Analgesic, Non-ulcerogenic and Antioxidant Activities of the Aqueous Stem Bark Extract of Morinda lucida (Rubiaceae) in Mice

Abstract

Aims: The objective of this study was to evaluate the analgesic; non ulcerogenic and antioxidant effects of the aqueous stem bark extract of Morinda lucida in mice. Place and Duration of Study: Department of Biological Sciences, Higher Teachers’ Training College; Department of Animal Biology and Physiology  and Department of Microbiology, Faculty of Science, University of Yaoundé I. Between August 2015 and November 2016. Materials and Methods: The phytochemical sifting was realized in other to find the chemical composition of the aqueous stem bark extract of Morinda lucida (ASBEML). The antioxydant activity was evaluated by the measurement the capacity of ASBEML to trap radical DPPH, to reduce Fe3 +, and measures it total polyphenols. The effects of ASBEML were tested on models of acute pain induced by acetic acid and formalin in mouse fasted since 12 hours. The ulcerogenic effect of this plant was evaluated by administration of different doses of the aqueous extract to mouse fasted since 48 hours. Results: The phytochemical tests revealed the presence of phenolics, flavonoïds, catechic tannins, alkaloids, saponins and triterpenes. The DPPH, FRAP and Folin-Ciocalteu tests showed that the aqueous stem bark extract of Morinda lucida has a significant antioxydant activity. The oral administration of ASBEML significantly and dose dependently reduced the number of abdominal constrictions induced by injection of acetic acid. A maximum inhibition of 80.20% was obtained at the dose of 400 mg/kg. Also, this extract (400 mg/kg) significantly and dose dependently inhibited both phases of pain induced by formalin injection; the first phase was reduced up to 53.7% while the second phase was reduced up to 75.88%. The oral administration of ASBEML doesn’t caused gastric ulcer. On the contrary, it significantly and dose dependently stimulated the mucus secretion. Conclusion: In sum, the ASBEML possesses antioxidant, analgesic (centrally and peripherally) and non-ulcerogenic properties.