Table 1.

Studies included in analysis.

Study	Type of study	Comparison	Study population	Follow-up	Inclusion criteria	Outcomes
Velussi et al. 1997 [26]	12-month open, controlled study	Silymarin plus standard therapy versus standard therapy alone	60 insulin-treated diabetics with alcoholic cirrhosis	4 mo	Age 45 to 70 years (i) NIDDM with alcoholic liver cirrhosis (ii) BMI < 29 kg/m2  (iii) Ascertained diabetes for a period of at least 5 years and being treated with insulin only (iv) Stable insulin therapy for a period of at least 2 years (v) Negative for markers of hepatitis A, hepatitis B, and hepatitis C and being not addicted to alcohol for a period of at least 2 years prior to the start of the study (vi) No bleeding from varices (vii) Liver biopsy (liver cirrhosis)	Fasting blood glucose Mean daily blood glucose levels Daily glycosuria levels HbA1c Malondialdehyde levels
Huseini et al. 2006 [28]	Randomized double-blind clinical trial	Silymarin plus conventional therapy versus placebo plus conventional therapy	51  patients with type 2 DM	4 mo	Type 2 diabetes according to ADA criteria (2003) (i) Age 40–65 years (ii) Having a fasting blood glucose level less than 250 mg/dL (iii) Duration of diabetes was more than 2 years, and their diabetes was not controlled exclusively by diet	Fasting blood glucose HbA1c Total cholesterol, LDL, and HDL and triglyceride GOT and GPT levels
Hussain 2007 [29]	Randomized, double-blind, placebo-controlled trial	silymarin + glibenclamide versus placebo + glibenclamide versus glibenclamide alone	59  patients with type 2 DM	4 mo	T2DM for at least 5 years (i) Already maintained on 10 mg/day glibenclamide and on diet control (ii) Fasting plasma glucose ≥ 10 mmol/L (iii) HbA1c ≥ 8% (iv) BMI ≥ 29 kg/m2	Fasting blood glucose HbA1c Body mass index (BMI)
Fallahzadeh et al. 2012 [19]	Randomized, double-blind, placebo-controlled, 2-arm parallel trial	Silymarin versus placebo	60  patients with type 2DM and macroalbuminuria	6 mo	Urinary albumin excretion >300 mg/24 h Treatment of hyperglycemia with (but not limited to) an oral hypoglycemic agent or insulin Treatment of hypercholesterolemia with a statin Presence of diabetic retinopathy	Absolute change in urinary albumin-creatinine ratio Urinary and serum levels of TNF-α Malondialdehyde and TGFβ
Ebrahimpour Koujan et al. 2015 [30]	Randomized, triple-blinded, placebo-controlled clinical trial	Silymarin versus placebo	40 patients with type 2 DM	45 days	Type 2 diabetes patients (i) taking hypoglycaemic medications, (ii) having a body mass index (BMI) between 27 and 35 kg/m2, and (iii) following a stable habitual diet for the past three months	Antioxidant indices Superoxide dismutase (SOD) and glutathione peroxidase (GPX) activity and total antioxidant capacity C reactive protein