Sun Protection

EGCG and Hinokitiol can Help Reduce Hyperpigmentation

By Evelin Maza

(-)-Epigallocatechin-3-gallate and Hinokitiol Reduce Melanin Synthesis via Decreased MITF Production (¹).

How to reduce hyperpigmentation? EGCG and hinokitiol already have well-known beneficial effects on human health. EGCG, or (-)-Epigallocatechin-3-gallate, is the main component in green tea. Many studies have proven its effects against oxidative stress, inflammation, and the development of cancer (²).

Hinokitiol, on the other hand, comes from the wood of certain trees such as cedar, and is an effective antibacterial (³). Commercially, it is used in cosmetics for hair, toothpaste, elimination of bad breath, etc.

But these two substances now have one more quality to brag about: they help prevent cosmetic problems. EGCG and hinokitiol reduce hyperpigmentation by lowering the amount of melanin found in the skin.

Hyperpigmentation is the darkening of the skin caused by excessive exposure to the sun, certain hormonal issues, or even acne (⁴). The amount of pigment in your skin, as well as the color of your hair, is determined by the amount of melanin in it.

Melanin is the name given to the natural pigments found in living beings Thus, one way to avoid unsightly pigmentation is to reduce the amount of melanin produced within the skin. This is where EGCG and hinokitiol come into play in a study conducted in Korea!

Background

The process of the production of melanin, or melanogenesis, involves many proteins, enzymes, internal factors, such as the person’s immune system, as well as external factors, such as the amount of ultraviolet radiation received.

The main proteins that were studied in this trial were: tyrosinase, Microphthalmia-associated transcription factor (MITF), and Extracellular signal-regulated kinase (ERK).

Tyrosinase is an enzyme which stimulates the production of melanin. Which means: the more tyrosinase, the more melanin is produced.

MITF is a protein which regulates many internal processes associated with pigmentation and the growth of melanin-producing cells. It actually stimulates the activity of tyrosinase. That is to say: the more MITF is present, the more active tyrosinase becomes, and the more melanin is produced.

Finally, ERK is a chain of proteins responsible for, among many other things, the regulation of melanogenesis (⁵). The activation of this pathway leads to less melanin; its inhibition leads to greater pigmentation.

In conclusion, in this study, these three substances were analyzed in order to determine whether EGCG and /or hinokitiol affected the production of melanin and through which specific process.

Study Summary

The material used as a substitute for human skin were Mel-Ab cells. These are lab-grown cells derived from mice which produce a lot of melanin. These cells were exposed to either EGCG, hinokitiol, or kojic acid for 4 days. Then, all of the groups were photographed with a special microscope in order to measure the amount of melanin present.

The kojic acid was used as a positive control. In other words, it has already been proven that kojic acid lowers melanin production in the skin (⁶); therefore, it would be a good point of comparison.

The viability of the cells was also analyzed after the 4-day treatment. The goal of studying this factor was to see if any of the substances used were cytotoxic. In other words, if they were harmful to the growth and development of the cells.

MITF, tyrosinase protein production, and ERK activation were also tested. Both separately and in combinations in order to see whether any of the substances had additive effects.

Results

It was proven that cells treated with EGCG, kojic acid, and hinokitiol were all less pigmented. That is to say, they contained less melanin. But, of the three, hinokitiol produced the lowest level of pigmentation.

EGCG and kojic acid, when used in combination, did not show any additive effect. How to reduce hyperpigmentation? EGCG and hinokitiol did show an even bigger hypopigmentating effect when used together, proving that these two substances function through different processes.

None of the substances (EGCG, kojic acid, and hinokitiol) had cytotoxic effects on the mice cells.

The ERK pathway was not activated by neither hinokitiol nor EGCG. But, lower amounts of MITF and tyrosinase were found after the 4-day treatment. This proves that their melanin-reducing effects are associated with these two factors!

Lastly, it was proven that hinokitiol had the strongest effect in lowering the amount of tyrosinase in the cells.

Conclusion…

To summarize, these scientists have proven that green tea offers yet another benefit for our overall health (⁷). And this time, the benefit is cosmetic! But not only that: they have also pinpointed just how these substances have these marvelous effects.

The conclusion is that EGCG and hinokitiol reduce the amount of melanin in our skin, preventing problems with hyperpigmentation. And they do so by lowering the levels of MITF and tyrosinase within our cells.

Study proves that tomatoes can protect the skin from UV radiation

By Evelin Maza, MBBS

Molecular evidence that oral supplementation with lycopene or lutein protects human skin against ultraviolet radiation: results from a double-blinded, placebo-controlled, crossover study (¹).

Many studies have confirmed that excessive exposure to the sun and its ultraviolet radiation (UVR) is detrimental to healthy skin. It has been confirmed to cause skin damage, wrinkling, and even cancer (²).

But, is the use of sunscreen and avoiding too much direct sunlight our only means of protection? Not anymore.

For years, studies have analyzed the efficacy of dietary supplements as a source of skin health. Carotenoids are of particular interest (³). Carotenoids are organic pigments produced by plants, algae, some bacteria, and even certain fungi. And the most vastly studied carotenoid is beta-carotene, which is found in yellow, orange, or red fruits and vegetables, such as carrots and apricots.

Alas, negative long-term side effects have been linked to the chronic use of big amounts of beta-carotene (⁴).

Therefore, other substances have been tested, such as lycopene, lutein, and carotenoid mixtures. Some of these studies have shown that tomatoes, rich in lycopene, offer great protection from the sun when mixed with beta-carotene, as well as on its own (^{5, 6}).

A randomized, double-blind, placebo-controlled, crossover trial which took place in Germany studied the standalone effects of lutein and lycopene-rich tomato supplements; and the findings were quite promising!

Study Summary

This study divided volunteers with no previous history of skin-related illnesses into 4 groups: lycopene active treatment, lycopene placebo treatment, lutein active treatment, and lutein placebo treatment.

Treatment was administered via softgel capsules. 2 capsules daily of 10 mg free lutein stabilized by 10% carnosic acid in the case of lutein and 4 capsules daily of 5 mg lycopene, as well as other tomato phytonutrients, such as phytoene and phytofluene, tocopherols and phytosterols, in the case of lycopene. With soybean oil capsules being used as placebo, as it offers the skin no protective effects against UVR.

The study consisted in 2 periods of 12-week treatments of either placebo or one of the two active agents. Each treatment period was preceded by a 2-week washout period. If a volunteer began with placebo, they were switched to an active lutein or lycopene supplement in the following treatment period, and vice versa.

Blood samples were taken at the beginning and end of each period to measure the rise in carotenoid levels.

Also, the participants were exposed to UVA/B and UVA1 and had 3 biopsies extracted. One from skin that wasn’t exposed to radiation, one from UVA/B-irradiated skin, and one from UVA1-irradiated skin. This was done at the beginning and end of each 12-week treatment period, 24 hours after the exposure to radiation.

With the biopsies, the researchers were able to measure the amount of certain proteins which are linked to oxidative stress, collagen breakdown, and skin inflammation caused by UV exposure. The genes analyzed were an enzyme that produces carbon monoxide (HO-1), intercellular adhesion molecule-1 (ICAM-1) and matrix metalloproteinase-1 (MMP-1).

Study Highlights

This particular trial is unique for two important reasons.

For one, most of the studies about the effects of UVR on healthy skin and the protection dietary supplements may offer use UV-induced sunburn reactions or the reddening of the skin as a sign of damage caused by sunlight (⁷).

But this study used biopsies and proteins linked to oxidative stress as a new way to measure the sun’s harmful effects.

And secondly, most studies about UV damage use UVA and/or UVB radiation emitted by a solar simulator. This only covers the shortwave types of ultraviolet radiation. Thus, this study set out to also cover and analyze longwave UV radiation, or UVA1. To document its effect on the skin via he measurement of proteins and the inhibition of said effects via carotenoid supplements.

Findings: Tomatoes have protective qualities against solar skin damage

Throughout all of the volunteers, it was found that the plasmatic levels of carotenoids increased significantly. Results which were confirmed by the low levels found in the blood samples during periods of placebo intake.

Yet, they found that lycopene levels weren’t affected by the order of the treatments. But lutein levels were notably lower when administered after a 12-week period of treatment with the soybean oil capsules.

Also, the biopsies showed that exposure to UVR in all of its forms increased the expressions of the genes linked to oxidative stress.

However, the biopsies taken after periods of active lycopene or lutein supplement treatment showed a much lower activity of these genes. And both supplements show the same efficacy of protection if taken during the first period of treatment.

Also, the protective qualities of these carotenoids applied to the three different types of radiation used equally.

Although the researchers still don’t know exactly how lycopene and lutein achieve these effects, it is thought that they balance out oxidative stress (⁸).

In conclusion, these German scientists proved that lycopene and lutein protect the skin against UV-induced damage.

How can I apply these results?

To sum up, you must avoid the damage and skin ageing which excessive exposure to the sun may cause, including loss of elasticity, drying, and wrinkling. This can be achieved by modifications in your diet.

By including dietary supplements rich in lycopene, lutein, and beta-carotene, you can prevent UVR-induced skin damage and even lower your risk of cancer.

An easy way to incorporate more carotenoids into your diet is by consuming more brightly colored fruits and vegetables, such as tomatoes, bell peppers, corn, and bananas, among others.

The researchers state that “To ingest 20 mg lutein and 20 mg lycopene, a cup of chopped kale (130 g) and a serving (242 g) of tomato juice would be enough.”

SOURCE:

Br J Dermatol. 2017 May;176(5):1231-1240. doi: 10.1111/bjd.15080. Epub 2017 Mar 15.

Molecular evidence that oral supplementation with lycopene or lutein protects human skin against ultraviolet radiation: results from a double-blinded, placebo-controlled, crossover study.

Grether-Beck S¹, Marini A¹, Jaenicke T¹, Stahl W², Krutmann J¹.

IUF - Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany.

Institute of Biochemistry and Molecular Biology I, Faculty of Medicine, Heinrich Heine University, Düsseldorf, Germany.