Fluoroquinolones are a potent form of chemotherapy

Ciprofloxacin and Norfloxacin Hybrid Compounds: Potential Anticancer Agents

BACKGROUND

The concept of utilizing drug repurposing/repositioning in the development of hybrid molecules is an important strategy in drug discovery. Fluoroquinolones, a class of antibiotics, have been reported to exhibit anticancer activities. Although anticancer drug development is achieving some positive outcomes, there is still a need to develop new and effective anticancer drugs. Some limitations associated with most of the available anticancer drugs are drug resistance and toxicity, poor bio-distribution, poor solubility, and lack of specificity, thereby reducing their therapeutic outcomes.

OBJECTIVES

Fluoroquinolones, a known class of antibiotics, have been explored by hybridizing them with other pharmacophores and evaluating their anticancer activity in silico and in vitro. Hence, this review provides an update on new anticancer drugs containing fluoroquinolones moiety, Ciprofloxacin and Norfloxacin between 2020 and 2023, their structural relationship activity, and the future strategies to develop potent chemotherapeutic agents.

METHODS

Fluoroquinolones were mostly hybridized via the N-4 of the piperazine ring on position C-7 with known pharmacophores characterized, followed by biological studies to evaluate their anticancer activity.

RESULTS

The hybrid molecules displayed promising and interesting anticancer activities. Factors such as the nature of the linker, the presence of electron-withdrawing groups, nature, and position of the substituents influenced the anticancer activity of the synthesized compounds.

CONCLUSION

The hybrids were selective towards some cancer cells. However, further in vivo studies are needed to fully understand their mode of action.

Synthesis of novel amidines via one-pot three component reactions: Selective topoisomerase I inhibitors with antiproliferative properties

Novel series of amidines were synthesized via the interaction between alicyclic amines, cyclic ketones, and a highly electrophilic 4-azidoquinolin-2(1H)-ones without any catalyst or additive. All the obtained products were elucidated based on NMR spectroscopy, mass spectrometry, and elemental analysis. The reaction conditions were optimized using cyclohexanone (2), piperidine (3a), and 4-azido-quinolin-2(1H)-one (1a) under an air atmosphere. The new compounds 4a-l and 5a-c were tested for antiproliferative activity against four cancer cell lines using doxorubicin as a reference drug. The most potent derivatives were compounds 4b, 4d, 4e, 4i, and 5c, with GI50 ranging from 1.00 µM to 1.50 µM. Compound 5c was the most effective derivative against the four cancer cell lines, outperforming doxorubicin. The compounds 4b, 4d, 4e, 4i, and 5c were studied further as topoisomerase I and IIα inhibitors. The compounds tested showed selective inhibition of topo I over topo IIα. Finally, docking studies explain why these compounds prefer topo I over topo IIα.

Toxicity induced by ciprofloxacin and enrofloxacin: oxidative stress and metabolism

Ciprofloxacin (CIP) (human use) and enrofloxacin (ENR) (veterinary use) are synthetic anti-infectious medications that belong to the second generation of fluoroquinolones. They have a wide antimicrobial spectrum and strong bactericidal effects at very low concentrations via enzymatic inhibition of DNA gyrase and topoisomerase IV, which are required for DNA replication. They also have high bioavailability, rapid absorption with favorable pharmacokinetics and excellent tissue penetration, including cerebral spinal fluid. These features have made them the most applied antibiotics in both human and veterinary medicine. ENR is marketed exclusively for animal medicine and has been widely used as a therapeutic veterinary antibiotic, resulting in its residue in edible tissues and aquatic environments, as well as the development of resistance and toxicity. Estimation of the risks to humans due to antimicrobial resistance produced by CIP and ENR is important and of great interest. Moreover, in rare cases due to their overdose and/or prolonged administration, the development of CIP and ENR toxicity may occur. The toxicity of these fluoroquinolones antimicrobials is mainly related to reactive oxygen species (ROS) and oxidative stress (OS) generation, besides metabolism-related toxicity. Therefore, CIP is restricted in pregnant and lactating women, pediatrics and elderly similarly ENR do in the veterinary field. This review manuscript aims to identify the toxicity induced by ROS and OS as a common sequel of CIP and ENR. Furthermore, their metabolism and the role of metabolizing enzymes were reported.