Any facts behind the DHEA hype?

The effect of DHEA treatment on the oxidative stress and myocardial fibrosis induced by Keshan disease pathogenic factors

Oxidative stress induced by the combined deficiencies of selenium (Se) and vitamin E (VE) is considered the basic factor of Keshan disease (KD). Dehydroepiandrosterone (DHEA) is a naturally occurring adrenal androgen that has antioxidant properties. We found that a Se- and VE-deficient diet induced KD lesions in rats, while 0.05, 0.125, and 0.25 g/kg DHEA caused a concentration-dependent inhibition in the development of oxidative stress and extracellular matrix (ECM) deposition in the left ventricles of the Se- and VE-deficient rats. In addition, DHEA counteracted activation of NFκB as well as the subsequent increase in TGFβ-1 and CTGF induced by the Se- and VE-deficient diet. These studies suggested that DHEA prevents oxidative stress and might be useful in treating Se and VE deficiency-related KD. These effects were based on its antioxidant effects and ECM deposition inhibition in left ventricles.

Effect of Ovary Lipid of Skipjack Tuna on Rat Serum Components after Stress Application

Lipid extracted from the ovary of skipjack tuna by the method that we developed is rich in phospholipid-type docosahexaenoic acid. The ovary lipid of skipjack tuna (OLS) was studied for its anti-stress activity in male Wistar rats, focusing on stress-related blood components: recovery from stress was examined after application of water immersion restraint stress. As a result, serum corticosterone (CORT) secretion was inhibited and decreased rapidly after stress application in rats given OLS compared with control rats. As CORT acts as a glucocorticoid, non-esterified fatty acid (NEFA) is expected to increase by stress application. However, the concentration tended to be lower in rats given OLS than in control rats. With respect to OLS concentration, OLS increased serum dehydroepiandrosterone, secretion concentration-dependently. In addition, as with the recovery study, it tended to inhibit the increase in NEFA. These results indicate that OLS may have an anti-stress activity against acute stress.

Effect of Ovary Lipid from Skipjack Tuna (Katsuwonus pelamis) on Brain Monoamines in Rats

In our previous experiments with rats, ovary lipid from Skipjack Tuna (Katsuwonus pelamis) (OLS) was shown to have a mitigating effect on anxiety and/or fear in elevated T-maze tests. This suggests that OLS has some effect on the central nervous system (CNS) of rats. Thus, we performed experiments to examine the status of CNS in rats given OLS. The effect of OLS on chronic stress was also examined at the same time. The feed for control rats used oil and fat that have the same energy percentages for n-6 and n-3 fatty acids and the same n-6/n-3 ratio as OLS. As a result, rats given OLS for 28 days had lower serotonin levels in various brain areas regardless of stress application, showing that OLS affected the serotonin nervous system. From this, it was inferred that the ability of OLS to mitigate anxiety and/or fear resulted from its action on CNS, especially the serotonin nervous system. Substances other than the essential fatty acids may have been responsible for the action of OLS on monoamines and the metabolites. The effect of OLS on CNS, especially the serotonin nervous system, suggests that OLS may suppress anxiety.

Memory-enhancing effects of DHEAS in aged mice on a win-shift water escape task

The steroid hormone, dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) have been implicated in age-associated deficits in memory. Numerous studies have demonstrated the effectiveness of these neurosteroids to enhance retention and ameliorate the effects of various memory-blocking agents, but few studies have directly assayed their effects on memory in aged animals. The present study investigated the memory-enhancing effects of DHEAS in a win-shift (nonmatching-to-sample) task in aged mice using water escape motivation. Sixteen CD-1 mice, 18-20 months old, were trained to a moderate criterion of 7/10 correct trials and were then divided into two equal groups based on acquisition performance. One group received oral administration of DHEAS (1.5 mg/mouse/day) in a vehicle solution (0.0015% methyl salicylate) while the other group received the vehicle alone. DHEAS effects were assessed using a procedure in which delay intervals (0, 120, and 240 s) were interposed between sample and comparison trials over the course of three test sessions. The group receiving DHEAS recorded significantly higher retention scores across 3 days of testing, particularly at the 120-s delay interval, indicating that DHEAS enhanced working memory in these aged animals.

Biogerontological research in Canada

There is an ever increasing interest in the study of the aging process. This review is aimed to make an overview of the biological aging research in Canada. I will summarize, to the best of my knowledge, the biological aging research undertaken actually in Canadian institutions dealing with various aspects of this research using many different experimental approaches, models from animals to humans and a huge array of techniques. The biological aging research is developing continuously in Canada, however, it is very important that we assist in a near future to its huge explosion if we would respond to the needs of an ever increasing aging population. Initiatives recently proposed by the Canadian government concerning the creation of Canadian Institutes on Health Research will provide good opportunities to establish a performant, cost-effective, and innovative biological aging research.