No abstract

Leishmaniasis, African sleeping sickness and Chagas disease, caused by the kinetoplastid parasites Leishmania spp, Trypanosoma brucei and Trypanosoma cruzi, respectively, are among the most important parasitic diseases, affecting millions of people and considered to be within the most relevant group of neglected tropical diseases. The main alternative to control such parasitosis is chemotherapy. Nevertheless, the current chemotherapeutic treatments are far from being satisfactory. This review outlines the current understanding of different drugs against leishmaniasis, African sleeping sickness and Chagas disease, their mechanism of action and resistance. Recent approaches in the area of anti-leishmanial and trypanocidal therapies are also enumerated, new modulators from the mode of action, development of new formulations of old drugs, therapeutic switching and "in silico" drug design.

Like other tissues of the central nervous system, the retina is susceptible to damage by oxidative processes that result in several neurodegenerative disease such as age-related macular degeneration, diabetic retinopathy, glaucoma, ischaemic retinal disease, retinal disease produced by light oxidation, and detached retina, among other diseases. The use of antioxidant substances is a solution to some health problems caused by oxidative stress, because they regulate redox homeostasis and reduce oxidative stress. This is important for neurodegeneration linked to oxidation processes. In line with this, Ginkgo biloba is a medicinal plant with excellent antioxidant properties whose effects have been demonstrated in several degenerative processes, including retinal diseases associated with neurodegeneration. This review describes the current literature on the role of ginkgo in retinal diseases associated with neurodegeneration. The information leads to the conclusion that G. biloba extracts might be a good option to improve certain neurodegenerative retinal diseases, but more research is needed to determine the safety and efficacy of G. biloba in these retinal degenerative processes.

We have investigated a number of nucleophillic additions to L-erythrulose derivatives (4-12) bearing protective O-silyl, O-benzyl, and O-trityl groups in various relative positions. The results are discussed in the frame of chelated vs nonchelated transition states with additional support of previously published theoretical calculations. Sound evidence appears to exist for the formation of alpha-chelates as the key intermediates in nucleophillic additions to these alpha,beta-dioxygenated ketones. Since such evidence is still lacking in the case of beta-chelates, proposals of their intermediacy have been relegated in favor of the more solid Felkin-Anh model, which predicts the same stereochemical result. The behavior of these highly functionalized ketones does not always match that of structurally similar aldehydes.

The retina may suffer neurodegenerative damages, as other tissues of the central nervous system do, and serious eye diseases may develop. One of them is age-related macular degeneration, which causes progressive loss of vision due to retina degeneration. Treatment of age-related macular degeneration focuses on antioxidant agents and anti-vascular endothelial growth factor compounds, among others, that prevent/diminish oxidative stress and reduce neovascularisation respectively. The phytochemicals, medicinal plants and/or plant-diet supplements might be a useful adjunct in prevention or treatment of age-related macular degeneration owing to their antioxidant and anti-vascular endothelial growth factor properties. This review article presents the most investigated plants and natural products in relation to age-related macular degeneration, such as saffron, ginkgo, bilberry and blueberry, curcuma or turmeric, carotenoids, polyphenols, and vitamins C and E. This study provides up-to-date information on the effects, treatments, safety and efficiency of these phytotherapy products.