Inhibition of Human HepG2 Hepatocellular Carcinoma Cell Line Growth by Metabolites from a Clinical Strain of Pseudomonas aeruginosa D121 In Vitro

Inhibition of Human HepG2 Hepatocellular Carcinoma Cell Line Growth by Metabolites from a Clinical Strain of Pseudomonas aeruginosa D121 In Vitro
Ali Fazeli Kia,¹ Ehsan Soleimannezhadbari,² Hamed Charkhian,³ Şeref Buğra Tunçer,^4,*
1. Medical Student, Faculty of Medicine, Urmia Branch, Islamic Azad University, Urmia, Iran.
2. Department of Microbiology and Virology, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran.
3. Department of Cancer Genetics, Institute of Graduate Studies in Health Sciences, Istanbul University, Istanbul, Turkey.
4. Department of Cancer Genetics, Oncology Institute, Istanbul University, Istanbul, Turkey.
Introduction: Cancer, as the second leading cause of human mortality, imposes substantial social, economic, and psychological burdens on society. Although chemotherapy and radiotherapy remain among the most effective cancer treatments, their clinical use is often limited by severe side effects and the development of therapeutic resistance in tumor cells. Therefore, discovering novel anticancer compounds capable of inhibiting tumor cell growth represents a major research priority. Metabolites produced by Pseudomonas species have been reported to exhibit anticancer properties. Accordingly, the present study aimed to isolate and evaluate the anticancer effects of metabolites produced by a clinical strain of Pseudomonas aeruginosa D121.
Methods: HepG2 hepatocellular carcinoma cells were obtained from the Pasteur Institute of Iran cell repository, and culture media and related reagents were procured from Biowest, France. Cells were maintained in complete RPMI 1640 medium supplemented with 5% fetal bovine serum (FBS) and 1% penicillin-streptomycin. Cell cultures were monitored daily using an inverted microscope. Among 150 clinical isolates collected from hospitals in Urmia, Iran, P. aeruginosa D121 was selected for further study. Three colonies of the isolate were inoculated into 30 mL of Mueller-Hinton broth and incubated at 37°C with shaking at 150 rpm for 24 hours. The resulting bacterial suspension was centrifuged at 4000 rpm for 5 minutes and filtered through a 0.45 µm membrane filter. The 24-hour culture supernatant was subsequently lyophilized. HepG2 cells (2 × 10^4 cells/well) were seeded in 96-well plates and incubated for 24 hours at 37°C with 5% CO2.Cells were then treated with various concentrations of the lyophilized bacterial metabolites (12.5, 25, 50, 100, 200, and 400 µg/mL) for 24 hours. Cell viability was assessed using the MTT assay.
Results: The metabolites produced by the clinical strain P. aeruginosa D121 effectively inhibited the growth of HepG2 cells in a dose-dependent manner. Increasing metabolite concentrations led to a progressive reduction in cell viability. At 400 µg/mL, cell death reached 86% (P < 0.01). The IC50 of the metabolites was calculated as ≈178.95.
Conclusion: These findings indicate that bioactive compounds produced by P. aeruginosa D121 can effectively inhibit HepG2 hepatocellular carcinoma cell growth. With further investigation, these metabolites may serve as potential adjunctive or complementary agents in cancer therapy.
Keywords: Pseudomonas aeruginosa, HepG2, Metabolite, Anticancer, Cell viability.