Turmeric, a method for lightening dark circles?

Turmeric or Indian saffron is a perennial plant native to Southeast Asia. Generally, the part used in cosmetics or cooking is the rhizome. This underground stem indeed contains several active principles with interesting virtues. Numerous studies have focused on turmeric and have shown that it provides the skin with many benefits. As for dark circles, this ingredient is capable of acting on two particular types of dark circles: vascular and pigmented dark circles. Turmeric is thus included in the formulation of several eye contour treatments, such as creams or masks. It is recommended to use an eye contour based on turmeric for at least four weeks to observe results.

Note : The studies mentioned below were not conducted directly on the eye contour. Therefore, caution should be exercised regarding the effects of turmeric on dark circles.

Turmeric to diminish bluish dark circles.

Turmeric contains curcumin, a curcuminoid capable of influencing numerous biological processes. One study has notably demonstrated that this molecule stimulates microcirculation of the blood, a property beneficial for combating the stagnation of blood pigments which are responsible for the formation of vascular dark circles. The mechanism of action of curcumin on blood circulation has not yet been identified and further research is still required. However, the effect of curcumin is confirmed. No threshold concentration has yet been communicated.

Turmeric powder to diminish the appearance of brown under-eye circles.

While turmeric is capable of combating vascular dark circles, it is particularly effective on pigmented dark circles. Indeed, the active ingredients it contains act at different levels of the melanin synthesis process, the pigment responsible for the dark colour of this type of dark circles. A study conducted in vitro on skin cells showed that curcumin had a tyrosinase inhibitory effect. This effect was dose-dependent, meaning it varied linearly with the amount of curcumin used. For example, a concentration of 3.8 µg/mL of curcuminoid can reduce tyrosinase activity by almost 20%. Furthermore, the same study showed that curcumin induced a decrease in the expression of the gene coding for tyrosinase.

We should also note that curcumin has properties antioxidant, allowing it to neutralise the excess free radicals generated in the body following exposure to UV rays. These reactive oxygen species cause several damages in the skin cells and stimulate the production of melanin. Therefore, curcumin has a both preventive and corrective effect on brown circles.

This molecule is not the only one to have an effect on melanogenesis. Alpha-turmerone, a sesquiterpene found in turmeric powder, has also demonstrated its ability to inhibit this phenomenon in tests conducted on mice. More specifically, this molecule prevents the synthesis of the hormone α-MSH (α-melanocyte-stimulating hormone), a hormone that activates certain melanocortin receptors. These receptors trigger the production of melanin. Alpha-turmerone can also inhibit the phosphorylation of the CREB protein (C-AMP Response Element-Binding Protein). This phosphorylation triggers a cascade of reactions leading to the stimulation of tyrosinase transcription.

Key Takeaway : By acting on various mechanisms of melanogenesis, turmeric limits the production of melanin, the pigment that gives brown circles their colour.