Rendiconti Lincei

, Volume 28, Issue 4, pp 643–650 | Cite as

The effects of olive leaf extract from a Sicilian cultivar in an experimental model of hepatic steatosis

  • Ignazio Barbagallo
  • Giovanni Li Volti
  • Marco Raffaele
  • Alfio Distefano
  • Rosa Palmeri
  • Lucia Parafati
  • Maria Licari
  • Veronica Zingales
  • Roberto Avola
  • Luca Vanella


Olive oil is a well-known product for its health benefit, but the leaf has also been used as a traditional medicine in the Mediterranean for centuries. Olive leaves contain a great variety of chemical substances belonging to phenolic acids, phenolic alcohols, flavonoids and secoiridoids, and many other pharmacological active compounds with an important antioxidant effects such as oleuropein (OE), hydroxytyrosol (HT), tyrosol, cumaric acid, ferulic acid, caffeic acid, vanillic acid, rutin, verbascoside, luteolin, quercetin, dimethyloleuropein and ligstroside. Characterization of these compounds demonstrated that they can play an important role in human health, because of their ability to improve glucose homeostasis, ameliorate dyslipidemia and reduce inflammatory cytokine. The aim of this study was to investigate the effect of olive leaf extract (OLE) from Sicilian cultivar in an in vitro model of hepatic steatosis to evaluate the protective effects again free fatty acids accumulation in hepatocytes. We report here that OLE treatment ameliorated the lipid metabolism, and this effect was coupled with a parallel decrease in number of lipid droplets and a concomitant increase in FABP-4, SIRT-1 and HO-1 expression. Furthermore, OLE treatment induced a significantly reduction of the inflammatory cytokines IL-1β and TNF-α.


Olive Hepatocytes Lipid metabolism Steatosis Heme oxygenase Phenolic compounds 



Olive leaf extract


Heme oxygenase-1


Fatty acid binding protein 4


Sirtuin 1


Interleukin 1 beta


Tumor necrosis factor alpha


  1. Abraham NG, Junge JM, Drummond GS (2016) Translational significance of heme oxygenase in obesity and metabolic syndrome. Trends Pharmacol Sci 37:17–36. doi: 10.1016/ CrossRefGoogle Scholar
  2. Bahcecioglu IH, Yalniz M, Ataseven H, Ilhan N, Ozercan IH, Seckin D, Sahin K (2005) Levels of serum hyaluronic acid, TNF-alpha and IL-8 in patients with nonalcoholic steatohepatitis. Hepatogastroenterology 52:1549–1553Google Scholar
  3. Benavente-Garcia O, Castillo J, Lorente J, Alcaraz M (2002) Radioprotective effects in vivo of phenolics extracted from Olea europaea L. leaves against X-ray-induced chromosomal damage: comparative study versus several flavonoids and sulfur-containing compounds. J Med Food 5:125–135. doi: 10.1089/10966200260398152 CrossRefGoogle Scholar
  4. Blander G, Guarente L (2004) The Sir2 family of protein deacetylases. Ann Rev Biochem 73:417–435. doi: 10.1146/annurev.biochem.73.011303.073651 CrossRefGoogle Scholar
  5. Brandwilliams W, Cuvelier ME, Berset C (1995) Use of a free-radical method to evaluate antioxidant activity. Food sci technol-leb 28:25–30CrossRefGoogle Scholar
  6. Byrne CD, Targher G (2015) NAFLD: a multisystem disease. J Hepatol 62:S47–S64. doi: 10.1016/j.jhep.2014.12.012 CrossRefGoogle Scholar
  7. Cao J et al (2011) Lentiviral-human heme oxygenase targeting endothelium improved vascular function in angiotensin II animal model of hypertension. Human Gene Ther 22:271–282. doi: 10.1089/hum.2010.059 CrossRefGoogle Scholar
  8. Chau MD, Gao J, Yang Q, Wu Z, Gromada J (2010) Fibroblast growth factor 21 regulates energy metabolism by activating the AMPK-SIRT1-PGC-1alpha pathway. Proc Nat acad Sci USA 107:12553–12558. doi: 10.1073/pnas.1006962107 CrossRefGoogle Scholar
  9. Cirillo G et al (2016) Polyphenol conjugates and human health: a perspective review. Crit Rev Food Sci Nutr 56:326–337. doi: 10.1080/10408398.2012.752342 CrossRefGoogle Scholar
  10. Crespo J et al (2001) Gene expression of tumor necrosis factor alpha and TNF-receptors, p55 and p75, in nonalcoholic steatohepatitis patients. Hepatology 34:1158–1163. doi: 10.1053/jhep.2001.29628 CrossRefGoogle Scholar
  11. Day CP, James OF (1998) Steatohepatitis: a tale of two “hits”? Gastroenterology 114:842–845CrossRefGoogle Scholar
  12. Di Noia MA, Van Driesche S, Palmieri F, Yang LM, Quan S, Goodman AI, Abraham NG (2006) Heme oxygenase-1 enhances renal mitochondrial transport carriers and cytochrome C oxidase activity in experimental diabetes. J Biol Chem 281:15687–15693. doi: 10.1074/jbc.M510595200 CrossRefGoogle Scholar
  13. Garcia-Ruiz I, Solis-Munoz P, Fernandez-Moreira D, Munoz-Yague T, Solis-Herruzo JA (2015) In vitro treatment of HepG2 cells with saturated fatty acids reproduces mitochondrial dysfunction found in nonalcoholic steatohepatitis. Dis Mod Mech 8:183–191. doi: 10.1242/dmm.018234 CrossRefGoogle Scholar
  14. Gerhart-Hines Z et al (2007) Metabolic control of muscle mitochondrial function and fatty acid oxidation through SIRT1/PGC-1alpha. EMBO J 26:1913–1923. doi: 10.1038/sj.emboj.7601633 CrossRefGoogle Scholar
  15. Gomez-Lechon MJ, Donato MT, Martinez-Romero A, Jimenez N, Castell JV, O’Connor JE (2007) A human hepatocellular in vitro model to investigate steatosis. Chem Biol Interact 165:106–116. doi: 10.1016/j.cbi.2006.11.004 CrossRefGoogle Scholar
  16. Hijona E, Hijona L, Arenas JI, Bujanda L (2010) Inflammatory mediators of hepatic steatosis. Mediat Inflamm 2010:837419. doi: 10.1155/2010/837419 CrossRefGoogle Scholar
  17. Hirschey MD, Zhao Y (2015) Metabolic regulation by lysine malonylation succinylation, and glutarylation. Mol Cell Proteom 14:2308–2315. doi: 10.1074/mcp.R114.046664 CrossRefGoogle Scholar
  18. Hotamisligil GS, Bernlohr DA (2015) Metabolic functions of FABPs–mechanisms and therapeutic implications nature reviews. Endocrinology 11:592–605. doi: 10.1038/nrendo.2015.122 Google Scholar
  19. Javitt NB (1990) Hep G2 cells as a resource for metabolic studies: lipoprotein, cholesterol, and bile acids FASEB journal: official publication of the Federation of American Societies for. Exp Biol 4:161–168Google Scholar
  20. Jeong HS et al (2016) Anti-lipoapoptotic effects of Alisma orientalis extract on non-esterified fatty acid-induced HepG2 cells. Complement Altern Med 16:239. doi: 10.1186/s12906-016-1181-2 CrossRefGoogle Scholar
  21. Lee-Huang S, Zhang L, Huang PL, Chang YT, Huang PL (2003) Anti-HIV activity of olive leaf extract (OLE) and modulation of host cell gene expression by HIV-1 infection and OLE treatment. Biochem Biophys Res Commun 307:1029–1037CrossRefGoogle Scholar
  22. Leibiger IB, Berggren PO (2006) Sirt1: a metabolic master switch that modulates lifespan. Nat Med 12:34–36. doi: 10.1038/nm0106-34 CrossRefGoogle Scholar
  23. Li Volti G et al (2011) Effect of silibinin on endothelial dysfunction and ADMA levels in obese diabetic mice. Cardiovasc Diabetol 10:62. doi: 10.1186/1475-2840-10-62 CrossRefGoogle Scholar
  24. Li M, Guo K, Vanella L, Taketani S, Adachi Y, Ikehara S (2015) Stem cell transplantation upregulates Sirt1 and antioxidant expression, ameliorating fatty liver in type 2 diabetic mice. Int J Biol Sci 11:472–481. doi: 10.7150/ijbs.10809 CrossRefGoogle Scholar
  25. Lockyer S, Corona G, Yaqoob P, Spencer JP, Rowland I (2015) Secoiridoids delivered as olive leaf extract induce acute improvements in human vascular function and reduction of an inflammatory cytokine: a randomised, double-blind, placebo-controlled, cross-over trial. Br J Nutr 114:75–83. doi: 10.1017/S0007114515001269 CrossRefGoogle Scholar
  26. Ma KL, Ruan XZ, Powis SH, Chen Y, Moorhead JF, Varghese Z (2008) Inflammatory stress exacerbates lipid accumulation in hepatic cells and fatty livers of apolipoprotein E knockout mice. Hepatology 48:770–781. doi: 10.1002/hep.22423 CrossRefGoogle Scholar
  27. Malaguarnera M et al (2011) Oral acetyl-L-carnitine therapy reduces fatigue in overt hepatic encephalopathy: a randomized, double-blind, placebo-controlled study. Am J Clin Nutr 93:799–808. doi: 10.3945/ajcn.110.007393 CrossRefGoogle Scholar
  28. Manna C, Migliardi V, Golino P, Scognamiglio A, Galletti P, Chiariello M, Zappia V (2004) Oleuropein prevents oxidative myocardial injury induced by ischemia and reperfusion. J Nutr Biochem 15:461–466. doi: 10.1016/j.jnutbio.2003.12.010 CrossRefGoogle Scholar
  29. Mantzaris MD, Tsianos EV, Galaris D (2011) Interruption of triacylglycerol synthesis in the endoplasmic reticulum is the initiating event for saturated fatty acid-induced lipotoxicity in liver cells. FEBS J 278:519–530. doi: 10.1111/j.1742-4658.2010.07972.x CrossRefGoogle Scholar
  30. Marchesini G et al (1999) Association of nonalcoholic fatty liver disease with insulin resistance. Am J Med 107:450–455CrossRefGoogle Scholar
  31. Mariani S et al (2015) Plasma levels of SIRT1 associate with non-alcoholic fatty liver disease in obese patients. Endocrine 49:711–716. doi: 10.1007/s12020-014-0465-x CrossRefGoogle Scholar
  32. Marino M, Acconcia F, Bresciani F, Weisz A, Trentalance A (2002) Distinct nongenomic signal transduction pathways controlled by 17beta-estradiol regulate DNA synthesis and cyclin D(1) gene transcription in HepG2 cells. Mol Biol Cell 13:3720–3729. doi: 10.1091/mbc.E02-03-0153 CrossRefGoogle Scholar
  33. Miles EA, Zoubouli P, Calder PC (2005) Differential anti-inflammatory effects of phenolic compounds from extra virgin olive oil identified in human whole blood cultures. Nutrition 21:389–394. doi: 10.1016/j.nut.2004.06.031 CrossRefGoogle Scholar
  34. Nassir F, Ibdah JA (2016) Sirtuins and nonalcoholic fatty liver disease. World J Gastroenterol 22:10084–10092. doi: 10.3748/wjg.v22.i46.10084 CrossRefGoogle Scholar
  35. Onnerhag K, Nilsson PM, Lindgren S (2014) Increased risk of cirrhosis and hepatocellular cancer during long-term follow-up of patients with biopsy-proven NAFLD. Scand J Gastroenterol 49:1111–1118. doi: 10.3109/00365521.2014.934911 CrossRefGoogle Scholar
  36. Pais R, Pascale A, Fedchuck L, Charlotte F, Poynard T, Ratziu V (2011) Progression from isolated steatosis to steatohepatitis and fibrosis in nonalcoholic fatty liver disease. Clin Res Hepatol Gastroenterol 35:23–28CrossRefGoogle Scholar
  37. Pittala V, Vanella L, Salerno L, Romeo G, Marrazzo A, Di Giacomo C, Sorrenti V (2017) Effects of polyphenolic derivatives on heme oxygenase-system in metabolic dysfunctions. Curr Med Chem. doi: 10.2174/0929867324666170616110748 Google Scholar
  38. Purushotham A, Schug TT, Xu Q, Surapureddi S, Guo X, Li X (2009) Hepatocyte-specific deletion of SIRT1 alters fatty acid metabolism and results in hepatic steatosis and inflammation. Cell Metabol 9:327–338. doi: 10.1016/j.cmet.2009.02.006 CrossRefGoogle Scholar
  39. Rodgers JT, Puigserver P (2007) Fasting-dependent glucose and lipid metabolic response through hepatic sirtuin 1. Proc Nat Acad Sci USA 104:12861–12866. doi: 10.1073/pnas.0702509104 CrossRefGoogle Scholar
  40. Rodgers JT, Lerin C, Haas W, Gygi SP, Spiegelman BM, Puigserver P (2005) Nutrient control of glucose homeostasis through a complex of PGC-1alpha and SIRT1. Nature 434:113–118. doi: 10.1038/nature03354 CrossRefGoogle Scholar
  41. Rui L (2014) Energy metabolism in the liver. Compr Physiol 4:177–197. doi: 10.1002/cphy.c130024 CrossRefGoogle Scholar
  42. Rusu E et al (2015) Medical nutrition therapy in non-alcoholic fatty liver disease–a review of literature. J Med life 8:258–262Google Scholar
  43. Shen Y, Song SJ, Keum N, Park T (2014) Olive leaf extract attenuates obesity in high-fat diet-fed mice by modulating the expression of molecules involved in adipogenesis and thermogenesis. Evid based Complement Alternat Med 2014:971890. doi: 10.1155/2014/971890 Google Scholar
  44. Sodhi K et al (2015) Fructose mediated non-alcoholic fatty liver is attenuated by HO-1-SIRT1 module in murine hepatocytes and mice fed a high fructose diet. PLoS ONE 10:e0128648. doi: 10.1371/journal.pone.0128648 CrossRefGoogle Scholar
  45. Stienstra R, Mandard S, Patsouris D, Maass C, Kersten S, Muller M (2007) Peroxisome proliferator-activated receptor alpha protects against obesity-induced hepatic inflammation. Endocrinology 148:2753–2763. doi: 10.1210/en.2007-0014 CrossRefGoogle Scholar
  46. Talhaoui N, Gomez-Caravaca AM, Roldan C, Leon L, De la Rosa R, Fernandez-Gutierrez A, Segura-Carretero A (2015) Chemometric analysis for the evaluation of phenolic patterns in olive leaves from six cultivars at different growth stages. J Agric Food Chem 63:1722–1729. doi: 10.1021/jf5058205 CrossRefGoogle Scholar
  47. Tibullo D et al (2013) Nuclear translocation of heme oxygenase-1 confers resistance to imatinib in chronic myeloid leukemia cells. Curr Pharm Des 19:2765–2770CrossRefGoogle Scholar
  48. Tobita T et al (2016) SIRT1 Disruption in human fetal hepatocytes leads to increased accumulation of glucose and lipids. PLoS ONE 11:e0149344. doi: 10.1371/journal.pone.0149344 CrossRefGoogle Scholar
  49. Tokushige K, Hashimoto E, Tsuchiya N, Kaneda H, Taniai M, Shiratori K (2005) Clinical significance of soluble TNF receptor in Japanese patients with non-alcoholic steatohepatitis. Alcohol Clin Exp Res 29:298S–303SCrossRefGoogle Scholar
  50. Vanella L et al (2013) Increased heme-oxygenase 1 expression in mesenchymal stem cell-derived adipocytes decreases differentiation and lipid accumulation via upregulation of the canonical Wnt signaling cascade. Stem cell Res Ther 4:28. doi: 10.1186/scrt176 CrossRefGoogle Scholar
  51. Vázquez AJC, Janer ML (1973) Determinación de los polifenoles totales del aceite de oliva. Grasas Aceites 24:350–355Google Scholar
  52. Wainstein J, Ganz T, Boaz M, Bar Dayan Y, Dolev E, Kerem Z, Madar Z (2012) Olive leaf extract as a hypoglycemic agent in both human diabetic subjects and in rats. J Med Food 15:605–610. doi: 10.1089/jmf.2011.0243 CrossRefGoogle Scholar
  53. Yoon L, Liu YN, Park H, Kim HS (2015) Olive leaf extract elevates hepatic PPAR alpha mRNA expression and improves serum lipid profiles in ovariectomized rats. J Med Food 18:738–744. doi: 10.1089/jmf.2014.3287 CrossRefGoogle Scholar

Copyright information

© Accademia Nazionale dei Lincei 2017

Authors and Affiliations

  • Ignazio Barbagallo
    • 1
  • Giovanni Li Volti
    • 2
  • Marco Raffaele
    • 1
  • Alfio Distefano
    • 1
  • Rosa Palmeri
    • 3
  • Lucia Parafati
    • 3
  • Maria Licari
    • 1
  • Veronica Zingales
    • 1
  • Roberto Avola
    • 2
  • Luca Vanella
    • 1
  1. 1.Department of Drug Science, Biochemistry SectionUniversity of CataniaCataniaItaly
  2. 2.Department of Biomedical and Biotechnological SciencesUniversity of CataniaCataniaItaly
  3. 3.Department of Agriculture, Food and EnvironmentUniversity of CataniaCataniaItaly

Personalised recommendations