Natural anti-acne extract aids healthy skin microbiota

Firstly, the aim of this study was the characterization of the skin microbiota with a focus on Cutibacterium acnes(C. acnes) phylotypes in subjects with acne. Secondly, microbiota changes after 28 days’ treatment of berries, Rhodomyrtus tomentosaactive ingredient (RT), rich in acylphloroglucinols, polyphenols, and organic acids were analyzed. Clinical evaluations (lesion counts) were performed at baseline (D0) and after 28 days (D28) of twice-daily application of RT active ingredient. 

Acne is one of the most common skin diseases worldwide affecting up to 85% of the population.1 At the pathophysiological level, two factors play a crucial role: the sebaceous gland and Cutibacterium acnes. More precisely, located in the sebaceous gland-rich sites of skin,C. acnesis a grampositive aero-tolerant anaerobic bacterium belonging to the Actinobacteriaphylum. Several mechanisms have been proposed by which C. acnesaggravates acne, including augmentation of lipogenesis, comedone formation, and host inflammation.2 Recently, different strains of C. acneswere identified, showing that its subtypes could also be important in acne development.3 Despite controversial data in line with the population samplings, anatomic sites and typing methods, most studies report that strains from the type IA1 preferentially colonize skin with acne while others are not or poorly present in acne lesions (IB, II and III).4 Dagnelie et al.5 also reported that inflammatory severe acne of both the face and back is associated with diversity loss of C. acnesphylotypes, with a high predominance of phylotype IA1, both on the face (72.7%) and the back (95.6%). Thus, it seems that the severity of acne may be more related to the selection of its subtypes than to its proliferation. It is also important to note that other factors such as androgens and hormonal fluctuation or imbalance, poor nutrition, stress, pollution and  habits are important in the development and persistence of the disease.6 Moreover, although C. acnesis best-known for its connection with acne, it has been shown that other bacteria might also (indirectly) contribute to the inflammatory process. In fact, culture-based studies have reported that Cutibacterium granulosumis highly abundant in the comedones and pustules of acne patients, and displays stronger virulence (i.e., lipase activity) than C. acnes.7

Topical retinoids, benzoyl peroxide (BPO), which suppresses bacterial proliferation, hyperkeratinization and inflammation, and systemic antibiotics are currently the first-line treatments for mildto-moderate acne. Although highly effective, topical treatments affect skin barrier integrity and are often associated with side effects such as dryness, irritation, itching and redness.8 In this context, novel therapies are in high demand and an ethnopharmacological approach to discover new plant sources of anti-acne therapeutics could contribute to filling this void in effective therapies. Exploitation of natural resources, especially medicinal plants and their derived products are considered as promising alternative agents for the treatment of diseases.