Neuroprotective role of Origanum majorana essential oil loaded in mixed surfactants based nano emulsion against lipopolysaccharide-induced Alzheimer in mice

Abstract Purpose The current study aims to improve the oral bioavailability of Origanum majorana essential oil loaded nanoemulsions (OMEO -NEs) for the treatment of Alzheimer’s disease in mice induced by lipopolysaccharide (LPS). Methods Gas Chromatography–Mass Spectrometry analysis (GC–MS) analyses were performed to determine the Origanum majorana leaves essential components. Yield essential oil, phenolic content, and flavonoid content were also ascertained. Four NEs containing various concentrations of carboxy methyl cellulose (CMC) and a fixed concentration of Tween 80 as mixed emulsifiers. Plain OMEO and its chosen NE were tested for their antioxidant properties against DPPH & ABTS, hydrogen peroxide, and metal chelation assay. The mice in the in vivo study were divided into five groups at random (8 per group): Group 1: normal control group. Group 2: LPS positive group (250 µg/kg; intraperitoneal); Groups 3–5: Oral administration of 400 mg/kg of Blank NE, plain OMEO, and OMEO-NE for 7 days in conjunction with LPS. Results GC–MS identified the primary constituents which are α-Terpineol (21.85%), γ-Terpinene (12.43), and α-Caryophyllene (11.78%). The encapsulation efficiency % of NE was improved when the concentration of CMC was reduced. Particle size and zeta potential values in the prepared NE were reasonable. In every test, the chosen OMEO-NE showed stronger antioxidant activity than plain OMEO. When compared to LPS-treated mice, OMEO-NE increased cognitive function and decreased AChE, TLR4, and GFAP levels. Conclusion The current study provides opportunities for safer approaches that using compounds derived from plants and links it to nanotechnology, could be used in the pharmaceutical industry to treat Alzheimer’s disease.