Bacteriocins: New Potential Therapeutic Candidates in Cancer Therapy

The Bacteriocins Produced by Lactic Acid Bacteria and the Promising Applications in Promoting Gastrointestinal Health

Bacteriocins produced by lactic acid bacteria (LAB) are promising bioactive peptides. Intriguingly, bacteriocins have health benefits to the host and may be applied safely in the food industry as bio-preservatives or as therapeutic interventions preventing intestinal diseases. In recent years, finding a safe alternative approach to conventional treatments to promote gut health is a scientific hotspot. Therefore, this review aimed to give insight into the promising applications of LAB-bacteriocins in preventing intestinal diseases, such as colonic cancer, Helicobacter pylori infections, multidrug-resistant infection-associated colitis, viral gastroenteritis, inflammatory bowel disease, and obesity disorders. Moreover, we highlighted the recent research on bacteriocins promoting gastrointestinal health. The review also provided insights into the proposed mechanisms, challenges and opportunities, trends and prospects. In addition, a SWOT analysis was conducted on the potential applications. Based on properties, biosafety, and health functions of LAB-bacteriocins, we conclude that the future applications of LAB-bacteriocins are promising in promoting gastrointestinal health. Further in vivo trials are needed to confirm these potential effects of LAB-bacteriocins interventions.

Bacteriocins in Cancer Treatment: Mechanisms and Clinical Potentials

Cancer poses a severe threat to human health. Although conventional chemotherapy remains a cornerstone of cancer treatment, its significant side effects and the growing issue of drug resistance necessitate the urgent search for more efficient and less toxic anticancer drugs. In recent years, bacteriocins, antimicrobial peptides of microbial origin, have garnered significant attention due to their targeted antitumor activity. This unique activity is mainly attributed to their cationic and amphiphilic nature, which enables bacteriocins to specifically kill tumor cells without harming normal cells. When involving non-membrane-disrupting mechanisms, such as apoptosis induction, cell cycle blockade, and metastasis inhibition, the core mechanism of action is achieved by disrupting cell membranes, which endows bacteriocins with low drug resistance and high selectivity. However, the susceptibility of bacteriocins to hydrolysis and hemolysis in vivo limits their clinical application. To overcome these challenges, structural optimization of bacteriocins or their combination with nanotechnology is proposed for future development. This review aims to study the mechanism of action and current research status of bacteriocins as anticancer treatments, thus providing new insights for their clinical development and application.

Bioactive plantaricins as potent anti-cancer drug candidates: double docking, molecular dynamics simulation and in vitro cytotoxicity analysis

The medical community is desperate for a reliable source of medications to alleviate the severity of conventional cancer treatments and prevent secondary microbial infections in oncological patients. In this regard, plantaricins from lactic acid bacteria were explored as prospective drug candidates against known anti-cancer drug targets. Three plantaricins, JLA-9, GZ1-27 and BN, have a binding affinity of -8.8, -8.6 and -7.2 kcal/mol, respectively, with squalene synthase (SQS), a key molecule in lung cancer metastasis. All three plantaricins displayed analogous binding patterns as SQS inhibitors and generated hydrogen and hydrophobic interactions with ARG 47, ARG 188, PHE24, LEU183 and PRO292. Structural stability of docked complexes was validated using molecular dynamics simulation derived parameters such as RMSD, RMSF and radius of gyration. Based on MD simulation results, conformational changes and stabilities of docked SQS/plantaricin complexes with respect to the time frame were evaluated using machine learning (logistic regression algorithm). Double docking with SQS/matrix metalloproteinase MMP1 and PCA analysis revealed the potential of plantaricin JLA-9 as a multi-substrate inhibitor. Further, plantaricin JLA-9 induced a significant cytotoxic response against the lung carcinoma cell line (A549) in a dose and time dependent manner with inhibition concentration (IC50) of 0.082 µg/ml after 48 h. However, plantaricin JLA-9 did not induce cytotoxicity in normal lung cells (L-132), as the IC50 value was not obtained even at a higher dose of 0.8 µg/ml. In silico pharmacokinetic (ADMET) profile implies that plantaricin JLA-9 could be developed as new age anti-cancer therapeutic with a preference for parenteral administration.Communicated by Ramaswamy H. Sarma.

An investigation of bacteriocin nisin anti-cancer effects and FZD7 protein interactions in liver cancer cells

The bacteriocin, nisin, produced by Lactococcus and Streptococcus species during fermentation, is widely used for bio preservatives in a wide variety of foods. Liver cancer has a high mortality rate and is the fourth leading cause of cancer-related deaths worldwide. Recently, researchers have shown the anti-cancer effects of nisin through in vitro and in vivo studies. This study aimed to investigate the effect of nisin on liver cancer cell lines, which represented two subgroups of the disease model. Nisin exhibited significant growth inhibition and apoptosis in both cell lines, HuH-7, and SNU182. Drug resistance is the main problem in liver cancer and the epithelial-to-mesenchymal transition has a role in the development of drug resistance in hepatocellular carcinoma. The expression of EMT transcription factors ZEB1, SNAI1, and TWIST1 were analyzed depending on nisin treatment, TWIST1 expression was down-regulated after nisin treatment compared to the untreated SNU182 and HuH-7 cell lines. Besides, due to the reported correlation between the overexpression of Frizzled (FZD) proteins, specifically FZD7, in primary hepatocellular carcinomas (HCCs), molecular docking was assessed for Nisin A in the binding site of FZD7. Results confirmed that Nisin A was able to form important hydrogen bonding with key residues. This research not only determined the role of nisin in different liver cancer cell models but it also provided the first result of FZD7 and nisin interaction.