Methanolic extracts of Zingiberaceae family plants from Indonesia as antibacterial agents

Abstract

As a mega-biodiversity country, Indonesia has a high diversity of medicinal plants, one of which is a plant from the Zingiberaceae family. These plants contain secondary metabolite such as terpenoids, flavonoids, aromatic compounds, and polyphenols. These compounds are antibacterial in nature so they offer potential solutions to the rising threat of antibiotic-resistant bacterial strains that jeopardize global healthcare systems. In this study, methanolic extracts from the rhizomes of temu putih (Curcuma zedoaria), lempuyang wangi (Zingiber aromaticum), temu hitam (Curcuma aeruginosa), lengkuas merah (Alpinia purpurata), and jahe merah (Zingiber officinale var. Rubrum) were evaluated for their antibacterial efficacy. For the first time in Indonesia, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of these methanolic rhizome extracts were determined against Gram-positive (Staphylococcus aureus ATCC 25923, Bacillus cereus) and Gram-negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853) opportunistic pathogenic bacteria. The results of this study demonstrated that Zingiberaceae rhizome methanolic extracts exhibited antibacterial activity, with MIC values of 15.62 mg/mL and MBC values ranging from 31.25 to 62.5 mg/mL.