Lack of Effect of Sugar Cane and Sunflower Seed Policosanols on Plasma Cholesterol in Rabbits

Abstract

Objective: To evaluate the potential for a mixture of policosanol extracted from sunflower oil (SFP) to lower blood cholesterol levels in comparison to sugar cane policosanol (SCP) in rabbits.

Design: Twenty three Semi-lop rabbits were blocked into three groups matched on fasting plasma cholesterol levels then randomly assigned to one of three parallel treatment arms: Control (Vehicle 28.6% sunflower oil/70% water/1.4% emulsifier) n = 7; SFP, 100 mg/kg in vehicle, n = 8; SCP, 100 mg/kg in vehicle, n = 8. Rabbits were gavaged once every two days for four weeks. Blood was collected and analysed for plasma lipids.

Results: Total cholesterol, non-HDL and HDL cholesterol increased significantly following SCP supplementation relative to the control. SFP supplementation had no effect. Triglyceride levels decreased significantly following all dietary treatments (P < 0.05), possibly due to the emulsifier.

Conclusion: Dietary supplementation of normocholesterolemic rabbits with policosanol from sunflower oil does not appear to have any cholesterol lowering effect. A similar lack of efficacy observed with the commercial SCP product which we evaluated raises doubts about the purported cholesterol-lowering efficacy of these products, as reflected in the current literature.

• policosanol
• sugar cane
• sunflower seed
• total cholesterol
• LDL
• HDL

• BW = body weight
• HDL = high density lipoprotein cholesterol
• LDL = low density lipoprotein cholesterol
• non-HDL = non-high density lipoprotein cholesterol
• PGPR = polyglycerol polyricinoleate
• SCP = sugar cane policosanol
• SFP = sunflower seed oil policosanol
• TC = total cholesterol
• TG = triglycerides
• ADP = adenosine diphosphate
• AA = arachidonic acid
• TBARS = thiobarbituric acid reactive substances assay
• MDA = malonyldialdehyde
• Apo AI = apolipoprotein AI
• RCT = randomized controlled trial

This study was supported by Goodman Fielder Ltd. The authors would like to thank Dr Ron Bowrey, Dr Geoffrey Annison and Ms Donna Ross formerly of Goodman Fielder Ltd for their contributions to the study design and the preparation of the sunflower seed policosanol and also Johnson & Barana for the kind donation of the sugar cane wax (LesstanoL®) policosanol used in this study.

Notes

Presented in part in poster format at the International Society for the Study of Fatty Acids and Lipids (ISSFAL) meeting, July 2004, United Kingdom.