In Vitro Assessment of the Antibacterial Activity of Sapindus rarak (Lerak) and Its Influence on Cellular Immune Markers During Escherichia coli Infection

Lisa Savitri, Kharisul Ihsan, Elfred Rinaldo Kasimo, Rochmad Krissanjaya

Abstract


Antibiotic-resistant Escherichia coli remains a major public health concern, prompting interest in plant-derived compounds with both antimicrobial and immunomodulatory functions. This study evaluated the antibacterial activity of Sapindus rarak (lerak) extract and its influence on macrophage cytokine responses during E. coli stimulation. Lerak pericarp extract was prepared using 70% ethanol and tested against E. coli ATCC 25922 using broth microdilution. Immunomodulatory effects were assessed in RAW 264.7 macrophages exposed to heat-killed E. coli, followed by treatment with sub-MIC concentrations of the extract. The results showed moderate antibacterial activity, with a minimum inhibitory concentration of 250 microgram/mL and a minimum bactericidal concentration of 500 microgram/mL. Cell viability exceeded 90% at 50–100 microgram/mL, confirming suitability for immunological assays. Lerak significantly reduced TNF-alpha and IL-6 production while increasing IL-10 levels, indicating suppression of excessive inflammation and enhancement of regulatory responses. These findings suggest that S. rarak possesses dual antibacterial and immunomodulatory properties, highlighting its potential as a complementary therapeutic candidate for managing E. coli infections where inflammation contributes to disease severity.


Keywords


Sapindus rarak, antibacterial activity, Escherichia coli, macrophage cytokines, immunomodulation

Full Text:

PDF

References


Ahmed, S. M., Ibrahim, M. E., & Osman, M. E. (2020). Antimicrobial potential of saponin-rich plant extracts against Gram-negative pathogens. Journal of Ethnopharmacology, 250, 112469. https://doi.org/10.1016/j.jep.2019.112469

Asri, N. R., Hapsari, R. T., & Wulandari, D. (2022). Phytochemical composition and bioactivities of Sapindus rarak extracts. Biodiversitas, 23(3), 1452–1460. https://doi.org/10.13057/biodiv/d230326

Gupta, A., & Shah, P. (2021). Macrophage cytokine dysregulation during bacterial infections: implications for inflammation. Immunology Letters, 235, 42–50. https://doi.org/10.1016/j.imlet.2021.04.004

Hidayati, N., Prasetyo, A. R., & Lestari, D. (2023). Immunomodulatory activity of Indonesian medicinal plants: A review. Journal of Herbal Medicine, 37, 100643. https://doi.org/10.1016/j.hermed.2023.100643

Kim, J. H., Park, S. Y., & Lee, M. J. (2021). Triterpenoid saponins as antimicrobial agents: Mechanisms and applications. Fitoterapia, 152, 104915. https://doi.org/10.1016/j.fitote.2021.104915

Kusuma, A. W., Nurhayati, D., & Saputra, A. (2024). Modulation of macrophage cytokines by Southeast Asian medicinal plants. Journal of Ethnopharmacology, 312, 116410. https://doi.org/10.1016/j.jep.2023.116410

Martins, F. S., & Silva, R. O. (2021). The regulatory role of IL-10 in bacterial infections. Cytokine, 138, 155363. https://doi.org/10.1016/j.cyto.2020.155363

Murni, S., Fadhilah, I., & Putri, A. (2023). Antibacterial activity of Sapindus rarak against Gram-negative bacteria. Asian Pacific Journal of Tropical Biomedicine, 13(4), 175–182. https://doi.org/10.4103/2221-1691.347652

Navarro, L., & Pérez, M. A. (2022). Mechanistic insights into saponin-induced membrane disruption. Biochemical Pharmacology, 198, 114987. https://doi.org/10.1016/j.bcp.2021.114987

Rahman, M. M., & Idris, A. (2020). Pro-inflammatory responses in macrophages during pathogenic bacterial exposure. Frontiers in Cellular and Infection Microbiology, 10, 517. https://doi.org/10.3389/fcimb.2020.00517

Sari, P., & Yanti, D. (2025). Antibacterial properties of Sapindus rarak fruit extract: An in vitro evaluation. Journal of Tropical Pharmacy and Chemistry, 9(1), 1–10. https://doi.org/10.25026/jtpc.v9i1.567

Sharma, N., & Patel, D. (2021). Inhibition of NF-?B signaling by plant flavonoids reduces cytokine overproduction. Phytomedicine, 85, 153533. https://doi.org/10.1016/j.phymed.2021.153533

Singh, V., Kaur, A., & Tripathi, A. (2020). The emerging role of IL-10 in controlling inflammation. Journal of Inflammation Research, 13, 29–40. https://doi.org/10.2147/JIR.S234657

Tan, W. H., & Lim, S. L. (2020). Immunomodulatory effects of phenolic compounds in macrophage models. Food Chemistry, 325, 126870. https://doi.org/10.1016/j.foodchem.2020.126870

Zhang, L., & Liu, Q. (2019). Antibacterial effects of plant-derived saponins on Gram-negative bacteria: A biochemical perspective. Applied Microbiology and Biotechnology, 103(12), 4829–4841. https://doi.org/10.1007/s00253-019-09836-0

Zhao, Y., & Chen, H. (2022). Flavonoid-mediated suppression of inflammatory cytokines in macrophages. International Immunopharmacology, 108, 108759. https://doi.org/10.1016/j.intimp.2022.108759




DOI: https://doi.org/10.14421/biomedich.2026.151.209-213

Refbacks

  • There are currently no refbacks.


Bookmark and Share


Copyright (c) 2026 Lisa Savitri, Kharisul Ihsan, Elfred Rinaldo Kasimo, Rochmad Krissanjaya



Biology, Medicine, & Natural Product Chemistry
ISSN 2089-6514 (paper) - ISSN 2540-9328 (online)
Published by Sunan Kalijaga State Islamic University & Society for Indonesian Biodiversity.

CC BY NC
This work is licensed under a CC BY-NC