Structures, Activities and Drug-Likeness of Anti-Infective Xanthone Derivatives Isolated from the Marine Environment: A Review.

Marine organisms represent almost half of total biodiversity and are a very important source of new bioactive substances. Within the varied biological activities found in marine products, their antimicrobial activity is one of the most relevant. Infectious diseases are responsible for high levels of morbidity and mortality and many antimicrobials lose their effectiveness with time due to the development of resistance. These facts justify the high importance of finding new, effective and safe anti-infective agents. Among the variety of biological activities of marine xanthone derivatives, one that must be highlighted is their anti-infective properties. In this work, a literature review of marine xanthones with anti-infective activity, namely antibacterial, antifungal, antiparasitic and antiviral, is presented. Their structures, biological activity, sources and the methods used for bioactivity evaluation are described. The xanthone derivatives are grouped in three sets: xanthones, hydroxanthones and glycosylated derivatives. Moreover, molecular descriptors, biophysico-chemical properties, and pharmacokinetic parameters were calculated, and the chemical space occupied by marine xanthone derivatives is recognized. The chemical space was compared with marketed drugs and framed accordingly to the drug-likeness concept in order to profile the pharmacokinetic of anti-infective marine xanthone derivatives.

Functional characterisation of a cyst nematode acetylcholinesterase gene using Caenorhabditis elegans as a heterologous system.

Migration of plant-parasitic nematode infective larval stages through soil and invasion of roots requires perception and integration of sensory cues culminating in particular responses that lead to root penetration and parasite establishment. Components of the chemoreceptive neuronal circuitry involved in these responses are targets for control measures aimed at preventing infection. Here we report, to our knowledge, the first isolation of cyst nematode ace-2 genes encoding acetylcholinesterase (AChE). The ace-2 genes from Globodera pallida (Gp-ace-2) and Heterodera glycines (Hg-ace-2) show homology to ace-2 of Caenorhabditis elegans (Ce-ace-2). Gp-ace-2 is expressed most highly in the infective J2 stage with lowest expression in the early parasitic stages. Expression and functional analysis of the Globodera gene were carried out using the free-living nematode C. elegans in order to overcome the refractory nature of the obligate parasite G. pallida to many biological studies. Caenorhabditis elegans transformed with a GFP reporter construct under the control of the Gp-ace-2 promoter exhibited specific and restricted GFP expression in neuronal cells in the head ganglia. Gp-ACE-2 protein can functionally complement its C. elegans homologue. A chimeric construct containing the Ce-ace-2 promoter region and the Gp-ace-2 coding region and 3' untranslated region was able to restore a normal phenotype to the uncoordinated C. elegans double mutant ace-1;ace-2. This study demonstrates conservation of AChE function and expression between free-living and plant-parasitic nematode species, and highlights the utility of C. elegans as a heterologous system to study neuronal aspects of plant-parasitic nematode biology.

Enalapril reduces the expression of nuclear factor-kappaB and c-Jun N-terminal kinase in the renal cortices of five-sixths-nephrectomized rats.

BACKGROUND/AIM: Five-sixths-nephrectomized rats present renal functional and histological abnormalities which are attenuated by enalapril treatment. c-Jun N-terminal kinase (JNK), a mitogen-activated protein kinase, and nuclear factor-kappaB (NF-kappaB) pathways can be activated by angiotensin II which has been implicated in renal injury. The aim of this study was to investigate the effect of enalapril on the expression of NF-kappaB and JNK in renal cortices of five-sixths-nephrectomized rats. METHODS: Of the 65 rats studied, 25 underwent five-sixths nephrectomy and received no treatment, 15 underwent five-sixths nephrectomy and received enalapril, 15 were sham operated and received no treatment, and 10 were sham operated and received enalapril. On postoperative days 15 and 90, systolic blood pressure, glomerular filtration rate, and albumin excretion were determined. The rats were then killed and the kidneys removed for histology and immunohistochemistry. RESULTS: In five-sixths-nephrectomized rats, we observed functional and structural renal alterations, as well as greater NF-kappaB/JNK expression and higher macrophage counts. Enalapril treatment reduced all of these changes. CONCLUSION: The protective effect of enalapril on the kidney of five-sixths-nephrectomized rats might be related to the inhibition of NF-kappaB and JNK activation.