SKIN BRIGHTENING 59 120,00 100,00 80,00 -41% 60,00 40,00 20,00 0,00 Untreated Resveratrol
Larix Sibirica (50ppm)
Larix Sibirica (300ppm)
60,00 40,00 20,00 0,00 Untreated Resveratrol
Larix Sibirica (50ppm)
Larix Sibirica (300ppm)
Figure 7: DNA degradation of Larix sibirica powder (50ppm and 300ppm) in fibroblasts (at the top) and keratinocytes (down). Untreated cells, and cells treated with resveratrol were the negative and positive controls, respectively. Human Dermal Fibroblasts (HDF) and Human Epidermal Keratinocytes (HEK) were irradiated with 300 mJ/cm² and stored in the dark at room temperature.
Compared to untreated cells and
resveratrol, results indicated Siberian larch extract decreased DNA degradation up to 33% in keratinocytes and 41% in fibroblasts after irradiation (Fig 7).
Anti-ageing effect of Larix sibirica Oxidative stress has been widely described to degrade connective tissue as collagen and elastin via collagenase-1 upregulation (MMP-1) and to inhibit indirectly collagen synthesis in human skin. The potential anti- ageing effect of Siberian larch extract has been investigated on collagenase-1 activities and collagen synthesis. l Inhibition of collagenase-1 activities
The inhibitory effect of Siberian larch extract on collagenase-1 activity was determined utilising the collagenase assay method. Siberian larch powder was dissolved in ethanol absolute at 10 mg/mL (stock solution). Several aliquots of stock solution were added to the reaction mix, and the collagenase assay was performed.
The collagenase activity is inhibited quite linearly by increasing the concentration of Larix sibirica. The enzyme was inhibited completely by a concentration of 20 ppm of Larix sibirica (Fig 8).
l Collagen synthesis stimulation: Larix sibirica collagen pumper
Collagen synthesis is a very important tool since is related to the restructuration of tissues and their renewal. The effect of Larix sibirica on collagen synthesis of cells in culture has been studied according to a method for the determination of collagen produced. Total collagen content was determined as the total soluble collagen into culture
June 2019
medium using Sircol Collagen Assay (Biocolor) (Fig 9). Larix sibirica was very effective in inducing collagen synthesis in the cultured cells. By using Sircol Collagen Assay, in comparison to supernatants of cells grown in DMEM (negative control), an approximate 1.6; 3.3; and a 6-fold increase of collagen was detected in supernatants of cells grown respectively with 50 ppm, 100 ppm and 300 ppm Larix sibirica. These results are of extreme interest considering that the effect of 50 µg/mL acid ascorbic, a well-known inducer of collagen synthesis, is only a 1.2-fold increase respect to the control (Fig 9).
Discussion
Flavonoids, potent antioxidants, are frequently used in skin lightening agents. The main action behind the pigment
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0 510 15 Larix Siberica ppm
Figure 8: Effect of Larix sibirica on inhibition of collagenase-1. The enzymatic assay of collagenase was performed using N-(3-[2-furfuryl]acryloyl)-Leu-Gly–Pro-Ala (FALGPA)as substrate.
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reducing effect of flavonoids may be due to their capacity of scavenging ROS generated in the skin to inhibit second messengers that may stimulate melanogenesis. Antioxidant agents can also influence skin pigmentation by chelating copper at the active site of tyrosinase, a specific pigmentation enzyme.14 Results have shown that Larix sibirica
prevents melanogenesis by decreasing melanin synthesis. Interestingly, it has a specific action on the melanin biosynthesis process. Indeed, thanks to its antioxidant power, it reduces specifically the melanin synthesis content by suppression of key pigmentation genes like Tyr and or Mitf and genes involved in melanosome structure and biogenesis Pmel17 and Mart1. Therefore, Larix sibirica plays a key role in skin whitening and brightening. Moreover, lightening agents, by reducing
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% DNA degradation
% Collagen activity
% DNA degradation
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