Effects of Aloe preparation on the histamine-induced gastric secretion in rats

The effects of Aloe preparation containing 80% Aloe gel on the gastric acid, pepsin and mucus secretion were evaluated in histamine-induced gastric fistula model in rats by comparison to the effects of placebo and fresh Aloe gel. Aloe preparation and placebo at a dose of 8 ml/kg inhibited gastric acid but stimulated pepsin secretory rates. On the other hand, fresh Aloe gel at a dose of 6.4 ml/kg prolonged histamine stimulatory effects on the gastric acid secretion while it inhibited gastric pepsin secretion. Both Aloe preparation and placebo increased soluble mucus secretory rate in a dose-dependent manner whereas fresh Aloe gel had no effect. The Aloe preparation and placebo at a dose of 8 ml/kg increased the gastric visible mucus content while fresh Aloe gel slightly increased the visible mucus content. This study reveals that fresh Aloe gel prolonged the effects of histamine-stimulated acid secretion and inhibits pepsin secretion in histamine-treated rats. The Aloe preparation inhibited gastric acid, stimulated pepsin and mucus secretion. However, there were no difference in the secretory rates of Aloe preparation and placebo-treated rats at the same doses. This result indicates that the observed effects of Aloe preparation was mostly due to other compositions of the preparation rather than Aloe gel itself. Since the highest dose of Aloe gel preparation used in the present study was limited by the volume of the instilled solution in gastric fistula model, the effects of Aloe vera gel were not able to be observed in the present study might be due to the inadequate dose of the preparation.