Friday, August 26, 2011

DHEA Revives Liver of Aged Rats and Improves Antioxidant Reserves and Akt Signaling in Young and Old Rats.

Image 1:  I don't think celebrities realize it, but there is more to anti-aging than an unlined face. New studies show that DHEA could after all help with all sorts of age related diseases (img. antiagingpossible.com)
It's been a while since DHEA was in the news. While I have posted a handfull of mostly beneficial findings related to dehydroepitestosterone (DHEA), the hype that sourrounded its purported anti-aging effect in the late 1990s has completely abated. In view of DHEA's implication  (or rather the lack of the latter) in age-related autoimmune disease, sexual disfunction, osteoporisis, deteroiations of lipid metabolism, type 2 diabetes and cardiovascular and liver disease (Basci. 2007- igni´Čücance of  dehydroepiandrosterone  and  dehydroepiandrosterone  sulfate  in  different  diseases), it is questionable how people beyond the age of 40, when DHEA production declines by 2% per year(!) could not benefit from a carefully planned and monitored DHEA treatment. A group of scientists from Brazil obviously thought the same and decided to take a fresh look at what happens on a molecular level, when 3 (young rats) and 24 months (old rats) old male Wistar-rats are given 10mg/kg deyhdroepitestosterone [human equivalent: 1.62mg/kg; 80kg human: 130mg/day] subcutaneously per day for 5 weeks (Jacob 2011).
Figure 1: Relative changes in total, reduced and oxidized glutathione in young and old rats after 5 weeks on 10mg/kg DHEA (data adapted from Jacob 2011)
As you can see in figure 1, the treatment induced profound increases in total and reduced glutathione and age-dependendly increased (young) or decreased the absolute level of oxidized glutathione (GSSG). Despite the absolute increase in GSSG, usually a marker of oxidative stress, the more important GSH / GSSG ratio, i.e. the ratio of reduced to oxidized glutathion, a more comprehensive marker of the balance of pro- vs. anti-oxidant metabolic processes, improved even more in the twelve young rats, (+6% GSH/GSSG) than in their older companions (+1% GSH/GSSG).
Figure 2: p-Akt levels in young and old rats with and without DHEA supplementation (data adapted from Jacob 2011)
As a faithful student of the SuppVersity, the serine/threonine kinase Akt should not be a stranger to you, after all, mTOR and p706SK (the "muscle builders", you've read about in the context of BCAAs, leucine and exercise-induced protein synthesis), are among its intracellular substrates. In agreement with previous studies, chronic administration of DHEA increased p-Akt-expression in the study at hand (cf. figure 2). The scientists speculate "that the Akt activation in this organ [the liver] is a protective answer" and could, after all, be the underlying reason for the preservation / restauration of hepatic function in the old rats.
Image 2: Oral DHEA supplements are sold for a few bucks over-the-counter (at least in the USA). Yet,
esp. for people under the age of 35, it probably does not make sense to buy and use those. At least, for
as long as it takes for the results of the study at hand to be confirmed in humans. And the allegedly benign 7-Keto DHEA could wreak havoc on your natural corticosteroid metabolism.
So how much DHEA should I take? Given the fact that the name of this blog is SuppVersity, I should have apprehended DeDeRa's question on which form and how much DHEA I would suggest you take. My answer is quite simple: NONE! Why? Well, this is a rodent study done with injectable DHEA. Not only would it be imprudent to extrapolate any dosing suggestions for oral DHEA supplements in humans, without clinical tests, we cannot even be sure that the effects would be identical, even if we hit the right dosage. Thus, while I am convinced that DHEA is probably more benign than many other OTC "supplements", especially people under the age of 30-35 should think twice or better thrice before popping any DHEA supplement - this includes 7-keto, the cortisol-suppressant effects of which can wreak havoc on your natural corticosteroid balance, make you feel tired and sluggish and deprive your body of an important anti-inflammatory pathway.
Most importantly, however, the study does away with the longstanding prejudice that DHEA (at the given dosage) "represent[s] a toxic potential to [the] liver". The isolated finding that endogenous DHEA lead to increased oxidation in the liver (it still does, but the overall pro- vs. anti-oxidant balance still improves!), as well as insufficient funding by the pharmaceutical industry, who obviously is not interested in naturally occuring and thus non-patentable treatment methods, had been one of the primary reasons many scientists decided not to dig deeper into the ameliorative, preventive and restaurative effects of DHEA in the context of age-related diseases. Personally, I hope that the few new studies that have been published, lately, will encourage other researchers to have another look at a hormone with profound yet complex and complicated effects on numerable aspects of the mammalian metabolism.