Cell death triggered by synthetic flavonoids in human leukemia cells is amplified by the inhibition of extracellular signal-regulated kinase signaling

Recent Development of Flavonoids with Various Activities

Flavonoids, a series of compounds with C6-C3-C6 structure, mostly originate from plant metabolism. Flavonoids have shown beneficial effects on many aspects of human physiology and health. Recently, many flavonoids with various activities have been discovered, which has led to more and more studies focusing on their physiological and pharmacodynamic activities. The anti-cancer and anti-viral activities especially have attracted the attention of many researchers. Therefore, the discovery and development of flavonoids as anti-disease drugs has great potential and may make significant contribution to fighting diseases. This review focus on the discovery and development of flavonoids in medicinal chemistry in recent years.

Wikstroemiaganpi Extract Improved Atopic Dermatitis-Like Skin Lesions via Suppression of Interleukin-4 in 2,4-Dinitrochlorobenzene-Induced SKH-1 Hairless Mice

Plants of the genus Wikstroemia are used in Chinese traditional medicine to treat inflammatory diseases, such as arthritis, bronchitis, and pneumonia. The present study was designed to determine whether Wikstroemia ganpi (Siebold and Zucc.) Maxim. offers a potential means of treating 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD) in mice. Symptoms such as redness, edema, and keratinization in AD mice induced by DNCB were alleviated by the co-application of an ethanolic extract of W. ganpi for 2 weeks. The severity of skin barrier function damage was evaluated by measuring TEWL (transepidermal water loss). TEWLs of DNCB sensitized mouse dorsal skin were reduced by the application of a W. ganpi ethanolic extract, and skin hydration was increased. In addition, the infiltration of inflammatory cells into the dermis was significantly reduced, as were blood levels of IgE and IL-4, which play an important role in the expression of AD. The results of this experiment suggest that W. ganpi is a potential therapeutic agent for AD.

Activation of Caspase-3 by Terpenoids and Flavonoids in Different Types of Cancer Cells

BACKGROUND

Caspase-3 is accountable for the execution of apoptosis. Recently, it has gained attention as a promising target for the discovery of natural products as anticancer agents.

METHODS

We examined the efficacy of two different sets of natural products (terpenoids and flavonoids) towards caspase-3 activity adopting in silico, cell-free and cell-based activity and real-time gene expression analysis.

RESULTS

It was observed that terpenes activate caspase-3 activity in both the cell-free and cell-based systems, which was supported by the gene expression analysis, binding energy and activation constant. Flavonoids' action, however, was limited to the cell-based system and transcriptional regulation suggesting their indirect association, which enhanced the enzyme activity and up-regulated the expression of mRNA levels in the cells. Among the tested natural products, (+) carvone was observed to be the best activator of caspase-3 in K562 (34.4 μM), WRL-68 (22.3 μM), HeLa (18.7 μM), MCF-7 (39.4 μM) and MDA-MB-231 cell lines (45.1 μM).

CONCLUSION

Overall, terpenoids have a persistent activation of caspase-3 in all the investigated systems, while flavonoids circuitously affect the enzyme activity.

Natural and Synthetic Flavonoids: Structure-Activity Relationship and Chemotherapeutic Potential for the Treatment of Leukemia

Flavonoids and their derivatives are polyphenolic secondary metabolites with an extensive spectrum of pharmacological activities, including antioxidants, antitumor, anti-inflammatory, and antiviral activities. These flavonoids can also act as chemopreventive agents by their interaction with different proteins and can play a vital role in chemotherapy, suggesting a positive correlation between a lower risk of cancer and a flavonoid-rich diet. These agents interfere with the main hallmarks of cancer by various individual mechanisms, such as inhibition of cell growth and proliferation by arresting the cell cycle, induction of apoptosis and differentiation, or a combination of these mechanisms. This review is an effort to highlight the therapeutic potential of natural and synthetic flavonoids as anticancer agents in leukemia treatment with respect to the structure-activity relationship (SAR) and their molecular mechanisms. Induction of cell death mechanisms, production of reactive oxygen species, and drug resistance mechanisms, including p-glycoprotein efflux, are among the best-described effects triggered by the flavonoid polyphenol family.

Design, synthesis and antiproliferative activity of novel heterobivalent hybrids based on imidazo[2,1-b][1,3,4]thiadiazole and imidazo[2,1-b][1,3]thiazole scaffolds

Heterobivalent ligands constituted by two different pharmacophores that bind to different molecular targets or to two distinct sites on the same molecular target could be one of the methods used for the treatment of cancer. In view of the importance of imidazo[1,2-b][1,3]thiazole and imidazo[1,2-b][1,3,4]thiadiazole as privileged structures for the preparation of novel anticancer agents, we decided to explore the synthesis and biological evaluation of molecular conjugates comprising these fused bicyclic systems tethered at their C-6 position by a meta-(α-bromoacryloylamido)phenyl moiety. We found that most of the hybrid compounds displayed high antiproliferative activity toward a wide panel of cancer cell lines, with one-digit micromolar to submicromolar 50% inhibitory concentrations (IC50). We have observed that selected compounds 7d, 7e, 7n and 8c induced apoptosis, which was associated with the release of cytochrome c and cleavage of multiple caspases. Overexpression of the protective mitochondrial protein Bcl-2 did not confer protection to cell death induced by these compounds.

Properties and applications of flavonoid metal complexes

Flavonoid metal complexes have a wide spectrum of activities as well as potential and actual applications.

Synthesis and anticancer activities of 3-arylflavone-8-acetic acid derivatives

This paper describes the synthesis and the antiproliferative activities of compounds 9a-r, 3-aryl analogs of flavone-8-acetic acid that bear diverse substituents on the benzene rings at the 2- and 3-positions of the flavone nucleus. Their direct and indirect cytotoxicities were evaluated against HT-29 human colon adenocarcinoma cell lines, A549 lung adenocarcinoma cell lines and Human Peripheral Blood Mononuclear Cells (HPBMCs). The results indicate that most of the compounds bearing electron-withdrawing substituents (9b-m) exhibited moderate direct cytotoxicities. And compounds 9e and 9i showed comparable indirect cytotoxicities with 5, 6-dimethylxanthenone-4-acetic acid (DMXAA), and low direct cytotoxicities toward HPBMCs. Interestingly, the compounds 9n-r bearing methoxy groups at the 2- or 3-position of the flavone nucleus exhibited higher indirect cytotoxicities against A549 cell lines than DMXAA, and lower cytotoxicities against HPBMCs. In addition, compounds 9p-r were found to be able to induce tumor necrosis factor α (TNF-α) production in HPBMCs.