Ameliorative Effect of Olive Seed or Nano-olive Seed Powder Against Endothelial Dysfunction Induced by High Fat-High Fructose Diet in Rats

Abstract

Finding new uses for wastes of table olive and olive oil production are of great value to the economy, environment, and human health. This study was designed to investigate the possible modulatory effect of nano or native olive seeds powder (OSP) against endothelial dysfunction induced by high fat high fructose (HFHF) diet in rats. For the current work, 60 adult male Sprague-Dawley rats weighing 120g±5g were divided into six groups 10 rats for each group. Group 1: rats were fed a balanced diet and served as normal control. Group 2: rats were fed HFHF diet served as positive control rats diet for 8 weeks. Group 3: rats were fed HFHF diet supplemented with 5% olive seeds powder. Group 4: rats were fed HFHF diet supplemented with10% olive seeds powder. Group 5: rats were fed HFHF diet supplemented with 5% nano olive seeds. Group 6: rats were fed HFHF diet supplemented with 10% nano olive seeds. Results of phytochemical analysis of (OSP) showed that each 100g of OSP contains 1004.9 mg total polyphenols as gallic acid equivalent (GAE%) and 24 mg total flavonoids as quercetin equivalent (QE%). Results of the biochemical analysis indicated that feeding HFHFdiet caused a significant increment in serum glucose, insulin level, calculated HOMA-IR, lipids profile total cholesterol (TC), triacylglycerols (TAGs), low density lipoprotein cholesterol (LDL-C), very low density lipoprotein cholesterol (VLDL-C), lipase enzyme activity with a significant decrease in high density lipoprotein cholesterol (HDL-C) as compared to control group. Also, interleukin-6 (IL-6) and C-reactive protein (CRP), malondialdehyde (MDA), Endothelin (ET-1), vascular cellular adhesion molecule-1 (VCAM-1), and E- selectin were significantly increased in HFHF fed rats as compared to the control group. Whereas, serum nitric oxide, prostacyclin, endothelial nitric oxide synthase (eNos) activity were significantly decreased in HFHF fed rats as compared to the control group. These results suggesting that feeding rats HFHF diet for 8 weeks induced endothelial dysfunction. Also, the histopathological examination of aorta sections supported results of biochemical analysis showed significant swelling and corrugation of the endothelial cells that lining the intima in the untreated HFHF group as compared to the control group. Results confirmed that dietary supplementation with olive seed powder either in native or in nano form at the tested doses reversed both alterations biochemical parameters and pathological changes in aorta tissue. Moreover, Nano form showed a more powerful effect than native powder.