Anti-plasmodial and Radical Scavenging Activities of Croton megalobotrys
The root, stem bark and leaves of Croton megalobotrys were extracted and tested for their anti-plasmodial activity. In in vivo screening test against P. berghei (ANKA) infection in NMRI albino mice, the stem bark extract produced a statistically significant suppressive effect (74.5%; p<0.05) in early infection and a residual inhibitory effect of 86.9%. In an established infection, a mean survival time (MST) of 16.2 days was achieved although parasitaemia was not completely eliminated. Impressive anti-plasmodial activity was observed in in vitro test with IC50 values of 1.74 ± .47 µg/mL and 3.78 ± 1.03 µg/mL for the hexane fraction of the stem bark extract against D6 and W2 strains of P. falciparum respectively. The chloroform fraction of the stem bark extract yielded a cinnamate derivative (E)-tetratriacontyl- 3-(4-hydroxy-3-methoxyphenyl)-2-propenate, while the fourth semi-purified fraction of the chloroform fraction (AA-CC4) in qualitative DPPH assay showed activity at a loading dose of 0.05 µg, thus exhibiting radical scavenging activity comparable to that of ascorbic acid.
Anthonia O Abosi, Runner R T Majinda*