Anti-atherosclerotic potential of aqueous extract of Cinnamomum zeylanicum bark against glucocorticoid induced atherosclerosis in wistar rats

Introduction: Atherosclerosis is one of the major causes of disability of blood vessels which can result in development of many cardiovascular disorders. There is a strong association between atherosclerosis and insulin resistance and dyslipidemia. Aim: To study the anti-atherosclerotic potential of C. zeylanicum bark extract in insulin resistance associated atherosclerosis and worsened Atherogenic Index (AI) associated with dyslipidemia, which are the predominant complications of steroid diabetes in Wistar rats. Materials and Methods: A sum of 36 rats were categorized into five study groups and one plain control. In a 12 day study period, respective drug treatments were given every day throughout the study period whereas, dexamethasone dosage was started from day seven onwards. On day 12, fasting blood samples were collected and processed for lipid estimation and the determined values were also used to assess AI further. Animals were sacrificed under ether anaesthesia and the aorta was dissected away for its measurement and histopathological findings. One-way ANOVA was used to analyse the data and multiple comparison was done, interpreted based on Post-Hoc Scheffe test. Results: High dose of dexamethasone (8 mg/kg/i.p) in Dexa Control (DC) group produced significant dyslipidemia, increased risk of atherogenicity (p<0.05) and caused severe thickening (78.5% compared to Plain Control (PC) of wall of aorta. Rosiglitazone (ROSI) (8 mg/kg and 16 mg/kg) and C. zelanicum (CZE) extract treatments (500 mg/kg and 250 mg/kg) significantly prevented dyslipidemia, well maintained AI compared to dexa control (p<0.05). However, both the CZE treatments protected the aorta from atherosclerosis (40.3% and 30.2% compared to DC) and significantly prevented the dyslipidemia and reduced the risk of atherogenicity compared to ROSI treatment (p<0.05). Although, the CZE did not show difference in significance in maintaining very low density lipoprotein when compared to ROSI (p>0.05). The atherosclerotic changes were completely absent in both the CZE treatments whereas, ROSI treatments did not prevented the atherosclerosis of aorta completely as they showed moderate and mild atherosclerotic changes in the aorta. Conclusion: The aqueous extract of C. zelanicum bark exhibited marked protection against dexamethasone induced atherosclerosis and also minimized the atherogenic risk in Wistar rats.