Investigation of antimicrobial, antioxidant, and cytotoxic activities of Boesenbergia rotunda rhizome extract

Authors: HAN, CHRIS - University Of Hawaii; RAKSAT, ACHARA - University Of Hawaii; ATANU, MD SAMIUL HUQ - University Of Hawaii; CHANG, LENG KAR - University Of Hawaii; Wall, Marisa; CHANG, LENG CHEE - University Of Hawaii

Submitted to: Journal of Current Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/15/2023
Publication Date: 12/6/2023
Citation: Han, C., Raksat, A., Atanu, M., Chang, L., Wall, M.M., Chang, L. 2023. Investigation of antimicrobial, antioxidant, and cytotoxic activities of Boesenbergia rotunda rhizome extract. Journal of Current Science and Technology. 14(1). Article 20. https://doi.org/10.59796/jcst.V14N1.2024.20.
DOI: https://doi.org/10.59796/jcst.V14N1.2024.20

Interpretive Summary: Finger root (Boesenbergia rotunda) is a species of ginger containing an abundance of phytochemicals, including flavonoids, essential oils, and polyphenols. In Hawaii, there is an increasing rate of staph infections of methicillin-resistant Staphylococcus aureus (MRSA), and hence, a need for new agents to combat the increase of antimicrobial resistant bacteria. This study evaluated the antimicrobial, antioxidant, and cytotoxic activities of Hawaiian-grown Boesenbergia rotunda against clinical isolates of Gram-positive MRSA and methicillin-susceptible S. aureus (MSSA). Five compounds were isolated and identified from finger root extracts. Two compounds (isopanduratin A and cardamonin) showed potent antimicrobial, antioxidant, and cytotoxic activity against MRSA and MSSA strains.

Technical Abstract: In recent years, antimicrobial resistance (AMR) has become a global threat to public health. In Hawaii, there is an increasing rate of staph infections of methicillin-resistant Staphylococcus aureus (MRSA), and, hence, a need for new agents to combat the increase of AMR bacteria. This study evaluates the antimicrobial, antioxidant, and cytotoxic activities of Hawaiian-grown Boesenbergia rotunda. Test bacteria included clinical isolates of Gram-positive MRSA and methicillin-susceptible S. aureus (MSSA) as well as Gram-negative Serratia marcescens and Escherichia coli. Five compounds–cardamonin, pinostrobin, pinocembrin, pinostrobin chalcone, and isopanduratin A–were isolated from the ethyl acetate of B. rotunda rhizome extract, and their structures were identified by NMR spectroscopy. These samples exhibited antimicrobial activity against MRSA and MSSA strains, with minimum inhibitory concentration (MIC) values between 128 and 1 µg/mL, with isopanduratin A giving MIC values as low as 2 µg/mL. The antioxidant potential of samples was examined using a ferric-reducing antioxidant power (FRAP) assay. At 1 mg/mL of tested samples, FRAP values ranged between 8.74 to 17.76 µM/µg, with pinostrobin chalcone exhibiting the highest FRAP value (17.76 ± 0.65 µM/µg). Moreover, cytotoxicity was measured via a sulforhodamine B (SRB) assay. Cardamonin (IC50 of 19.43 ± 0.33 µM) and isopanduratin A (IC50 of 26.84 ± 1.06 µM) exhibited effectiveness against the lung cancer cell line A549. Compounds from B. rotunda showed potent antimicrobial, antioxidant, and cytotoxic activity against MRSA and MSSA strains and may have the potential for further evaluation and development for pharmaceutical applications.