Anti-spasmodic and Gastroprotective Activities of Harungana madagascariensis Leaf: A Traditional Anti-diarrhoea Remedy

Background: Harungana madagascariensis Lam. ex Poir. (Hypericaceae) leaf extract is used by some communities in the Niger Delta to treat diarrhoea, ulcers, and wounds. Objectives: This study investigated the antispasmodic, antimotility and gastroprotective properties of methanol:dichloromethane (1:1) extract of H. madagascariensis leaves (HME). Materials and Methods: The antispasmodic activity was evaluated in vitro using actions on contractions of guinea pig ileum and rabbit jejunum provoked by spasmogens. The actions of HME on gastrointestinal transit was assessed in vivo using normal defaecation and charcoal meal transit time tests in rodents. The actions of HME on gastric ulcers produced by ethanol and indomethacin were investigated. The HME was also subjected to phytochemical analysis and acute toxicity tests. Results: The HME suppressed contractions of isolated rabbit jejunum and guinea pig ileum elicited by histamine and acetylcholine. The extract elicited significant (P<0.05) reduction of normal defaecation (12.50 - 100%) and gastrointestinal propulsion of charcoal meal in mice (17.60 - 43.08%). Additionally, the extract significantly (P<0.05) prevented both ethanol- and indomethacin-induced stomach ulcers. An oral LD50 >5000 mg/kg in mice was obtained by an acute toxicity assay on HME. Conclusion: The findings showed that the leaf of H. madagascariensis has gastroprotective, antispasmodic, and antimotility properties.