Botulinum Toxin Blocks Mast Cells and Prevents Rosacea Like Inflammation
Overview
Affiliations
Background: Rosacea is a chronic inflammatory skin condition whose etiology has been linked to mast cells and the antimicrobial peptide cathelicidin LL-37. Individuals with refractory disease have demonstrated clinical benefit with periodic injections of onabotulinum toxin, but the mechanism of action is unknown.
Objectives: To investigate the molecular mechanism by which botulinum toxin improves rosacea lesions.
Methods: Primary human and murine mast cells were pretreated with onabotulinum toxin A or B or control. Mast cell degranulation was evaluated by β-hexosaminidase activity. Expression of botulinum toxin receptor Sv2 was measured by qPCR. The presence of SNAP-25 and VAMP2 was established by immunofluorescence. In vivo rosacea model was established by intradermally injecting LL-37 with or without onabotulinum toxin A pretreatment. Mast cell degranulation was assessed in vivo by histologic counts. Rosacea biomarkers were analyzed by qPCR of mouse skin sections.
Results: Onabotulinum toxin A and B inhibited compound 48/80-induced degranulation of both human and murine mast cells. Expression of Sv2 was established in mouse mast cells. Onabotulinum toxin A and B increased cleaved SNAP-25 and decreased VAMP2 staining in mast cells respectively. In mice, injection of onabotulinum toxin A significantly reduced LL-37-induced skin erythema, mast cell degranulation, and mRNA expression of rosacea biomarkers.
Conclusions: These findings suggest that onabotulinum toxin reduces rosacea-associated skin inflammation by directly inhibiting mast cell degranulation. Periodic applications of onabotulinum toxin may be an effective therapy for refractory rosacea and deserves further study.
Managing a Burning Face: Clinical Manifestations and Therapeutic Approaches for Neurogenic Rosacea.
Aedo G, Chahuan M, Gatica E, Herrera I, Parada L, Seguel A Int J Mol Sci. 2025; 26(5).
PMID: 40076987 PMC: 11901027. DOI: 10.3390/ijms26052366.
Jia T, Xia Y, Yi M, Zhang X, Zheng Y, Che D Inflammopharmacology. 2025; .
PMID: 39821787 DOI: 10.1007/s10787-025-01639-8.
The Multifaceted Role of Botulinum Toxin A in Improving the Retention Rate of Fat Grafting.
Wang B, Chen Y, Dai Y Aesthetic Plast Surg. 2024; .
PMID: 39643703 DOI: 10.1007/s00266-024-04603-z.
Botulinum Toxin Effects on Freezing of Gait in Parkinson's Disease: A Systematic Review.
Tambasco N, Nigro P, Mechelli A, Duranti M, Parnetti L Toxins (Basel). 2024; 16(11).
PMID: 39591229 PMC: 11598804. DOI: 10.3390/toxins16110474.
Poly-d,l-Lactic Acid Via Transdermal Microjet Drug Delivery for Treating Rosacea in Asian Patients.
Seo S, Wan J, Thulesen J, Jalali A, Vitale M, Kim S J Cosmet Dermatol. 2024; 23(12):3993-3998.
PMID: 39248245 PMC: 11626325. DOI: 10.1111/jocd.16556.