Bioactive Compound Characterization and Phytopharmacological Potentials of Tulbaghia violacea Fruits and Seeds

Tulbaghia violacea is an established medicinal plant that is indigenous to southern Africa. All its plant parts have been profiled for their phytochemical constituents and medicinal potentials except for the seeds and fruits. Thus, this study assessed the seeds (air-dried) and fruits (freeze-dried), extracted with six solvents, for their bioactive compounds, antioxidant capacities, and antibacterial activities. All the 10 tested phytochemicals were detected across the six solvents, with more phytochemicals detected in the fruits. The fruit aqueous extract gave the highest yield (37.4%), while the hexanoic fruit extract had the lowest extraction yield (3.27%). The fruit had higher phenolic content across the solvents except in methanol. Conversely, except in hexanoic extracts, the seed had higher total proanthocyanidin contents across the solvents. In addition, the fruit had a higher total antioxidant capacity than the seeds, similar to the observation in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. T. violacea fruit and seeds showed antibacterial activity against Escherichia coli, Staphylococcus aureus, and Enterococcus faecalis, but this activity was dose-dependent. However, neither the fruit nor the seed extract had any antibacterial effect on Klebsiella pneumoniae. This study showed that T. violacea fruits and seeds may be additional resources with medicinal benefits for human use.