Anti-inflammatory and antioxidant potential of Dichrostachys cinerea root bark, an Ivorian anti-asthmatic herbal

Objectives : root bark of Dichrostachys cinerea is used in Ivorian folk for the treatment of asthma. This study aimed to evaluate anti-inflammatory and antioxidant activities of this plant. Methods : an aqueous-alcoholic extract was obtained from the root bark. Two tests i.e. rat's paw irritation with formalin and rat's paw oedema induced by carrageenan were used to appreciate the anti-inflammatory activity. The antioxidant activity was performed using ABTS (2.2-azinobis 3 ethyl-benzothiazoline-6-sulfonic acid), DPPH (1.1 diphenyl 1-2-picrylhydrazyl), and FRAP (Ferric Reducing Antioxidant Power) tests. Results : the extract, only at 1000 mg/kg b.wt, reduced significantly the licking time (22.03 1.08 s) in the second period of formalin-induced irritation test. Concerning the carrageenan-induced oedema test, oedema was weakly reduced 1, 2, and 3 hours after injection of carrageenan. Indeed, levels of inhibition were respectively 1.71 0.56 %, 1.45 0.70%, 4.5 1.91% for the extract at 10 mg/kg b.wt; 3.71 0.33%, 6.50 0.10%, 10.75 0.42% for the extract at 100 mg/kg b.wt. and 3.47 0.40%, 10.54 0.48%, 13.50 0.93 for the extract at 1000 mg/kg b.wt. The extract did not exert any antioxidant activity through both ABTS and DPPH methods, but with FRAP one, low doses showed a high antioxidant activity (86.33 1.78%) similar to that of Trolox (90.99 6.47%) used as reference. Conclusion : the herbal lacks anti-inflammatory activity. However, it induced an antioxidant activity which could be recommended to neutralize the free radicals involved in the bronchial hyperactivity phenomena during acute asthma.