53ANTIMICROBIAL AND ANTIOXIDANT EFFECTS OF THE CHLOROFORM EXTRACTS OF XANTHIUM STRUMARIUM (L.)The crude chloroform extracts of Xanthium strumarium leaves (CLXS) and stem barks (CSXS) have been evaluated for their antimicrobial and antioxidant activity. Antimicrobial activity of the extracts was evaluated against various Grampositive, Gram-negative bacteria and fungi using disc diffusion technique. The average zone of inhibition exhibited by extract was found ranging from 10-24 mm and Kanamycin (30μg/disc) was used as standard. Antioxidant potentiality of the extracts was investigated on DPPH free radical scavenging activity and the IC50 value was found 53.60µg/ml, 57.06µg/ml and 37.21µg/ml for CSXS, CLXS and standard ascorbic acid, respectively. These results suggest into the plant extracts could be used as a potential therapeutics in many pathological conditions.tamanna061@hotmail.comResearch422014Antimicrobial activity,pathogenic bacteria,antioxidant,free radicalSayema KhanumLecturer, Department of Pharmacy, Southeast University, Banani, Dhaka-1213, Bangladesh.