Adjunctive silymarin supplementation and its effects on disease severity, oxidative stress, and inflammation in patients with Alzheimer’s disease

Background: Brain tissue in Alzheimer's patients is exposed to oxidative stress. Silymarin is an adjunct drug that has anti-inflammatory and antioxidant properties. Objective: This study aimed to evaluate the effect of silymarin on biomarkers of oxidative stress, inflammation, and disease severity in Alzheimer's patients. Methods: This randomized, single-blind clinical trial study was performed on 33 patients with Alzheimer's disease (AD) whose disease was confirmed by DSM-5 criteria and by brain imaging. Patients in the case group received three 250 mg silymarin capsules daily (each containing 150 mg silymarin), as an adjunctive medication in addition to the routine medication regimen. In the placebo group (control), patients received the same amount of placebo. All patients underwent Mini Mental State Exam (MMSE) and a panel of blood tests including malondialdehyde, neopterin, catalase, paraoxonase-1, total oxidative status, and total antioxidant capacity to reevaluate the changes pre/postintervention at the end of the trimester. Results: The catalase and MDA serum levels after the adjunctive silymarin treatment decreased significantly (Catalasebefore silymarin= 9.29 ± 7.02 vs Catalaseafter silymarin= 5.32 ± 2.97, p = 0.007 and MDAbefore silymarin= 4.29 ± 1.90 vs MDAafter silymarin= 1.66 ± 0.84, p < 0.001) while MMSE increased notably (MMSEbefore silymarin= 10.39 ± 6.42 vs MMSEafter silymarin= 13.37 ± 6.81, p < 0.001). Conclusion: Silymarin can be effective as an adjunct drug and a powerful antioxidant in reducing oxidative stress and improving the course of AD.