STUDY OF THE ANTIOXIDANT PROPERTIES OF THE WATER EXTRACT IN SYRIAN CITRUS LIMON AND CITRUS AURANTIUM LEAVES

Abstract

Citrus are well-known fruits which possess enormous medicinal properties. This research aimed to
investigate the most effective compounds (phenolics and flavonoids), in the water extract’s leaves of
two essential Syrian Citrus “Citrus limon and Citrus aurantium” using conventional spectrophotometric
technique. The antioxidant activity of Citrus limon and Citrus aurantium was analyzed by 2,2-diphenyl1-picrylhydrazyl (DPPH) and 2,2'-azino-bis[3- ethylbenzothiazoline-6-sulphonic acid] (ABTS) assays,
the IC50 values of DPPH and ABTS free radicals were measured. Vitamin C was used in this research
as the positive antioxidant control. The results indicated that total phenolics (TPC) and total flavonoids
content (TFC) for water extract’s leaves of Citrus aurantium (TPC=95.70±0.80 mg/g, and
TFC=64.20±0.70 mg/g) were higher than those of Citrus limon (TPC=128.11±0.50 mg/g, and
TFC=103.60±0.50 mg/g). Furthermore, the water extract’s leaves of Citrus aurantium exhibited potent
scavenger of free radicals, with IC50 values of 22.5±0.700 µg/ml and 27.5±0.050 µg/ml for DPPH tests,
respectively. Whilst the water extract’s leaves of Citrus limon and Citrus aurantium’s radical potential,
with IC50 values of 2.4±0.40 µg/ml and 3.33±0.40 µg/ml for ABTS tests, respectively. Based on
acquired results, both water extract’s leaves of Syrian Citrus could be recommended as a promising
source of bioactive compounds valuable for avoiding threating diseases connected to oxidative stress
such as cancer, aging, atherosclerosis, cardiovascular and neurodegenerative diseases.