Topical Formulation of Allicin Comprising Penetration Enhancer: Evaluation of Anti-psoriatic Potential

Abstract

Background: Psoriasis was described as a persistent inflammatory skin condition characterized by abnormal epidermal growth and excessive keratinization, both of which impeded effective drug absorption.

Objectives: To enhance transdermal penetration, topical formulations incorporating skin permeability enhancers gained popularity for their ability to facilitate drug penetration and improve therapeutic outcomes.

Methods: In this study, allicin was isolated from Allium sativum clove, ointment was developed incorporating eucalyptus, basil, and cardamom oil, and antipsoriatic potential was explored on rat ear and dorsal skin of Wistar rats through the application of imiquimod (IMQ). Allicin 1% and 2% ointment was applied once daily at a dose of 200 and 400 mg/day for 10 days following the development of psoriasis. Evaluation parameters include PASI scoring, ear thickness, body weight and organ weight assessments, antioxidant and anti-inflammatory profiles, and histopathological examinations.

Results: The formulated ointments showed characteristic properties and were found to be stable in the range of 4 to 37°C. Allicin 2% ointment with 0.5% each essential oils significantly alleviated PASI score (p<0.01) based on psoriasis-like symptoms and ear thickness (p<0.001). Allicin treatment did not show any symptoms of acute topical toxicity and was safe on body weight gain and relative organ index. Allicin treatment significantly (p<0.05-0.001) lowered lipid peroxidation, IL-6, TNF-α, keratinocyte hyperproliferation and lymphocytic infiltration in the psoriatic tissue.

Conclusion: Allicin, 2% ointment, applied 400 mg/day dose in combination with essential oil, showed promising elevation of psoriasis symptoms along with antioxidant and anti-inflammatory profile in a lower dose, once a day application.