10.22376/ijpbs.2019.10.1.p1-12 Volume 4 Issue 2 2013 (April - June) The effectiveness of crude methanolic extracts of lessThan i greaterThan Bridelia lessThan /i greaterThan lessThan i greaterThan ferruguinea, Tridax procumbens, Ocimum gratissimum lessThan /i greaterThan and lessThan i greaterThan Lawsonia inermis lessThan /i greaterThan against clastogenicity induced by sodium arsenite (SA) was evaluated using an lessThan i greaterThan in-vivo lessThan /i greaterThan rat bone marrow cell micronuclei test and the DPPH radical scavenging assay. Methods: 50 mg/kg body weight of the extracts were given by gavaging to the rats in five groups for seven consecutive days as a dietary supplement followed by a single dose of SA (2.5 mg/kg per body weight) which was administered intraperitoneally. Results: Preliminary screening of the clastogenicity showed that aqueous extracts of these plants have no significant clastogenic activity in rat. Pre-treatment of rats for seven days with extracts orally before exposure to SA resulted in a significant reduction of the degree of formation of micronuclei in polychromatic erythrocytes of the bone marrow. The degree of reduction of arsenite was of the order lessThan i greaterThan B. ferrugenia lessThan /i greaterThan greaterThan O. lessThan i greaterThan gratissimum lessThan /i greaterThan greaterThan lessThan i greaterThan T. procumbens lessThan /i greaterThan greaterThan lessThan i greaterThan L. inermis lessThan /i greaterThan . Phytochemical analysis carried out on the extracts revealed the presence of known chemical constituents. The phytochemical constituents might be responsible for the strong DPPH scavenging activities exhibited by the plant extract. Conclusion: This study suggests that lessThan i greaterThan B. ferruguinea, T. procumbens, O. gratissimum, lessThan /i greaterThan and lessThan i greaterThan L. inermis lessThan /i greaterThan extracts have anticlastogenic potential and possibly due to their antioxidant properties.Therefore, the plant extracts may be useful in the stoppage of arsenite-induced toxicity in areas where arsenic is a potential environmental contaminant. ADEWALE ADETUTU, OLUSOJI ABIODUN OWOADE AND OLUBUNMI SIMEON OYEKUNLE Medicinal plants; Cancerprevention; Phytochemical; Anticlastogenicity; Chemoprevention. 777-783