Prospects of Topoisomerase Inhibitors as Promising Anti-Cancer Agents

Topoisomerases are very important enzymes that regulate DNA topology and are vital for biological actions like DNA replication, transcription, and repair. The emergence and spread of cancer has been intimately associated with topoisomerase dysregulation. Topoisomerase inhibitors have consequently become potential anti-cancer medications because of their ability to obstruct the normal function of these enzymes, which leads to DNA damage and subsequently causes cell death. This review emphasizes the importance of topoisomerase inhibitors as marketed, clinical and preclinical anti-cancer medications. In the present review, various types of topoisomerase inhibitors and their mechanisms of action have been discussed. Topoisomerase I inhibitors, which include irinotecan and topotecan, are agents that interact with the DNA-topoisomerase I complex and avert resealing of the DNA. The accretion of DNA breaks leads to the inhibition of DNA replication and cell death. On the other hand, topoisomerase II inhibitors like etoposide and teniposide, function by cleaving the DNA-topoisomerase II complex thereby effectively impeding the release of double-strand DNA breaks. Moreover, the recent advances in exploring the therapeutic efficacy, toxicity, and MDR (multidrug resistance) issues of new topoisomerase inhibitors have been reviewed in the present review.

An Explicative Review on the Progress of Quinazoline Scaffold as Bioactive Agents in the Past Decade

In the last decade, quinazoline has been one of the most explored scaffolds by researchers around the globe in medicinal chemistry. Its unique structural features provide a wide range of substitutions for nitrogen and carbonyl groups. In the current situation of COVID-19, hydroxychloroquine, an antimalarial drug of the quinoline category, was used for the treatment of severe infections. Various substitution patterns, hybrids, and conjugates of quinazoline have been developed and studied for various pharmacological activities like anticancer, anti-inflammatory, antimalarial, antitubercular, etc. The scaffold can be considered a potential molecule for various pharmacological activities, especially antimicrobial and anti-hypertensive. This review article aims to study the physicochemical properties, chemistry, and pharmacological profile of quinazoline.

Quinoline-derivatives as privileged scaffolds for medicinal and pharmaceutical chemists: A comprehensive review

The quinoline scaffolds are privileged for their numerous biological activities in the pharmaceutical field. This moiety constitutes a well-known space in several marketed preparations. The quinoline scaffolds gained attention in modern days being an important chemical moiety in the identification, designing, and synthesis of novel potent derivatives. The current review is developed to shine the light on critical and significant insights on the quinoline derivatives possessing diverse biological activities such as analgesic, anti-inflammatory, antialzheimer, anti-convulsant, anti-oxidant, antimicrobial, anti-cancer activities and so on. A detailed summary of quinoline ring from its origin to the recent advancements regarding its synthesis, green chemistry approaches, patented methods, and its marketed drugs is presented in the review. We attempted to review the literature compiling the critical information that has potential to encourage fellow researchers and scientists for the design and development of quinoline scaffold based active molecules that have improved therapeutic performance along with profound pharmacological properties.

Discovery of Zafirlukast as a novel SARS-CoV-2 helicase inhibitor using in silico modelling and a FRET-based assay

The coronavirus helicase is an essential enzyme required for viral replication/transcription pathways. Structural studies revealed a sulphate moiety that interacts with key residues within the nucleotide-binding site of the helicase. Compounds with a sulphoxide or a sulphone moiety could interfere with these interactions and consequently inhibit the enzyme. The molecular operating environment (MOE) was used to dock 189 sulphoxide and sulphone-containing FDA-approved compounds to the nucleotide-binding site. Zafirlukast, a leukotriene receptor antagonist used to treat chronic asthma, achieved the lowest docking score at -8.75 kcals/mol. The inhibitory effect of the compounds on the SARS-CoV-2 helicase dsDNA unwinding activity was tested by a FRET-based assay. Zafirlukast was the only compound to inhibit the enzyme (IC50 = 16.3 µM). The treatment of Vero E6 cells with 25 µM zafirlukast prior to SARS-CoV-2 infection decreased the cytopathic effects of SARS-CoV-2 significantly. These results suggest that zafirlukast alleviates SARS-CoV-2 pathogenicity by inhibiting the viral helicase and impairing the viral replication/transcription pathway. Zafirlukast could be clinically developed as a new antiviral treatment for SARS-CoV-2 and other coronavirus diseases. This discovery is based on molecular modelling, in vitro inhibition of the SARS-CoV helicase activity and cell-based SARS-CoV-2 viral replication.

An overview of the synthetic route to the marketed formulations of pyrimidine: A Review

Pyrimidine and its derivatives are a very important class of heterocyclic compounds that show interesting applications in the field of medicinal chemistry. Pyrimidine not only plays an important role as an organic reaction intermediate but also has a wide range of interesting biological activities viz. antibacterial, antifungal, anticancer, anti-inflammatory, antiviral, and antiprotozoal activity, etc. Numerous methods are available for the formation of pyrimidine derivatives have been reported in the literature. The advantage of pyrimidine as a starting material for different therapeutically potent derivatives has given momentum to this research. This review aims to report the new work on the synthesis of marketed drugs which consist of pyrimidine moiety.

Recent Progress in the Development of Quinoline Derivatives for the Exploitation of Anti-Cancer Agents

BACKGROUND

Along with the progress in medicine and therapies, the exploitation of anti-cancer agents focused more on the vital signaling pathways and key biological macromolecules. With rational design and advanced synthesis, quinoline derivatives have been utilized frequently in medicinal chemistry, especially in developing anti-cancer drugs or candidates.

METHODS

Using DOI searching, articles published before 2020 all over the world have been reviewed as comprehensively as possible.

RESULTS

In this review, we selected the representative quinoline derivate drugs in market or clinical trials, classified them into five major categories with detailed targets according to their main mechanisms, discussed the relationship within the same mechanism, and generated a summative discussion with prospective expectations. For each mechanism, the introduction of the target was presented, with the typical examples of quinoline derivate drugs.

CONCLUSION

This review has highlighted the quinoline drugs or candidates, suited them into corresponding targets in their pathways, summarized and discussed. We hope that this review may help the researchers who are interested in discovering quinoline derivate anti-cancer agents obtain considerable understanding of this specific topic. Through the flourishing period and the vigorous strategies in clinical trials, quinoline drugs would be potential but facing new challenges in the future.

Reporting of adverse events for marketed drugs: Need for strengthening safety database

Pharmacovigilance is an evolving discipline in the Indian context. However, there is limited regulatory guidance for adverse event reporting outside the purview of clinical trials. There are number of deficiencies in the framework for adverse event reporting from the perspective of pharma industry, health-care professional and general public due to which adverse events for marketed drugs are highly underreported. This article discusses the need to strengthen national safety database by promoting and mandating reporting of adverse events by all the stakeholders.

Prescribing patterns and safety monitoring of duloxetine using the Danish Register of Medicinal Product Statistics as a source

BACKGROUND

The safety and pattern of use of a medicinal product cannot be fully studied prior to its marketing. In Denmark, the Danish Health and Medicines Authority (DHMA) monitors marketed drugs. An available source is the Register of Medicinal Product Statistics (RMPS), which can possibly be used for these purposes.

OBJECTIVE

To investigate utilisation and potential safety issues of relatively new antidepressants containing the active ingredient duloxetine (Cymbalta(®) and Xeristar(®)) by using dispensing data available in the RMPS.

METHODS

A retrospective study using dispensing data was designed to estimate the size and composition of the user population and patterns of use of the antidepressants Cymbalta(®) and Xeristar(®) (active ingredient: duloxetine) in the period from 1 January 2005 to 31 December 2010. Data were retrieved from Epikur, a register subset of the RMPS.

RESULTS

Both women and men in different age groups used duloxetine for depression. Some users switched to another antidepressant. Prescription of the drug for persons below the age of 18 years revealed a potential safety issue. Concomitant treatment with Cymbalta(®) or Xeristar(®) and fluvoxamine, isocarboxazid, Yentreve(®), or ciprofloxacin also revealed potential safety issues.

CONCLUSIONS

The present study indicated that the RMPS is applicable in monitoring the pattern of use and potential safety issues related to duloxetine when it is prescribed for depression. Switching to other antidepressants could reflect some potential safety issues. Use of duloxetine for persons below the age of 18 years and its concomitant use with contraindicated drugs also indicated potential safety issues.