Phytochemical analysis and acute oral toxicity of aqueous extracts of vernonia amygdalina (delile) and nauclea latifolia (smith)

The phytochemical screenings and acute oral toxicity of the aqueous extracts of Vernonia amygdalina and Nauclea latifolia were carried out. The leaf extract of V. amygdalina had the highest yields of alkaloids, flavonoids and saponins with 16.00%, 9% and 9% respectively. Tannins yield was found to be highest in N. latifolia where 6.70x10-5mol/dm3 was recorded in its stem extract. An evaluation of the acute oral toxicity of aqueous extracts of these plants showed no mortality of any of the rats at 1000 and 2000mg/kg after 72 hours. The LD50 of the two plants extracts were greater than 3,000mg/kg except the V. amygdalina stem bark which was 2449.49mg/kg. Treatment with V. amygdalina and N. latifolia produced no significant changes (P= 0.999 and P= 0.798) in Pack Cell Volume and White Blood Cell counts respectively. The t-test analysis showed that there was significant difference (P= 0.0005) in the weight in relation to the different extracts concentrations. The possession of the active secondary metabolites potentiates their medicinal values and at lower concentrations per body weight (<2000mg/kg) the plants extracts can be used for a prolonged period with little or no adverse effect.