NOVEL ANTIOXIDANT ACTIVITY OF CYATHULA PROSTRATA (L.) BLUME)

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 (IC 50 ) 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 IC 50 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.