Phytochemical Contents and Antioxidant Capacity of the Leaves of Aloe greatheadii var. davyana from Four South African Provinces

Abstract

The current study was aimed at the determination of the phytochemical contents and antioxidant capacity of the leaves of A. greatheadii from four provinces of South Africa. The leaves samples of A. greatheadii were collected at four different locations in South Africa; namely, Limpopo province (Polokwane), Gauteng province (Ga-Rankuwa), Mpumalanga province (Siyabuswa) and North-West province (Brits) during the summer season of the year. The ground samples were then extracted in a serial sequential procedure with different organic solvents using cold maceration extraction method. The extracts were then subjected to quantitative phytochemical analysis for the determination of total phenolic, total tannin, total flavonoid and total saponin content. In addition, the antioxidant capacity of the methanol extracts were evaluated through the DPPH assay. Quantitative phytochemical analysis showed variation in the total phenolic, total tannin, total flavonoid and total saponin contents of the samples from different locations, with specific phytochemicals found in higher amounts at different locations. However, upon calculation of the total phytochemical content the high amount was recorded with the Limpopo province sample. Variation in the antioxidant capacity (EC50 based) of the samples from different locations was demonstrated, with the Limpopo and Mpumalanga provinces’ samples showing high capacity. The results demonstrated that the variation in geographical locations has an effect on the phytochemical contents and antioxidant capacity of the leaves of A. greatheadii. Furthermore, the Limpopo province area with a high altitude appeared to be providing suitable growing conditions for high accumulation of phytochemicals and higher antioxidant capacity.