A Review on the Antimicrobial Activity of Schiff Bases: Data Collection and Recent Studies

Schiff bases (SBs) have extensive applications in different fields such as analytical, inor‐ ganic and organic chemistry. They are used as dyes, catalysts, polymer stabilizers, luminescence chemosensors, catalyzers in the fixation of CO2 biolubricant additives and have been suggested for solar energy applications as well. Further, a wide range of pharmacological and biological applica‐ tions, such as antimalarial, antiproliferative, analgesic, anti‐inflammatory, antiviral, antipyretic, an‐ tibacterial and antifungal uses, emphasize the need for SB synthesis. Several SBs conjugated with chitosan have been studied in order to enhance the antibacterial activity of chitosan. Moreover, the use of the nanoparticles of SBs may improve their antimicrobial effects. Herein, we provide an ana‐ lytical overview of the antibacterial and antifungal properties of SBs and chitosan‐based SBs as well as SBs‐functionalized nanoparticles. The most relevant and recent literature was reviewed for this purpose

A Look at the Importance of Chirality in Drug Activity: Some Significative Examples

[EN] Chirality plays an important role in the development of many pharmaceuticals, being a general property of 'handedness'; nevertheless, a large number of pharmaceuticals are still marketed and administered as racemates. Chirality is all around and even within us; indeed, receptors and enzymes are chiral entities and interact in a specific manner with chiral drugs. Consequently, controlling enantiomeric purity and isolating the enantiomers from chiral drugs remains a crucial subject for analytical, clinical, and regulatory purposes, thus, improving the drug safety profile. The classical examples of spontaneous enantiomerization and severe toxicity related to chirality are represented by ibuprofen and thalidomide, respectively, but numerous other cases have been reported in the literature. This review intends to offer a brief overview on the most common chiral drugs used in therapy for the treatment of various diseases.Ceramella, J.; Iacopetta, D.; Franchini, A.; De Luca, M.; Saturnino, C.; Andreu, I.; Sinicropi, MS.... (2022). A Look at the Importance of Chirality in Drug Activity: Some Significative Examples. Applied Sciences. 12(21):1-22. https://doi.org/10.3390/app122110909122122

Benzothiazole-Containing Analogues of Triclocarban with Potent Antibacterial Activity

Triclocarban (TCC) is a polychlorinated, aromatic, antimicrobial agent commercially used since the 1950s in personal care products for the prevention of spoilage and infections. Humans are frequently exposed to TCC due to its widespread use, leading to its substantial release into the aquatic environment. With the recent ban of TCC from some personal care products, implemented in 2016, many replacement antimicrobial compounds have been studied by researchers. Herein, we report the synthesis and biological activity of a series of diarylureas, analogues of TCC that bear the benzothiazole nucleus as one of the two aryl moieties. Among the studied compounds, 2bF and 2eC showed the highest antimicrobial activity against Staphylococcus aureus, being also more active than TCC, with MIC values of 8 µg/mL versus 16 µg/mL of TCC. Moreover, compound 2bB was much more active than TCC against Enterococcus faecalis, a Gram-positive bacterium that is, unfortunately, strongly responsible for nosocomial infections. Finally, interesting results were found for compound 2bG that, even though less active than the others, exerts an interesting bactericidal action

Target Therapy in Cancer Treatment: mPGES-1 and PARP

Target therapy is an approach focusing on specific protein or signaling pathways. This therapy is directly aimed to a molecular target such as a receptor, growth factor or enzyme in cancer cells. These targets are used by the tumor cells themselves to obtain uncontrolled proliferation, resistance to traditional therapies and to increase the number of blood vessels in the tissue of origin (neoangiogenesis). A purpose of target therapy may be to counteract the growth and proliferation of cancer cells through the use of drugs or monoclonal antibodies capable of inhibiting the receptor for the epidermal growth factor (EGFR), that is crucial in the process of neo-angiogenesis, protein kinases (PKs), as regulators of cell growth signals and human epidermal growth factor type 2 (HER2), which is essential in stimulating growth and proliferation of cancer cells. Among anticancer drugs, Bevacizumab, a humanised monoclonal antibody produced by recombinant DNA technique, is used for the first-line treatment of metastatic breast cancer, as it inhibits EGFR and the vascular endothelial cell growth factor (VEGF). Abemaciclib, a protein kinase inhibitor drug, is also used for the treatment of the same cancer. In 20-30% of primary breast tumors, the excessive expression of HER2 is observed; thus, HER2 inhibitors may represent another plausible therapy. A potent HER2 inhibitor is the recombinant humanized igG1 monoclonal antibody Trastuzumab, which was first tested in 1992 and is currently used for the treatment of HER2 positive breast cancer. Unfortunately, despite the numerous advances in finding new therapies, patients treated with these drugs often suffer from severe undesirable side effects. Therefore, the search for new therapeutic targets may be desirable. In this paper we analyse particularly two targets studied quite recently: the microsomal prostaglandin E2 synthase type 1 (mPGES-1) and poly (ADP-ribose) polymerase (PARP) proteins

COVID-19 at a Glance: An Up-to-Date Overview on Variants, Drug Design and Therapies

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a member of the Coronavirus family which caused the worldwide pandemic of human respiratory illness coronavirus disease 2019 (COVID-19). Presumably emerging at the end of 2019, it poses a severe threat to public health and safety, with a high incidence of transmission, predominately through aerosols and/or direct contact with infected surfaces. In 2020, the search for vaccines began, leading to the obtaining of, to date, about twenty COVID-19 vaccines approved for use in at least one country. However, COVID-19 continues to spread and new genetic mutations and variants have been discovered, requiring pharmacological treatments. The most common therapies for COVID-19 are represented by antiviral and antimalarial agents, antibiotics, immunomodulators, angiotensin II receptor blockers, bradykinin B2 receptor antagonists and corticosteroids. In addition, nutraceuticals, vitamins D and C, omega-3 fatty acids and probiotics are under study. Finally, drug repositioning, which concerns the investigation of existing drugs for new therapeutic target indications, has been widely proposed in the literature for COVID-19 therapies. Considering the importance of this ongoing global public health emergency, this review aims to offer a synthetic up-to-date overview regarding diagnoses, variants and vaccines for COVID-19, with particular attention paid to the adopted treatments

NUTRACEUTICAL FUNCTIONS OF GREEN TEA

Today, the diffusion of neoplastic diseases is a widespread phenomenon. Thus, it is always necessary to identify new molecules able to fight them. In this paper, we will deal with the interesting antineoplastic properties of green tea. We will describe the different and plausible anticancer mechanisms of epigallocatechin gallate (EGCG), the major polyphenol found in green tea, and in particular the biochemical and computational discovery of a new target for the treatment of this disease will be discussed. The bio-active substances present in tea are essentially represented by methylxanthines, as well as by the antioxidant phenolic fraction (flavonoids). Among the other active substances contained in lower concentrations there are vitamins (B, C and K), amino acids (L-theanine) and minerals (aluminium and manganese). Tea extracts, particularly EGCG, could represent the starting point for the potential emergence of new drugs for the treatment of neoplastic diseases. Other activities of tea, as the involvement in neurodegenerative diseases prevention, as well as the antioxidant, antibacterial, antifungal and antiviral effects, will be also briefly described

Multidrug Resistance (MDR): A Widespread Phenomenon in Pharmacological Therapies

Multidrug resistance is a leading concern in public health. It describes a complex phenotype whose predominant feature is resistance to a wide range of structurally unrelated cytotoxic compounds, many of which are anticancer agents. Multidrug resistance may be also related to antimicrobial drugs, and is known to be one of the most serious global public health threats of this century. Indeed, this phenomenon has increased both mortality and morbidity as a consequence of treatment failures and its incidence in healthcare costs. The large amounts of antibiotics used in human therapies, as well as for farm animals and even for fishes in aquaculture, resulted in the selection of pathogenic bacteria resistant to multiple drugs. It is not negligible that the ongoing COVID-19 pandemic may further contribute to antimicrobial resistance. In this paper, multidrug resistance and antimicrobial resistance are underlined, focusing on the therapeutic options to overcome these obstacles in drug treatments. Lastly, some recent studies on nanodrug delivery systems have been reviewed since they may represent a significant approach for overcoming resistance

Triclosan: A Small Molecule with Controversial Roles

Abstract: Triclosan (TCS), a broad-spectrum antimicrobial agent, has been widely used in personal care products, medical products, plastic cutting boards, and food storage containers. Colgate Total® toothpaste, containing 10 mM TCS, is effective in controlling biofilm formation and maintaining gingival health. Given its broad usage, TCS is present ubiquitously in the environment. Given its strong lipophilicity and accumulation ability in organisms, it is potentially harmful to biohealth. Several reports suggest the toxicity of this compound, which is inserted in the class of endocrine disrupting chemicals (EDCs). In September 2016, TCS was banned by the U.S. Food and Drug Administration (FDA) and the European Union in soap products. Despite these problems, its application in personal care products within certain limits is still allowed. Today, it is still unclear whether TCS is truly toxic to mammals and the adverse effects of continuous, long-term, and low concentration exposure remain unknown. Indeed, some recent reports suggest the use of TCS as a repositioned drug for cancer treatment and cutaneous leishmaniasis. In this scenario it is necessary to investigate the advantages and disadvantages of TCS, to understand whether its use is advisable or not. This review intends to highlight the pros and cons that are associated with the use of TCS in humans