Hypolipidemic and Hypoglycemic Effects of Silybum marianum (L.) Gaertn. (Milk Thistle) Ethanol Seed Extract in Streptozotocin-induced Diabetes in Rats

Abstract

Background Metabolic syndrome (MS) is considered a challenging health problem worldwide. However, the search for alternative treatments to alleviate MS is lacking. Purpose This study defines Silybum marianum (milk thistle) ethanol seed extract (SMESE) in terms of polyphenol and flavonoid content, antiglycation effect, α-amylase activity, and hypolipidemic and hypoglycemic effects in streptozotocin (STZ)-induced diabetic rats. Materials and Methods S. marianum seeds were collected, ground, and extracted with 80% ethanol. The α-amylase inhibitory activities of 10, 30, and 100 µg/mL SMESE were evaluated using spectrophotometric methods. The inhibitory activity of SMESE against advanced glycation end-product formation was evaluated using fluorescence spectrophotometry. In vivo, 48 Wistar male albino rats were used. Eight animals served as the normal control (group 1), and 40 rats were injected with 60 mg/kg STZ to induce diabetes. Diabetic rats were divided into five groups: diabetic control (group 2) and positive control that received the hypoglycemic reference drug metformin at 100 mg/kg (group 3). Groups 4, 5, and 6 were administered the seed extract orally at 30, 100, and 300 mg/kg, respectively. Body weight, serum glucose, lipid profile, and malondialdehyde (MDA) levels were measured weekly for five weeks after SMESE administration. Results SMESE administration inhibited BSA glycation and α-amylase activity. In vivo, SMESE administration increased body weight (BW), decreased serum glucose levels, and reduced triglyceride, total cholesterol, low-density lipoprotein, very low-density lipoprotein, and MDA levels but increased high-density lipoprotein levels. Conclusion Data indicate the beneficial hypoglycemic and antihyperlipidemic effects of SMESE, suggesting its potential use in controlling lipid metabolism.