In vitro antioxidant activity, total phenolics and flavonoids from celery (Apium graveolens) leaves

Apium graveolens has several beneficial properties including antioxidant activity. The leaves of A. graveolens was extracted with methanol and partitioned with water, ethyl acetate and butanol. The phenolic content of the extracts was determined by Folin-Coicalteu method and antioxidant activity was assayed through some in vitro models such as antioxidant capacity by radical scavenging activity using α, α-diphenyl-β-picrylhydrazyl (DPPH), β-carotene-linoleate, reducing power, metal chelating effects and phosphomolybdenum method. The phenolic content of the extracts were expressed as gallic acid equivalents and was found to be highest in methanol (51.09 mg/g) followed by water extract (46.40 mg/g), ethyl acetate (22.70 mg/g) and butanol extract (19.43 mg/g). At 250 µg/ml concentration, the antioxidant and free radical scavenging activities of the extracts assayed through DPPH and reducing power were found to be highest with methanol extract followed by water, ethyl acetate and butanol extract. The antioxidant activity of butylated hydroxyl toluene (BHT) was higher than the extracts at each concentration points. The results indicated that the extent of antioxidant activity of the extract is in accordance with the amount of phenolics present in that extract and the celery leaf vegetable being rich in phenolics may provide a good source of antioxidants.   Key words: Apium graveolens, antioxidant activity, α-diphenyl-β-picrylhydrazyl (DPPH), flavonoid content, reducing power, total phenolic content.