The effects of seasonal variation and multiple debarking on antioxidant activity of Sclerocarya birrea (Anacardiaceae) stem bark

The effects of seasonal variation and multiple debarking on antioxidant activity of Sclerocarya birrea (Anacardiaceae) stem bark

Abstracts L’Herit. using HPLC, HRMS and NMR of isolated components. The benzopyranone rich profile of P. sidoides was not comparable to that of P. lur...

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Abstracts

L’Herit. using HPLC, HRMS and NMR of isolated components. The benzopyranone rich profile of P. sidoides was not comparable to that of P. luridum or P. triste. Only trace amounts of benzopyranones were detected in P. luridum extracts, which were un-surprisingly dominated by hydrolysable tannins, organic alkane acids and a crystalline triterpene. In contrast, extracts from P. triste yielded substantially greater quantities of benzopyranones than measured in P. sidoides and this pattern was conservative across individuals and populations. The process of structure elucidation of major compounds is ongoing; however preliminary data clearly demonstrates that the chemistry of P. triste is different from that of P. sidoides. The unique chemical profile of P. triste may point toward a different therapeutic niche, although this is not yet evident from crossexamination of recorded ethnomedicinal use and requires further pharmacological research. doi:10.1016/j.sajb.2017.01.148

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This study represents a quantitative survey to capture oral-traditional plant use knowledge of the Hardeveld. This is the largest (21 400 km2) and botanically most diverse part of Namaqualand, with 1 513 species, of which 12% are endemic. We wish to demonstrate the power and rigor of the Matrix Method to provide insight, not only into the relative importance of the useful plant species, but also in the regional patterns of plant use knowledge in Namaqualand. Our survey revealed a total of 226 species of useful plants in the Hardeveld. These include one species entirely new to science and 21 newly recorded useful species. Ten species are newly recorded medicinal plants, 17 species are hitherto unrecorded food plants and six were added to the list of Namaqualand craft plants. A total of 168 new vernacular names were recorded, including 35 new Nama names, 78 new Afrikaans names and various new variations of names. At least 109 medicinal uses have remained scientifically unknown, with 28 new food uses and 41 new craft uses. The data is therefore of sufficient depth and detail to provide future researchers with fascinating opportunities for local, regional, continental and even global comparisons. doi:10.1016/j.sajb.2017.01.150

The effects of seasonal variation and multiple debarking on antioxidant activity of Sclerocarya birrea (Anacardiaceae) stem bark M. Nndwammbia, M.H. Ligavha-Mbelengwaa, I.D.I. Ramaiteb, C.P. Anokwurub a Department of Botany, School of Life Science, University of Venda, Private Bag X5050, Thohoyandou 0950, South Africa b Department of Chemistry, School of Life Science, University of Venda, Private Bag X5050, Thohoyandou 0950, South Africa E-mail address: [email protected] (M. Nndwammbi) Sclerocarya birrea Hochst., commonly known as Marula, is an indigenous medium to large sized deciduous tree of the family Anacardiaceae. It possess medicinal value and, therefore, it is used for treating a variety of diseases. Its leaves are mostly used to treat colds and flu, the bark for treating diarrhea and toothache, and the roots for treating sore eyes. This study aimed to evaluate the effects of debarking and seasonal variation on antibacterial activity of S. birrea stem bark. Bark samples were collected from individual trees during the four seasons. The debarking study was conducted by sampling from only three trees throughout the four seasons in a year while three trees were selected every season for the seasonal variation study. Methanol extracts of the ground powder obtained from the samples collected were used to determine antioxidant activity using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity method. In the seasonal variation study, spring exhibited the lowest IC50 value of 22.55 μg/ml while winter had the highest IC50 value of 46 μg/ml. The effects of debarking was pronounced in winter with the IC50 of 221.32 μg/ml compared to spring which had the lowest IC50 value of 42.70 μg/ml. The study has shown that the antioxidant activity of S. birrea is highest in spring while debarking during winter can be detrimental to the defense capacity of the plant. doi:10.1016/j.sajb.2017.01.149

Quantitative ethnobotany of the Khoe-San descendants of the Hardeveld, Namaqualand, South Africa J.M. Nortje, B.-E. Van Wyk Department of Botany and Plant Biotechnology, University of Johannesburg, PO Box 524, Auckland Park 2006, South Africa E-mail address: [email protected] (J.M. Nortje)

Acacia saligna’s soil legacy effects persist longer than ten years after clearing M.M. Nsikania, A. Novoaa,b, B. Van Wilgena, J.-H. Keeta, M. Gaertnera,c a Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch, South Africa b Invasive Species Programme, South African National Biodiversity Institute, Kirstenbosch Research Centre, Claremont, South Africa c Invasive Species Unit, Environmental Resource Management Department, City of Cape Town, Westlake Conservation Office, OuKaapseWeg, Tokai 7966, Cape Town, South Africa E-mail address: [email protected] (M.M. Nsikani) To reduce the negative impacts of invasive plants, management interventions such as control or eradication are usually necessary. It is often assumed that the impacts of invasive plants will diminish immediately after such interventions. However, in some cases the invader can have legacy effects in the soil that might persist for long periods, preventing the natural restoration of the areas managed. Therefore, to achieve the re-establishment of a functional native ecosystem it is important to understand for how long such legacies can persist in the soil. This paper explores this issue, using Acacia saligna in South Africa as a case study. We collected soil samples in invaded, non-invaded and previously invaded sites (representing two, six and ten years after clearing) and analysed the levels of pH, carbon, nitrogen, available phosphorus, ammonium, nitrate, and electrical conductivity. We also analysed enzyme activities (β-1, 4-glucosidase, urease and acid phosphatase). Acacia saligna invasion alters overall soil characteristics but specifically raises pH by 0.6-1.8. Moreover, soils characteristics (e.g. pH) are not restored to natural conditions after control (soil legacy effects persist longer than ten years after clearing). Furthermore, A. saligna control elevates soil NO3- levels and these can remain higher than invaded (1.55-6.67 mg/kg) and non-invaded (2.16-4.35 mg/kg) sites longer than ten years after clearing. Elevated NO3- often facilitates secondary invasion and/or weedy native species dominance which may hinder the restoration of functional native ecosystems. Therefore, strategies to manage areas previously invaded by A. saligna should take into account the removal of litter from the target invader, secondary invaders and weedy native species. doi:10.1016/j.sajb.2017.01.151