Chemical constituents, antibacterial and anti-inflammatory properties of Pyrus calleryana Dcne. essential oil

Pyrus calleryana, commonly known as bean pear, is a medicinal and edible plant, especially its fruit is utilized in traditional Chinese medicine and processed into fruit wine. Essential oils have proven to be potent antibacterial and anti-inflammatory agents. Hence, this study firstly investigated the chemical components, antibacterial and anti-inflammatory properties of P. calleryana fruit essential oil (EO). According to GC-FID/MS analysis, P. calleryana fruit EO was composed mainly of linalool (20.9 %), & alpha;-terpineol (14.4 %), E-nerolidol (11.7 %), trans- 3-hexenol (9.4 %), n-hexadecanoic acid (7.4 %), geraniol (6.9 %), and trans-2-hexenol (4.8 %). For antibacterial action against Gram-negative bacteria, it revealed a strong antibacterial effect against Escherichia coli, Pseudo-monas aeruginosa, and Proteus vulgaris with minimal inhibitory concentration (MIC) (19.53-312.50 & mu;g/mL) and minimal bactericidal concentration (MBC) (39.06-625.00 & mu;g/mL) values. In the evaluation of anti-inflammatory activity using Gram-negative bacteria lipopolysaccharide (LPS)-induced RAW264.7 macrophages, P. calleryana fruit EO dramatically suppressed pro-inflammatory mediators (NO and PGE2) and cytokines (TNF-& alpha;, IL-1 & beta;, and IL-6) over-secretion without cytotoxicity. Meanwhile, it decreased LPS-stimulated mRNA expression of pro-inflammatory cytokines and mRNA and protein expression of iNOS and COX-2. Furthermore, it inhibited LPS-induced ROS generation, MAPKs phosphorylation, and NF-& kappa;B nuclear translocation. Hence, P. calleryana fruit EO has bifunctional antibacterial and anti-inflammatory activities and may be a promising therapeutics for in-fectious diseases with great potential for utilization in the fields of functional foods and pharmaceuticals.