A wide spectrum of immune abnormalities has been described by numerous studies involving β-thalassemic patients with multiple transfusions. The abnormalities observed are both quantitative and functional, and concern several components of the immune response. Flavonoids are phenolic compounds widely distributed in plants, which were reported to exert multiple biological effects, including antioxidant and free radical scavenging abilities. Silymarin, a flavonolignan complex isolated from milk thistle (Silybum marianum L. Gaertn), have been classified as cytoprotective, antioxidant, anti-inflammatory, and especially as hepatoprotective agents. Silymarin is already being used clinically for treatment of liver diseases.It is considered safe and well-tolerated, with reported adverse events similar to placebo. Several studies have also reported immunomodulatory actions of silymarin. It increases lymphocyte proliferation, interferon gamma, interleukin (IL)-4 and IL-10 secretions by stimulated lymphocytes in a dose-dependent manner. It has been shown that in vitro treatment of peripheral blood mononuclear cells with silymarin causes restoration of the thiol status and increases in T cell proliferation and activation. Because reactive oxygen species and iron overload play important roles in the pathophysiology of thalassemia, silymarin may be an effective therapy due to its antioxidant, immunomodulatory, cytoprotective and iron chelating activities. The present study designed to investigate the therapeutic activity of orally administered silymarin for treatment of β-thalassemia major, a well-known and prevalent disease in Iran, which is associated with oxidative stress, iron overload and immune abnormalities.

Inclusion Criteria:

• Homozygous beta-thalassemia major
• Regularly blood transfusion
• Iron chelation therapy with subcutaneous desferrioxamine (DFO)40.0 mg/Kg/day for 5-7 days/week

Exclusion Criteria:

• Chronic hepatitis B infection
• Active hepatitis C infection
• A history of a positive HIV test
• Chronic renal or heart failure
• Iron chelation therapy with deferiprone
• Pregnancy
• Gastrointestinal conditions preventing absorption of an oral medication o
• noncompliance with prescribed therapy