Surfactin

Surfactin, a highly powerful biosurfactant produced by various strains of the genus Bacillus, exhibits antibacterial, antiviral, antitumor, and hemolytic activities^[1]. Surfactin increases the permeability of Propionibacterium acnes’ cell wall, allowing alkaline phosphatase to leak into the extracellular environment, and prevents Staphylococcus aureus adhesion as well as biofilm formation on surfaces^[2]. Surfactin has been widely used in preclinical models to inhibit the growth of various cancer cells and as a component of nanocarriers to improve the efficiency and targeting of drug delivery^[3].

In vitro, Surfactin inhibited the growth of MCF-7 cells in a dose- and time-dependent manner, with IC₅₀ values at 24, 48, and 72h of 82.6μM, 27.3μM, and 14.8μM, respectively^[4]. Pretreatment with 60µg/ml Surfactin for 1 hour downregulated lipopolysaccharide (LPS)-induced TLR4 protein expression in macrophages and reduced the levels of IFN-γ, IL-6, iNOS, and nitric oxide (NO)^[5]. Treatment with 30µM Surfactin for 24 hours induced apoptosis in LoVo cells, accompanied by DNA fragmentation, changes in membrane polarity, and an increase in the cleavage level of caspase-3^[6].

In vivo, Surfactin treatment via daily intragastric administration at a dose of 80mg/kg for 6 consecutive weeks alleviated dextran sulfate sodium (DSS)-induced colitis and depression-like behaviors in mice, and mitigated gut microbiota dysbiosis and colonic intestinal barrier dysfunction^[7]. Daily oral administration of Surfactin at a dose of 80mg/kg for 12 consecutive weeks improved pancreatic function and glucose metabolism, promoted insulin secretion, and inhibited glucagon release in type 2 diabetic mice^[8].

References:
[1] Seydlová G, Svobodová J. Review of surfactin chemical properties and the potential biomedical applications[J]. Central European Journal of Medicine, 2008, 3(2): 123-133.
[2] Chen X, Lu Y, Shan M, et al. A mini-review: mechanism of antimicrobial action and application of surfactin[J]. World Journal of Microbiology and Biotechnology, 2022, 38(8): 143.
[3] Wu Y S, Ngai S C, Goh B H, et al. Anticancer activities of surfactin and potential application of nanotechnology assisted surfactin delivery[J]. Frontiers in pharmacology, 2017, 8: 761.
[4] Cao X, Wang A H, Jiao R Z, et al. Surfactin induces apoptosis and G2/M arrest in human breast cancer MCF-7 cells through cell cycle factor regulation[J]. Cell biochemistry and biophysics, 2009, 55(3): 163-171.
[5] Zhang Y, Liu C, Dong B, et al. Anti-inflammatory activity and mechanism of surfactin in lipopolysaccharide-activated macrophages[J]. Inflammation, 2015, 38(2): 756-764.
[6] Kim S, Kim J Y, Kim S H, et al. Surfactin from Bacillus subtilis displays anti‐proliferative effect via apoptosis induction, cell cycle arrest and survival signaling suppression[J]. FEBS letters, 2007, 581(5): 865-871.
[7] Chen X, Zhao H, Lu Y, et al. Surfactin mitigates dextran sodium sulfate-induced colitis and behavioral disorders in mice by mediating gut–brain-axis balance[J]. Journal of Agricultural and Food Chemistry, 2023, 71(3): 1577-1592.
[8] Chen X, Zhao H, Lu Y, et al. Surfactin mitigates a high-fat diet and streptozotocin-induced type 2 diabetes through improving pancreatic dysfunction and inhibiting inflammatory response[J]. International journal of molecular sciences, 2022, 23(19): 11086.