To Evaluation the Extracts from the Stem Barks of Aquilaria Sinensis Modulate the Inflammation---Natural Products Affect the Functions of Neutrophil and Neutrophil Extracellular Traps

This study investigates the mechanism underlying the inhibiting effect of two natural products, ASSB-21 and ASSB-2, from the stem barks of Aquilaria sinensis on neutrophils induced inflammatory effects. These compounds inhibited inflammatory response from activated human neutrophil, such as respiratory burst, cathepsin G release, migration, neutrophil extracellular traps (NET) and the interaction between human platelets and neutrophils. ASSB-21 was found to inhibit fMLP-induced superoxide anion production and cathepsin G release in a concentration dependent manner. The IC50 value for ASSB-21 on fMLP-induced superoxide anion is 6.03±1.03 μM. ASSB-21 inhibited fMLP-induced chemotaxis (ASSB-21 inhibited the migration distance, migration direction and migration speed induced by fMLP). Moreover, ASSB-21 inhibited fMLP-induced adhesion molecular expression (CD11b) expression. In order to figure out the effect on ASSB-21 on neutrophils, the intracellular signaling triggered by fMLP were evaluated. ASSB-21 was found to inhibit fMLP-induced p38 and ERK phosphorylation in human neutrophils. ASSB-21 did not affect fMLP-induced intracellular calcium mobilization. Moreover, ASSB-21 inhibited neutrophil extracellular traps (NET) caused by PMA. However, ASSB-21 was not found to inhibit PMA-induced superoxide anion production. ASSB-2 inhibited fMLP-induced superoxide anion production in a concentration dependent manner. The IC50 value for ASSB-21 on fMLP-induced superoxide anion is 1.35±0.16 μM. ASSB-2 inhibited fMLP-induced ERK, PI3K/AKT phosphorylation. Moreover, ASSB-2 was not found to inhibit fMLP-induced p38 phosphorylation in human neutrophils. However, ASSB-2 inhibited fMLP or PMA induced AKT phosphorylation. According to this information, the effect of ASSB-2 on PI3K activity was evaluated in our experiment. In a preliminary data, ASSB-2 was found to inhibit the activity of PI3K activity. In another set of experiments, ASSB-21 and ASSB-2, were found to inhibit fMLP induced neutrophil-platelet aggregation in the whole blood system. We build up an experimental system which activated-platelets induced NET formation. According to this information, we speculate that ASSB-21 and ASSB-2 could inhibit activated-platelets induced NET formation. In conclusion, ASSB-21 and ASSB-2 opposes fMLP-mediated neutrophil activation and inflammation by interring intracellular signaling. According to this information, the inhibitory effect of ASSB-21 and ASSB-2 on neutrophil NET which caused by PMA or activated-platelets will be studied. Finally, we will perform an ischemia-reperfusion animal model in mouse liver and a thrombosis animal model in mouse mesentery. Therefore, the more studies will be carried out in our future study. The detail mechanism for ASSB-21 or ASSB-2 on these animal models will be carried on and evaluate the applications of natural products in the future.

Project ID:PC10901-1734
External Project ID:MOST108-2320-B182-025-MY3