The effect of allicin supplementation on inflammation, oxidative stress and clinical symptoms in patients with multiple sclerosis

To determine the effects of allicin supplementation on inflammatory and oxidative stress biomarkers, and neurological, metabolic, and psychological clinical parameters in patients with relapsing-remitting multiple sclerosis (RRMS).

Phase III randomized, double-blind, placebo-controlled, parallel-group trial with 76 participants (38 per group). Randomization was done using permuted blocks of 4 and 6 via Sealed Envelope.

Patients recruited from the Multiple Sclerosis Society of Ahvaz. Baseline and week-10 clinical, neurological, biochemical, and questionnaire assessments conducted. Randomization and blinding applied for participants and researchers.

Inclusion criteria: age 18–55 years, confirmed diagnosis of RRMS by a neurologist based on the 2017 McDonald criteria, EDSS score ≤ 5.5, ability and willingness to provide informed consent, and adherence to daily supplementation. Exclusion criteria: known allergy to garlic, history of severe gastrointestinal disorders, uncontrolled psychiatric disorders, presence of other autoimmune diseases, active malignancy, use of medications affecting inflammation, oxidative stress, or coagulation, recent change in MS medications or corticosteroid use within the past 3 months, active infection or systemic illness at baseline, pregnancy or breastfeeding, and inability or unwillingness to cooperate with study procedures.

Intervention group: 2 Dineh garlic tablets/day for 10 weeks (400 mg dried garlic powder, 1.1 mg allicin per tablet; Dinehiran Co., Qazvin, Iran). Placebo group: identical corn-starch tablets produced by the same company, administered on the same schedule.

Inflammation, Oxidative stress, Clinical outcomes

Block‍‌‍‍‌ randomization with variable block sizes of 4 and 6 in a 1:1 allocation ratio will be used for randomization. An independent researcher will generate the random sequence by the Sealed Envelope online system (https://www.sealedenvelope.com/simple-randomiser/v1/lists), and allocation will be hidden by using the consecutively numbered, non-transparent, sealed envelopes each of which will have a unique alphanumeric code corresponding to the intervention container labeled. A team member, who is not involved in recruitment or assessment, will assign participants to the allicin or placebo ‍‌‍‍‌group.

This study is double-blind. Participants and outcome assessment (including neurologist performing EDSS and T25FW evaluations) will remain blinded to group allocation. Care providers and laboratory personnel will also not be informed of treatment assignments to maintain blinding integrity.