Fabrication of mesoporous silica nanoparticles for releasable delivery of licorice polysaccharide at the acne site in topical application.

Glycyrrhizae Radix et rhizome/licorice is a precious herb in traditional Chinese medicine (TCM). TCM's polysaccharides are medicinally active. But herbal polysaccharides pose some limitations for topical applications. Therefore, this study aimed to utilize licorice polysaccharide via mesoporous silica nanoparticles (MSN) for anti-acne efficacy in topical delivery. The polysaccharide (GGP) was extracted with a 10 % NaOH solution. Chemical characterization suggested that GGP possesses an Mw of 267.9 kDa, comprised primarily of Glc (54.1 %) and Ara (19.12 %), and probably 1,4-linked Glc as a backbone. Then, MSN and amino-functionalized MSN were synthesized, GGP entrapped, and coated with polydopamine (PDA) to produce nanoparticle cargo. The resulted product exhibited 76 % entrapment efficiency and an in vitro release of 89 % at pH 5, which is usually an acne-prone skin's pH. Moreover, it significantly increased Sebocytes' cellular uptake. GGP effectively acted as an anti-acne agent and preserved its efficacy in synthesized nanoparticles. In vivo, the results showed that a 20 % gel of MSN-NH2-GGP@PDA could mediate an inflammatory response via inhibiting pro-inflammatory cytokines and regulating anti-inflammatory cytokines. The MSN-NH2-GGP@PDA inhibited TLR2-activated-MAPK and NF-κB pathway triggered by heat-killed P. acnes. In conclusion, fabricated MSN entrapped GGP for biomimetic anti-acne efficacy in topical application.

Efficacy and Safety of Micronized Isotretinoin Administered Once Daily Without Food in Patients With Recalcitrant Nodular Acne.

INTRODUCTION: Micronized isotretinoin 0.4 to 0.8 mg/kg/day administered in 2 divided doses with or without meals is approved for the treatment of severe nodular acne in patients aged 12 years or older. Although practitioners may suggest once-daily dosing to increase patient compliance, supporting data are limited. METHODS: In this pilot study, patients aged 12 years or older with severe nodular acne (Investigator's Global Assessment [IGA] =>4 and >5 facial nodules) received once-daily micronized isotretinoin 0.4 to 0.8 mg/kg/day without food for 20 weeks. The coprimary efficacy endpoints were changes from baseline in nodular lesion count (NLC) and percentage of patients with a =>90% reduction in NLC at week 24. Secondary endpoints included percentage of patients achieving IGA 0/1; reductions in inflammatory lesion count (ILC) and noninflammatory lesion count (NILC); adverse events (AEs); and severity of erythema, dryness, peeling, oiliness, burning, and pruritus. Analyses included all enrolled patients with the last observation carried forward. RESULTS: Twenty-two of 24 patients completed the study. From baseline to week 24, NLC decreased by a median (quartile [Q]1, Q3) of 6 (5, 7), all patients experienced complete clearance of nodules, 23/24 (96%) patients achieved IGA 0/1, and ILC and NILC decreased by a mean +/- standard deviation of 97.8% +/- 5.7% and 98.4% +/- 6.2%, respectively (all P<0.0001). There were small, significant, early increases in the severity of erythema, dryness, and peeling; 2 patients experienced 3 AEs considered unrelated to treatment. CONCLUSIONS: Once-daily micronized isotretinoin administered without food was efficacious and well tolerated in patients with severe nodular acne.  J Drugs Dermatol. 2024;23(6):423-428.     doi:10.36849/JDD.7863.

Consensus Statements on the Use of Novel Formulations of Isotretinoin: A Modified Delphi Process.

Oral isotretinoin remains a mainstay of treatment for severe, recalcitrant nodular acne. Novel formulations of isotretinoin have been developed over the past decade, including lidose isotretinoin and micronized isotretinoin. It is important to understand the differences between isotretinoin formulations to help guide clinical decision-making and selection of isotretinoin therapy. This study aims to provide evidence-based consensus statements regarding the use of novel formulations of isotretinoin for the treatment of moderate-to-severe acne. The Expert Consensus Group consisted of dermatologists with expertise in the treatment of acne. Voting members met in person to conduct a modified Delphi process; a maximum of 2 rounds of voting were conducted for each consensus statement. A total of 5 statements were generated regarding the use of novel formulations of isotretinoin, addressing the efficacy, tolerability, and side effects of novel isotretinoin formulations. All 5 statements achieved agreement with high consensus. The Expert Consensus Group agrees that individualized selection of isotretinoin therapy is important to maximize efficacy and minimize side effects. Compared to generic isotretinoin, micronized isotretinoin may require lower doses to achieve sufficient plasma concentrations. With the increased bioavailability of micronized formulation, there is no need to calculate cumulative dose; instead, the general recommendation with micronized isotretinoin is to treat for at least 5 months, or longer if needed to achieve clearance. Micronized isotretinoin can be taken in the fed or fasted state and has an acceptable safety profile. J Drugs Dermatol. 2024;23(6):429-432.     doi:10.36849/JDD.7971.

Disparities in State Medicaid Coverage of Tretinoin for Pigmentary Disorders Compared to Acne Vulgaris.

BACKGROUND: Melasma and post-inflammatory hyperpigmentation (PIH) are common cosmetic dermatologic conditions that predominantly affect patients with skin phototypes III-VI. Comparing treatment coverage for these pigmentary disorders to treatment coverage for acne vulgaris may demonstrate disparities in insurance coverage for diseases that primarily affect patients of color. OBJECTIVE: Describe differences in Medicaid coverage for topical tretinoin for melasma and PIH vs. acne vulgaris in all 50 states and the District of Columbia. METHODS: This is a cross-sectional study of Medicaid insurance plans in all 50 states and the District of Columbia conducted between February 1 and 28, 2023. Data was collected from online publicly available preferred drug lists, prior authorization criteria, and email/telephone inquiries. Information was collected regarding coverage restrictions, including age restrictions, diagnostic restrictions, preferred drug status, and prior authorization requirements. RESULTS: Complete coverage data for all three clinical indications was retrieved from 30 (58.8%) states; partial coverage data for acne vulgaris was retrieved from 16 (31.4%) states; no coverage data was retrieved from 5 (9.8%) states. Of states reporting coverage data, topical tretinoin is covered in 45 (97.8%) states for acne vulgaris and 10 (33.3%) states for melasma and post-inflammatory hyperpigmentation. There was decreased Medicaid coverage of topical tretinoin for acne vulgaris compared to melasma and PIH (P<0.05).  Conclusion: There is differential Medicaid coverage for acne vulgaris compared to pigmentary disorders which disproportionately affect patients of color. Greater advocacy is required to ensure equal treatment for conditions that affect racial minority patients. J Drugs Dermatol. 2024;23(6):e151-e153.     doi:10.36849/JDD.8069e  .

Triple-Combination Clindamycin Phosphate 1.2%/Adapalene 0.15%/Benzoyl Peroxide 3.1% Gel for Acne in Adult and Pediatric Participants.

BACKGROUND: Topical clindamycin phosphate 1.2%/adapalene 0.15%/benzoyl peroxide 3.1% gel (CAB) is the first fixed-dose triple-combination approved for the treatment of acne. This post hoc analysis investigated the efficacy and safety of CAB in pediatric (<18 years) and adult (greater than or equal to 18 years) participants. METHODS: In two multicenter, double-blind, phase 3 studies (NCT04214639 and NCT04214652), participants greater than or equal to 9 years of age with moderate-to-severe acne were randomized (2:1) to 12 weeks of once-daily treatment with CAB or vehicle gel. Pooled data were analyzed for pediatric and adult subpopulations. Assessments included treatment success (greater than or equal to 2-grade reduction from baseline in Evaluator's Global Severity Score and a score of 0 [clear] or 1 [almost clear], inflammatory/noninflammatory lesion counts, Acne-Specific Quality of Life (Acne-QoL) questionnaire, treatment-emergent adverse events (TEAEs), and cutaneous safety/tolerability. RESULTS: At week 12, treatment success rates for both pediatric and adult participants were significantly greater with CAB (52.7%; 45.9%) than with vehicle (24.0%; 23.5%; P<0.01, both). CAB-treated participants in both subgroups experienced greater reductions from baseline versus vehicle in inflammatory (pediatric: 78.6% vs 50.4%; adult: 76.6% vs 62.8%; P<0.001, both) and noninflammatory lesions (pediatric: 73.8% vs 41.1%; adult: 70.7% vs 52.2%; P<0.001, both). Acne-QoL improvements from baseline to week 12 were significantly greater with CAB than with a vehicle. Most TEAEs were of mild-to-moderate severity; no age-related trends for safety/tolerability were observed.  Conclusions: CAB gel demonstrated comparable efficacy, quality of life improvements, and safety in pediatric and adult participants with moderate-to-severe acne. As the first fixed-dose, triple-combination topical formulation, CAB represents an important new treatment option for patients with acne. J Drugs Dermatol. 2024;23(6):394-402.     doi:10.36849/JDD.8357.

Hypothalamic-Pituitary-Adrenal Axis Response in Patients With Acne Vulgaris Treated With Clascoterone.

BACKGROUND: Clascoterone cream 1% is a topical androgen receptor inhibitor approved to treat acne vulgaris in patients =>12 years of age. This report provides details of patients who developed laboratory signs of hypothalamic-pituitary-adrenal (HPA) axis suppression without clinical signs of adrenal suppression during the clascoterone development program. METHODS: Two open-label, multicenter, Phase 2 trials evaluated HPA axis suppression in patients with moderate-to-severe acne vulgaris. Study 1 (NCT01831960) enrolled cohorts of adults =>18 years of age and adolescents =>12 to <18 years of age. Study 2 (NCT02720627) enrolled adolescents 9 to <12 years of age. Patients applied clascoterone twice daily at maximum-exposure dosages for 14 days. Adrenal suppression was evaluated via cosyntropin stimulation test (CST) at baseline and day 14. Patients with an abnormal CST result (serum cortisol level =<18 µg/dL) had a follow-up CST approximately 4 weeks later. Blood was collected for pharmacokinetic analysis. Other safety assessments included adverse events (AEs), physical examination/vital signs, and electrocardiography. RESULTS: Overall, 5/69 clascoterone-treated patients had an abnormal CST result on day 14, including 1/20 adults, 2/22 patients aged =>12 to <18 years, and 2/27 patients aged 9 to <12 years. All patients had normal cortisol levels at follow-up testing approximately 4 weeks later. No relationship was observed between abnormal CST results and clascoterone plasma concentrations or the amount of study drug applied. No clinically relevant AEs or clinically significant changes in safety measures were observed in patients with adrenal suppression. CONCLUSION: Clascoterone induced laboratory evidence of mild, reversible HPA axis suppression under maximum-use exposure. J Drugs Dermatol. 2024;23(6):433-437.     doi:10.36849/JDD.7997.

An Open-label Study to Investigate the Efficacy and Tolerability of Dapsone Gel, 7.5% in the Treatment of Acne Vulgaris in Men and Women With Skin of Color.

INTRODUCTION: Acne vulgaris is a common skin disease prevalent in skin of color patients. Studies have demonstrated that dapsone gel, 7.5% (Aczone) used once daily is effective, safe, and well-tolerated for the treatment of acne in both men and women. However, minimal data are available in skin of color populations. This single-center, open-label clinical study investigated the efficacy and safety of dapsone gel, 7.5% in the treatment of moderate to severe acne vulgaris in patients with Fitzpatrick skin types IV-VI. METHODS: Twenty (20) adult subjects with moderate to severe acne and Fitzpatrick skin types IV-VI were enrolled in this study and treated with dapsone gel, 7.5% once daily for 24 weeks. RESULTS: Dapsone gel, 7.5% applied daily for 24 weeks reduced acne severity, post-inflammatory hyperpigmentation, and decreased new inflammatory and noninflammatory acne lesions in skin of color patients with moderate to severe acne vulgaris. Treatment resulted in improved acne health-related quality of life and patient symptoms related to acne, including patient-reported post-inflammatory hyperpigmentation, especially with a treatment duration of 18 weeks or longer.  Limitations: The sample size was small and underpowered to detect statistically significant changes in some endpoints. CONCLUSION: Dapsone gel 7.5% was safe, well-tolerated, and efficacious in treating acne vulgaris and post-inflammatory hyperpigmentation in skin-of-color patients. Larger studies involving skin-of-color populations with acne vulgaris are warranted. J Drugs Dermatol. 2024;23(6):410-417. doi:10.36849/JDD.7897.

Investigating the Relationship Between Acne and Vasodilatory Medications in a Hospital-Wide Adult Population.

Acne vulgaris is a common chronic dermatological condition characterized by obstruction and inflammation of pilosebaceous units. Recent research on a different dermatologic condition has demonstrated that the use of vasodilatory medications is associated with a decreased relative risk of rosacea. This finding is significant due to the overlapping inflammatory pathways involved in rosacea and acne. Herein, a retrospective cohort study was designed to determine the correlation between vasodilator usage and the risk of developing acne within 5 years, contrasting it with thiazide diuretics, chosen as a control due to its non-vasodilatory antihypertensive mechanism and availability of data. Angiotensin-converting enzyme (ACE) inhibitors (RR, 0.775; 95% CI, 0.727-0.826; P<0.05), angiotensin receptor blockers (ARBs) (RR, 0.739; 95% CI, 0.685-0.797; P<0.05), beta-blockers (BB) (RR, 0.829; 95% CI, 0.777-0.885; P<0.05), and calcium channel blockers (CCB) usage (RR, 0.821, 95% CI, 0.773-0.873; P<0.05) were associated with a significantly lower risk of developing acne within 5 years of initiating therapy compared to thiazide diuretics. It is unclear if thiazide diuretics are more likely to cause acne within the adult population or if vasodilators are protective against the development of acne. Finding mechanisms and therapeutics that lower the risk of developing acne is of significant public health interest, and this study provides a step toward this endeavor. Further research is required to uncover the underlying mechanisms for this reduction in the development of acne.  J Drugs Dermatol. 2024;23(6):446-449.     doi:10.36849/JDD.8362.

Steroids Used to Treat Acne Vulgaris: A Review of Efficacy, Safety, and Clinical Considerations.

Acne vulgaris is prevalent among adolescents and adults worldwide and can significantly impact patients' quality of life. Steroidal molecules, including oral and intralesional corticosteroids, combined oral contraceptives (COCs), oral spironolactone, and topical clascoterone, are an important part of the acne treatment armamentarium. The recommended use, mechanism of action, and available evidence supporting the use of steroids for acne treatment are reviewed, and differences in acne clinical presentation and treatment approaches based on patient characteristics relevant to the selection of an appropriate steroid are also discussed. Steroid-based approaches target the systemic or local hormones (ie, testosterone and androgens) and inflammation that contribute to acne pathogenesis. Oral corticosteroids are primarily used as a short-term adjunctive therapy early in treatment, whereas intralesional corticosteroid injections are used for individual acne lesions. COCs and oral spironolactone are limited to female patients who wish to avoid pregnancy. Topical clascoterone can be used by female and male patients 12 years of age and older. Patients' characteristics (including age and patients with darker skin color) and preferences for the route of administration can impact treatment response and adherence, respectively. Overall, healthcare providers must be aware of the differences among steroidal acne treatments and use shared decision-making to select the optimal therapy. J Drugs Dermatol. 2024;23(6):404-409.     doi:10.36849/JDD.7846.

Topical Clindamycin in the Management of Acne Vulgaris: Current Perspectives and Recent Therapeutic Advances.

Clindamycin is a lincosamide-derivate antibiotic that has been widely used both systemically and topically for approximately 5 decades. The antimicrobial profile of clindamycin primarily covers several gram-positive bacteria and anaerobic bacteria, with multiple clinical applications supported in the literature and with widespread real-world use. Topical clindamycin has been used primarily for the treatment of acne vulgaris, with both monotherapy and combination therapy formulations available commercially. This article reviews the use of clindamycin as a topical agent with emphasis on therapy for acne vulgaris, and addresses modes of action, reported anti-inflammatory properties that may relate to therapeutic outcomes, recommendations to avoid the emergence of antibiotic-resistant bacteria, tolerability and safety considerations, and published data from clinical studies completed over a span of several years. A discussion of a newly FDA-approved triple-combination formulation is also included.  J Drugs Dermatol. 2024;23(6):438-445.     doi:10.36849/JDD.8318.

Isotretinoin's Effect on Fasting Lipid Profile in Acne Patients.

OBJECTIVE: To determine the isotretinoin's effect on fasting lipid profile in patients with acne. STUDY DESIGN: Observational study. Place and Duration of the Study: Outpatient Department of Dermatology, Dow International Medical College, Dow University of Health Sciences, Karachi, Pakistan, from 22nd June to 21st December 2022. METHODOLOGY: Patients of clinically moderate and severe acne were selected and prescribed a dose of 0.5mg /kg cap isotretinoin for 6 months. They were advised to get a fasting lipid profile at the baseline and then after two months of isotretinoin therapy. National Cancer Institute Common Terminology Criteria for Adverse Events v5.0 grading system and Adult Treatment Panel III were used for the grading of abnormalities. McNemar Bowker test was used to assess the difference in variables [serum triglycerides (TGs), cholesterol, high-density lipoproteins (HDL), and low-density lipoproteins (LDL)] at the baseline and after 2 months follow-up. RESULTS: A total of 214 patients were evaluated. After 2 months of isotretinoin therapy, TGs and cholesterol levels were elevated to higher grade in 2% of the patients. Likewise in 1% of patients, LDL levels rised to higher grade. Moreover, HDL levels declined to lower grade in 2% of the patients taking isotretinoin. CONCLUSION: Insignificant alterations in the various serum lipid parameters were observed in acne patients during isotretinoin therapy. It is advisable to obtain a baseline fasting lipid profile in all acne patients on isotretinoin and repeated in those with baseline abnormal levels and in patients with a clinical sign of metabolic syndrome and a family history of dyslipidemias. KEY WORDS: Acne, Hyperlipidemias, Isotretinoin, Laboratory monitoring.

Minocycline-Induced Black Bone Disease in Foot and Ankle Surgery: A Case Report.

BACKGROUND: Bone and periarticular tissue discoloration can be an unexpected finding that is often disconcerting for surgeons and may alter surgical plans and overall patient management. Common causes of bone discoloration include infection, avascular necrosis, and bone inflammation. Minocycline-induced black bone disease is a rare and relatively benign abnormality encountered in foot and ankle surgery that can cause significant black, blue, and gray discoloration of bone. METHODS: Unanticipated intraoperative findings of diffuse black, blue, and gray bone discoloration during an elective forefoot operation raised concern for a metabolically malignant process and prompted the conversion of plans for a first metatarsophalangeal joint implant arthroplasty to a Keller arthroplasty. The plan for proximal interphalangeal joint arthroplasties of the lesser digits were continued as planned. Bone specimens were sent for pathologic analysis. RESULTS: Postoperative analysis identified chronic use of a minocycline for acne vulgaris. Pathologic analysis of the specimens ruled out malignant processes. Altogether, the data available led to the diagnosis of minocycline-induced black bone disease. Since the last follow-up, the patient has healed well without complications. CONCLUSIONS: Our case report underscores the importance of including the chronic use of tetracyclines in medical history intake during preoperative visits to assist the surgeon in intraoperative decision-making.

Editor's Highlights - June 2024.

Acne and hidradenitis suppurativa (HS) are chronic inflammatory skin conditions that significantly impact patients' quality of life. In the June issue of the Journal, we highlight the challenges in treating acne in skin of color (SOC) patients. Recent studies focusing on trifarotene, a selective retinoic acid receptor gamma agonist, demonstrated significant improvements in acne severity and postinflammatory hyperpigmentation in SOC patients. We will also delve into the early and aggressive treatment of HS and highlight a link between HS and increased cardiovascular risk. These insights demand a paradigm shift toward a more proactive and holistic management of HS, integrating skin and systemic health considerations to enhance patient outcomes significantly.

A randomized controlled double-blinded split-face prospective clinical trial to assess the efficacy, safety, and tolerability of a novel 3-step routine compared to benzoyl peroxide for the treatment of mild to moderate acne vulgaris.

Adult acne vulgaris affects up to 43-51% of individuals. While there are numerous treatment options for acne including topical, oral, and energy-based approaches, benzoyl peroxide (BPO) is a popular over the counter (OTC) treatment. Although BPO monotherapy has a long history of efficacy and safety, it suffers from several disadvantages, most notably, skin irritation, particularly for treatment naïve patients. In this prospective, randomized, controlled, split-face study, we evaluated the comparative efficacy, safety, and tolerability of a novel 3-step azelaic acid, salicylic acid, and graduated retinol regimen versus a common OTC BPO-based regimen over 12 weeks. A total of 37 adult subjects with self-reported mild to moderate acne vulgaris were recruited. A total of 21 subjects underwent a 2-week washout period and completed the full study with 3 dropping out due to product irritation from the BPO routine, and 13 being lost to follow-up. Detailed tolerability surveys were conducted at Week 4. Additional surveys on tolerability and product preferences were collected monthly, at Week 4, Week 8, and Week 12. A blinded board-certified dermatologist objectively scored the presence and type of acne lesions (open or closed comedones, papules, pustules, nodules, and cysts) at baseline, Week 4, Week 8, and Week 12. Patients photographed themselves and uploaded the images using personal mobile phones. Detailed Week 4 survey results showed across 25 domains of user-assessed product performance, the novel routine outperformed the BPO routine in 19 (76%) which included domains in preference (e.g. "I would use this in the future) and performance ("my skin improved" and "helped my acne clear up faster"). Users of the novel routine reported less facial redness, itching, and burning, though differences did not reach statistical significance. In terms of efficacy, both products performed similarly, reducing total acne lesions by 36% (novel routine) and 40% (BPO routine) by Week 12. Overall, accounting for user preferences and tolerability the novel routine was more preferred than the BPO routine in 79% of domains (22/28). Differences in objective acne lesion reduction were not statistically significant (p = 0.97). In a randomized split-face study, a 3-step azelaic acid, salicylic acid, and graduated retinol regimen delivered similar acne lesion reduction, fewer user dropouts, greater user tolerability, and higher use preference compared to a 3-step BPO routine based in a cohort of participants with mild-to-moderate acne vulgaris.

A Randomized Clinical Trial to Evaluate the Efficacy of an Oral Probiotic in Acne Vulgaris.

The relevance of the gut microbiota in some skin inflammatory diseases, including acne vulgaris, has been emphasized. Probiotics could play a role in the modulation of the microbiota, improving the clinical course of this disease. A 12-week randomized, double-blind, placebo-controlled, clinical trial with patients aged 12 to 30 years with acne vulgaris was conducted. The study product was a capsule composed of the probiotic Lacticaseibacillus rhamnosus (CECT 30031) and the cyanobacterium Arthrospira platensis (BEA_IDA_0074B). Patients with improvement in the Acne Global Severity Scale were 10/34 (29.41%) in the placebo group compared with 20/40 (50%) in the probiotic group (p = 0.03). A significant reduction (p = 0.03) in the number of non-inflammatory acne lesions was observed in the probiotic group (-18.60 [-24.38 to -12.82]) vs the placebo group (-10.54 [-17.43 to -3.66]). Regarding the number of total  lesions, a reduction almost reaching statistical significance (p = 0.06) was observed in the probiotic group (-27.94 [-36.35 to -19.53]) compared with the placebo group (-18.31 [-28.21 to -8.41]). In addition, patients with improvement attending the Global Acne Grading System were 7/34 (20.58%) in the placebo group vs 17/40 (42.50%) in the probiotic group (p = 0.02). The number of adverse events was similar in both groups. The probiotic used in this study was effective and well tolerated, and it should be considered for acne vulgaris patients.

Research progress on the role of macrophages in acne and regulation by natural plant products.

Acne vulgaris is one of the most common skin diseases. The current understanding of acne primarily revolves around inflammatory responses, sebum metabolism disorders, aberrant hormone and receptor expression, colonization by Cutibacterium acnes, and abnormal keratinization of follicular sebaceous glands. Although the precise mechanism of action remains incompletely understood, it is plausible that macrophages exert an influence on these pathological features. Macrophages, as a constituent of the human innate immune system, typically manifest distinct phenotypes across various diseases. It has been observed that the polarization of macrophages toward the M1 phenotype plays a pivotal role in the pathogenesis of acne. In recent years, extensive research on acne has revealed an increasing number of natural remedies exhibiting therapeutic efficacy through the modulation of macrophage polarization. This review investigates the role of cutaneous macrophages, elucidates their potential significance in the pathogenesis of acne, a prevalent chronic inflammatory skin disorder, and explores the therapeutic mechanisms of natural plant products targeting macrophages. Despite these insights, the precise role of macrophages in the pathogenesis of acne remains poorly elucidated. Subsequent investigations in this domain will further illuminate the pathogenesis of acne and potentially offer guidance for identifying novel therapeutic targets for this condition.

Investigation into the Anti-Acne Effects of Castanea sativa Mill Leaf and Its Pure Ellagitannin Castalagin in HaCaT Cells Infected with Cutibacterium acnes.

Acne vulgaris is a prevalent skin disorder affecting many young individuals, marked by keratinization, inflammation, seborrhea, and colonization by Cutibacterium acnes (C. acnes). Ellagitannins, known for their antibacterial and anti-inflammatory properties, have not been widely studied for their anti-acne effects. Chestnut (Castanea sativa Mill., C. sativa), a rich ellagitannin source, including castalagin whose acne-related bioactivity was previously unexplored, was investigated in this study. The research assessed the effect of C. sativa leaf extract and castalagin on human keratinocytes (HaCaT) infected with C. acnes, finding that both inhibited IL-8 and IL-6 release at concentrations below 25 µg/mL. The action mechanism was linked to NF-κB inhibition, without AP-1 involvement. Furthermore, the extract displayed anti-biofilm properties and reduced CK-10 expression, indicating a potential role in mitigating inflammation, bacterial colonization, and keratosis. Castalagin's bioactivity mirrored the extract's effects, notably in IL-8 inhibition, NF-κB inhibition, and biofilm formation at low µM levels. Other polyphenols, such as flavonol glycosides identified via LC-MS, might also contribute to the extract's biological activities. This study is the first to explore ellagitannins' potential in treating acne, offering insights for developing chestnut-based anti-acne treatments pending future in vivo studies.