463 DELIVERING SUSTAINABLE SOLUTIONS TO IMPROVE WELLBEING
PERFORMANCE OF TETRAPEPTIDE-1
The peptide efficacy mimics the biological effect of microcurrent devices that use low level
electrical signals (typically less than 1000 µA) to effectively combat aging indicators, such
as facial sagging and wrinkles, which has yielded remarkable outcomes.13–15 These signals
prompt cellular responses across various skin layers. Within the dermis, microcurrents
stimulate enhanced extracellular matrix production and dermal contraction capabilities.16
Simultaneously, at the muscular level, these signals contribute to elevate the tone of facial
muscles. Both microcurrents and the peptide presented herein counteract facial sagging by
orchestrating a mechanism involving MBNL1, an RNA-binding protein that is pivotal in
the transdifferentiation of fibroblasts to myofibroblasts, a cell type exhibiting heightened
contraction ability.17–18
As shown in Figure 9, treatment with the tetrapeptide increased the MBNL1 protein amount
in fibroblasts in a dose response manner and in a similar way to microcurrent stimulation.
To further confirm the myofibroblast phenotype, EDA-fibronectin, a cell marker implicated
in cell contraction and adhesion functions,19–20 was measured in HDFa cells after treatment
with the novel peptide. As shown in Figure 10, the novel peptide induced the accumulation
of EDA-fibronectin markers in fibroblasts by 72.3% compared to the control, thus
confirming modulation toward the myofibroblast phenotype. Furthermore, the increase of
EDA-fibronectin with tetrapeptide-1 was greater than that of the microcurrent stimulation.
Finally, to further confirm the microcurrent-like effect of the novel tetrapeptide, we
evaluated the ability of the peptide to induce collagen contraction (Figure 11). The novel
peptide induced collagen contraction by 37.5% with respect to the control condition, thus
showing similar efficacy when compared to microcurrent stimulation.
PERFORMANCE OF S REBAUDIANA EXTRACT
S rebaudiana extract acts in a similar way to retinoids by helping to minimize the
appearance of wrinkles and homogenizing the skin tone but in a gentler way. It has
Figure 8. Percentage of inhibition of IL1alpha release in HEKa cell culture after incubation during 24 hours
with THW biotech ingredient concentrate with or without the metabolic stress. Data shown as MEAN ± SEM
of the mean of three to four independent experiments. Statistical significance: versus control (**p 0.01),
versus metabolic stress (****p 0.0001), calculated using an unpaired student’s t-test.

464 JOURNAL OF COSMETIC SCIENCE
been shown to induce the expression of genes related to the pathway of retinoids in vitro,
promotes activities such as skin regeneration, enhances ECM proteins, and boosts cellular
resistance to oxidative stress, all while minimizing the skin inflammation associated with
retinoids similarly to bakuchiol. In vivo, the ingredient helped to minimize the appearance
of wrinkles, homogenized the skin tone, and reduced the number of dark spots.
Treatment with S rebaudiana extract increased retinol binding protein (RBP1) gene
expression by 18.2% in a statistically significant manner (data not shown), which improves
the amount of retinol entering the cell. Therefore, the combination of the extract with
retinol can reduce the use of retinol in formulations to minimize potential adverse effects.
Moreover, as shown in Figure 12, the active ingredient also enhanced the expression of
nuclear receptors RAR and RXR with similar efficacy to retinoic acid, which triggers the
transcriptional activity of retinoid-responsive genes that impart the final benefits.
To determine if S rebaudiana extract can deliver benefits similar to retinoids, several
end points were measured. As shown in Figure 13, S rebaudiana extract increased the
production of the HAS2 gene, similarly to retinoic acid, which potentially leads to an
Figure 9. (A) Percentage of variation in MBNL1 levels. Data shown as MEAN ± SEM of the mean of three
independent experiments. Statistical significance: *p 0.05, ***p 0.001, calculated using an unpaired
student’s t-test. (B) Representative images showing MBNL1 (green) protein in fibroblasts after tetrapeptide-1
treatment and after microcurrent stimulation (1000 µA, 70 mV/mm, 1 hour).