Propionic acid produced by Cutibacterium acnes fermentation ameliorates ultraviolet B-induced melanin synthesis

Abstract

Ultraviolet irradiation induces melanin accumulation, which can be reduced by the use of chemical whitening products. However, the associated safety concerns of such products have prompted the search for natural and harmless alternatives. This study aimed to identify a natural acidic formulation to reduce skin pigmentation. The metabolite propionic acid (CH3CH2COOH, PA) was the most abundant fatty acid in the filtrate from Pluronic F68 (PF68) fermentation of Cutibacterium acnes (C. acnes) and reduced the DOPA-positive melanocytes by significantly inhibiting cellular tyrosinase activity via binding to the free fatty acid receptor 2 (FFAR2). Moreover, 4 mM PA treatment did not alter melanocyte proliferation, indicating that it is an effective solution for hyperpigmentation, causing no cellular damage. The reduced DOPA-positive melanocytes and tyrosinase activity were also observed in mice ear skin tissue injected with a mixture of C. acnes and PF68, supporting that the inhibition of melanogenesis is likely to be mediated through fermentation metabolites from C. acnes fermentation using PF68 as a carbon source. Additionally, PA did not affect the growth of its parent bacteria C. acnes, hence is a potent fermentation metabolite that does not disrupt the balance of the skin microbiome.

Pilot Study on the Forehead Skin Microbiome and Short Chain Fatty Acids Depending on the SC Functional Index in Korean Cohorts

“…Hydration and barrier integrity may play a role in creating a favorable environment to inhibit pathogen invasion through the stabilization of the commensal microbiome. Furthermore, the postbiotic materials of bacteria such as SCFAs may act as a good immune regulator in aiding host defense against pathogens and or ameliorating inflammation and hyperpigmentation due to UV damage [22,48,49]. Our study has showed a significant difference in diversity and domination in the microbial communities of dry and moist forehead skins.…”

“…The SCFA have been known to play a crucial role in ameliorating metabolic and inflammatory diseases in the gut microbiome [46,47]. A few in vitro studies investigated the effects of SCFAs produced by Cutibacterium acnes (previously known as Propionibacterium acnes) and Staphylococcus epidermidis on the skin [22,[48][49][50] or by using the SCFA directly [51,52]. In our study, the levels of propionate were significantly higher in the moist group compared with the dry group (Figure 5B) which also had significantly higher Cutibacterium levels (Figure 2B).…”

Boosting the Optical Absorption of Melanin-like Polymers

“…Melanin is a series of ubiquitous biological macromolecular pigments, widely present in various organisms in nature, including humans. − As the most representative synthetic analogue to melanin, polydopamine (PDA) possesses similar chemical functional groups and stacked internal structure, which provides a variety of unique functions: metal chelation, − free radical scavenging, and surface modification . Besides that, PDA has also been widely used in ultraviolet shielding, sensors, − fluorescent materials, and water purification .…”

Latilactobacillus sakei Wikim0066 Protects Skin through MMP Regulation on UVB-Irradiated In Vitro and In Vivo Model

“…Butyric acid, the major SCFA in the human intestine, has been reported to mediate FFAR2 to regulate the production of UVB-induced pro-inflammatory cytokines on the dorsal skin of mice [ 31 ]. Moreover, propionic acid has been reported to inhibit the pigmentation induced by UVB [ 32 ]. Compared with the SCFA content of other Lactobacillus genera suggested in our previous study, wikim0066 showed a high level of butyric acid content ( Table 2 ) [ 33 ].…”