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Patients with psoriasis have reported that glycerin,
an inexpensive, harmless, slightly sweet liquid high
on the list of ingredients in many skin lotions, is
effective at combating their psoriasis and now
scientists have objective evidence to support their
reports. Scientist found that whether applied
topically or ingested in drinking water, glycerin,
or glycerol, helps calm the classic scaly, red,
raised and itchy patches in their psoriasis model.
The studies also provide more evidence of the
different ways glycerin enables the healthy
maturation of skin cells through four stages that
result in a smooth, protective skin layer. Psoriasis
is an immune-mediated problem that typically
surfaces in young adults in which skin cells instead
multiply rapidly, piling up into inflamed patches.
The glycerin, a natural alcohol and water attractor
known to help the skin look better, also safely
helped it function better by helping skin cells
mature properly. Topically, glycerin is known to
have a soothing, emollient effect. But another key
part of its magic, which is its conversion to the
lipid, or fat, phosphatidylglycerol, which
ultimately regulates the function of keratinocytes,
major skin cell type, and suppresses inflammation in
the skin. Glycerin gets into the skin through
avenues like aquaporin-3, a channel expressed in
skin cells, and the MCG scientists have shown that
once inside, aquaporin 3 funnels glycerin to
phospholipase-D-2, an enzyme that converts fats in
the external cell membrane into cell signals,
ultimately converting glycerin to
phosphatidylglycerol. The topical application of
phosphatidylglycerol reduced inflammation and the
characteristic raised skin patches in a mouse model
of psoriasis. This time they decided to look at the
impact of its widely available precursor glycerin.
For the new studies, they used imiquimod, which is
known to produce psoriasis-like plaques on humans
using it for problems like genital warts and some
skin cancers, to produce an animal model. The mice
either drank the sweet natural alcohol or the
scientists applied it topically. Either way,
glycerin helped reduce development of the
characteristic skin lesions, the scientists report,
a finding which helps underline that glycerin works
in more than one way to improve the skin condition.
Externally, glycerin showed its action as an
emollient because even in mice missing
phospholipase-D-2, it was beneficial. Additionally,
topically it appears to compete with hydrogen
peroxide for space inside the aquaporin 3 channel.
Hydrogen peroxide is commonly known as a mild
antiseptic but we produce it as well and at low
levels it's a cell signaling molecule. But at high
levels, hydrogen peroxide produces destructive
oxidative stress, which can actually cause
psoriasis. The scientists found that topical
glycerin reduced the levels of hydrogen peroxide
entering skin cells. When they added glycerin and
hydrogen peroxide at the same time directly to skin
cells, they found that glycerin protected against
the oxidative stress from hydrogen peroxide. |