Effect of rose fruit extract on facial skin pores

The size of facial pores, which is indicated by total area etc., is increased with age.3 Facial pore deformation is also induced by decreased elasticity with ageing. Young women are aware of conspicuous pores on the nose, which can be caused by excess of sebum secretion. On the other hand, middle-aged women are aware of conspicuous pores on the cheek, which can be caused by decreased skin elasticity.3

Furthermore, young and middle-aged women are aware of not only pores morphology but also keratotic plugs and darkish rings around pores. Recent studies address the problem of conspicuous pores raising issues such as anatomical structure, possible causes, seasonal change, menstrual cycle and care.2,4-6 From these results, many cosmetics for facial pores containing active ingredient have been developed. However, there are few cosmetics for facial pores containing natural plant extract as an active ingredient. In this study, evaluated were activities of various plant extracts, and found was remarkable activity, for facial pores care, in rose fruit extract.

In vitro assay

Testosterone 5 a-reductase (TSR) assay
A TSR assay was carried out using S-9 mixture and by gas chromatographic determination.7

Androgen receptor antagonist assay
Androgen-dependent cells (SC-3) were used for this assay. SC-3 was incubated with a test sample in the presence of 10-9 mol/L dihydrotestosterone for 48 h. After incubation, androgen-dependent cell growth was determined by MTT assay.8

Effect on involucrin synthesis
Keratinocytes were incubated with a test sample for 48 h and involucrin content was determined by direct ELISA.

Effect on filaggrin synthesis
Keratinocytes were incubated with a test sample for 5 days and filaggrin content was determined by Western Blotting. Reconstructed human epidermal model (EPI-200) was obtained from Kurabo Ltd (Japan) and treated with a test sample onto stratum corneum for 8 days. Culture medium was changed every 2 or 3 days. After treatment, reconstructed human epidermal models were fixed with 10% buffered formalin for 48 h, and embedded in paraffin. Tissue sections at 6 µm were stained with monoclonal anti-human filaggrin antibody.

Astringency effect
A test sample added to the albumin solution and protein tannin aggregation was assessed by absorption spectrometer. Results were shown by nephelometric turbidity unit (NTU).

Effect on type I collagen synthesis
Fibroblasts were incubated with a test sample for 72 h and type I collagen protein content in the culture medium was determined by ELISA.

Effect on melanogenesis
B16 melanoma cells were incubated with a test sample for 96 h and the melanin content was determined.

Effect on lipid peroxidation
Lipid peroxidation was evaluated by the ferric thiocyanate method.

Clinical study

1% rose fruit extract lotion was topically applied on cheek pores of healthy volunteers (n=8, mean age 35.1) twice a day for 4 weeks. The treated area was replicated at 0 week and 4 week. Each replica was used to evaluate the area of the pores by using 2D image-analysis system (Asahi Biomed, Japan). Skin condition of the treated area was evaluated by the tape stripping method.

A few layers of stratum corneum were stripped off by using cellophane tape. The skin conditions were observed by staining with methylene bule and rhodamine B solution.

Results

Effects of rose fruit extract on sebum secretion were evaluated by determining the inhibitory effect on TSR activity and androgen receptor binding. Rose fruit extract showed inhibitory effects on TSR activity and androgen receptor binding.

In order to examine the effect of rose fruit extract on keratinocyte differentiation, promoting effect on involucrin synthesis was investigated. Rose fruit extract showed promoting effect on involucrin synthesis in a dose-dependent manner (Table 2). To examine the moisturising result, the effect of rose fruit extract on filaggrin synthesis in keratinocytes was evaluated.

As shown in Figure 1, rose fruit extract demonstrated promoting effect on filaggrin synthesis in a dose-dependent manner. To investigate the promoting effect of rose fruit extract on a reconstructed human epidermal model, rose fruit extract was used on stratum corneum for 8 days. Filaggrin expression in the granule layer was dramatically increased by treatment with 1000 µg/mL and 2000 µg/mL rose fruit extract in a dose-dependent manner compared with the control (Fig. 2).

Astringency effect was evaluated by using the albumin solution test described above. Rose fruit extract showed strong astringency effect (Table 3). To evaluate skin elasticity effect of rose fruit extract, the promoting effect of type I collagen synthesis was determined. Rose fruit extract showed promoting effect on type I collagen synthesis in a dose-dependent manner (Fig. 3). For blackhead pore care, inhibitory effect of rose fruit extract on melanogenesis was evaluated by using B16 melanoma cells. Rose fruit extract showed an inhibitory effect on melanogenesis without any cell toxicity (Table 4).

Inhibitory effect on lipid peroxidation was measured by the ferric thiocyanate method. Rose fruit extract (160 µg/mL) inhibited linoleic acid peroxidation at the same level as a-tocopherol (Fig. 4). In the clinical study, age-related increases were observed in the area of pores (Fig. 5). The appearance of conspicuous pores on average and the skin condition were significantly improved by the topical application of 1% rose fruit extract lotion on human cheeks for 4 weeks (Fig. 6 and Fig. 7).

Discussion

In this study, investigated were the plant extracts for facial pores care and found was remarkable activity in rose fruit extract.

Rose fruit extract inhibited androgen effect, melanogenesis and lipid peroxidation. It also showed a normalisation effect on keratinocyte differentiation, a skin moisturising effect, an astringency effect and an improvement of skin elasticity. These results suggest that rose fruit extract might be able to improve conspicuous facial pores in both young and middleaged women.

In a clinical study it was demonstrated that the appearance of conspicuous pores on average, and the skin condition, were significantly improved by the topical application of 1% rose fruit extract lotion on human cheeks for 4 weeks. Especially dramatic improvement was observed in over 30s volunteers. However, TEWL and water content did not change in this study. A recent paper reported that, in women in their 40s, the skin recovery rate influenced the pore opening area and in women in their 20s, the skin extensibility influenced the pore opening area.3

Though skin recovery rate and extensibility were not evaluated in the clinical study, it seemed that rose fruit extract increased collagen content in the dermis, which leads to increase skin recovery rate and improved conspicuous facial pores.

Conclusion

These results revealed that rose fruit extract might be useful for facial skin pore care because of its biological activities. Rose fruit extract can allay a facial problem that concerns women of various ages.

References

1 Iida T., Inomata S., Katsuta Y. Effect of sebum component on skin condition around facial pores and improvement of conspicuous pores by polyoxyethylene/polyoxy- propylene dimethyl ether. Fragrance Journal, 3 (2004) 41-47.

2 Katsuta Y., Iida T., Inomata S., Denda M. Unsaturated fatty acids induce calcium influx into karatinocytes and cause abnormal differentiation of epidermis, J. Invest. Dermatol., 124 (2005) 1008-1013.

3 Murakami M., Kawamura A., Jie G., Tanno O. Three-dimensional morphological analysis of facial pores in women and factors involved in age-related changes in pore shape. J. Jpn. Cosmet. Sci. Soc., 30 (2006) 237-244.

4 Nishijima T., Sugata K. Intra-epidermal structure around the opening of sebaceous follicle, Frag. J., 3 (2004) 48-52.

5 Takada K., Iida T., Gozu Y., Moriyama M., Sakai K., Haze S., Yoshida S., Iikura T., Inomata S. Effect of seasonal change or menstrual cycle on human facial pores. J. Jpn. Cosmet. Sci. Soc., 30 (2006) 1-4.

6 Roh M., Han M., Kim D., Chung K. Sebum output as a factor contributing to the size of facial pores. Br. J. Dermatol., 155 (2006) 890-894.

7 Yamashita T., Masaki H., Sakon K., Tezuka T. Inhibition of 5a-reductase by plant extract. J. Soc. Cosmet. Chem. Jpn. 25 (1991) 117-121.

8 Kasayama S., Koga M., Kouhara H., Sumitani S., Wada K., Kishimoto T., Sato B. Unsaturated fatty acids are required for continuous proliferation of transformed androgen-dependent cells by fibroblast growth factor family proteins, Cancer Res., 54 (1994) 6441-6445.

ABSTRACT
In order to develop the novel cosmetic ingredients from plants for facial skin pores care, focused on was the cause of conspicuous pores, and found was remarkable activity in rose fruit extract.

Rose fruit extract showed inhibitory effects on androgen, melanogenesis and lipid peroxidation. It also showed a normalisation effect on keratinocyte differentiation, a skin moisturising effect, an astringency effect and an improvement of skin elasticity. To examine the effect of rose fruit extract on facial skin pores, 1% rose fruit extract lotion was topically applied on cheek pores of healthy volunteers (n=8) twice a day for 4 weeks. The treated area was replicated at before and after treatment. Each replica was used to evaluate the area of the pores using a 2D image-analysis system. These results revealed that rose fruit extract might be useful for facial skin pore care because of its biological activities. Rose fruit extract can allay a facial problem that concerns women of various ages.