Methylenedioxy flavonoids: assessment of cytotoxic and anti-cancer potential in human leukemia cells

Anti-Cancer Activity of Synthesized 5-Benzyl juglone on Selected Human Cancer Cell Lines

BACKGROUND

Cancer is a malignant disease that causes millions of deaths each year worldwide. As one of the cancer therapeutic strategies, chemotherapy is a means to destroy rapidly dividing cells. The main problem with cancer chemotherapy is the lack of selectivity of conventional chemotherapeutic drugs, leading to toxicity towards normal cells. Therefore, the discovery of anti-cancer agents with selectivity for fast-growing cancer cells is desirable.

OBJECTIVE

In this study, we report the synthesis and identification of synthesized 5-benzyl juglone as a potential anticancer agent with selectivity toward certain cancer cell lines.

METHODS

An efficient synthetic method for 5-benzyl juglone was established. The proliferation of cancer cell lines and a normal cell line treated by the target compound was studied using an MTT assay. In addition, the cell cycle arrest and apoptosis were determined by flow cytometry.

RESULTS

Based on the Diels-Alder (D-A) reaction between 3,6-dimethoxy benzyne intermediate and furan, further acid-catalyzed intramolecular rearrangement, and CAN-mediated oxidation, a convenient synthesis of 5-benzyl juglone was achieved with high overall yield. The results from in vitro biological evaluation indicated that the juglone derivative exhibited potent antiproliferative activity against HCT-15 human colorectal cancer cells with an IC50 value of 12.27 μM. It exerted high inhibitory activity toward MCF-7 human breast cancer cells and, to a much lesser extent, to corresponding MCF-10A human breast epithelial normal cells with an IC50 ratio (IC50 in MCF-7 divided by IC50 in MCF-10A) of 0.62.

CONCLUSION

The mechanistic investigations indicated that 5-benzyl juglone could induce cell cycle arrest at the G0/G1 phase and promote apoptosis of HCT-15 cells. The apoptotic effects possibly contributed to its higher selectivity toward cancer cells than normal cell lines.

Phytochemicals Derived from Goniothalamus elegans Ast Exhibit Anticancer Activity by Inhibiting Epidermal Growth Factor Receptor

Cancer is a major health burden and a leading cause of death worldwide, with numerous new molecules being studied and developed as therapeutic agents. In this study, the cytotoxicity of compounds derived from Goniothalamus elegans was evaluated for possible anticancer activity. It was observed that the crude methanol extract of G. elegans exerted the strongest cytotoxic activity against SW-480, AGS, and SK-LU-1 cell lines. In addition, two isolated alkaloids—namely, lysicamine and liriodenine—also showed strong inhibitory ability against similar cancer cell lines. To further investigate the compounds’ mechanism of action, a molecular docking approach was utilized to evaluate the potential of the two candidates to interact with the epidermal growth factor receptor. This assay estimated that lysicamine and liriodenine acquired protein binding affinities of −8.8 and −9.7 kcal/mol, respectively. Finally, the stabilities of the ligand–protein complexes were evaluated using molecular dynamics simulations of 100 ns each.

Chromanone-A Prerogative Therapeutic Scaffold: An Overview

Chromanone or Chroman-4-one is the most important and interesting heterobicyclic compound and acts as a building block in medicinal chemistry for isolation, designing and synthesis of novel lead compounds. Structurally, absence of a double bond in chromanone between C-2 and C-3 shows a minor difference from chromone but exhibits significant variations in biological activities. In the present review, various studies published on synthesis, pharmacological evaluation on chroman-4-one analogues are addressed to signify the importance of chromanone as a versatile scaffold exhibiting a wide range of pharmacological activities. But, due to poor yield in the case of chemical synthesis and expensive isolation procedure from natural compounds, more studies are required to provide the most effective and cost-effective methods to synthesize novel chromanone analogs to give leads to chemistry community. Considering the versatility of chromanone, this review is designed to impart comprehensive, critical and authoritative information about chromanone template in drug designing and development.

Pathways Related to the Anti-Cancer Effects of Metabolites Derived from Cerrado Biome Native Plants: An Update and Bioinformatics Analysis on Oral Squamous Cell Carcinoma

BACKGROUND

Oral cancer is a significant health problem worldwide. Oral squamous cell carcinoma (OSCC) is a malignant neoplasm of epithelial cells that mostly affects different anatomical sites in the head and neck and derives from the squamous epithelium or displays similar morphological characteristics. Generally, OSCC is often the end stage of several changes in the stratified squamous epithelium, which begin as epithelial dysplasia and progress by breaking the basement membrane and invading adjacent tissues. Several plant-based drugs with potent anti-cancer effects are considered inexpensive treatments with limited side effects for cancer and other diseases.

OBJECTIVE

The aim of this review is to explore whether some Brazilian plant extracts or constituents exhibit anti-tumorigenic activity or have a cytotoxic effect on human oral carcinoma cells.

METHODS

Briefly, OSCC and several metabolites derived from Brazilian plants (i.e., flavonoids, vinblastine, irinotecan, etoposide and paclitaxel) were used as keywords to search the literature on PubMed, GenBank and GeneCards.

RESULTS

The results showed that these five chemical compounds found in Cerrado Biome plants exhibit anti-neoplastic effects. Evaluating the compounds revealed that they play a main role in the regulation of cell proliferation.

CONCLUSION

Preserving and utilising the biodiversity of our planet, especially in unique ecosystems, such as the Cerrado Biome, may prove essential to preserving and promoting human health in modern contexts.

Novel Polymethoxylated Chalcones as Potential Compounds Against KRAS-Mutant Colorectal Cancers

BACKGROUND/OBJECTIVE

KRAS-mutant colorectal cancers (CRC) are tumors that are associated with poor prognosis. However, no effective treatments are available to target them. Therefore, we designed and synthesized novel chalcone analogs, small organic molecules, to investigate their effects on KRAS-mutant CRC cells.

METHODS

Fourteen new chalcone analogs were synthesized, optimized, characterized, and tested against two KRAS-mutant CRC cell lines (HCT-116 and LoVo), one p-53 and BRAF mutant CRC cell line (HT-29) and one normal immortalized colon cells (NCE-1 E6/E7). Effects on cell viability, apoptosis, cell cycle, migration, colony formation, EMT, and angiogenesis were investigated.

RESULTS

Compounds 3 and 14 were the most effective. Compound 3 showed potent activity against HCT-116 and LoVo cell lines (GI50 of 6.10 μM and 7.00 μM, respectively). While compound 14 showed GI50 of 8.60 μM and 8.80 μM on HCT-116 and LoVo cell lines, respectively. Both compounds were approximately 2-3 times more selective toward cancer cells rather than normal colon cells. Compound 3 was effective in inducing apoptosis in HCT-116 cells via Bax upregulation and Bcl-2 downregulation. Invasion and metastasis of KRAS-mutant cells were modulated by compounds 3 and 14 through significant inhibition of cell migration and the prevention of colony formation. In addition, they reversed EMT by downregulation of EMT markers (vimentin, fascin, and β- catenin) and upregulation of cell-cell adhesion marker, E-cadherin. Furthermore, compounds 3 and 14 had significantly inhibited angiogenesis in ovo.

CONCLUSION

Compounds 3 and 14 represent potent and selective leads for KRAS-mutant CRC cells, thus, further in vitro and in vivo studies are necessary to confirm their effect on KRAS-mutant CRCs.

Aldehyde biphenyl chalcones induce immunogenic apoptotic-like cell death and are promising new safe compounds against a wide range of hematologic cancers

Aim: Investigate the apoptotic mechanisms of two new aldehyde biphenyl chalcones on leukemia cells. Materials & methods: From a series of 71 new chalcones, we selected the two most cytotoxic. Results: JA3 and JA7 were cytotoxic not only against hematological malignancies but also against solid tumor and cancer stem cells, yet with no toxicity to normal cells. Moreover, they induced immunogenic apoptotic-like cell death independently of promyelocytic leukemia protein, with extensive mitochondrial damages downstream of endoplasmic reticulum stress. Preventing endoplasmic reticulum stress and the upregulation of proapoptotic machinery inhibited JA3- and JA7-induced cell death. Likewise, blocking receptor Fas protected cells from killing. They increased the antileukemic effect of cytarabine and vincristine and killed leukemic cells collected from patients with different acute leukemia subtypes. Conclusion: JA3 and JA7 represent new promising prototypes for the development of new chemotherapeutics.

Synthesis of chromones, annulated with oxygen-containing heterocycles with two hetero atoms at C(7)-C(8) bond

The present review represented the advanced synthetic strategies for chromones annulated at the C(7)-C(8) bond with five-membered, six-membered, and seven-membered oxygen-containing heterocycles with two heteroatoms, such as 6H-[1,3]dioxolo[4,5-h]chromen-6-one, 2,3-dihydro-7H-[1,4]dioxino[2,3-h]chromen-7-one, 3,4-dihydro-2H,8H-[1,4]dioxepino[2,3-h]chromen-8-one, 2,3-dihydro-1H,7H-chromeno[7,8-b][1,4]oxazin-7-one, 4H,12H-pyrano[2,3-a]phenoxazine-4-one and 9,10-dihydro-4H,8H-chromeno[8,7-e][1,3]oxazin-4-one. The biological activity of naturally occurring and modified synthetic fused hetarenochromones has been also highlighted.

4'-Hydroxy-6,7-methylenedioxy-3-methoxyflavone: A novel flavonoid from Dulacia egleri with potential inhibitory activity against cathepsins B and L

A new flavone, 4'-hydroxy-6,7-methylenedioxy-3-methoxyflavone 1, and two other nucleosides, ribavirin 2 and adenosine 3, were isolated from the leaves of Dulacia egleri. The nucleosides were identified by spectroscopic techniques (1D, 2D-NMR) while the structure of the flavonoid was established by 1D, 2D-NMR analysis, including HRESIMS data. The results obtained in the biological assays showed that the compound 1 was able to inhibit cathepsins B and L with IC₅₀ of 14.88 ± 0.18 μM and 3.19 ± 0.07 μM, respectively. The mechanism of inhibition for both enzymes were determined showing to be competitive at cathepsin B with Ki = 12.8 ± 0.6 μM and non-linear non-competitive with positive cooperativity inhibition at cathepsin L with K_i = 322 ± 33 μM, αK_i = 133 ± 15 μM, βK_i = 5.14 ± 0.41 μM and γK_i = 13.2 ± 13 μM.

Studies on free radical scavenging, cancer cell antiproliferation, and calf thymus DNA interaction of Schiff bases

Thirty-nine Schiff bases were synthesized by performing microwave-assisted condensation of the corresponding aldehydes and aromatic amines. Their reactive nitrogen species (RNS) scavenging activity and inhibitory effects against cancer cell growth were then subsequently investigated. Additionally, the interaction between the calf thymus DNA (ctDNA) and selected Schiff bases was evaluated using fluorescence spectroscopy, and their binding parameters were determined. The yields of the various compounds ranged from moderate to excellent (43-99%) after only a 2-min reaction. The hydroxylated Schiff bases 2, 8, 15, 16, 18, 20, 29, 32, 34, and 37 were found to be potent scavengers of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals with half-maximal scavenging concentration (SC₅₀) values lower than that of the positive control, resveratrol. The presence of hydroxyl substituents on the aromatic rings also proved essential to the cytotoxicity of the compounds. The binding constants (K_b) obtained using fluorescence spectroscopy ranged from 0.37 to 3.07×10⁵Lmol^-1, and were strongly influenced by the structure and hydroxylation degree. Schiff bases 3 and 8 showed promising cytotoxic activity, with half-maximal growth inhibitory (GI₅₀) values in the same order of magnitude as those exhibited by the reference drug, doxorubicin against various cell lines. Interestingly, these compounds also showed the highest K_b, suggesting that the cytotoxic activity could be related to their interaction with the DNA of the tumor cells. The results of this study highlighted some Schiff bases as potential lead compounds for the design of new free radical scavengers and anticancer agents.

Hyaluronic acid-modified didecyldimethylammonium bromide/ d-a-tocopheryl polyethylene glycol succinate mixed micelles for delivery of baohuoside I against non-small cell lung cancer: in vitro and in vivo evaluation

Baohuoside I is an effective but a poorly soluble antitumor drug. In this study, we prepared baohuoside I-loaded mixed micelles with didecyldimethylammonium bromide (DDAB) and d-a-tocopheryl polyethylene glycol succinate (TPGS) (DTBM) and active targeting mixed micelles (HDTBM) with hyaluronic acid (HA) as the targeting ligand on the surface of the mixed micelles. We performed a systematic comparative evaluation of the antiproliferative effect, cellular uptake, antitumor efficacy, and in vivo tumor targeting of these micelles using A549 cells. HDTBM showed improved cellular uptake and had a greater hypersensitizing effect on A549 cell lines than baohuoside I; half-maximal inhibitory concentration (IC₅₀) was 8.86 versus 20.42 μg/mL, respectively. Results of the antitumor efficacy study and the imaging study for in vivo targeting showed that the mixed-micelle formulation had higher antitumor efficacy and achieved effective and targeted drug delivery. Therefore, our results indicate that HA/baohuoside I-M may be used as a potential antitumor formulation.

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.

Arylidene indanone scaffold: medicinal chemistry and structure–activity relationship view

Arylidene indanone (AI) scaffolds are considered as the rigid cousins of chalcones, incorporating the α,β-unsaturated ketone system of chalcones forming a cyclic 5 membered ring.

Established Human Cell Lines as Models to Study Anti-leukemic Effects of Flavonoids

Despite the extensive work on pathological mechanisms and some recent advances in the treatment of different hematological malignancies, leukemia continues to present a significant challenge being frequently considered as incurable disease. Therefore, the development of novel therapeutic agents with high efficacy and low toxicity is urgently needed to improve the overall survival rate of patients. In this comprehensive review article, the current knowledge about the anticancer activities of flavonoids as plant secondary polyphenolic metabolites in the most commonly used human established leukemia cell lines (HL-60, NB4, KG1a, U937, THP-1, K562, Jurkat, CCRF- CEM, MOLT-3, and MOLT-4) is compiled, revealing clear anti-proliferative, pro-apoptotic, cell cycle arresting, and differentiation inducing effects for certain compounds. Considering the low toxicity of these substances in normal blood cells, the presented data show a great potential of flavonoids to be developed into novel anti-leukemia agents applicable also in the malignant cells resistant to the current conventional chemotherapeutic drugs.

Combining fisetin and ionizing radiation suppresses the growth of mammalian colorectal cancers in xenograft tumor models

Fisetin (3,7,3′,4′-tetrahydroxyflavone), which belongs to the flavonoid group of polyphenols and is found in a wide range of plants, has been reported to exhibit a number of biological activities in human cancer cells, including antioxidant, anti-inflammatory, antiangiogenic, anti-invasive and antiproliferative effects. Although previous in vitro studies have shown that fisetin treatment increases the apoptotic rate and enhances the radiosensitivity of human colorectal cancer cells, the in vivo effects of fisetin on tumor growth remain unclear. In the present study a murine xenograft tumor model was employed to investigate the therapeutic effects of fisetin in combination with radiation on CT-26 colon cancer cells and human HCT116 colorectal cancer cells. This revealed that intratumoral injection of fisetin significantly suppressed the growth of CT-26 tumors compared with the untreated control group, but had little effect on the growth of HCT116 tumors. However, fisetin in combination with 2-Gy radiation enhanced tumor suppressor activity in murine colon and human colorectal xenograft tumors, as compared with 2-Gy fractionated radiation administered alone for 5 days and fisetin alone. Interestingly, fisetin downregulated the expression of the oncoprotein securin in a p53-independent manner. However, securin-null HCT116 tumors showed only moderate sensitivity to fisetin treatment, and the combination of fisetin and radiation did not significantly suppress securin-null HCT116 tumor growth compared with normal HCT116 tumors. Therefore, the role of securin in mediating the effect of fisetin on colorectal cancer growth warrants further investigation. In conclusion, the results of the current study provide important preclinical data for evaluating the efficacy of fisetin and radiation combination treatment as an adjuvant chemoradiotherapy for human colorectal cancers.

d-α-Tocopheryl polyethylene glycol succinate/Solutol HS 15 mixed micelles for the delivery of baohuoside I against non-small-cell lung cancer: optimization and in vitro, in vivo evaluation

Baohuoside I, extracted from the Herba epimedii, is an effective but a poorly soluble antitumor drug. To improve its solubility, formulation of baohuoside I-loaded mixed micelles with d-α-tocopheryl polyethylene glycol succinate and Solutol HS 15 (BTSM) has been developed in this study. We performed a systematic comparative evaluation of the antiproliferative effect, cellular uptake, antitumor efficacy, and in vivo tumor targeting of these micelles using non-small-cell lung cancer (NSCLC) A549 cells. Results showed that the obtained micelles have a mean particle size of ~62.54 nm, and the size of micelles was narrowly distributed. With the improved cellular uptake, BTSM displayed a more potent anti-proliferative action on A549 cell lines than baohuoside I; half-maximal inhibitory concentration was 7.83 vs 20.37 µg/mL, respectively. The antitumor efficacy test in nude mice showed that BTSM exhibited significantly higher antitumor activity against NSCLC with lesser toxic effects on normal tissues. The imaging study for in vivo targeting demonstrated that the mixed micelles formulation achieved effective and targeted drug delivery. Therefore, BTSM might be a potential antitumor formulation.

Enhanced anticancer activity in vitro and in vivo of luteolin incorporated into long-circulating micelles based on DSPE-PEG2000 and TPGS

OBJECTIVES

This study aimed to evaluate enhanced anticancer activity in vitro and in vivo of luteolin-loaded long-circulating micelles (DTLLMs) formulated.

METHODS

DTLLM was the luteolin formulation prepared with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-methoxy-poly (ethylene glycol 2000) (DSPE-PEG2000 ) and d-α-tocopheryl polyethylene glycol succinate (TPGS) in this study. We performed a systematic comparative evaluation of the antiproliferative effect, cellular uptake, antitumour efficacy and in vivo tumour targeting of these micelles using non-small cell lung cancer (NSCLC) A549 cells.

KEY FINDINGS

Results showed that the obtained micelles have a mean particle size of around 42.34 nm, and the size of micelles was narrowly distributed. With the improved cellular uptake, DTLLM displayed a more potent antiproliferative action on A549 cell lines than luteolin; half-maximal inhibitory concentration (IC50 ) was 7.29 vs 19.14 μg/ml, respectively. The antitumour efficacy test in nude mice showed that DTLLM exhibited significantly higher antitumour activity against NSCLC with lesser toxic effects on normal tissues. The imaging study for in vivo targeting demonstrated that the long-circulating micelles formulation achieved targeted drug delivery and make drug release slow to prolong the circulating time.

CONCLUSION

DTLLM might be a potential antitumour formulation.

Chalcone Scaffold in Anticancer Armamentarium: A Molecular Insight

Cancer is an inevitable matter of concern in the medicinal chemistry era. Chalcone is the well exploited scaffold in the anticancer domain. The molecular mechanism of chalcone at cellular level was explored in past decades. This mini review provides the most recent updates on anticancer potential of chalcones.

Optimization and anticancer activity in vitro and in vivo of baohuoside I incorporated into mixed micelles based on lecithin and Solutol HS 15

Baohuoside I, extracted from the Herba epimedii, is an effective but a poorly soluble antitumor drug. To improve its solubility, formulation of baohuoside I-loaded mixed micelles with lecithin and Solutol HS 15 (BLSM) has been performed in this study. We performed a systematic comparative evaluation of the antiproliferative effect, cellular uptake, antitumor efficacy, and in vivo tumor targeting of these micelles using non-small cell lung cancer (NSCLC) A549 cells. Results showed that the obtained micelles have a mean particle size of around 62.54 nm, and the size of micelles was narrowly distributed. With the improved cellular uptake, BLSM displayed a more potent antiproliferative action on A549 cell lines than baohuoside I; half-maximal inhibitory concentration (IC₅₀) was 6.31 versus 18.28 µg/mL, respectively. The antitumor efficacy test in nude mice showed that BLSM exhibited significantly higher antitumor activity against NSCLC with lesser toxic effects on normal tissues. The imaging study for in vivo targeting demonstrated that the mixed micelles formulation achieved effective and targeted drug delivery. Therefore, BLSM might be a potential antitumor formulation.

Recent advances of chroman-4-one derivatives: synthetic approaches and bioactivities

Chroman-4-one scaffold is a privileged structure in heterocyclic chemistry and drug discovery. Also, chroman-4-ones are important intermediates and interesting building blocks in organic synthesis and drug design. The structural diversity found in the chroman-4-one family led to their division into several categories including benzylidene-4-chromanones, flavanones (2-phenyl-4-chromanones), isoflavanones (3-phenyl-4-chromanones), spirochromanones, and C-4 modified chroman-4-ones such as hydrazones and oxime derivatives. This review addresses the most significant synthetic methods reported on 4-chromanone-derived compounds and consequently emphasizes on the biological relevance of such compounds.