Anti-cancer effects of 2-oxoquinoline derivatives on the HCT116 and LoVo human colon cancer cell lines

Green synthesis and biological evaluation of novel 5-fluorouracil derivatives as potent anticancer agents

This study reports the formation of 5-FU co-crystals with four different pharmacologically safe co-formers; Urea, Thiourea, Acetanilide and Aspirin using methanol as a solvent. Two fabrication schemes were followed i.e., solid-state grinding protocol, in which API and co-formers were mixed through vigorous grinding while in the other method separate solutions of both the components were made and mixed together. The adopted approaches offer easy fabrication protocols, no temperature maintenance requirements, no need of expensive solvents, hardly available apparatus, isolation and purification of the desired products. In addition, there is no byproducts formation, In fact, a phenomenon embracing the requirements of green synthesis. Through FTIR analysis; for API the N-H absorption frequency was recorded at 3409.02 cm-1 and that of -C[bond, double bond]O was observed at 1647.77 cm-1. These characteristics peaks of 5-FU were significantly shifted and recorded at 3499.40 cm-1 and 1649.62 cm-1 for 5-FU-Ac (3B) and 3496.39 cm-1 and 1659.30 cm-1 for 5-FU-As (4B) co-crystals for N-H and -C[bond, double bond]O groups respectively. The structural differences between API and co-crystals were further confirmed through PXRD analysis. The characteristic peak of 5-FU at 2θ = 28.79918o was significantly shifted in the graphs of co-crystals not only in position but also with respect to intensity and FWHM values. In addition, new peaks were also recorded in all the spectra of co-formers confirming the structural differences between API and co-formers. In addition, percent growth inhibition was also observed by all the co-crystals through MTT assay against HCT 116 colorectal cell lines in vitro. At four different concentrations; 25, 50, 100 and 200 µg/mL, slightly different trends of the effectiveness of API and co-crystals were observed. However; among all the co-crystal forms, 5-FU-thiourea co-crystals obtained through solution method (2B) proved to be the most effective growth inhibitor at all the four above mentioned concentrations.

In Vitro and in Vivo antitumor activity and the mechanism of siphonodictyal B in human colon cancer cells

Liphagal, isolated from the marine sponge Aka coralliphaga, exhibits phosphatidylinositol 3‐kinase alpha (PI3Kα) inhibitory activity and cytotoxic effects in human cancer cells. Siphonodictyal B, the biogenetic precursor of liphagal, also has PI3K inhibitory activity. However, its cytotoxic or antitumor activities have not been evaluated. In this study, we demonstrated that siphonodictyal B inhibits several kinases such as CDK4/6, CDK7, and PIM2 in addition to PI3K in vitro and that siphonodictyal B exhibits more potent cytotoxic effects than liphagal against human colon cancer cell lines. Furthermore, treatment with siphonodictyal B resulted in increased PARP cleavage, a larger sub‐G1 fraction, and a larger annexin V‐positive cell population, all of which are indicative of apoptosis induction. As a mechanism of apoptosis induction, we found that siphonodictyal B activates the p38 MAPK pathway, leading the upregulation of proapoptotic factors. Moreover, siphonodictyal B increased ROS levels, thus promoting p38 MAPK pathway activation. NAC, an ROS scavenger, almost completely reversed both the cytotoxic and p38 MAPK pathway‐activating effects of siphonodictyal B. These results indicate that the p38 MAPK pathway might be involved downstream of ROS signaling as part of the mechanism of siphonodictyal B‐induced apoptosis. Finally, siphonodictyal B displayed antitumor effects in a human colon cancer xenograft mouse model and increased p38 phosphorylation in tumor tissue. These results suggest that siphonodictyal B could serve as the basis of a novel anticancer drug.

Design, synthesis and pharmacological evaluation of new 3-(1H-benzimidazol-2-yl)quinolin-2(1H)-one derivatives as potential antitumor agents

A series of new 3-(1H-benzimidazol-2-yl)quinolin-2(1H)-one derivatives (5a₁-5d₆) were designed and synthesized as antitumor agents. In vitro antitumor assay results showed that some compounds exhibited moderate to high inhibitory activity against HepG2, SK-OV-3, NCI-H460 and BEL-7404 tumor cell lines, and most compounds exhibited much lower cytotoxicity against the HL-7702 normal cell line compared to 5-FU and cisplatin. In vivo antitumor assay results demonstrated that 5a₃ exhibited effective inhibition on tumor growth in the NCI-H460 xenograft mouse model and that 5d₃ displayed excellent antiproliferative activity in the BEL-7402 xenograft model. These results suggested that both 5a₃ and 5d₃ could be used as anticancer drug candidates. Mechanistic studies suggested that compounds 5a₃ and 5d₃ exerted their antitumor activity by up-regulation of Bax, intracellular Ca²⁺ release, ROS generation, downregulation of Bcl-2, activation of caspase-9 and caspase-3 and subsequent cleavage of PARP, inhibition of CDK activity and activation of the p53 protein.