• Evaluating antilipemic effects of Silybum marianum versus Atorvastatin in atherosclerotic rabbits
  • Aida Ashrafzadeh,1 Shahrzad Kamfiruzi,2 Shiva Saleh,3 Hossein Kargar Jahromi,4,* Bahareh Ebrahimi,5
    1. Student Research Committee, Jahrom University of Medical Sciences, Jahrom
    2. Student Research Committee, Jahrom University of Medical Sciences, Jahrom
    3. Student Research Committee, Jahrom University of Medical Sciences, Jahrom
    4. Research center for non-Communicable Disease, Jahrom University of Medical Sciences, Jahrom, Iran
    5. Shiraz Geriatric Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.


  • Introduction: Atherosclerosis is a chronic inflammatory disease that remains the major cause of mortality, morbidity and disability in the developed world. The incidence of cardiovascular disease (CVD) varies from one region to another and it seems to be higher in Iran. Disorder of plasma lipoprotein and metabolism of lipids are the most recognized risk factors. Increased permeability to low-density lipoprotein (LDL) and its sequestration in the extracellular matrix plays role in the pathogenesis of atherosclerosis. In contrast to the LDL with atherogenic potential, HDL particles prevent atherosclerotic plaque formation. HDL transports cholesterol reversely from the peripheral tissues to the liver and acts as an anti-inflammatory and anti-oxidative agent. Recent studies have shown a correlation between CVD and triglyceride components, apolipoproteins, such as chylomicron, VLDL, LDL, and HDL. Several studies show that Milk thistle (Silybum marianum), a herbaceous plant, has potential anti-oxidative and immunomodulatory effects, reduces inflammation and inhibits oxidation of LDL. So, in this study, we aimed to evaluate the therapeutic effects of Silybum marianum seed extract.
  • Methods: Thirty-six male white New Zealand rabbits were divided into six groups as follows: control group; groups 2-6 were induced atherosclerosis by a high-fat diet, 2% cholesterol and 14% coconut oil, for eight weeks. Then: Group 2, was dissected; groups 3 to 6, animals were fed with the standard diet for the second eight weeks: Group 3, atherogenic control group (AC); group 4, Atorvastatin group (AV); group 5, Silymarin extract 1 (SM1), which were gavaged daily whit SMSE 100 mg/kg; group 6, Silymarin extract 2 (SM2), atherosclerotic rabbits were gavaged with SMSE high dose (200 mg/kg). After a therapeutic period with SMSE for two months, we evaluated serum concentrations of TG, TC, LDL, VLDL, and HDL were measured with biochemical kits from Pars Azmoon company- Iran.
  • Results: The serum levels of the lipid profile are shown in Table 1. There was a statistically (P< 0.05) increase in the mean concentration of TC, TG, HDL, LDL, VLDL in AC, AV and SM1 groups compared with the control group, while there were no significant differences between the control group and SM2 in the level of TC, TG and LDL. These results indicated that the high dose of SMSE was significantly more effective in lowering levels of TC, TG, LDL and VLDL than the low dose of SMSE and AV. Serum levels of the lipid profile of SM groups showed that they performed better than the values of the group treated with AV (VLDL in both doses, TG, TC and LDL in higher dose), indicating the effectiveness of the SMSE treatment. Table 1:The mean serum level of studied parameters in five groups Control Atherogenic Control Atorvastatin Silymarin (100mg/kg) Silymarin (200mg/kg) Triglycerides 71.50±7.2 162.16±11.2* 99.00±4.6*$ 102.83±5.9*$ 79.83±12.0$#@ Total cholesterol 29.50±4.0 220.00±18.3* 51.83±7.8*$ 55.16±7.2*$ 37.33±5.3$#@ HDL 17.16±2.8 53.66±7.5* 39.00±5.7*$ 36.33±2.2*$ 35.00±6.3*$ LDL 31.00±3.9 67.00±5.4* 44.16±4.9*$ 40.16±4.7*$ 33.66±3.9$#@ VLDL 8.50±1.9 25.50±1.9* 17.00±1.4*$ 19.16±1.7*$# 14.66±1.6*$#@ VLDL: Very-low-density lipoprotein; LDL: Low-density lipoprotein; HDL: High-density lipoprotein *P<0.05, level of significance compared with the control (c) group $ P<0.05, level of significance compared with the atherogenic control (AC) group # P<0.05, level of significance compared with the Atorvastatin (AV) group @ P<0.05, level of significance compared with the Silybum Marianum seed extract (SM1) group
  • Conclusion: Silymarin had affected lipid profile and 200 mg/kg SMSE was more effective than AV and even managed to control levels of TG, TC and LDL. Our results showed that rabbits treated with SMSE and AV experienced a significant increase in serum HDL and decrease in TC, TG, LDL and VLDL levels compared to atherosclerosis animals, meanwhile, the higher dose of SMSE was statistically more effective than the lower dose and AV. In accordance with results obtained by Radjabian (2010), SMSE can dose-dependently modify lipoprotein profiles. Other articles, demonstrated that Silymarin can affect the metabolism and the concentration of blood fats by inhibiting 3-hydroxy-3-methylglutheryl coenzyme A (HMG-CoA) reductase, a key enzyme in cholesterol synthesis, in the liver and also by lowering blood cholesterol by inhibiting its absorption in the gastrointestinal tract. In conclusion, this study indicates that SMSE, especially the high dose, may have good anti-atherosclerotic effects compared to Atorvastatin since it controls lipid profile.
  • Keywords: Atherosclerosis, Lipids, Silybum marianum, Rabbit