The Effects of Dark Purple Glutinous Rice Variety Leum Phua on Scopolamine-Induced Memory Deficits in Mice.

Abstract

Background and Objective: Leum Phua is a special variety of glutinous rice which has been reported to have very high antioxidant property. Oxidative stress is widely accepted as an important factor in destroying many biological systems including nervous system. The aim of this experiment is to investigate the effects of Leum Phua rice on brain function, especially learning and memory, in male mice.

Methods: Morris water maze and passive avoidance tests were used to test the effects of Leum Phua rice aqueous extract (LP) on normal and scopolamine-induced memory deficit in young adult mice. LP was given to mice at the dose of 90 or 180 mg/kg by gavages once daily. On day 15, mice were trained and, on day 16 were tested in passive avoidance apparatus. Another group of animals, on day 15-17, animals were tested in Morris water maze. The latency time for entering the dark chamber (in passive avoidance) and step on platform (in Morris water maze) were determined. On each test day, certain groups of animals were received intraperitoneal injection of 1 mg/kg scopolamine 15 min before the test.

Results: The results showed that LP at either 90 or 180 mg/kg could improve learning and memory in mice in both passive avoidance and Morris water maze tests. Learning and memory of the animals were impaired by scopolamine treatment and the effects could be antagonized by LP, especially at 180 mg/kg.

Conclusion: The results suggested that LP has learning and memory enhancing effects. The effect of LP might be due to high concentration of antioxidants in Luem Phua rice.

Key words: dark purple glutinous rice var. Leum Phua, learning and memory, scopolamine-induced memory deficit