Seasonal Variations of Proximate Composition, Phytochemicals and Antioxidant Properties of Roots and Leaves Extracts of Amaranthus spinosus (Pig Weed)

The objective of this paper is to evaluate the seasonal variations of proximate composition, phytochemicals and antioxidant properties of roots and leaves extracts of Amaranthus spinosus (pig weed) using appropriate standard procedures. The qualitative phytochemical analysis indicates the presences of phenols, flavonoids, alkaloids, cardiac glycoside, steroids, tannins and saponins in all the extract in both seasons. The moisture contents of dry season root (12.05 %), leaves (11.50 %) and rainy season plant root and leaves were 3.44% and 7.46%. The ash (19.45 %) and protein content (17.52 %) were high in the leaves during dry season when compared to rainy season (9.73 %, 7.55 %). The quantitative phytochemical screening showed that the phenolic contents of the methanol extract in dry season root (4.60±1.40), leaves (9.36±1.55) were higher when compared rainy season root (3.39±1.18) and leaves (3.45±1.19). The methanol extract indicated that the total antioxidant capacity, total flavonoids and total phenols were higher in dry season (320.30 ± 8.80, 20.17 ± 5.75 and 25.57 ± 7.00) when compared to rainy season (290.65 ± 8.16, 17.57 ± 5.85, 19.17 ± 5.75). In conclusion, methanol extract of A. spinosus antioxidant activities was higher than other extracts in dry season when compared to rainy season.