Yougasphree Naidoo, Benita Kalicharan, Jerusha Naidoo and CT Sadashiva
Posters: Nat Prod Chem Res
Many members of the genera Stachys and Pycnostachys have been used as ornamental plants, or as edible foods and in traditional medicine. Stachys natalensis Hochst., is a perennial, straggling shrub with fragrant leaves that are densely covered with hairs. Pycnostachys urticifolia Hook., commonly known as ?Hedgehog sage? possesses strongly scented leaves and conspicuous conical-shaped blue flowers. The leaves and roots of P. urticifolia are traditional used to treat sore throats and mouth infections. The aim of this study was to determine and compare the phytochemistry and anti-oxidant activity of the S. natalensis and P. urticifolia. Preliminary phytochemical tests performed on the leaf methanolic extracts of both species, revealed the presence of phenolics, alkaloids, flavonoids and terpenoids amongst other bioactive compounds. Stachys natalensis and P. urticifolia leaf extracts also contained a considerable level of total phenolics (3.43 ? 0.01 mg GAE/g dry material and 3.58 ? 0.088 mg GAE/g dry material respectively) measured by the Folin-ciocaltue method and total flavonoids (3.04 ? 0.01 mg QE/g dry material and 1.99 ? 0.007 mg QUE/g dry material respectively) measured by the aluminium chloride assay. The free radical scavenging ability of the methanolic extracts of S. natalensis and P. urticifolia quantified by the DPPH assay demonstrated significant anti-oxidant activity (EC50=49.49 ? 3.87 ug/ml and EC50=46.22 ? 4.44 ug/ml respectively) compared to the standard anti-oxidant ascorbic acid (EC50=12.03 ug/ml). The perceived therapeutic benefits of these plants are likely to lie within their suite of secondary metabolites and indicate the potential for their use as natural anti-oxidants.
Yougasphree Naidoo is Senior Lecturer and Academic Leader (Cellular Biology) in the School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa. She is a cell biologist and microscopist by training, with a strong interest in plant secretory structures, particularly of those potential medicinal plants indigenous to southern Africa. Through her research, she has discovered several novel microscopic trichomes in the leaves of many southern African plants and is one of few South African experts in this field with an active publishing record.
