Efficacy, Tolerability, and Face Lipidomic Modification of New Regimen with Cleanser and Corrective Serum in Women with Acne-Prone Skin

Abstract

Acne-prone skin is a common condition in adult women, and skin imperfections could affect quality of life and self-esteem. This study aimed to investigate the efficacy of a cosmetic combination regimen for face care (a cleanser gel and a serum containing niacinamide, retinol, and alpha hydroxy acids). A total of 20 women with acne-prone mixed or oily skin were enrolled in a prospective 42-day trial. Sebum content, skin radiance, skin profilometry, and evaluation of face area occupied by pores were evaluated at baseline and after 14, 28, and 42 days. In addition, a face lipidomic evaluation was performed at baseline and after 42 days. Finally, self-assessment questionnaires at each visit checkpoint were performed to evaluate efficacy and tolerability of the tested products. All the subjects but one concluded the study. Both products were very well tolerated and 84% of the subjects reported a global clinical improvement. Skin sebum content was significantly (p < 0.05) reduced at each of the evaluation time points (−9.9% at day 14, −19.4% at day 28, and −23.7% at day 42). The tested regimen significantly decreased the gloss parameter (mattifying effect) at day 14, 28, and 42, with a maximum reduction of 7.2% at the end of the study period. The pores area demonstrated a significant reduction at each of the checkpoint evaluations in comparison with baseline. Inflammatory and non-inflammatory lesions were significantly reduced by 16% at day 28 and day 42 (p < 0.01). Lipidomic analysis demonstrated that this cosmetic face care regimen induced significant and positive effects in face sebum lipids composition, characterized by a significant increase in ceramides and triacylglycerols and a decrease in fatty acids and oxidized fatty acids.

1. Introduction

Acne-prone skin is a common condition in adult women, and skin imperfections could affect quality of life and self-esteem [1]. Adult female acne (AFA) could have different pathological mechanisms, clinical manifestations, and lesion distribution in comparison with juvenile acne [2]. However, AFA and adult acne-prone skin are often also associated with increased sebum production, visible pores, and post-inflammatory hyperpigmentation [3].

1.1. Adult Female Acne

Acne vulgaris is a common condition with a prevalence of approximately 85% and occurs mostly during adolescence [4]. Acne can persist into adulthood, with a 50.9% prevalence in women ages 20 to 29 years and 26.3% in women ages 40 to 49 years [5,6]. Adult female acne (AFA) affects women over the age of 25 and may persist continuously or manifest for the first time in adulthood [7]. AFA lesions are mainly located on the lower third of the face, especially on the chin and jawline [8]. However, a more recent epidemiologic study by Dreno et al. [9] suggests that this hormonal distribution may not be the most common clinical presentation of acne in adult women. Studies have observed cases of localization in other areas of the face and back [7]. In AFA, acne lesions range from comedones to papules and pustules, cysts, and/or nodules [6].

1.2. Etiopathogenesis of AFA

The etiopathogenesis of acne is multifactorial, involving androgenetic hormone stimulation, sebaceous gland hyperactivity, alteration of lipid composition, follicular hyperkeratinization, microbial colonization (mainly by C. acnes), and a consequent inflammatory response [7,10,11].

The role of hormones in Acne vulgaris is well established. The androgens stimulate the sebaceous gland growth and sebum production, while estrogens have the opposite effect. Therefore, the estrogen/androgen ratio influences the sebaceous glands’ activity [7,12]. In relation to AFA and hormones, an increasing sensitivity of the sebaceous gland to androgenetic hormones could be observed, in addition to an increase in peripheral hormonal conversion (hyperactivity of enzymes involved in the metabolism of androgens) [7].

In acne patients, there is an abnormal proliferation of keratinocytes, stimulated by pro-inflammatory cytokines released after the activation of Toll-like receptors (TLR 2 and 4), activated by molecular patterns present in C. acnes, sebaceous hypersecretion, and squalene peroxidation [11].

In addition, the skin microbiome (including C. acnes) plays a key role in maintaining skin health and homeostasis [13].

Other factors could contribute to AFA pathophysiology, such as exposure to ultraviolet radiation, stress, diet, pollution, smoking, and lifestyle [7,10].

The alteration of the epidermal barrier function has been identified as a possible factor involved in acne development. The damage of the barrier and the consequent increase in transepidermal water loss (TEWL) may be involved in the inflammatory cascade characteristic of this pathology [7,14].

1.3. Skin Barrier Alteration in A. vulgaris

The pathophysiology of acne is related to skin barrier dysfunction [15]. The higher sebum secretion, larger sebaceous gland, and subclinical inflammation could contribute to alterations in barrier integrity: an increase in filaggrin expression, decreased free fatty acids, linoleic acid, sphingosine, and total ceramide levels could be observed [16,17,18,19]. A study conducted by Yamamot et al. [18] showed elevated TEWL and lower conductance in the mild–moderate acne patients compared to healthy subjects. Impaired water barrier function could be related to decreased skin ceramides that may play a role in comedone formation [18]. In addition, some ingredients in topical acne products (e.g., Benzoyl peroxide and retinoids) may irritate the skin. Therefore, some topical acne therapies can induce skin barrier alteration [17].

1.4. Quantitative and Qualitative Change in Sebum

Human sebum, a product of the sebaceous gland, is a mixture of triglycerides and free fatty acids (that together account for the predominant proportion 57.5%), wax ester (26%), squalene (12%), and cholesterol (4.5%) [20].

An increase in sebum production and alteration of its composition are among the factors involved in the etiopathogenesis of acne. Alteration in sebum composition has been reported in AFA with a reduction in the content of linoleic acid, an essential fatty acid, and an increase in peroxidase squalene [21]. The composition and content of skin surface lipids (SSLs) are essential for the normal physiological function of the skin barrier. However, acne patients have significantly reduced free sphingosine and total ceramides in their stratum corneum, which is indicative of a deficient intercellular lipid membrane and correlates with impairment of the stratum corneum permeability barrier. In general, patients with acne-prone skin have lower triglyceride (TG) levels than patients without acne. C. acnes produces enzymes that break down TGs in sebum, producing fatty acids (FAs) that induce skin inflammation and abnormal follicular keratinization.

It is well known that C. acnes proliferates when sebum production increases and regional variation in C. acnes density correlates with sebum secretion [22]. C. acnes strains with high virulence express more triglyceride lipases, increasing sebum concentration of free palmitate and oleate. Alteration in sebum lipid composition (dyseborrhea) is a major player in the induction of inflammatory acne. The adherence, biofilm formation, and growth of C. acnes are increased by free fatty acids (FFAs). Oxidized FFAs are also able to activate TLR-2 and TLR-4, which is a crucial event in the pathogenesis of acne [23].

Adjuvant cosmetic skin care regimens are considered important for the management of this frequent skin condition. A cleanser gel composed of emollient, anti-irritation and anti-bacterial substances and a serum containing niacinamide, retinol, and exfoliating and keratolytic compounds (lactic and glycolic acids) have been recently developed. The serum was specifically formulated for the oily, acne-prone skin of adult women. So far, no clinical and instrumental data regarding efficacy and effect on sebum composition have been collected with these two products.

1.5. Study Aim

The aim of this study was to investigate the efficacy and tolerability of a cosmetic combination regimen for face care (a cleanser gel and a serum) in terms of improvement of acne lesions, sebum production, mattifying effect, skin pores’ occupied area, and composition of sebum (lipidomic analysis).

2. Materials and Methods

2.1. Study Design

The clinical trial was conducted by COMPLIFE S.r.l. A total of 20 women with acne-prone mixed or oily skin, with or without sensitive skin showing significant acne imperfections (enlarged pores and post-acne hyperpigmentation), were enrolled in a prospective 42-day trial after their informed consent was obtained. Main inclusion criteria were healthy female subjects aged 25–45 years, acne-prone skin, and with or without post-inflammatory hyperpigmentation. Main exclusion criterion was the presence of acute or chronic diseases able to interfere with the study outcomes. Subjects were instructed to clean their faces with the cleanser and then rinse with water twice a day, in the morning and evening. The application of the corrective serum on clean and dry skin in the morning and evening was indicated. Sebum content was evaluated by means of Sebumeter 815 (Courage + Khazaka, Köln, Germany), skin radiance (gloss parameter) was evaluated by using spectrophotometer/colorimeter CM-700D (Konica Minolta, Tokyo, Japan), the measured parameter was the 8° gloss (gloss value with the specular reflection in the direction of 8°), skin profilometry was evaluated by using PrimosCR SF (Candfield Scientific Europe, BV, Utrecht, The Netherlands) and evaluation of the face area occupied by pores was performed by using VISIA CR images, which were evaluated at baseline and after 14, 28, and 42 days. All the study procedures were carried out under temperature and humidity-controlled conditions (temperature 18–26 °C and humidity 50 ± 10%).

In addition, face lipidomic evaluation by a skin stripping technique, using ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (ULPC-Q-TOF-MS), was performed at baseline and after 42 days. Acne lesion count was visually assessed by the investigator, counting the total number of acne lesions of the face (comedones, papules, and pustules). A clinical evaluation on pictures taken with VisiaCR was performed at baseline using a 4-point score (from 1: excessive presence of sebum to 4: normal skin); at the time of 14, 28, and 42 days, a clinical improvement score was also calculated (from 1: NO variation to 4: remarkable improvement). Finally, self-assessment questionnaires at each visit checkpoint were performed to collect subjects’ opinions on efficacy and tolerability of the tested products.

2.2. Statistical Analysis

Statistical analysis was performed using GraphPad statistical software version 10.3.0. The level of statistical significance was reported as follows: * p < 0.05, ** p < 0.01, and *** p < 0.001. Paired t-Test and Wilcoxon tests were used according to the distribution of variables analyzed.

3. Results

All the subjects but one (lost to follow-up) concluded the 42-day treatment period. Both products were very well tolerated. Clinical improvement in comparison with baseline was observed in 53% of subjects at day 14, in 79% at day 28, and in 84% at day 42 (Figure 1).

An increase in sebum production is among the factors involved in the etiopathogenesis of acne. In this study, the sebum measurement is based on the internationally recognized Sebumeter^® photometric method (Sebumeter 815, Courage + Khazaka GmbH).

The Sebumeter^® is a device that can directly measure the amount of lipids on the skin’s surface. This system relies on a direct photometric reading of lipids collected on a probe that turns transparent in proportion to the content of skin lipids. The values are then automatically calculated into µg sebum/cm² of the skin.

Figure 2 illustrates the evolution of sebum content expressed in µg/cm². Skin sebum production significantly (p < 0.05) reduced at each evaluation time point (−9.9% at day 14, −19.4% at day 28, and −23.7% at day 42) in comparison with baseline, confirming a significant improvement of this parameter.

Skin radiance/skin brightness is the ability of the skin to reflect the light, and it is measured by using the spectrophotometer/colorimeter CM-700D (Konica-Minolta, Tokyo, Japan). The instrument emits diffuse light that reaches the skin, measuring the reflected light and calculating a parameter known as “gloss”. A decrease in gloss parameter indicates a mattified effect, an improvement of the aesthetics of the face and its good cosmetic effect.

As illustrated in Figure 3, the tested regimen was also able to significantly (p < 0.05) decrease the gloss parameter (mattifying effect) at day 14, 28, and 42 with a maximum reduction of 7.2% at the end of the study period.

No significant differences were observed at any checkpoints regarding skin profilometry analysis. Pores area measurement, evaluated by VISIA analysis, demonstrated a significant reduction at each checkpoint evaluation in comparison with baseline. At day 42, the pores area was 10% (p < 0.001) lower than baseline value. Inflammatory and non-inflammatory lesions at baseline were 19 ± 2 and were significantly reduced by 16% at day 28 and day 42 (p < 0.01).

Lipidomic analysis demonstrated that this cosmetic face care regimen induced significant and positive effects in face sebum lipids composition. In particular, at the end of the treatment period, a significant increase in different ceramides and a significant decrease in fatty acid (FA) and oxidized FA (OxFA) was observed. Ceramides’ subclasses increased significantly (p = 0.002; Wilcoxon test) by 28% from baseline to day 42 (14 ng/cm² vs. 11.1), with a fold change of 1.7 ± 0.6 in comparison with baseline.

Ceramides are members of the sphingolipid family. They represent the building blocks of epidermal barrier structure but are also bioactive metabolites involved in epidermal self-renewal and immune regulation. Ceramides constitute a hydrophilic extracellular lipid matrix, which is indispensable for permeability barrier function. In addition, ceramides also act as an active second messenger, regulate keratinocyte proliferation and differentiation, enhance proinflammatory cytokine production, and modulate immune responses [24]. In acne patients, altered ceramide levels have been observed; in particular, the levels of ceramides are reduced [15]. In this study, as we can see from Figure 4, the quantity of ceramides compared to T0 is increased.

OxFA sebum content was significantly reduced by 65% (p = 0.023). In addition, the lipidomic analysis demonstrated that, in comparison with baseline, the tested products significantly (p = 0.007) increased the amount of triacylglycerols (TAGs) by 25% (Figure 4) with a fold change of 1.3 ± 0.1. Triacylglycerols are the most abundant lipids in the skin. They are found both in the skin’s lipid barrier and in sebum. In general, patients with acne-prone skin have lower TAG levels than patients without acne. It is generally believed that the bacterium C. acnes, present in greater quantities in the microbiome of acne skin, produces a variety of enzymes that break down TAGs in sebum, producing fatty acids (FA) that induce skin inflammation and abnormal follicular keratinization [25].

During this study, the dermatologists assessed both physical signs (skin erythema, skin oedema, skin dryness, skin desquamation) and functional signs (stinging/itching sensation, burning sensation, tight feeling, other). None of the subjects showed the onset of dermatological physical or functional signs. All subjects tolerated the test product during the study period.

Self-assessment questionnaire results demonstrated that 84% of the subjects reported a global clinical improvement. Ninety-five percent reported improvement in skin hyperpigmentation, pores reduction, uniform skin texture, and reduction in skin imperfections. The total number of subjects (100%) confirmed that the treatment spreads easily on the skin, and does not leave a greasy feeling and residue on the skin after application.

4. Discussion

AFA and acne-prone skin in adult females can have different triggers or aggravating factors such as smoking, stress, obesity, endocrine alterations, use of cosmetics, and excessive exposure to solar radiation [7,26]. Also, excessive and aggressive washing behaviors could worsen this condition. Alteration of skin barrier function has been documented in AFA subjects [7,27]. Acne in women is associated with anxiety and depression [28,29]. AFA and acne-prone skin are commonly troublesome and difficult to treat, and maintenance treatment is often required for long periods. Generally, AFA is considered more complex to manage in comparison with juvenile acne vulgaris [30]. The use of cosmeceuticals and cosmetics can benefit the drug treatments by reducing side effects, the need for topical antibiotics, and improving adherence to the therapeutic regimen. However, data on the efficacy of adjuvant treatments is limited and usually based on in vitro research instead of randomized controlled trials. Acne cosmeceuticals generally include cleansing agents for oily or sensitive skin, sebaceous secretion regulators, anti-inflammatory products, moisturizers, and sunscreens [7]. In this study, we evaluated in vivo the clinical and instrumental efficacy of a peculiar serum formulation specifically designed for acne-prone and oily skin in adult women in combination with a specific cleanser. This regimen has been demonstrated to improve skin alterations specific to acne-prone and oily skin in adult women. An additional and relevant effect of this approach was the capability to modify the sebum composition of the skin. The regimen was also very well tolerated without any relevant skin reaction. Some limitations must be taken into account in evaluating our results. The main limit of the study design was that this trial was a prospective open evaluation. However, most of the study outcomes were evaluated instrumentally (VISIA determination, sebum composition analysis, etc.), increasing the internal validity of the results obtained.

5. Conclusions

The tested face care regimen, consisting of a cleanser and a specific serum, has been demonstrated to be effective in improving sebum production, reducing gloss parameters and areas occupied by pores, and in reducing acne lesions in women with acne-prone skin. Interestingly, this regimen has induced a relevant sebum composition modification, characterized by a significant increase in ceramides and triacylglycerols and a decrease in FA and OxFA. OxFA, like 22 carbon oxisqualene, is a product of the squalene oxidation, and it is well known that the degree of squalene peroxidation was found to correlate positively with the size of the comedones and led to the release of inflammatory mediators, suggesting a proinflammatory activity [20]. Therefore, these results can explain the clinical improvement effects we have observed. The study products also have a good tolerability profile: the product was well tolerated by all subjects and no adverse effects were recorded during treatment.

This study confirmed the clinical efficacy and tolerability of the cosmetic regime consisting of a cleanser and a specific serum, providing the dermatologist with a useful cosmetic tool, in vivo tested, to support adult females with acne. Indeed, well-targeted use of cosmeceuticals and cosmetics can benefit drug treatment by reducing side effects, reducing the need for topical antibiotics, and improving adherence to the therapeutic regimen. This study underlined the importance of investing in future research in cosmetics to make skin care more personalized, predictive, and scientifically driven.