SKIN CARE A Sebum
140 120 100 80 60 40 20 0
Placebo C
120 100 80 60 40 20 0
Placebo
Zn-peptide 13.5 µg/mL
Number of visible pores *
0 weeks ■ 2 weeks ■ 4 weeks ■ 6 weeks ■
* * **
0 weeks ■ 2 weeks ■ 4 weeks ■ 6 weeks ■
0 weeks Placebo B
Zn-peptide 13.5 µg/mL
A
55
B 2 weeks
Retinol 0.2%
0 weeks ■ 2 weeks ■ 4 weeks ■ 6 weeks ■ Protoporphyrin IX (C. acnes number)
4 weeks
120 115 110 105 100 95 90 85 80
Placebo
Zn-peptide 13.5 µg/mL
Retinol 0.2%
6 weeks
Zn-peptide 13.5 µg/mL
Retinol 0.2%
Figure 3: Zn-peptide inhibited sebum production and reduced the number of visible skin pores. Retinol, on the other hand, increased skin oiliness after two weeks of treatment which normalized later although it did not fall below the placebo level. Sebum level was determined by a sebumeter (A). The number of visible skin pores was determined by an image analysis of whole-face images: (B) representative pictures of the image analysis, (C) quantification
corresponding concentrations and retinol (Figure 1A). These results show that both the hexapeptide and zinc components contribute to the observed effect of the Zn-peptide complex.
Inhibition of hyperkeratinization Another typical event in acne pathogenesis is abnormal differentiation and hyperkeratinization of follicular keratinocytes leading to the increased cohesiveness of corneocytes and their impaired desquamation. The accumulated mass of keratinized corneocytes together with sebum obstruct follicles resulting in their extension and creating favorable conditions for the colonization of C. acnes.6 Zn-peptide complex as well as the
hexapeptide alone were shown to downregulate genes associated with keratinocyte
A
140 120 100 80 60 40 20 0
Overall skin redness B
differentiation in the same manner as retinol whereas zinc of corresponding concentrations had no such effect (Figure 1B). The results show that the hexapeptide component of Zn-peptide complex is responsible for this effect.
Antimicrobial activity towards C. acnes C. acnes is a bacterium living in and on the human skin as part of the normal human skin microbiome. It predominantly resides deep within the sebaceous hair follicles. It is well- established that C. acnes overgrowth plays a significant role in the pathogenesis of acne.7 In the human skin, C. acnes does not live
in a planktonic form but creates a biofilm, a community of bacteria embedded in self- produced matrix protecting it against the human immune system and also against
Zn-peptide 13.5 µg/mL 0 weeks
■ 0 weeks ■ 2 weeks ■ 4 weeks ■ 6 weeks
2 weeks C 0 weeks Retinol 0.2% 2 weeks
130 120 110 100 90 80 70 60 50 40
Placebo Zn-peptide 13.5 µg/mL
Retinol 0.2%
Figure 4: Zn-peptide reduced the number of C. acnes. Retinol, on the other hand, increased C. acnes number after two weeks of treatment which normalized later although it did not fell below the placebo level. These changes are probably associated with the similar trend in the sebum level observed after retinol treatment. The level of protoporphyrin IX was determined by an image analysis of the whole-face images: (A) representative image of orange fluorescence of porphyrins, products of C. acnes corresponding to the bacteria number,10
(B) quantification
antimicrobial therapies.8 Zn-peptide complex showed enhanced
antimicrobial activity towards C. acnes growing in biofilm in comparison to its separate components: hexapeptide and zinc (Figure 1C). Because retinol does not possess any direct antimicrobial properties, it was not evaluated.
Anti-inflammatory activity Inflammation is regarded as a key part in the pathogenesis of acne. In the past, inflammation was thought to be a secondary event induced by C. acnes overgrowth. Recently, inflammatory processes are believed to be involved in all stages of acne development and acne is nowadays considered as a genuinely inflammatory disease.9 UVB irradiation of keratinocytes strongly
TEWL ** ** *
■ 0 weeks ■ 2 weeks ■ 4 weeks ■ 6 weeks
Placebo Zn-peptide 13.5 µg/mL
Retinol 0.2%
Figure 5: Zn-peptide calmed the skin, reduced the overall skin redness and reinforced skin barrier function by reducing TEWL. Retinol, on the other hand, irritated the skin after two weeks of treatment as shown by the increased skin redness. Retinol also gradually increased TEWL values reflecting skin barrier impairment. These results confirm a well-documented skin irritation potential of retinol which hinders its use by many people especially those with the sensitive skin. The overall skin redness was determined by an image analysis of the whole-face images: (A) quantification, (B) representative images after two weeks of treatment. TEWL was determined by a tewameter (C)
www.personalcaremagazine.com July 2023 PERSONAL CARE
Overall skin redness (% of placebo)
Number of visible pores (% of placebo)
Sebum (% of placebo)
Protoporphyrin (% of placebo) Overall skin redness (% of placebo)
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92
