Leaves and Spiny Burs of Castanea Sativa from an Experimental Chestnut Grove: Metabolomic Analysis and Anti-Neuroinflammatory Activity

Abstract

Castanea sativa cultivation has been present in Mediterranean regions since ancient times. In order to promote a circular economy, it is of great importance to valorize chestnut groves’ by-products. In this study, leaves and spiny burs from twenty-four Castanea trees were analyzed by 1H NMR metabolomics to provide an overview of their phytochemical profile. The Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) performed on these data allowed us to distinguish ‘Marrone’ from ‘Castagna’, since the latter were generally more enriched with secondary metabolites, in particular, flavonoids (astragalin, isorhamnetin glucoside, and myricitrin) were dominant. Knowing that microglia are involved in mediating the oxidative and inflammatory response of the central nervous system, the potential anti-inflammatory effects of extracts derived from leaves and spiny burs were evaluated in a neuroinflammatory cell model: BV-2 microglia cells. The tested extracts showed cytoprotective activity (at 0.1 and 0.5 mg/mL) after inflammation induction by 5 µg/mL lipopolysaccharide (LPS). In addition, the transcriptional levels of IL-1β, TNF-α, and NF-kB expression induced by LPS were significantly decreased by cell incubation with spiny burs and leaves extracts. Taken together, the obtained results are promising and represent an important step to encourage recycling and valorization of chestnut byproducts, usually considered “waste”.

Plant Secondary Metabolites: An Opportunity for Circular Economy

“…Regarding the agricultural sector, chestnuts wastes from Castanea sativa Miller, such as spiny burs, are noteworthy for their polyphenol content [ 86 , 87 , 88 , 89 ], including gallic acid and ellagic acid derivatives, together with glycosylated flavonoid [ 90 , 91 ]. By-products derived from chestnut flour production such as chestnut peels are sources of polyphenols, in particular, tannins [ 86 , 88 , 92 ].…”

By-Products of Agri-Food Industry as Tannin-Rich Sources: A Review of Tannins’ Biological Activities and Their Potential for Valorization

“…The anti-inflammatory properties of extracts from the spiny burs of C. sativa have also been tested in vitro using LPS induction in the BV-2 cell line, simulating a microglia model. The treatment showed cytoprotection of the downregulation of the expression of IL-1β, tumor necrosis factor-α (TNF-α) and nuclear factor-κB (NF-κB) [ 38 ]. Following similar approaches, an inflammatory process was induced in the HaCaT cell line using tumor necrosis factor-α (TNF-α).…”

PACAP and VIP Modulate LPS-Induced Microglial Activation and Trigger Distinct Phenotypic Changes in Murine BV2 Microglial Cells

“…To address this issue, in the current study, we used BV2 cells, an immortalized, murine microglial cell line sharing several biochemical properties with primary microglia [50]. BV2 microglia is broadly used as a viable cellular model to investigate the anti-inflammatory properties of several compounds [51,52]. BV2 cells were activated in vitro using LPS, and cells were administered with either PACAP or VIP at concentrations previously identified to be effective; this was followed by biochemical, morphological analyses and assessment of cell migration.…”