In vitro antiplasmodial activity, cytotoxicity, antioxidant action and GC-FID analysis of Allanblackia floribunda Oliv

Abstract This study evaluated the in vitro antiplasmodial efficacy and cytotoxicity of Allanbackia floribunda stem bark extract, leaf extract and oil. It also assessed the phytochemical compositions and antioxidant action of the stem bark fractions as well as the phytochemical fingerprint of the most active fraction (dichloromethane). Trager and Jensen method was used to culture Plasmodium falciparum , Mark III test developed by WHO was used to assess the antiplasmodial activity of the plant’s crude extract and fractions against the ring stage of P. falciparum strain, Pf3D7. Cytotoxicity was determined against Vero cell line using microculture tetrazolium (MTT) test. Gas chromatography with flame ionization detection (GC-FID) was employed to identify phytochemical fingerprint of the most active fraction. The stem bark extract had better antiplasmodial activity (IC 50Pf3D7 of 4.3 ± 0.17 μg/mL) compared with the leaf extract (IC 50Pf3D7 , 8.0 ± 0.28 μg/mL) and oil (IC 50Pf3D7  > 100 μg/mL). Both the leaf and stem bark extracts were found to be non-cytotoxic compared with the standard cytotoxic drug, doxorubicin. The selectivity indices (S.I.) of the extracts against the parasite were 20.06 and 8.85 for the stem bark and leaf respectively. Dichloromethane fraction had the highest inhibition against the P. falciparum parasite with IC 50Pf3D7 of 1.51 μg/ mL. GC-FID analysis showed high presence antiplasmodial flavonoids and terpenes. This investigation confirmed that A. floribunda stem bark has potent activity against P. falciparum, and it is relatively safe to normal cell. Article Highlights Allanblackia floribunda methanol stem bark and leaf extracts could inhibit the growth of chloroquine sensitive Plasmodium falciparum (Pf3D7) in vitro. The stem bark infusion of Allanblackia floribunda was found to be nontoxic and safe at moderate doses to normal cell line (Vero cell line). Dichloromethane fraction of the stem bark showed excellent inhibition against chloroquine sensitive malaria parasite.