Comparing Nutritional Quality, Antioxidant, and Antiulcer Activity of Two Amaranthaceae Plants: Achyranthes aspera and Amaranthus spinosus

Abstract

Achyranthes aspera and Amaranthus spinosus are species of medicinal plants from the Amaranthaceae family, used to treat wounds, asthma, malaria, gonorrhea, burns, and diabetes. In this study, the nutritional value and phytochemical constituents in A. aspera and A. spinosus were determined using inductively coupled plasma-optical emission spectrometry and column chromatography, respectively. The antiulcer activity was determined using the α-chymotrypsin assay while the antioxidant activity was evaluated using the 2, 2-diphenyl-1-picrylhydrazyl radical scavenging assay, ferric reducing antioxidant power, and phosphomolybdate assay. The results showed leaves of A. spinosus to contribute between 43.4% and 97.8% toward the recommended dietary allowance for iron; therefore, it is recommended for consumption by patients suffering from chronic anemia. Arsenic, cadmium, and lead were not detected in the leaves of the two species giving credence to their use as nutraceuticals in South Africa while the concentration of cobalt, nickel, and selenium were below the detection limit of the instrument. The phytochemical analysis resulted in the isolation of oleanolic acid, lutein, pheophytin a, and chondrillasterol glucoside. The antioxidant activity was high for lutein, ethyl acetate extract from A. aspera, chondrillasterol glucoside, and the methanol extract from A. spinosus, relative to the control. The antiulcer activity using the α-chymotrypsin inhibition assay showed lutein to have maximum chymotrypsin inhibitory activity. Findings from this study show lutein, pheophytin a, chondrillasterol, and its derivatives to serve as potential taxonomic markers for species in the Amaranthaceae family.