Mini Reviews in Medicinal Chemistry - Volume 9, Issue 13, 2009

The Cruciferae (also known as the Brassicaceae) are the family of plants that include the various familiar members of the species Brassica oleracea (e.g., broccoli, cabbage, cauliflower, kale, Brussels sprouts) as well as many other plants that are widely consumed in various parts of the world. Forage and root brassicas are widely used as winter feeds for cattle and sheep. A striking and characteristic chemical property of cruciferous plants is their high content of glucosinolates (more than 120 types), which often approaches 1% or more of their dry weight. The interest devoted to this group of natural products is caused by the appreciable biological effects of both the intact glucosinolates (GSLs) and especially the complex group of glucosinolate transformation products produced in non-enzymatic and enzymatic reactions. Depending on the concentration and structural types of these compounds, their biological effects can be toxic, antinutritional or beneficial to health. Most serious economic problems in livestock seem to result from rapeseed meal; arising from GSLs or their breakdown products. In contrast, GSLs and their isothiocyanate (ITC) hydrolysis products are reportedly well-known protectors against carcinogenesis. GSLs play further protective and evolutionarily important roles in plants. These include allelopathy (suppression of growth of neighboring plants), specific positive and negative feeding cues for some insects and broad antibiotic properties including nematocidal, antimicrobial, antifungal, antiprotozoal and insecticidal activities. The controversy in the referred actions contributed to crucifers' phytochemicals has been exclusively discussed.

Many findings have evidenced antioxidant properties of hyaluronan, both in vitro and in vivo, by means of which it can scavenge free radicals and exert its effect on pathologies. The aim of this review is to summarize the available data on the features and clinical profile of hyaluronan, with regard in particular to its antioxidant capacity and to its related physico-chemical properties. Additionally, hyaluronan and its derivatives are examined, with the focus on their therapeutic uses, protection against cellular damage, and their role as inflammatory mediators. Finally, therapies associated to the antioxidant effect of hyaluronan are discussed.

New Platinum and Ruthenium complexes display antitumour and antimetastatic potentials and lower host toxicities. This mini-review examines some the more recent developments in this field, and explores their interactions with biologically-relevant species. The article also refers to more recent work in the area of molybdenum and copper(II) chemistry.

Over the last years significant advances have been made in the area of drug delivery with the development of modified-release (MR) dosage forms. The present review is divided into two parts, one dealing with technologies for the design of modified-release drug delivery tablets and the other with the use of synthetic and natural polymers that are capable of controlling drug release.

Carnitine is well-known for its role in the transport of fatty acids to the mitochondrial matrix, where β- oxidation takes place. This work describes novel functions for this compound and novel data on its pharmacokinetics.

Beta-lactams are the most frequently used antimicrobials in combating infections. In the case of gram-positive bacteria resistant to beta-lactams, glycopeptides are the first choice. The occurrence, mechanisms and genetic background of the resistance of pathogenic staphylococci, streptococci and enterococci to beta-lactam and glycopeptide antibiotics were discussed. The resistances to well-established antimicrobials, as well as new agents (ceftobiprole, oritavancin, telavancin, dalbavancin) were taken into consideration in the text.

Hyaluronan is a glycosaminglycan present in practically all tissues as an important component of the extracellular matrix. In spite of its apparent simple chemical structure, hyaluronan is a molecule with multiple and complex physiogical and pathological functions. Hyaluronan is able to regulate a variety of biological processes such as cellular growth, migration, differentiation and inflammation, not only in normal but also in cancer tissues. Besides, increasing evidence suggests hyaluronan as a potent modulator of immune responses which supports a potential role of this molecule in cancer immunotherapy.

Advances in the prevention and treatment of cancer require the continued development of novel and improved chemopreventive and chemotherapeutic agents. Throughout history, natural products have afforded a rich source of anticancer agents with diverse chemical structures and bioactivities. Recent technological and methodologic advances in structure elucidation, organic synthesis, and biological assay have resulted in the isolation and clinical evaluation of various novel anticancer agents. In this review, we will present the anticancer activities, mechanism of action, structure and activity relationships of six important anticancer agents from natural products, that is, taxol, betulinic acid, camptothecin, resveratrol, podophyllotoxin and curcumin.

Non-ionic surfactants have been proposed as dual action anti-viral and spermicidal agents to tackle viral infections, namely HIV. Given very promising in vitro results, nonoxynol-9 has been widely used. However, toxic effects were reported, paradoxically increasing the incidence of transmission of HIV/Sexually Transmitted Diseases in vivo. Thus, there has been a growing interest in identifying and evaluating a new generation of accessible and easy-to-use molecules with simultaneous spermicidal and microbicide action. Different biochemical compounds and mechanisms of action are currently being studied. This article reviews the diverse strategies and mechanisms of action of these novel compounds, as well the necessary systematic studies needed to evaluate their possible toxicity.