The extract of peanut shell enhances neurite outgrowth of neuronal cells: Recycling of agricultural waste for development of nutraceutical products

Abstract

Peanut shell is an agricultural waste having an urgent need to be utilized. The ethanolic extract of peanut shell extract, named as PSE, having enrichment of flavonoids with neurotrophic function, can develop as dietary supplements. In cultured PC12 cells, SH-SY5Y cells and rat primary neurons, the application of PSE increased the proportion of differentiated cells. In parallel, the neuronal differentiation markers, i.e. neurofilaments, were increased at both mRNA and protein levels under PSE treatment. In revealing the signaling cascade, extracellular signal-regulated kinase1/2 (ERK1/2) and protein kinase B (Akt) were activated by PSE. The PSE-induced cell differentiation was blocked by the kinase inhibitors, U0126 and LY294002. The phytochemicals within PSE, e.g. luteolin, eriodictyol and 5,7-dihydroxychromone, induced transcription of neurofilaments in cultures, which in combination could partially account for the neurotrophic functions of PSE. This result supports the waste product from peanut production could be recycled in developing high value nutraceutical products.

Keywords

• Agricultural waste
• Peanut shell
• Flavonoid
• Luteolin
• Neurite outgrowth
• Neurotrophic factor