A purified and lyophilized Pseudomonas aeruginosa derived pyocyanin induces promising apoptotic and necrotic activities against MCF-7 human breast adenocarcinoma

Abstract

Background Pyocyanin, a specific extracellular secondary metabolite pigment produced by Pseudomonas aeruginosa, exhibits redox activity and has toxic effects on mammalian cells, making it a new and potent alternative for treating cancer. Breast cancer (BC) treatment is now defied by acquired and de novo resistance to chemotherapy, radiation, or targeted therapies. Therefore, the anticancer activity of purified and characterized pyocyanin was examined against BC in our study. Results The maximum production of pyocyanin (53 µg/ml) was achieved by incubation of the highest pyocyanin-producing P. aeruginosa strain (P32) in pH-adjusted peptone water supplemented with 3% cetrimide under shaking conditions at 37 °C for 3 days. The high purity of the extracted pyocyanin was proven by HPLC against standard pyocyanin. The stability of pyocyanin was affected by the solvent in which it was stored. Therefore, the purified pyocyanin extract was lyophilized to increase its shelf-life up to one year. Using the MTT assay, we reported, for the first time, the cytotoxic effect of pyocyanin against human breast adenocarcinoma (MCF-7) with IC50 = 15 μg/ml while it recorded a safe concentration against human peripheral blood mononuclear cells (PBMCs). The anticancer potential of pyocyanin against MCF-7 was associated with its apoptotic and necrotic activities which were confirmed qualitatively and quantitively using confocal laser scanning microscopy, inverted microscopy, and flow cytometry. Caspase-3 measurements, using real-time PCR and western blot, revealed that pyocyanin exerted its apoptotic activity against MCF-7 through caspase-3 activation. Conclusion Our work demonstrated that pyocyanin may be an ideal anticancer candidate, specific to cancer cells, for treating MCF-7 by its necrotic and caspase-3-dependent apoptotic activities.

Antibacterial, antibiofilm, and anti-quorum sensing activities of pyocyanin against methicillin-resistant Staphylococcus aureus: in vitro and in vivo study

“…The laboratory extraction, purification, and characterization of PCN as well as cytotoxicity evaluation were discussed in our previous study [ 20 ]. In the present study, the sub-toxic concentrations of PCN (less than 45 µg/ml) were used for evaluation of the antibacterial, antibiofilm, and anti-QS activities of PCN against MRSA isolates.…”

The two faces of pyocyanin - why and how to steer its production?

“…However, the authors concluded that the tested concentration of PYO in murine models (100 mg/ kg) was toxic and cannot be applied in therapy, rather than the dose of 750 µg/mL presented by Hamad et al (2020) that did not cause observable toxicity in tested rodents. PYO potential was also demonstrated in cancer research, where the viability of liver, pancreas, breast, lung, cervix, and skin cancer cell lines was reduced by this potential drug (Zhao et al 2014;Patil et al 2017;Moayedi et al 2018;Abdelaziz et al 2022). PYO may be used to produce other substances expressing anticancer properties.…”

“…Company (Elbargisy 2021;Abdelaziz et al 2022). Furthermore, the optimal temperature of incubation differs among the strains, and the most used values are within the range of 28-37℃.…”

Genomic and metabolic versatility of Pseudomonas aeruginosa contributes to its inter-kingdom transmission and survival

“…Pyocyanin, the signature metabolite of P. aeruginosa, is a blue-green, water-soluble phenazine pigment [114,115]. Phenazine compounds are commonly found in nature and are produced by bacteria such as Streptomyces and Pseudomonas.…”

“…Specifically, pyocyanin disrupts the beating of human cilia and inhibits mammalian cell respiration thereby helping P. aeruginosa colonize the host lungs [122]. Pyocyanin is a zwitterion that crosses the host cell membrane and oxidizes NADH and NADPH molecules, generating reactive oxygen species (ROS) [115,123,124]. The ROS further contributes to cytotoxicity in the respiratory, vascular and central nervous systems of the eukaryotic hosts [125].…”