Antidiabetic and Cytotoxicity Screening of Five Medicinal Plants Used by Traditional African Health Practitioners in the Nelson Mandela Metropole, South Africa

Abstract

Diabetes mellitus is a growing problem in South Africa and of concern to traditional African health practitioners in the Nelson Mandela Metropole, because they experience a high incidence of diabetic cases in their practices. A collaborative research project with these practitioners focused on the screening of Bulbine frutescens, Ornithogalum longibracteatum, Ruta graveolens, Tarchonanthus camphoratus and Tulbaghia violacea for antidiabetic and cytotoxic potential. In vitro glucose utilisation assays with Chang liver cells and C2C12 muscle cells, and growth inhibition assays with Chang liver cells were conducted. The aqueous extracts of Bulbine frutescens (143.5%), Ornithogalum longibracteatum (131.9%) and Tarchonanthus camphoratus (131.5%) showed significant increased glucose utilisation activity in Chang liver cells. The ethanol extracts of Ruta graveolens (136.9%) and Tulbaghia violacea (140.5%) produced the highest increase in glucose utilisation in C2C12 muscle cells. The ethanol extract of Bulbine frutescens produced the most pronounced growth inhibition (33.3%) on Chang liver cells. These findings highlight the potential for the use of traditional remedies in the future for the management of diabetes and it is recommended that combinations of these plants be tested in future.

Antidiabetic Medicinal Plants Used in the Eastern Cape Province of South Africa: An Updated Review

“…An infusion of fresh leaves in a cup of boiling water is taken for coughs, arthritis and colds [46]. A report by van Huyssteen et al [47] showed that whole plant aqueous extract of B. frutescens increased glucose uptake in Chang liver cells. This effect was greater than the standard positive control, metformin, used in the study.…”

Metabolomics analysis of Brazilian and Nigerian Asteraceae species, targeting hyperglycemia-modulating metabolites

“…Another of the mechanisms for managing hyperglycaemia is via improving insulin sensitisation to enhance glucose uptake ( VAN DE VENTER et al, 2008). Extract of Vernonia amygdalina leaves has been shown to significantly improve glucose utilization in C2C12 muscle cells (ERASTO et al, 2009), corroborating the ethnomedicinal antidiabetic use of the plant.…”

“…Extract of Vernonia amygdalina leaves has been shown to significantly improve glucose utilization in C2C12 muscle cells (ERASTO et al, 2009), corroborating the ethnomedicinal antidiabetic use of the plant. Others include extracts of Euclea undulata, Schkuhria pinnata (DEUTSCHLÄNDER et al, 2009), Tanacetum nubigenum (KHAN et al, 2018), Ruta graveolens and Tulbaghia violacea, among others ( VAN HUYSSTEEN et al, 2011).…”

“…The following settings were employed to preprocess the data using Mzmine TM (BMC Bioinformatics, United Kingdom): mass detection using exact mass algorithm (noise level, 1.0E6); chromatogram builder (minimum time span in min, 0.2; minimum height, 3.0E6; m/z tolerance, 0.001 m/z or 5.0 ppm); chromatogram deconvolution using baseline cut-off (minimum peak height, 3.0E6; peak duration, 0.2 to 5.0; baseline level, 1.0E6); isotopic peaks grouper (m/z tolerance, 0.002 m/z or 5 ppm; retention time tolerance in min, 0.2; maximum charge, 2; representative isotope, most intense); gap filling (intensity tolerance, 30%; m/z tolerance, 0.001 m/z or 5.0 ppm; retention time tolerance in min, 0.5) and alignment using join aligner (m/z tolerance, 0.001 m/z or 5 ppm; weight for m/z, 20; retention time tolerance, 5%; weight for retention time, 20). The data matrices of both positive and negative ionization modes were subsequently combined on one spreadsheet, after preprocessing individually, and prior to multivariate statistical analysis, the generated data matrix was subjected to log10transformation ( VAN DEN BERG et al, 2006;BALLABIO;CONSONNI, 2013;OVENDEN et al, 2014). Unsupervised (HCA and PCA) and supervised (PLS-DA) statistical analysis, using the software SIMCA 13.0.3.0© (Umetrics, Sweden), were used to perform data mining.…”

“…The box and whisker plot of a data set presents a graphical view of the data with the center box representing 50% of the data (3rd and 4th quartile of data) while the "whiskers" represent 25% of the data each (1st and 2nd quartile of data). Log transformation was applied to the data to reduce the heteroscedascity (Figure 5b) ( VAN DEN BERG et al, 2006;BALLABIO;CONSONNI, 2013;DI GUIDA et al, 2016;LI et al, 2017;BAPTISTA et al, 2018).…”