Preparation, characterization and in-vitro efficacy of quercetin loaded liquid crystalline nanoparticles for the treatment of asthma

The present study aims to formulate quercetin loaded liquid crystalline nanoparticles (LCN) and surface modified liquid crystalline nanoparticles (sm-LCN) as well as investigate their anti-inflammatory activity in human primary bronchial epithelial cell line (BCi-NS1.1) induced with lipopolysaccharide (LPS). Quercetin LCN were prepared using ultrasonication method. The formulated LCNs and sm-LCNs were characterised in terms of particle size, zeta potential as well as the drug encapsulation efficiency. Furthermore, their morphology and in vitro release profile were also studied. In addition, the anti-inflammatory activity of quercetin LCN and sm-LCNs were evaluated by measuring the concentration of pro-inflammatory markers namely interleukin (IL)-1β, IL-6 and IL-8 in BCI-NS1.1 cell lines via cytometric bead array. The molecular mechanism inherent to the inclusion of quercetin into monoolein nanosystem and surface modification of the nanosystem with chitosan was elucidated via molecular mechanics simulations. Quercetin LCN and sm-LCN significantly (p < 0.05) decreased the production of IL-1β, IL-6 and IL-8 compared to LPS only group. Encapsulation of quercetin into LCN and sm-LCN further enhanced its anti-inflammatory activity compared to quercetin in dimethyl sulfoxide (DMSO). In addition to that, quercetin LCN and sm-LCN also exhibited comparable activity to fluticasone in terms of significantly (p < 0.05) reducing the production of IL-1β and IL-6. Quercetin loaded LCN and sm-LCN could be a potential therapeutic intervention for asthma as they are efficacious in suppressing the production of key pro-inflammatory cytokines associated with the development of asthma.