|
|
| |
 11
November 2003 - Can extracts of natural substances like
plants inhibit DHT
production just like drugs can? According to these recent
studies phytosterols, otherwise known as chemicals derived
from plants, can in fact inhibit DHT production?
Inhibiting
DHT inhibition is the key to halting and reversing genetic
hair loss thats also known as Male Pattern Baldness or
Androgenetic Alopecia. DHT is formed when an enzyme called
5 Alpha Reductase changes the male hormone testosterone
into the much more powerful form known as DHT.
Plant-based
products like Revivogen and Crinagen utilize topical formulations
of these phytosterols to inhibit DHT without the side effects
associated with other oral hair loss treatments like Propecia.
In
the first study (see below) researchers were able to determine
that in different cell systems, the lipido-sterolic extract
of Serenoa repens also known as Saw Palmetto or Permixon
inhibited both type 1 and type 2 5alpha-reductase activity
(5alphaR1 and 5alphaR2). The DHT inhibition was attributed
to the free fatty acids in the Saw Palmetto
In the second study (see below), polyphenols, which are found in green tea
amongst other things, were also shown to inhibit DHT. These powerful compounds
can help with hair loss even when taken orally but side effects can occur
as in the case of drug treatments.
For
those people unwilling to take drugs like Propecia or unable
to tolerate the side effects resulting from taking natural
supplements orally, topical solutions incorporating free
fatty acids offer the best option for treating hair loss. |
|
|
Inhibition of type 1 and type 2
5alpha-reductase activity by free fatty acids, active ingredients
of Permixon.
Raynaud JP, Cousse H, Martin PM.
J Steroid
Biochem Mol Biol. 2002 Oct;82(2-3):233-9 D.R.I.T.T.,
Universite Pierre et Marie Curie, 4 Place Jussieu, Paris,
France.
In different cell systems, the lipido-sterolic
extract of Serenoa repens (LSESr, Permixon inhibits both
type 1 and
type 2 5alpha-reductase activity (5alphaR1 and 5alphaR2).
LSESr is mainly constituted of fatty acids (90+/-5%) essentially
as free fatty acids (80%). Among these free fatty acids,
the main components are oleic and lauric acids which represent
65% and linoleic and myristic acids 15%.To evaluate the inhibitory
effect of the different components of LSESr on 5alphaR1 or
5alphaR2 activity, the corresponding type 1 and type 2 human
genes have been cloned and expressed in the baculovirus-directed
insect cell expression system Sf9. The cells were incubated
at pH 5.5 (5alphaR2) and pH 7.4 (5alphaR1) with 1 or 3nM
testosterone in presence or absence of various concentrations
of LSESr or of its different components. Dihydrotestosterone
formation was measured with an automatic system combining
HPLC and an on-line radiodetector.The inhibition of 5alphaR1
and 5alphaR2 activity was only observed with free fatty acids:
esterified fatty acids, alcohols as well as sterols assayed
were inactive. A specificity of the fatty acids in 5alphaR1
or 5alphaR2 inhibition has been found. Long unsaturated chains
(oleic and linolenic) were active (IC(50)=4+/-2 and 13+/-3
microg/ml, respectively) on 5alphaR1 but to a much lesser
extent (IC(50)>100 and 35+/-21 microg/ml, respectively)
on 5alphaR2. Palmitic and stearic acids were inactive on
the two isoforms. Lauric acid was active on 5alphaR1 (IC(50)=17+/-3
microg/ml) and 5alphaR2 (IC(50)=19+/-9 microg/ml). The inhibitory
activity of myristic acid was evaluated on 5alphaR2 only
and found active on this isoform (IC(50)=4+/-2 microg/ml).The
dual inhibitory activity of LSESr on 5alpha-reductase type
1 and type 2 can be attributed to its high content in free
fatty acids.
|
| |
| Structure-activity relationships
for inhibition of human 5alpha-reductases by polyphenols.
Hiipakka RA, Zhang HZ, Dai W, Dai Q, Liao S.
Biochem Pharmacol. 2002 Mar 15;63
Department of Biochemistry and Molecular Biology, The Ben
May Institute for Cancer Research, and The Tang Center for
Herbal Medicine Research MC6027, University of Chicago, 5841
S. Maryland, Chicago, IL 60637, USA.
The enzyme steroid 5 alpha-reductase (EC 1.3.99.5) catalyzes
the NADPH-dependent reduction of the double bond of a variety
of 3-oxo-Delta(4) steroids including the conversion of testosterone
to 5 alpha-dihydrotestosterone. In humans, 5 alpha-reductase
activity is critical for certain aspects of male sexual differentiation,
and may be involved in the development of benign prostatic
hyperplasia, alopecia, hirsutism, and prostate cancer. Certain
natural products contain components that are inhibitors of
5 alpha-reductase, such as the green tea catechin (-)-epigallocatechin
gallate (EGCG). EGCG shows potent inhibition in cell-free
but not in whole-cell assays of 5 alpha-reductase. Replacement
of the gallate ester in EGCG with long-chain fatty acids
produced potent 5 alpha-reductase inhibitors that were active
in both cell-free and whole-cell assay systems. Other flavonoids
that were potent inhibitors of the type 1 5alpha-reductase
include myricetin, quercitin, baicalein, and fisetin. Biochanin
A, daidzein, genistein, and kaempferol were much better inhibitors
of the type 2 than the type 1 isozyme. Several other natural
and synthetic polyphenolic compounds were more effective
inhibitors of the type 1 than the type 2 isozyme, including
alizarin, anthrarobin, gossypol, nordihydroguaiaretic acid,
caffeic acid phenethyl ester, and octyl and dodecyl gallates.
The presence of a catechol group was characteristic of almost
all inhibitors that showed selectivity for the type 1 isozyme
of 5 alpha-reductase. Since some of these compounds are consumed
as part of the normal diet or in supplements, they have the
potential to inhibit 5 alpha-reductase activity, which may
be useful for the prevention or treatment of androgen-dependent
disorders. However, these compounds also may adversely affect
male sexual differentiation.
|
|
 |
| |
| ADVERTISEMENT |
|
|
