Antioxidant and Topical Efficacy of Calendula officinalis Rinse in Recurrent Aphthous Stomatitis

Background and Objectives: Recurrent aphthous stomatitis is among the most common chronic oral mucosal conditions, characterized by recurrent, painful ulcerations that significantly impair patients’ quality of life. Current therapies, particularly topical corticosteroids, are primarily palliative, aiming to accelerate healing and reduce discomfort, but they do not prevent recurrence and may be associated with adverse effects when used long term. Consequently, interest has grown in natural, plant-based therapies that combine safety with antioxidant and anti-inflammatory efficacy. Calendula officinalis (marigold) is a medicinal plant traditionally used for wound healing and inflammation control. This randomized, double-blind, placebo-controlled trial investigated the clinical efficacy, antioxidant activity, and safety of two concentrations of Calendula officinalis oral rinse compared with betamethasone sodium phosphate and placebo in patients with minor recurrent aphthous stomatitis.
Methods: Forty-eight patients with minor recurrent aphthous stomatitis were randomly assigned to receive one of four treatments: 25% Calendula officinalis rinse, 20% Calendula officinalis rinse, betamethasone sodium phosphate, or placebo. Treatments were administered under standardized conditions. Clinical parameters (ulcer size, pain intensity, and erythema) were assessed on Days 0, 4, and 7. Salivary antioxidant biomarkers superoxide dismutase, glutathione, and malondialdehyde were measured to evaluate oxidative stress modulation.
Results: The 25% Calendula officinalis group showed the fastest and most significant improvement, with marked reductions in ulcer size, pain, and erythema by Day 4, sustained through Day 7, and superior to all other groups (p ≤ 0.05). Antioxidant analysis revealed increased salivary superoxide dismutase and glutathione levels and decreased malondialdehyde, particularly with 25% Calendula officinalis No adverse effects were reported.
Conclusion: Calendula officinalis oral rinse, especially at 25%, appears to be a safe, well-tolerated, and effective alternative or adjunct to corticosteroids in minor RAS management, providing rapid symptom relief while modulating oxidative stress. Larger multicenter trials are warranted to confirm these findings and evaluate long-term recurrence prevention