Biological potential of eight medicinal plants collected in the restored landscape after mining in South Kalimantan

Abstract

Land restoration is expected to enhance the supply of valuable ecosystem resources such as herbaceous bushes and weeds. This study aimed to determine the primary phytochemical constituents and bioactivities of methanol extracts from eight bushes and weeds collected from a restored post-mining landscape in South Kalimantan, Indonesia. Qualitative phytochemical analysis showed the presence of phenolic compounds, flavonoids, tannins, alkaloids, steroids, terpenoids and saponins in the methanol extracts of herbaceous plants. Their antioxidant activity was measured by using the 2,2-diphenyl-1-picryl-hydrazyl-hydrate assay. Their superoxide dismutase (SOD) activity was also measured. In addition, selected plant extracts were screened against the common human pathogens Staphylococcus aureus and Candida albicans. Phytochemical analysis showed that the methanol extracts contained all the bioactive compounds examined in this study except the one from Lycopodium cernuum, which lacked flavonoids and alkaloids. Further investigation revealed that all methanol extracts except the one from L. cernuum had promising antioxidant potential. The methanol extracts from Chromolaena odorata (stem), Trema micrantha, Melastoma malabathricum (flower and leaf) and Thypa angustifolia exhibited effective antibacterial activity. In addition, the methanol extracts from M. malabathricum (flower and leaf), T. micrantha, Scleria sumatrensis and Breynia cernua (leaf) exhibited effective antifungal activity. M. malabathricum (flower and leaf) has the greatest potential as a herbaceous plant since its methanol extract exhibits the most potent antioxidant, antibacterial and antifungal activities.