X-Message-Number: 21365
Date: Sat, 8 Mar 2003 10:18:42 -0800 (PST)
From: Doug Skrecky <>
Subject: superoxide dismutase mimetic EUK-8 is a bust
No Increase in Lifespan in Caenorhabditis Elegans Upon Treatment With the
Superoxide Dismutase Mimetic EUK-8.
Free Radical Biology & Medicine Vol.34, No. 2, pp, 277-282, 2003
ABSTRACT: The superoxide dismutase mimetic EUK-8 has been reported to
extend lifespan in the nematode Caenorhabditis elegans. However, in five
trials administering EUK-8 in liquid culture with E. coli, and two trials
using defined liquid medium, we observed no increase in C. elegans
lifespan.Instead we saw a dose-dependent reduction of lifespan and
fertility. We conclude that extension of C. elegans lifespan by EUK-8 may
only occur under very particular culture conditions.
[comment by poster:]
Here' a short summary of what does work to increase lifespan in C.
elegans:
Interventions that reduce the metabolic rate of C. elegans also
increase lifespan. (Proc. Natl. Acad. Sci. 96: 11399-11403 September
1999) Such interventions include reducing environmental temperature,
genetic alterations such as age-1, or daf-2 mutations, and (probably)
depletion of coenzyme Q in the diet.
I had believed that calories were a factor as well, since addition of
E. coli bacteria to medium, increases nematode size, and reduces
lifespan. However it has been found recently that lifespan increases
occur in nematodes that are switched to a medium containing an E. coli
mutant which does not synthesize coenzyme Q. Thus it would appear that it
is the coenzyme Q content, rather than calories, which modulates lifespan
via medium alterations. (see below)
(Mechanisms of Ageing and Development 6: 413-429 1977)
Temperature effects
Degrees C Average lifespan (days)
____________________________________
6 17.8
10 34.7
14 20.8
16 23.0
20 14.5
24 9.9
25.5 8.9
(note on 6 C result: Chilling damage can occur at very low temperatures,
as cell membranes undergo a phase change, and leak cell contents.)
(Genetics 141: 1399-1406 December 1995)
Genetic/Temperature effects
Degrees C Strain Mean Maximum Lifespan (days)
_____________________________________________________
15 wild 25 33
15 age-1. fer-15 29 60
15 daf-2 43 62
15 daf-2, age-1, fer-15 52 74
20 wild 18 28
20 daf-2 36 78
20 daf-2, daf-20 50 83
25 wild 12 25
25 age-1, fer-15 23 41
25 daf-2 33 60
25 daf-2, age-1, fer-15 33 56
(Science 272: 1010-1013 May 17, 1996)
More Genetic/Temperature effects
Degrees C Strain Mean lifespan (days)
________________________________________
18 daf-2 29.7
18 daf2, clk-1 34.0
25 N2 8.5
25 clk-1 8.6
25 daf-2 15.9
25 daf-2, clk-1 49.1
(Science 295: 120-123 2002
Genetic/Temperature/Coenzyme Q effects
Degrees C strain Coenzyme Q Mean Maximum lifespan (days)
_________________________________________________________________
20 N2 +Q 13 25
20 N2 -Q 27 41
25 daf-2(e1370) +Q 30 46
25 daf-2(e1370) -Q 38 54
25 daf-2, clk-1 +Q 46 68
25 daf-2, clk-1 -Q 52 84
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