Evaluation and Exploitation of Bioactive Compounds of Walnut, Juglans regia

In the last few years, great importance has been given to natural materials (such as walnuts, peanuts, chestnuts) due to their medicinal and pharmaceutical uses induced by the presence of natural agents, including polyphenols. Juglans regia is a traditional plant that has been used since ancient times in traditional medicine for the treatment of various diseases like microbial infections, stomach ache, thyroid dysfunctions, cancer, heart diseases and sinusitis. Recently, scientific attention for the phytochemical profile of walnut by-products is increasing due to their valuable active constituents. Natural polyphenols are important compounds present in walnut with valuable properties that have been studied for the treatment of inflammation, cancer or anti-ageing effect. The use of nanocarriers as a drug delivery system is now a promising strategy to get more stable products and is easier to apply in a medical, therapeutic and pharmaceutical environment. The aim of this work was to review the latest information provided by scientific investigators regarding the nutritional value, bioactive compounds, antioxidant and antitumor activity of walnut by-product extracts. Moreover, this review provides comprehensive information on the nanoencapsulation of bioactive constituents for application in clinical medicine, particularly in cancer research.