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Hypoxis colchicifolia is extensively used in traditional medicine in Southern Africa. Providing a rationale and indicating the toxicity of the plant is essential for its future use as a natural therapeutic agent. In this study H. colchicifolia corm and leaf extracts were qualitatively assessed for phytochemical constituents and total phenolic content. The antioxidant potential of the extracts was evaluated using the 1,1-Diphenyl-2- picryl-hydrazyl assay, 2,2′-azinobis-(3-ethylbenzothiazolline)-6-sulfonic acid assay, phosphomolybdenum assay, cupric ion reducing capacity assay and the ferric reducing antioxidant power assay. All extracts indicated the presence of key phytochemical constituents and no toxicity. The extracts showed good antioxidant potential against various free radicals. Most extracts exhibited a lower IC50 than that of the positive control (rutin) against free radicals, thus indicating the good antioxidant potential of the extracts. The extracts of leaves and corms cannot be used interchangeably due to differences in the phytochemical composition. Acetone and methanol extracts show the most favorable results demonstrating the solvents’ effectiveness in the phytochemical extraction of H. colchicifolia. The study also sheds light on the use of H. colchicifolia leaves as a natural alternative, which has not been previously explored. The H. colchicifolia extracts exhibit promising antioxidant potential, validating their use as a tonic for good health.

Phytotherapeutic treatments have been on the ascendancy over the years as the quest for alternate and easily accessible health care is on the rise. Tulbaghia acutiloba has been used by both traditional healers and the South African population for the management of chronic conditions, but lacks scientific authentication. Hydro-methanolic extracts (roots, rhizomes, leaves and flowers) of the plant were evaluated for their antioxidant activities, biochemical and phytochemical profile. Additionally, the heavy metal content and antihypertensive effects including Angiotensin 1-Converting Enzyme Inhibitory (ACEI) activities were investigated. The antioxidant ability of the hydro-methanolic extracts were determined by 2, 2-diphenyl-1-picryl hydrazyl (DPPH), hydrogen peroxide and nitric oxide scavenging activities. Phytochemical profile was assessed using qualitative and quantitative methods whereas the heavy metal toxicity was determined by using Inductively- Coupled Plasma-Optical Emission Spectrometry (ICP-OES). In vitro ACEI activity was determined by the hydrolysis of the tripeptide, hippuryl –L-Histidyl-L-leucine (Hip-His-Leu). All the extracts showed potent antioxidant activities which was concentration dependent. Phytochemical analysis showed the presence of phenols, amino acids and alkaloids in all the extracts. The leaves showed a relatively higher total phenolic content of 43.26±1.15 mgGAE/g. Gas Chromatography–Mass Spectrometry (GC-MS) analysis showed the presence of major compounds such as α-linolenic acid in the leaves as well as oleic acid and palmitic acid in other parts of the plants. Toxicity of heavy metal was undetected in all extracts of the plant. All the extracts of the plants showed a >50% ACE inhibition at different concentrations with the leaves showing a relatively higher inhibitory activity (76.66 ± 1.65, IC50; 154.23 μg/ml) compared with the other parts of the plants. It is therefore concluded in this study that the biological activities and phytochemical component of the hydro-methanolic extracts of T. acutiloba is indicative of its possible use for the treatment as well as prevention of hypertension and oxidative stressrelated diseases.