Abstract

Cyathula prostrata is a herbal recipe used in traditional medicine for the treatment of chest troubles, dysentery, diarrhea, craw-craw,
scabies, sexual disease, rheumatism, tumours and inflammatory conditions amongst many others. There is not yet any claim on the use of
the plant as an antioxidant agent, hence the need for this study. The crude extract, fractions and isolates tested positive for the characteristic
rapid TLC free-radical scavenging activity with β-carotene and DPPH reagents. The ethyl acetate fraction gave marginally similar
antioxidant activity (IC50) as the crude extract at 0.76 µg mL-1 while the activity demonstrated by the butanol fraction was equally marginal
at 0.77 µg mL-1
. However, HOO-1 and HOO-2 gave moderate activity at 0.53 µg mL-1
and 0.56 µg mL-1
respectively which were
comparably better than the antioxidant activity obtained with vitamin E and A at 0.60 µg mL-1
and 1.11 µg mL-1
respectively. Furthermore,
vitamin C recorded an IC50 of 0.49 µg mL-1 which was comparatively better than the activity given by either HOO-1 or HOO-2. The
antioxidant activities given by the extract, fractions, HOO-1 and HOO-2 were instructive as the phytochemical screening of the C.
prostrata indicated the presence of terpenes, flavonoids and tannins which have been reported in previous studies to exhibit antioxidant
activities. The results of the antioxidant assays have revealed a novel potential for the use of C. prostrata as an antioxidant agent. Hence, it
is proposed that the mechanism of action of the antioxidant activity obtained especially with HOO-2 could have proceeded in the same way
(a 2H stabilized resonance) as that of the antiscurbitic activity of vitamin C in literature

Key words: Free-radical; antioxidant; β-carotene; DPPH; Cyathula prostrata