantly expressed in pathological conditions and in a tissue-specific manner such as development and progression of cancer. Herein, we highlight the characteristics, functions, and mechanisms of action of circRNAs in cancer; we also provide an overview of recent progress in the circRNA field and future application of circRNAs as cancer biomarkers and novel therapeutic targets.

Circular RNAs in Cancer

Evaluation of natural products on inhibition of inducible cyclooxygenase (COX-2) and nitric oxide synthase (iNOS) in cultured mouse macrophage cells.

Eugenol suppresses cyclooxygenase-2 expression in lipopolysaccharide-stimulated mouse macrophage RAW264.7 cells

Chemotherapy, one of the principal approaches for cancer patients, plays a crucial role in controlling tumor progression. Clinically, tumors reveal a satisfactory response following the first exposure to the chemotherapeutic drugs in treatment. However, most tumors sooner or later become resistant to even chemically unrelated anticancer agents after repeated treatment. The reduced drug accumulation in tumor cells is considered one of the significant mechanisms by decreasing drug permeability and/or increasing active efflux (pumping out) of the drugs across the cell membrane. The mechanisms of treatment failure of chemotherapeutic drugs have been investigated, including drug efflux, which is mediated by extracellular vesicles (EVs). Exosomes, a subset of EVs with a size range of 40-150 nm and a lipid bilayer membrane, can be released by all cell types. They mediate specific cell-to-cell interactions and activate signaling pathways in cells they either fuse with or interact with, including cancer cells. Exosomal RNAs are heterogeneous in size but enriched in small RNAs, such as miRNAs. In the primary tumor microenvironment, cancer-secreted exosomes and miRNAs can be internalized by other cell types. MiRNAs loaded in these exosomes might be transferred to recipient niche cells to exert genome-wide regulation of gene expression. How exosomal miRNAs contribute to the development of drug resistance in the context of the tumor microenvironment has not been fully described. In this review, we will highlight recent studies regarding EV-mediated microRNA delivery in formatting drug resistance. We also suggest the use of EVs as an advancing method in antiresistance treatment.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/ijc.30669

Sang Kook Lee

Papers

Evaluation of the antioxidant potential of natural products.

Circular RNAs in Cancer

Evaluation of natural products on inhibition of inducible cyclooxygenase (COX-2) and nitric oxide synthase (iNOS) in cultured mouse macrophage cells.

Eugenol suppresses cyclooxygenase-2 expression in lipopolysaccharide-stimulated mouse macrophage RAW264.7 cells

The role of exosomes and miRNAs in drug-resistance of cancer cells.