Modulation of phagocytosis, chemotaxis, and adhesion of neutrophils by areca nut extracts.
BACKGROUND
A higher prevalence of periodontal diseases among areca chewers than non-areca chewers has been demonstrated. Neutrophils, representing the first line of the host defense mechanism against microbial infection, play important roles in maintaining periodontal health. This study determined the possible effects of areca nut on phagocytosis, chemotaxis, and adhesion of human neutrophils.


METHODS
Aqueous extracts of ripe areca nut without husk (rANE) and fresh and tender areca nut with husk (tANE) were examined for their effects on neutrophil phagocytosis using flow cytometry and confocal laser scanning microscopy. The effects of rANE and tANE on chemotaxis and adhesion of neutrophils to human aortic endothelial cells were examined using fluorescence-labeled neutrophils.


RESULTS
Both rANE and tANE inhibited the phagocytic activity of neutrophils in a dose-dependent manner. The levels of internalized fluorescent bacteria in neutrophils decreased after ANE treatment. However, exposure of neutrophils to rANE and tANE stimulated the chemotaxis activity of neutrophils to N-formyl-Met-Leu-Phe (fMLP) and enhanced adhesion of neutrophils to human aortic endothelial cells in a dose-dependent manner. Moreover, treatment of neutrophils with rANE was more effective than incubation with tANE.


CONCLUSIONS
Components of areca nut inhibited phagocytosis activity of neutrophils but enhanced chemotaxis and adhesion of neutrophils. Alterations in functions of neutrophils may lead to signs of clinical diseases associated with areca chewing. The components in ANEs that are responsible for these observations remain to be elucidated.
Hung
Shan-Ling
SL
Institute of Oral Biology, National Yang-Ming University, Taipei, Taiwan.
Lee
Ya-Yun
YY
Liu
Tsung-Yun
TY
Peng
Ji-Lung
JL
Cheng
Yi-Yun
YY
Chen
Yen-Ting
YT
D001114:Areca / Q000009:adverse effects*; D002448:Cell Adhesion / Q000187:drug effects; D002634:Chemotaxis, Leukocyte / Q000187:drug effects; D042783:Endothelial Cells; D005434:Flow Cytometry; D006801:Humans; D018613:Microscopy, Confocal; D009504:Neutrophils / Q000187:drug effects*; D009754:Nuts / Q000009:adverse effects; D010587:Phagocytosis / Q000187:drug effects*; D010936:Plant Extracts / Q000009:adverse effects*; D013295:Streptococcus mutans / Q000276:immunology
D010936:Plant Extracts