Objective: In this research, fatty acid profile and polyphenolic content of an ethanolic extract
of walnut from Juglans regia L. collected in Central Italy, were characterized. The potential antioxidant
and anti-inflammatory effects of the extract were investigated in the human keratinocytes cell line.
Methods: Fatty acid profile was determined by gas chromatography/mass spectrometry analysis, total
phenolic content by Folin-Ciocalteu method and aluminum chloride colorimetric method was used for
determination of total flavonoids. Kertatinocytes were exposed to t-butyl hydroperoxide or Tumor Necrosis
Factor alfa in the absence or presence of extract. Reduced glutathione was determined by Sedlak
method; lipid peroxidation was assessed by measuring thiobarbituric acid reactive substances. t-butyl
hydroperoxide and Tumor Necrosis Factor alfa-induced intracellular reactive oxygen species were
monitored by fluorescent probes. The expression of some genes related to the inflammatory process
(IL-6, IL-8, ikB, and ICAM) were analysed by Real-time PCR.
Results: JRE contains a favourable fatty acid profile with low saturated fats (19%) and high-unsaturated
fats (81%) with a prevalence of the omega-6 linoleic acid (48%). Also a significant amount of polyphenols
was found (5,0052 mg gallic acid equivalent/gdw). Antioxidant and anti-inflammatory properties of
JRE were observed on analysed cellular model. JRE antioxidants counteracted ROS production, GSH depletion
and lipid peroxidation as well downregulated the expression of some genes related to the inflammatory
process. Moreover, polyunsaturated fatty acids exhibited anti-inflammatory properties.
Conclusion: The obtained results uphold walnut as dietary adjunct in health promotion and drive towards
its development in drug therapy against chronic inflammatory disorders, including inflammatory