Antinociceptive and anti-inflammatory effects of the methanolic stem bark extract of Antrocaryon klaineanum Pierre (Anacardiaceae) in mice and rat.
BACKGROUND
Antrocaryon klaineanum is used by traditional healers to treat many disorders including pain and inflammatory diseases. This study aimed to evaluate the analgesic and antiinflammatory activities of methanol extract of A. klaineanum in mice and rats.


METHODS
Reverse phase high-performance liquid chromatography (RP-HPLC) was performed to establish the chromatographic fingerprint and to identify various chemical components of the plant extract. The anti-nociceptive activity of methanol extract of A. klaineanum was assessed using the acetic acid-induced abdominal constriction model, formalin test, capsaicin and cinnamaldehyde induced-neurogenic pain and hot plate test. Anti-inflammatory activity was assessed on carrageenan-induced inflammation. Extract was administrated orally at 200, 400 and 600mg/kg.


RESULTS
Phytochemical analysis indicated the presence of proanthocyanidins, phenolic acids and flavonoids. The results of anti-nociceptive and anti-inflammatory activities showed that methanol extract significantly (p<0.01) reduced the pain induced by acetic acid with an inhibition percentage of 45.49% (600mg/kg). In the formalin test, the extract also significantly (p<0.01) reduced linking time in both phase (neurogenic and inflammatory) of the test with inhibition percentage of 56.28% and 60.73% respectively at the dose of 600mg/kg. The methanol extract of A. klaineanum significantly (P<0.001) reduced neurogenic pain linking time induced by capsaicin and cinnamaldehyde by 82.54% and 75.94% at the highest dose (600mg/kg) respectively. More over the extract significantly increase the reaction time in hot plate test. In the inflammatory test, the plant extract significantly reduced the carrageen induced rat paw oedema from 30min to 6h with a maximum percentage inhibition of 89.88% (6h) at the dose of 600mg/kg.


CONCLUSIONS
These results demonstrate that the methanol extract of A. klaineanum may possess analgesic and anti-inflammatory effects and provide support of the traditional use of this plant in the treatment of different pain and inflammatory conditions. Further investigation could reveal metabolites of the extract responsible for the observed effects.
Department of Animal Biology and Physiology, Faculty of Sciences, P.O. Box 24157, University of Douala, Cameroon.
Annie Laure Magne
ALM
Fongang
Department of Biology Science, Faculty of Medicine and Pharmaceutical Sciences, P.O. Box 2701, University of Douala, Cameroon.
Edwige
E
Laure Nguemfo
Department of Chemistry, Faculty of Sciences, P.O. Box 24157, University of Douala, Cameroon.
Yolande
Y
Djouatsa Nangue
Department of Animal Biology and Physiology, Faculty of Sciences, P.O. Box 24157, University of Douala, Cameroon.
Calvin
C
Bogning Zangueu
Department of Chemistry, Faculty of Sciences, P.O. Box 24157, University of Douala, Cameroon.
Yannick
Y
Fouokeng
Department of Chemistry, Faculty of Sciences, P.O. Box 24157, University of Douala, Cameroon.
Anatole Guy Blaise
AGB
Azebaze
University of Castilla-La Mancha, Regional Institute for Applied Chemistry Research (IRICA), Ciudad Real 13071, Spain.
Eulogio
E
José Llorent-Martínez
Department of Physical and Analytical Chemistry, University of Jaén, Campus Las Lagunillas S/N, E-23071 Jaén, Spain.
Maria Luisa Fernández-de
MLF
Córdova
Department of Animal Biology and Physiology, Faculty of Sciences, P.O. Box 24157, University of Douala, Cameroon. Electronic address: alainberd@yahoo.fr.
Alain
A
Bertrand Dongmo
Institute of Pharmacology and Toxicology, Technical University of Munich, Biedersteinerstr. 29, 80802 Munich, Germany.
Wolfgang
W
Vierling
D027926:Anacardiaceae / Q000737:chemistry*; D000700:Analgesics / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004487:Edema / Q000188:drug therapy / Q000473:pathology; D007249:Inflammation / Q000188:drug therapy / Q000473:pathology; D000432:Methanol / Q000737:chemistry; D051379:Mice; D010146:Pain / Q000188:drug therapy / Q000473:pathology; D024301:Plant Bark; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D018547:Plant Stems; D051381:Rats; D017208:Rats, Wistar
D000700:Analgesics; D000893:Anti-Inflammatory Agents; D010936:Plant Extracts; D000432:Methanol
Analgesic; Anti-inflammatory; Antrocaryon klaineanum; Inflammation; Pain