Advisor(s)
Abstract(s)
Juglans regia L. (walnut) green husks are an important fraction of waste resulting from the walnut production,
thus representing an interesting natural matrix to explore as a source of bioactive compounds. In this work, the
hydroethanolic extract of walnut green husks was studied considering the phytochemical composition and the
biological activity using different cell model assays, most of them evaluated for the first time for this matrix.
From the HPLC-DAD-ESI/MSn analysis, sixteen compounds were identified, being the extract mostly composed
of naphthalene derivatives (including tetralone derivatives) and less abundant in phenolic compounds
(hydroxycinnamic acids and flavonols). The cytotoxic potential of the extract was assessed against tumour (MCF-
7, NCI–H460, HeLa and HepG2) and non-tumour (PLP2) cell lines. Moreover, the antioxidant activity of the
extract was evaluated by inhibition of the oxidative haemolysis (OxHLIA) and the formation of thiobarbituric
acid reactive substances (TBARS), and the anti-inflammatory potential by the inhibition of the NO production by
the RAW264.7 cell culture. The antibacterial effects of the extract were also evaluated against Gram-negative
and Gram-positive bacteria. The results obtained represent a stepping stone for the development of future applications
using walnut green husks as a source of added value compounds with bioactive potential.
Description
Keywords
Anti-inflammatory Antibacterial Antioxidant Cytotoxicity Juglans regia L. husks Naphthalene derivatives Phenolic compounds
Citation
Vieira, Vanessa; Pereira, Carla; Abreu, Rui M.V.; Calhelha, Ricardo C.; Alves, Maria José; Coutinho, João A.P.; Ferreira, Olga; Barros, Lillian; Ferreira, Isabel C.F.R. (2020). Hydroethanolic extract of Juglans regia L. green husks: A source of bioactive phytochemicals. Food and Chemical Toxicology. ISSN 0278-6915. 137, p. 1-8