Bixa orellana leaves extract inhibits bradykinin-induced inflammation through suppression of nitric oxide production.
OBJECTIVE
The present study was conducted to assess the anti-inflammatory effect of a crude aqueous extract of Bixa orellana leaves (AEBO) and to examine the possible involvement of nitric oxide (NO) in its anti-inflammatory mechanism.


METHODS
The air-dried, powdered leaves were soaked in distilled water (1:20 w/v) at 50°C for 24 h and the supernatant obtained was freeze-dried (yield 8.5% w/w). The dosage was recorded as the mass of extract per kg b.w. of rats in all inflammatory assays (bradykinin-induced paw edema, peritoneal vascular permeability and NO assay).


RESULTS
Pretreatment with AEBO for 4 consecutive days exhibited significant inhibitory activity against inflammatory models, the bradykinin-induced hind paw edema model and bradykinin-induced increased peritoneal vascular permeability at both doses in dose-dependent manner. In addition, AEBO was also found to significantly suppress the production of NO at doses of 50 and 150 mg/kg.


CONCLUSIONS
This study provides scientific data to support the traditional use of B. orellana leaves in treating inflammation. Results from this study suggest that AEBO exerts anti-inflammatory effects. Part of this anti-inflammatory effect may be associated with its antibradykinin activity and may be related to a reduction of the NO production.
Department of Biomedical Sciences, Universiti Putra Malaysia, Serdang, Malaysia.
Y
Y
Yoke Keong
A K
AK
Arifah
S
S
Sukardi
A H
AH
Roslida
M N
MN
Somchit
A
A
Zuraini
D000704:Analysis of Variance; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D001681:Biological Assay; D031212:Bixaceae / Q000737:chemistry*; D001920:Bradykinin / Q000037:antagonists & inhibitors* / Q000187:drug effects; D002199:Capillary Permeability / Q000187:drug effects; D004195:Disease Models, Animal; D004487:Edema / Q000188:drug therapy; D007249:Inflammation / Q000188:drug therapy*; D008297:Male; D009569:Nitric Oxide / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D010936:Plant Extracts / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000893:Anti-Inflammatory Agents; D010936:Plant Extracts; D009569:Nitric Oxide; D001920:Bradykinin