The present study evaluated the biological potential of methanol and aqueous extracts of the twigs and fruits of Cotoneaster integerrimus Medik. Lethality bioassays performed on Artemia salina showed that aqueous and methanol C. integerrimus extracts were non-toxic in the concentration range (0.1-20 mg/ml), with a LC50 ≥ 2.5 mg/ml, for each single extract. The protective effect of the extracts was assessed in vitro against hydrogen peroxide-induced lactate dehydrogenase (LDH) activity and tumor necrosis factor (TNF)α gene expression in colon cancer HCT116 cell line. All the extracts downregulated (H