Potential anti-inflammatory effects of Pingyin Rose Essential Oil on Lipopolysaccharide-induced HaCaT Cells

Abstract Background: Skin is the primary defense to human body from external exposure of harmful stimulation. Excessive and improper immune-regulation could cause chronic inflammation resulting in different skin diseases. Pingyin Rose is a well-known component of traditional Chinese medicine (TCM) because of its wide range of bioactivities and so do PREO.Aim: The present work aims to characterize the Pingyin rose essential oil (PREO) composition, investigate the beneficial effects of PREO on the skin inflammation in vitro and determine ligands for OR2AT4 in silico from PREO components.Materials and Methods: PREO was quantified by GC-MS and molecular docking was performed for OR2AT4 with top two components. HaCaT cells were induced with lipopolysaccharides (LPS) to study downregulation of oxidative stress and inflammation through NF-κB signaling. Result and Discussion: According to our results, Citronellal (54.28%) and geraniol (9.26%) are the principal compounds of PREO and both deemed to be potential ligand for OR2AT4. PREO could significantly reduce the expression of the TLR4-NF-κB pathway in LPS-induced HaCaT cells. PREO could also prevent LPS-mediated oxidative stress, including the increase of SOD and MDA, decrease of mRNA expression for inflammatory markers (TNF-α, IL-1β, IL-6, IL-8) and several genes involved in TLR4 pathway, that is also an evident for PREO as potential anti-inflammatory therapeutic. PREO also inhibits NF-κB p65 and IκB-α protein phosphorylation. Conclusion: Our findings revealed that PREO could decrease inflammatory protein expressions, possibly functioning with the reduction of oxidative stress and inflammatory cytokines via downregulating NF-κB pathway. PREO component can interact with OR2AT4 and paly roles in other physiological activities.