Beautifying skin with natural milk tripeptides

Enzyme technology

A unique enzyme technology has been developed recently to produce proline-rich peptides from milk casein. This involves controlled hydrolysis of proline-rich proteins to produce a peptide mixture with defined size distribution and rich in tripeptides. This product is called milk tripeptides (MTP); INCI name: hydrolysed milk protein. The peptides have a proline at the carboxyl terminus due to a specific cleavage process. Figure 1 is a simple illustration of the process. Collagen which is the main component of the skin’s extracellular matrix is also rich in poline. With the presence of the proline in MTP, it was expected to induce the collagen production in the skin, therefore it could be used as an active ingredient against age-related skin phenomena.

Results and discussion

These milk tripeptides were evaluated via in vitro and in vivo tests to prove that they can induce collagen-1 production and deliver anti-ageing benefits.

In vitro test:

Fibroblasts isolated from a 55-year-old donor were used for collagen assay. The cells were starved for 72 hours prior to treatment with 10 ng/ml transforming growth factor b1 or with different levels of the milk tripeptides and then incubated for 48 hours. The collagen was quantified using the immuno-labelling fluorescence assay.

Figure 2 shows that MTP stimulated collagen-1 formation in aged fibroblasts. Compared to control, 0.001, 0.01, 0.02 and 0.03% MTP stimulated collagen levels 1.9, 2.4, 3.2 and 5.5 fold, respectively. Even as little as 0.03%, MTP performed better than the positive control, TGF-b1.

The collagen-1 stimulating property of MTP was further tested versus 2 commercial products of hydrolysed milk protein in the market. Results (Fig. 3) showed that MTP at 0.01 and 0.03% can stimulate collagen production better than Product A at 0.01 and 0.03% as well as Product B despite use of higher levels of 0.1 and 1.0%.

In vivo test

Sixty-four healthy female volunteers aged 49.4 +/– 8.7 with visible crow’s feet participated in the study. It was conducted as a double blind, placebo controlled, half face study. Each panellist applied O/W formulation with 0.5% MTP or without MTP, twice daily for a period of 12 weeks. Parameters measured were skin hydration using a corneometer and skin profile using PRIMOS. With PRIMOS, the skin roughness parameters Rz and Ra were determined describing deep and fine wrinkles, respectively. At the end of the study, the panelists were also asked to do a self-assessment and fill out a questionnaire.

For skin hydration, a comparison of treatment after 4 weeks of application was performed. Results (Fig. 4) showed that even only after 4 weeks, MTP can increase the moisture content of the skin versus placebo.

A decrease was observed on parameters Rz and Ra at all time points measured from the side of the face that was treated with the O/W formulation containing MTP. Significant reduction of both deep and fine wrinkles was observed after three months’ application. Figure 5 shows that MTP has a clear mid-term effect in wrinkle reduction after daily application for 8 weeks.

Figure 6 shows that MTP significantly reduced deep and fine wrinkles after daily application for 12 weeks. Figure 7 illustrates the effect of MTP on wrinkle reduction at the crow’s feet area of one of the panelists after 12-weeks’ application of the cream. Both placebo and MTP containing the O/W cream were well tolerated by the panellists. At the end of the study, they were asked to do a self-assessment with regard to skin appearance. This was a blind study test so the panelists did not know which side of their face they had applied the cream with and without MTP. The panelists rated the following cosmetic benefits from 1 (lowest) to 7 (highest): (a) gives radiant and juvenile look, (b) reduces wrinkles and fine lines, (c) refines skin picture, (d) immediate smooth and soft look, (e) skin is supplemented with moisture and (f) satisfied with skin care. All panellists rated the cream with MTP higher than the placebo on all attributes.

Conclusion

The outstanding results of both in vitro and in vivo studies discussed above have proven MTP’s efficacy as an anti-ageing active. This new ingredient offers cosmetic manufacturers the efficacy, the natural platform and the cost advantage in formulating anti-ageing cosmetic products. MTP provides the new milky way to care for and beautify the skin.

ABSTRACT
The use of peptides as active ingredient in personal care has been gaining popularity in the recent years. Synthetic peptides are seen as one of the most potent skin actives in cosmetics but pose drawbacks such as the difficulty in manufacturing them, stability issues in formulations, and the fact that they are very expensive. Peptides obtained from simple hydrolysis of natural proteins do not have the same effect on the skin as synthetic peptides. However, with the recent development of a unique enzyme technology that can produce proline-rich peptides from milk protein, cosmetic manufacturers can now try this new natural milk tripeptides with a scientifically proven efficacy but at a reasonable price.