Antioxidant, enzyme inhibitory and apoptotic activities of alkaloid and flavonoid fractions of Amaranthus spinosus

Abstract

Plants belonging to the genus Amaranthus is widely consumed by humans and animals and is known for their nutritive value and health beneficial effects. Literature indicated the potential of Amaranthus spinosus plants as efficient radical scavengers and chain-breaking antioxidants as well as their efficacy against inflammatory insults. It has been claimed that the phenolic compounds present in the A. spinosus are responsible for its pharmacological values. However, there is no clear cut information available on this matter; therefore, the study compared the crude A. spinosus extract and its alkaloid and flavonoid fractions as a possible chain-breaking antioxidant and cytotoxic molecules. The study observed a significantly higher (p < 0.001) anticancer potential for the alkaloid fraction (23.29 ± 2.19 μg/mL). Corroborating with this, the expression of apoptotic genes were significantly upregulated in the higher concentration of different extract treated cells; besides, at the same doses, the antiapoptotic genes were downregulated. The DPPH radical scavenging has been significantly high (p < 0.001) in flavonoid fraction (22.19 ± 3.55 μg/mL); whereas, hydrogen peroxide scavenging was found to be similar in crude and flavonoid fractions (30.22 ± 3.12 and 27.95 ± 2.71). The study thus suggests that antineoplastic properties of the plant might have contributed by the bioactive compounds in the alkaloid fraction; whereas, bioactive flavonoid components constituted the radical scavenging properties of the plant. Thus, the differential pharmacological activities of the plant may be due to the synergism between these classes of phytocompounds.