Effect of phytoestrogen and antioxidant supplementation on oxidative DNA damage assessed using the comet assay

Antioxidant species may act in vivo to decrease oxidative damage to DNA, protein and lipids thus reducing the risk of coronary heart disease and cancer. Phytoestrogens are plant compounds which are a major component of traditional Asian diets and which may be protective against certain hormone-dependent cancers (breast and prostate) and against coronary heart disease. They may also be able to function as antioxidants, scavenging potentially harmful free radicals. In this study, the effects of the isoflavonoids (a class of phytoestrogen) genistein and equol on hydrogen peroxide-mediated DNA damage in human lymphocytes were determined using alkaline single-cell gel electrophoresis (the comet assay). Treatment with hydrogen peroxide significantly increased the levels of DNA strand breaks. Pre-treatment of the cells with both genistein and equol offered protection against this damage at concentrations within the physiological range. This protection was greater than that offered by addition of the known antioxidant vitamins ascorbic acid and alpha -tocopherol, or the compounds 17 beta -oestradiol and Tamoxifen which have similar structures to isoflavonoids and are known to have weak antioxidant properties. These findings are consistent with the hypothesis that phytoestrogens can, under certain conditions, function as antioxidants and protect against oxidatively-induced DNA damage. (C) 2001 Elsevier Science B.V. All rights reserved.

In vitro isoflavone supplementation reduces hydrogen peroxide-induced DNA damage in sperm

Isoflavones are plant compounds, proposed to have health benefits in a variety of human diseases, including coronary heart disease and endocrine-responsive cancers. Their physiological effects include possible antioxidant activity, therefore suggesting a role for isoflavones in the prevention of male infertility. The aim of this study was to test the antioxidant effects of the isoflavones genistein and equol on sperm DNA integrity, assessed in vitro after hydrogen peroxide-mediated damage, using the cornet assay. Pre-treatment with genistein or equol at doses of 0.01-100 mumol/l significantly protected sperm DNA against oxidative damage. Both ascorbic acid (10-600 mumol/l) and alpha-tocopherol (1-100 mumol/l) also protected. Compared with ascorbic acid and alpha-tocopherol, added at physiological concentrations, genistein was the most potent antioxidant, followed by equol, ascorbic acid, and alpha-tocopherol. Genistein and equol added in combination were more protective than when added singly. Based on these preliminary data, which are similar to those observed previously in lymphocytes, these compounds may have a role to play in antioxidant protection against male infertility.

Diagnostic and prognostic biomarker discovery strategies for autoimmune disorders.

Current clinical, laboratory or radiological parameters cannot accurately diagnose or predict disease outcomes in a range of autoimmune disorders. Biomarkers which can diagnose at an earlier time point, predict outcome or help guide therapeutic strategies in autoimmune diseases could improve clinical management of this broad group of debilitating disorders. Additionally, there is a growing need for a deeper understanding of multi-factorial autoimmune disorders. Proteomic platforms offering a multiplex approach are more likely to reflect the complexity of autoimmune disease processes. Findings from proteomic based studies of three distinct autoimmune diseases are presented and strategies compared. It is the authors' view that such approaches are likely to be fruitful in the movement of autoimmune disease treatment away from reactive decisions and towards a preventative stand point.

Modelling distributional trends to inform conservation strategies for endangered species

Aim: Species loss has increased significantly over the last 1000 years and is ultimately attributed to the direct and indirect consequences of increased human population growth across the planet. A growing number of species are becoming endangered and require human intervention to prevent their local extirpation or complete extinction. Management strategies aimed at mitigating a species loss can benefit greatly from empirical approaches that indicate the rate of decline of a species providing objective information on the need for immediate conservation actions, e.g. captive breeding; however, this is rarely employed. The current study used a novel method to examine the distributional trends of a model endangered species, the freshwater pearl mussel, Margaritifera margaritifera (L.).
Location: United Kingdom and Republic of Ireland.
Methods: Using species presence data within 10-km grid squares since records began three-parameter logistic regression curves were fitted to extrapolate an estimated date of regional extinction.
Results: This study has shown that freshwater pearl mussel distribution has contracted since known historical records and outlier populations were lost first. Within the United Kingdom and Republic of Ireland, distribution loss has been greatest in Scotland, Northern Ireland, Wales and England, respectively, with the Republic of Ireland containing the highest relative proportion of M. margaritifera distribution, in 1998.
Main conclusions: This study provides empirical evidence that this species could become extinct throughout countries within the United Kingdom within 170 years under the current trends and emphasizes that regionally specific management strategies need to be implemented to prevent extirpation of this species.

Feeding and digestive strategies in deposit-feeding holothurians

Deposit-feeding holothurians employ a range of feeding and digestive strategies depending on the Particular environment to which they are adapted. Habitat and feeding specialisation is reflected in the tentacles, which show high diversity.

Prokaryotes on the tentacles of deep-sea holothurians: A novel form of dietary supplementation

Bathyal and abyssal epibenthic holothurians have a layer of bacteria lying over the tentacular epidermis and below the cuticle. Thus the tentacles of deep-sea holothurians may provide ideal conditions for subcuticular bacteria. These bacteria appear to be regulated by phagocytosis, which, together with pinocytosis would facilitate transfer of bacterial metabolites to the holothurian. Their abundance suggests a previously unknown pathway for energy transformation and assimilation of particular significance in an environment where food is limiting.