The aim of the work was the investigation of pharmacological activity of unique dihydroflavonol glycoside, micranthoside, extracted from the leaves Eupatorium micranthum Less. introduced into Georgia. Mature human T-cell leukemia cell lines (Jurkat) were analyzed in the study under the modeled oxidative stress. For modelling of oxidative stress 30% hydrogen peroxide (H(2)O(2)) (Sigma) (100 microM) was added to Jurkat cell incubation suspension with subsequent incubation for 24, 48 h. Under the effect of H(2)O(2) there was significant elevation of superoxide and peroxyl radical levels, as well as free NO levels, and reduced antioxidant enzyme SOD activity. It was shown that dihydroflavonol glycoside, micranthoside, extragated from Eupatorium micranthum Less., has marked antioxidant properties, it inhibits hyperproduction of reactive oxygen species, and protects cells against oxidative damage, stimulates cell proliferation and inhibits necrosis in cell line.