Xylopia aethiopica (Annonaceae) fruit extract suppresses Freund's adjuvant-induced arthritis in Sprague-Dawley rats.

BACKGROUND

Xylopia aethiopica is used in a decoction of the dried fruit to treat bronchitis, asthma, arthritis, rheumatism, headache, neuralgia and colic pain. The aim of the study is to evaluate the anti-arthritic effects of a 70% aqueous ethanol extract of the fruit of Xylopia aethiopica in a chronic inflammatory model.

METHODS

Adjuvant arthritis was induced in Sprague-Dawley rats by intraplantar injection of Complete Freund's adjuvant into the right hind paw. Foot volume was measured by water displacement plethysmometry. The oedema component of inflammation was evaluated as the percentage change in paw swelling and the total oedema induced calculated as area under the time course curves. In addition to X-ray radiography, histopathology of ankle joints supported by haematological analysis was used to assess the anti-arthritic action of the extract of Xylopia aethiopica (XAE).

RESULTS

Xylopia aethiopica extract (100, 300 and 600 mg kg(-1)) modified the time course curve significantly reducing hind paw oedema in the ipsilateral paw at all dose levels when administered both prophylactically and therapeutically. In addition XAE significantly suppressed the systemic spread of the arthritis from the ipsilateral to the contralateral limbs. The radiological pictures of the joints particularly metatarsal, phalanges and the ankle joint space of rats in the XAE-treated group showed protective effect against adjuvant-induced arthritis while histopathology revealed significant reduction in mononuclear infiltration, pannus formation and bone erosion. The haematological analysis in the test animals revealed significant improvement relative to the CFA model group.

CONCLUSIONS

Xylopia aethiopica XAE suppresses joint inflammation and destruction in arthritic rats.