Melatonin and Lifespan

Jo Robinson jor at teleport.com
Sun Nov 26 16:16:27 EST 1995

Axel Kowald (a_kowald at chemie.fu-berlin.de) wrote:
: Hi 

: I just started reading the melatonin story from Jo Robinson and it's very
: good. I don't know if it has been mentioned before but I have two questions for
: Jo or anyone else.

: Firstly, when the Italian group found an extension of the life span, was it an
: extension of the mean or the maximum lifespan ?   Only if the maximum lifespan is
: increased one can speak of an retardation of the ageing process. Most treatments,
: except for dietary restriction, only increase the mean lifespan.

	*** In the Maestroni anti-aging study, only an increase in mean
lifespan was reported.  (752 days for controls; 931 days in melatonin-treated
mice.)  They do not list data about the maximum survival time of the mice nor
am I aware of the maximum survival time for that particular species. [C57BL/
6J inbred mice]  Ann. N.Y. Academy of Science 521:140-148.
: Secondly the antioxidant capacity of melatonin. Even if it is the most potent
: antioxidant I don't think it can cause its effects through its antioxidative
: properties. As mentioned it is also one of the most potent hormones having still
: an effect on the picogram scale. If it is present in so minute quantities in the
: bloodstream its antioxidative effect can only be small.
	Not true.  Melatonin's antioxidant effects have been shown to be
profound in in vivo studies.  As mentioned in an earlier thread, its 
unparalleled potency as an antioxidant, its preference for accumulating in
the nucleus of the cell, and its close association with the DNA molecule
(at one point it was believed that melatonin "intercalated" with the
DNA molecule, insinuating itself inbetween the base pairs.  That observation
has not been confirmed) are believed to be the reason why.  I suggest that
you read the results of some of the melatonin antioxidant studies.
	For starters:
	"The pineal hormone melatonin inhibits DNA-adduct formation induced
by the chemical carcinogen safrole in vivo." Cancer Letters 1993; 70:
	"Melatonin protects human blood lymphocytes from radiation
induced chromosome damage" Mutation Research 1995;346:23-31.
	"INhibitory effect of melatonin on cataract formation in
newborn rats: evidence for an antioxidant role for melatonin" J.
of Pineal Research 1994; 17:94-100.
	And of course, Reiter's recent review, "A review of the evidence
supporting melatonin's role as an antioxidant" J. of Pineal Research
1995; 18:1-11.

	Melatonin has been shown to have unparalled antioxidant properties,
both in vitro and in vivo.  We now await the human studies, which will
be forthcoming in the next five years.

|       Jo Robinson		    |            jor at teleport.com             |
|      (503)284-4676                |     2826 NE 18th Portland, OR 97212     | 

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