Hello everyone, it’s been a long time, I really miss it! After thinking for a long time, I finally picked a slightly flavorful whitening ingredient (glutathione) to chat about!
What is glutathione?
Glutathione (GSH) is a tripeptide composed of glutamic acid, cysteine, and glycine. It is the main antioxidant in the body and plays an important role in maintaining the thiol state and detoxification in cells.
Although glutathione exists in two states: reduced glutathione (GSH) and oxidized glutathione (GSSG), oxidized glutathione is actually two reduced forms of glutathione bound to sulfur atoms. However, most of its storage in the body exists in a reduced form.
Glutathione is widely present in animals and plants, and it can participate in biotransformation, converting harmful toxins in the body into harmless substances that are excreted from the body, thereby helping to maintain normal immune system function.
The ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG) determines the redox state of cells.
The GSH/GSSG ratio of healthy cells in a quiescent state is greater than 100, while in cells exposed to oxidative stress, the ratio decreases to 1:10.
Glutathione is also considered a thiol buffer that maintains the thiol groups of many proteins. Glutathione is only produced in the cytoplasm and actively injected into mitochondria.
Reduced glutathione (GSH) is formed in cells through three ways:
(1) De novo synthesis is carried out through a two-step process catalyzed by glutamate cysteine ligase (GCL) and glutathione synthase (requiring ATP).
(2) Reduce oxidized GSSG to reduced GSH (requiring NADPH) through glutathione reductase.
(3) Recovery of cysteine from conjugated glutathione via GGTP (requiring NADPH).
The benefits of glutathione
antioxidant
Glutathione is the “main antioxidant” in the human body, which directly binds to oxidative compounds that can damage cell membranes, DNA, and more.
It can immediately neutralize various oxidants, including superoxide, nitric oxide, carbon free radicals, hydroperoxides, peroxynitrite, and lipid peroxides.
Whitening effect
Many literature studies have shown that glutathione belongs to thiol compounds, which can inhibit enzyme activity by binding to copper ions at tyrosine active sites, and act as an antioxidant to scavenge reactive oxygen species and free radicals or as a regulator of redox balance, thereby inhibiting the synthesis of overall melanin.
Although glutathione has been validated for its whitening efficacy in some clinical trials, the evidence for glutathione as a whitening agent is still insufficient.
There is literature indicating that after discontinuing glutathione, skin color will return to its original state.
Can glutathione penetrate the skin?
From a molecular weight perspective, glutathione has the potential for transdermal absorption!
There is literature studying the effect of different relative molecular weights of hyaluronic acid (HA) on the transdermal absorption of glutathione (GSH). Hyaluronic acid (HA) with different relative molecular weights has a significant impact on the amount of glutathione (GSH) that can penetrate the skin, and as the relative molecular weight of HA increases, the inhibitory effect on GSH penetration through the skin becomes stronger.
By comparing the storage capacity of glutathione (GSH) in the stratum corneum and dermis of isolated skin with the increase of hyaluronic acid (HA) with different relative molecular weights, the results show that hyaluronic acid with low relative molecular weight has the best storage capacity. However, the only regret is that no experimental data on transdermal recovery has been seen.
summary
In short, glutathione is a good skincare ingredient with both natural drawbacks and its own advantages.
Glutathione, as a peptide, is naturally unstable and easily breaks down in water, rendering it ineffective.
Glutathione has transdermal absorption ability. In order for glutathione to fully exert its effects, it is necessary to ensure that glutathione is retained in the stratum corneum and dermis layer as much as possible to achieve antioxidant and whitening effects.
