ETHNOPHARMACOLOGICAL RELEVANCE: Laportea aestuans (L.) Chew (Urticaceae) was historically ingested together with chalk by pregnant women in Ghana when suffering from heartburn. The aim of this study was to evaluate the antacid activity of the aerial parts of L. aestuans.

MATERIALS AND METHODS: Aerial parts of L. aestuans were collected in the Accra region of Ghana. The antacid activity was measured according to Fordtran׳s titration model. 90mL tap water and test material in a 500mL beaker were warmed to 37°C on a magnetic stirrer and was continuously stirred at approximately 30rpm in order to mimic the movements of the stomach. A titration was carried out with an artificial gastric acid to the end point of pH 3. The acid secretion rate was approximately 3mL and pH was monitored with a pH meter. Concentrations of 666 and 1332mg dried plant material were tested, both with and without addition of calcium carbonate (CaCO3).

RESULTS: Both CaCO3 and L. aestuans had a significant better ability than water to neutralise an artificial stomach acid. 666mg plant material together with CaCO3 compared to CaCO3 alone showed approximately the same neutralisation time. When mixing 1332mg plant material with CaCO3 the neutralisation time was significantly higher than for CaCO3 alone and exhibited an antacid profile that was able to maintain the neutralising activity one pH-unit higher for an extended period of time.

CONCLUSION: The results indicate that L. aestuans showed an antacid activity when combined with CaCO3. With further investigations of the active compound, mechanism of action and possible toxicity, the plant could form the basis of a novel antacid.