Materials and methods:The anti-respiratory burst activities of eight phenolics (20 mM) were assessed by determining luminol-dependent chemiluminiscence in rat PMNs. Cytotoxicity of active compounds (1-1000 mM) was assayed by Trypan blue dye exclusion method. Cell-free models were employed to evaluate scavenging capacity of active compounds (20 mM) against reactive oxygen species.Results: The PMA-induced respiratory burst was significantly inhibited (p50.05) by six isoprenylated phenolics (AS1-6) at the concentration of 20 mM (below the toxic concentration) with the inhibition rate ranging from 25.0 to 99.6%. The inhibitory potency estimated by IC 50 was in the order of AS1 (3.1 mM) 4AS6 (5.9 mM) 4AS2 (9.1 mM) 4AS3 (10.0 mM) 4AS5 (29.7 mM) 4AS4 (57.7 mM). AS1-4, four isoprenylated flavones, potently quenched superoxide anion, hydroxyl radical, and hydrogen peroxide at the concentration of 20 mM with their scavenging rates in the range of 30.1-78.1%, 35.4-69.7%, and 65.5-86.3%, respectively. In contrast, AS5-6, two isoprenylated 2-arylbenzofurans, showed less effect than that exhibited by AS1-4. Conclusion and discussion: The isoprenylated phenolics from A. styracifolius can potently inhibit PMA-induced respiratory burst in rat neutrophils without showing cytotoxicity. The inhibitory effects of these isoprenylated phenolics on the respiratory burst might depend on their different types of structure.

Through a qualitative analysis of the combustion outcomes, almost no aldehydes have produced after the burning of the tea-leaves. However, the aldehydes can be produced obviously after the burning of tobacco. When tea-leaves were mixed with tobacco, the harmful substances can be drastically reduced in the burning, such as nicotine. Also, the difficulty of smoking will be intensified with the increase of the content of tea-leaves. People can feel the difficulty of smoking when the content of tea-leaves is over 50%, the feeling can be obviously when the content of tea-leaves is over 60%. It is necessary to control the content of tea-leaves less than 40% to ensure the health of human body.