Abstract:
Antioxidants have been discovered to play an important unction in protecting the body
rom damage caused by reactive ree radicals via interacting with ree radicals, chelating,
and serving as oxygen scavengers. Dialium ovoideum thwaites, an endemic plant in Sri
Lanka, which is locally identified as Gal Siyambala. Leaves o D. ovoideum thwaites have
been reported to possess antioxidant properties. Hence, this study aimed to investigate
the phytochemical profile and evaluate the antioxidant properties o the ethanol extract
o the bark o D. ovoideum thwaites. The extract was prepared using the Soxhlet extraction
method and it was subjected to phytochemical screening using standard procedures. The
gravimetric method was utilized to conduct the quantitative analysis o flavonoids,
tannins, and saponins. Folin-Ciocalteau assay was used to determine the total phenolic
content. DPPH radical scavenging and erric-reducing power assays were used to
determine the antioxidant properties. The results o qualitative phytochemical screening
showed the presence o phenols, flavonoids, saponins, steroids and tannins. In
quantitative analysis, the phytochemical constituents indicated 10.7% (w/w) o
flavonoids, 1.1% (w/w) o tannins and 0.9% (w/w) o saponins. The total phenolic
content was 233.4±22.7 mg gallic acid equivalent/g extract while the IC50 value or the
DPPH assaywas 68.5±6.3 µg/mL which is comparable to ascorbic acid (32.0±2.1 µg/mL).
The reducing potential o the extract showed that it possesses a significant (p<0.05)
reductive potential as compared with the ascorbic acid standard. Results revealed that
the ethanol extract o the bark o D. ovoideum thwaites exhibits antioxidant properties
which are positively correlated with its total phenolic content.