Exploring the Immunostimulant Activity of Selected Nuts in Relation to their Metabolic Profile RSPG 2.1

Abstract

ABSTRACT Immune system is the potent army that defends our body against various infections and diseases through innate and adaptive immunity. Immunostimulant are those substances that activate the immune system by triggering stimulation or rising activity of any of its components. Nowadays, COVID-19 is a pandemic that lasts with no specific treatment and maximizing the capability of immune system defense is one of the routes for its management. Herbal medicine is one of the essential sources for enhancing immunity because of their affordability, availability, minor side effects and people preference. Hazelnut, Walnut, almond and peanut are from the most widespread edible nuts that are rich in fats, fibers, vitamins, proteins and minerals. Our aim is to determine the shells and edible nut in vitro immunostimulant activity as well as metabolomics profiling of the four nut extracts. 500 grams of each of nuts and shells were powdered then defatted and extracted by using n-hexane and ethanol (95%) followed by evaporation of the pooled extracts under reduced pressure using the rotary evaporator in a temperature not exceeding 60˚C followed by measurement of yield of each of hexane and ethanol extracts. For nuts, total phenolic were found to be in Peanut Almond, Hazelnut and Walnut of 13.4538, 17.8237, 9.7978, and 17.6237 respectively and for shells, 240.0753, 21.4559, 159.6989, and 328.0860 respectively. The antioxidant activity of the shells and nuts was measured by: DPPH, and ABTS assays through measuring inhibition percentage as well as FRAP by measuring absorbance which have been indicated the significant antioxidant capability especially walnut peanut shells. The toxicity of each of nuts’ and shells’ extracts has been assessed though MTT viability test which indicated their safety on the differentiated THP-1. Addition of extracts to LPS-stimulated macrophages especially peanut and walnut shells have downregulated the expression of AP-1 and in turn decreased TNF-α and IL-8 production. On the other hand, NF- κB contributed to the downregulation of iNOS and COX-2. UPLC-MS metabolic profiling of the four nuts shells and nuts has been done detecting around 128 metabolites.