Growth Inhibitory and Cytotoxic Effects of the Methanol Extracts of Ficus Exasperata Vahl (Moraceae) Root Bark

Ficus exasperata is a medicinal plant characterized by its coarse and abrasive simple leaves. In ethnomedicine, the root bark is used in treating tumor related ailments. The cytotoxic and anti-proliferative effects of the methanol extract of the root bark and its organic solvent fractions were examined using the tadpoles of Raniceps ranninu s and radicle length of guinea corn Sorghum bicolor seeds respectively. The methanol extract showed significant concentration dependent toxicity on the tadpoles as the percentage mortality of 56.67±1.23 obtained at a concentration 10µg/ml was increased to 100 at 20 µg/ml. The chloroform and the aqueous fractions did not show remarkable effects although 100% mortality was obtained at 80 µg/ml with the chloroform fraction. The crude extract gave an LC 50 of 8.67µg/ml while the aqueous and chloroform fractions produced LC 50 values of 57.33 and 28.67 µg/ml respectively. The extract significantly (P<0.01) reduced the radicle length of the seeds treated with 0.5-4 mg/ml of the extract throughout the 96h incubation period. At 96h, the control seeds produced average length of 51.4 ± 2.72 mm while the seeds treated with 2 and 4 mg/ml had average lengths of 42.2 ± 1.63 and 31.8 + 2.71 mm respectively. The aqueous fraction was more effective than the chloroform fraction as it produced 47.56% reductions in radicle lengths compared with the controls. The results suggest the probable use of the plant in treating tumor related ailments and purification did not enhance activity.