Document Type : Research Paper
Authors
1
Department of Biology and Physiology of Animal Organisms, Faculty of Sciences, University of Douala, P.O. Box 24157, Douala-Cameroon
2
Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Science, University of Douala, P.O. Box 2701, Douala-Cameroon
3
Department of Animal Biology and Physiology, Faculty of Sciences, University of Yaoundé I, P.O. Box 812, Yaoundé-Cameroon
4
Department of Pharmaceutical Sciences, Faculty of Medicine and Pharmaceutical Science, University of Douala, P.O. Box 2701, Douala-Cameroon
Abstract
The present study aims to evaluate the antinociceptive activity of the hydroalcoholic fraction from the stem bark of Xeroderris stuhlmannii (HAFXS) and its probable mechanisms. The antinociceptive activity of HAFXS (50,100, and 200 mg/kg) was determined using the acetic acid writhing test (1%), formalin test (1%), tail immersion test (54 ± 1 °C), capsaicin (32 µg/ml), and cinnamaldehyde tests (0.66 %). Possible pathways mediating antinociceptive effects were evaluated using the following antagonists: propranolol, prazosin, yohimbine, atropine, glibenclamide, tetraethylammonium, naloxone, and L-NAME. The HAFXS (200 mg/kg) showed significant (P<0.0001) inhibition of abdominal writhing induced by acetic acid (72.24 %), formalin (in the first phase, 51.89 %), capsaicin (72.37 %), or cinnamaldehyde (56.48 %). HAFXS also significantly increased (p<0.0001) the latency time of tail immersion in hot water with a maximum time of 7.53 seconds. Pre-treatment with propranolol, yohimbine, and atropine did not reverse the antinociceptive activity of HAFXS. However, the previous injection of naloxone, glibenclamide, and prazosin to the animals significantly reduces the analgesic activity of HAFXS, indicating that antinociceptive activity is mediated by the opioid system and α1-adrenergic receptors. Furthermore, data analysis indicates that the mechanisms underlying HAFXS analgesia could also be linked to its ability to modulate TRPA1 and TRPV1 channels. This study demonstrates the antinociceptive properties of HAFXS, which act through various mechanisms.
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