Abstract

Chinese arbutus (Myrica rubra) fruits or Yumberry, are stony red fruits with berry-like edible portions growing in China, India, Japan and some other south eastern Asian countries. A 50% juice under the trade name Yumberry is available in some countries. It is rich in polyphenols and proanthocyanidins. This study investigated the effect of 4 weeks administration of the juice as a substitute for the normal rats' drinking water on ethanol- and stress-indomethacin-induced ulcer, carrageenan-induced paw inflammation and croton oil-induced hemorrhoids in male Wistar rats. Consumption of Yumberry drink for 4 weeks almost completely protected the rats against the alcohol-induced gastric ulcers (p < 0.05) with no significant effect against the combined cold stress-indomethacin-induced ulcers (p < 0.05). The treatment significantly suppressed carrageenan-induced oedema in the rat's paw in a time-dependent manner (p < 0.05 to p < 0.001, N = 8). The treatment also significantly suppressed experimentally-induced hemorrhoids by 74 ± 5.9% (p < 0.001, N = 8). The different mechanisms of actions of the observed beneficial actions are discussed. The results of this study pointed for the first time the direct protective effects of M. rubra beverage on the gastric mucosa and its direct anti-inflammatory effect against skin and rectal inflammations.

Key words: Bayberry, gastric ulcers, inflammation, hemorrhoids.