The effects of the blue rose

In recent years, attention has focused not only on intestinal bacteria but also on the bacterial flora of the skin and scalp. Research on skin and scalp flora in relation to diseases such as atopic dermatitis¹ , dandruff² , and alopecia areata³ is increasing. There are also reports that the bacterial flora of the skin changes with ageing⁵ , and the flora is attracting attention not only in diseases but also in cosmetics. Tribeauté has developed an extract of Blue Rose flowers as a cosmetic ingredient. The Blue Rose is a variety that was created as a result of many years of breeding. The Blue Rose is a rare species because it is susceptible to disease and pests and is difficult to cultivate. The flower extract is said to improve the diversity of indigenous skin bacteria. Therefore a human study was conducted to confirm the effect of the blue rose flower extract on scalp flora and scalp and hair.

Test design: 22 subjects who had oily scalp, scalp acne or scalp scales and between 23 and 59 aged were enrolled. All subjects signed an informal consent form. Test product contained blue rose extract was applied on scalp twice a day in the morning and evening.

Measurement of Scalp Microbiome: The scalp bacteria were collected using eSwabTM kit (COPAN, USA) in parietal region (10 cm behind the hairline) at baseline and after 4 weeks. The collected samples were requested to a genetic analysis company (Macrogen, Korea) and the analysis was performed to collect quantitative data on the distribution and amount of scalp bacteria.

Measurement of Scalp condition: The scalp sebum was measured by Sebumeter SM815 (C+K, Germany) on the border between the forehead and the hairline. The scalp scale was collected using D-squame disc (Cuderm, USA) on the skin of frontal hairline and analysed with SquameScan (Heiland electronic, Germany). The scalp smell was measured by OMX-SRM (SHINYEI, Japan) on parietal region. The odor strength level is shown from 0 to 999 by comparing odor gas alcoholic substances) and purified air.

Measurement of Hair Diameter and hair tensile strength: The hair diameter was measured by micrometer (METROLOGY, Taiwan). The hairs were randomly selected five hairs in parietal region. The hair tensile strength was measured using the Fibra.one (DiaStron Ltd., UK) with single fibre tensile accessory. Three hairs were randomly selected and the mean was analysed.

Statistical analysis: Statistical analysis was conducted using the SPSS® software program (IBM, USA). To determine whether variables followed normal distribution or not, Shapiro-Wilks test was used. Statistical analysis of variables for parametric was conducted using the Repeated Measures ANOVA. If value was non-parametric, all of them were initially mcompared by the Wilcoxon Signed Ranks Test. When Wilcoxon Signed Rank Test was adapted, Bonferroni-adjusted p-values was used. All data are represented by means and standard deviation (SD). Differences were considered statistically significant at p < 0.05. 

Figure 1 shows the state of the scalp microbiome after 4 weeks treatment with the test products. Part a shows the Phylum-level scalp microbiome after treatment. Part b shows the Top 10 genera scalp microbiome. As compared to baseline, there were significant differences in 6 Genera. 5 (Lawsonella, Paracoccus, Moraxella, Methylobacterium and Neisseria) out of them were significantly increased and the other (Staphylococcus) was significantly decreased 4 weeks after treatment (p<0.05) Part c on the other hand, shows the Top 10 species scalp microbiome. As compared to baseline, there were significant differences in 7 Species. 4 (Staphylococcus caprae, Corynebacterium accolens, Staphylococcus aureus and Staphylococcus warneri) out of them were significantly increased and the other 3 (Staphylococcus capitis, Corynebacterium amycolatum and Corynebacterium simulans) were significantly decreased 4 weeks after treatment (p<0.05).

In Figure 2, the changes of alpha diversity and beta diversity after 4 weeks treatment, are visible. As Part a and b show: the Alpha diversity (Chao1 and Shannon) was significantly increased at 4 weeks after treatment (p<0.05 vs baseline). While the Beta diversity (unweighted UniFrac) was significantly different between baseline and after treatment (p<0.01, ANOSIM).

The changes in the scalp condition after 4 weeks of treatment of the test product are demonstrated in Figure 3. Sebum output level, Scalp scale and Scalp smell were significantly decreased 2 and 4 weeks after the treatment (p<0.05 vs baseline)

Figure 4 focuses on the changes in the hair condition after 4 weeks of treatment with the test product. The hair diameter and hair tensile strength were also significantly increased 2 and 4 weeks after treatment (p<0.05 vs baseline), as seen in part a and b. Part c and d shows, that increases in hair diameter were weakly correlated with decreases in Staphylococcus or S. capitis.

An open study was conducted on a total of 22 adult male and female subjects suffering from scalp sebum, acne, and dandruff. After four consecutive weeks of twice-daily use of a hair tonic containing 0.1% blue rose flower extract, the relative abundance of Staphylococcus on the scalp decreased and the diversity of the scalp flora increased. Along with the change in the bacterial flora, the condition of the scalp also improved, and hair diameter and hair strength increased. Hair diameter increased with a decrease in Staphylococcus or S. captis, and a weak correlation was observed between the two. It is thought that controlling the scalp bacterial flora may normalise the hair cycle.

References:  

1 Microorganisms. 2021 Feb 19;9(2):432.  

2 PLoS One. 2019;14:e0225796.  

3 Microorganisms 2022, 10, 864.  

4 J Invest Dermatol. 2022 ; 142(7):1934-1946

# p < 0.05, ## p < 0.01 vs baseline, RM ANOVA

* p < 0.05, **p < 0.01 vs baseline, Wilcoxon signed ranks test

Jumpei Horikoshi, Hyunsuk Ban 

Tribeauté, Japan

www.tribaute.com