Abstract: Four flavonoids including kaempferol (1), isoscutellarin (2), umbelliferone (3) and cichoriin (4) have been isolated from Streptomyces sp. Tc052, an endophyte in the root tissue of Alpinia galanga Swartz. The evaluation for protective effect of compounds 1-4 against glutamate-induced cytotoxicity in hippocampal HT22 cell line was conducted. Compounds 1 and 2 showed significant effective protection ratios of 62.4+2.8 and 55.3+3.4%, respectively, at a concentration of 100 μM, whereas compounds 3-4 were inactive. Compounds 1 and 2 showed potent scavenging effects on DPPH radical exhibiting IC50 value of 60.74 and 75.65 μM, respectively. These results suggest that compounds 1 and 2 may possess the neuroprotective activity against oxidative cellular injuries.