Protective Effects of Berry Volatiles on Lipopolysaccharide-Induced Acute Lung Injury in Human A549 Cells

Abstract

Abstract Objectives Berry volatiles are primary or secondary compounds produced when tissue disrupts, and responsible for the flavor and aroma of berries. Berry volatiles has been recently reported to have anti-inflammatory effect. Acute lung injury is one of the severe consequences of lung inflammation increasing respiratory stress and pulmonary edema with high mortality. Thus, the objective of this study was to investigate the anti-inflammatory effect of three berry volatiles (blackberry, black raspberry, and blueberry) on lipopolysaccharide (LPS)-induced acute lung injury in lung epithelial A549 cells and its mechanism. Methods A549 cells were pretreated with three different dilutions (2, 4, and 8-fold) of blackberry, black raspberry, and blueberry volatile extract for 1 h. Cells were then stimulated with or without LPS (10 μg/mL) for 24 h. The cell viability was measured with one-step diphenyl tetrazolium bromide (MTS) assay. The level of pro-inflammatory cytokines in the culture media was examined by using enzyme-linked immunosorbent assay (ELISA) kit. Apoptosis of A549 cells were evaluated by using death detection ELISA kit. All statistical tests were analyzed by using one-way ANOVA, followed by Tukey's multiple comparisons. Significant difference was defined at P < 0.05. Results Two-fold diluted berry volatiles (blackberry, black raspberry, and blueberry) significantly decreased A549 cell viability by 24%, 52% and 61%, respectively compared to the control (P < 0.05). Concentration of interleukin-8 (IL-8) was remarkably higher when LPS stimulated A549 cells compared to the control (P < 0.05). However, 2-fold diluted berry volatiles significantly suppressed LPS-induced IL-8 level compared to LPS treated group (P < 0.01). 2-fold diluted blackberry, black raspberry, and blueberry volatiles also showed significant apoptotic effect on A549 cells compared to the control (P < 0.05). Conclusions These results showed that blackberry, black raspberry, and blueberry volatiles suppress inflammatory responses by modulating pro-inflammatory cytokines and apoptosis. This study suggests that volatiles from berries (blackberry, black raspberry, and blueberry) may have a potential impact on lung inflammation. Funding Sources Arkansas Biosciences Institute.