The anti-inflammatory effects and the inhibition of neutrophil responsiveness by Barleria lupulina and Clinacanthus nutans extracts.
OBJECTIVE
To investigate the anti-inflammatory activities of Barleria lupulina Lindl and Clinacanthus nutans (Burm.f.) Lindau extracts using two neutrophil-dependent acute inflammatory models and, in order to elucidate underlying cellular mechanisms, the effects of the extracts on human neutrophil responsiveness was investigated.


METHODS
The in vivo inflammatory models examined were carrageenan-induced paw oedema and ethyl phenylpropiolate-induced ear oedema in rats. Myeloperoxidase (MPO) activity was assayed as an indicator of neutrophil migration. Human neutrophil functional responsiveness was determined by measuring fMLP-induced chemotaxis, superoxide anion generation (SAG), and release of MPO and elastase. Apoptosis was assessed morphologically and flow-cytometrically. Neutrophil viability was assessed by trypan blue exclusion and MTT cytotoxicity assays.


RESULTS
Both extracts induced powerful dose-dependent inhibitory effects in both edema models in rats. Importantly, there was a significant inhibition of MPO activity in the inflamed tissue indicating that the anti-inflammatory effect of the extracts is associated with reduced neutrophil migration. Although both extracts did not affect neutrophil viability or apoptosis, treatment of neutrophils with the extracts concentration-dependently inhibited fMLP-induced chemotaxis, SAG, and MPO and elastase release.


CONCLUSIONS
These findings suggest that the powerful anti-inflammatory properties of Barleria lupulina Lindl and Clinacanthus nutans (Burm.f.) Lindau extracts are mediated, in part, by inhibition of neutrophil responsiveness.Barleria lupulina Lindl, Clinacanthus nutans (Burm. f.)Lindau; Oedema formation; Neutrophil responsiveness.
Wanikiat
Payong
P
Department of Pharmacology, Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand. scpwt@mahidol.ac.th
Panthong
Ampai
A
Sujayanon
Pacharawan
P
Yoosook
Chalobon
C
Rossi
Adriano G
AG
Reutrakul
Vichai
V
D027901:Acanthaceae / Q000737:chemistry*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D017209:Apoptosis; D004578:Electron Spin Resonance Spectroscopy; D006801:Humans; D019272:Leukocyte Elastase / Q000378:metabolism; D008297:Male; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects* / Q000201:enzymology; D009195:Peroxidase / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000893:Anti-Inflammatory Agents; D010936:Plant Extracts; D009240:N-Formylmethionine Leucyl-Phenylalanine; D009195:Peroxidase; D019272:Leukocyte Elastase