The efficient culture and purification of antimicrobial peptides (AMPs), along with intense antioxidant activity, have drawn the interest to study antioxidant activity mechanism. We report the culture conditions optimization, efficient biosynthesis, and purification of an antioxidant peptide MS15 from Bacillus velezensis obtained from fermented food that would generate heme oxygenase-1 (HO-1) expression and lead to nuclear factor erythroid 2-related factor-2 (Nrf2) nuclear translocation. We explored the ability of kinetics and potency for the bacterial killing to work against various pathogenic bacteria. A bioassay showed the lysis zone of MS15 by tricine SDS-PAGE near at 6 kDa. MALDI-TOF/MS verified molecular weight, and the existence of a molecular mass of 6091 Da was reported by purity. The MIC of MS15 ranged from 2.5–160 μg/mL for many pathogenic bacteria, showing greater potency. In macrophage RAW 264.7 cells, MS15 was exposed to assess its inhibitory effect against the generation of reactive oxygen species (ROS) in oxidative stress. In the sample treated group, the translation, and transcriptional levels of CAT (catalase), GPx (glutathione peroxidase), and SOD (superoxide dismutase) were significantly greater. In short, MS15 has significant antioxidant properties, reducing ROS production in RAW 264.7 cells, and raising the translation and transcriptional rates of antioxidant enzymes with stimulating HO-1 induction facilitated by Nrf2.

Efforts to isolate a broad-spectrum antimicrobial peptide (AMP) from microbial sources have been on the rise recently. Here, we report the identification, the optimization of the culture conditions, and the characterization of an efficient AMP from the Bacillus strain designated MS07 that exhibits antimicrobial and antibiofilm activity. The production of MS07 was maximized by evaluating the culture conditions by the response surface methodology to obtain optimum media compositions. The biochemical integrity of MS07 was assessed by a bioassay indicating inhibition at ~6 kDa, like tricine-SDS-PAGE. MALDI-TOF confirmed the molecular weight and purity, showing a molecular mass of 6.099 kDa. Peptide MS07 exhibited antimicrobial activity against both Gram-positive and Gram-negative bacteria. The MIC of MS07 for Escherichia coli, Alcaligenes faecalis, MRSA, and Pseudomonas aeruginosa ranged from 16–32 µg/mL, demonstrating superior potency. The biomass was diminished by about 15% and 11%, with rising concentrations up to 8 × MIC, for P. aeruginosa and E. coli biofilm, respectively. MS07 exhibited an 8 µM and 6 µM minimum bactericidal concentration against the biofilm of the Gram-negative strains P. aeruginosa and E. coli, respectively. Peptide MS07 reduced and interrupted the biofilm development in a concentration-dependent manner, as determined by BacLight live/dead staining using confocal microscopy.

Due to increasing concerns about the contamination of animal food products with antibiotic-resistant bacteria and their byproducts, phytogenic feed additives in animal diets have been explored as antibiotic alternatives. In this study, we investigated the effect of ginger root extract (GRE), green tea extract (GTEC caffeinated and GTED decaffeinated), and onion peel combined (OPEC) on the activity of C. perfringens toxin genes and Eimeria tenella sporozoites. To this end, two Clostridium perfringens strains, CP19 and CP240 (Rollins Diagnostic Lab, Raleigh, NC, USA), were cultured (three replicates per treatment) as follows: without additives (Control), with Bacitracin Methylene Disalicylate (BMD), with GRE, with GTEC, with GTED, and, finally, with OPEC for 0, 2, 4, 6, 8, and 24 h. RNA was extracted to determine the expression of tpeL, alpha toxin (α-toxin), and NetB and we measured the protein concentration of NetB-positive C. perfringens toxin. Also, we evaluated the cytotoxic effect of green tea and ginger extracts on E. tenella sporozoites. Results show that phytogenic extracts, GRE, GTEC, and GTED, significantly reduced (p < 0.05) the level of expression of α-toxin gene compared to control; however, BMD treatment showed much less effect. Furthermore, NetB and tpeL encoding gene expression was significantly (p < 0.05) reduced by GRE and GTED, as well as BMD treatment, compared to the control. In contrast, GTEC treatment did not change the expression levels of these genes and was similar to control. With the CP240 strain, all the selected phytogenic extracts significantly reduced (p < 0.05) the expression of selected genes, except for OPEC, which was similar to control. GRE, GTEC, and GTED all reduced the viability of concentration of E. tenella sporozoites. Overall, our data show that these selected phytogenic extracts reduced the level of expression of toxin encoding genes associated with necrotic enteritis and decreased the viability of sporozoites which cause coccidiosis in broiler chicken.

Head and Neck Squamous Cell Carcinoma (HNSCC) imposes a significant health burden, necessitating innovative therapeutic strategies to enhance treatment efficacy. Current treatments such as surgery, radiation, and chemotherapy have limited effectiveness and yield severe side effects, emphasizing the need for targeted therapies. We have focused on DNA polymerase beta (Polβ) and its roles in replication stress, cellular responses to DNA damaging therapies, and DNA damage response modifiers. Our investigations reveal a regulatory role for base excision repair (BER) proteins, including Polβ, in the cellular response to inhibitors of poly(ADP-ribose) glycohydrolase (PARG), an enzyme involved in poly(ADP-ribose) (PAR) degradation. The inhibition of PARG, in HNSCC cells, elicits replication stress. Further, this activates the PAR-induced S-phase/ATR checkpoint, leading to a block to replication, cell cycle arrest, and the onset of apoptosis. However, Polβ overexpression mitigates this response, reducing replication-stress induced PAR foci formation, suggesting a modulation of replication checkpoint activation. We found that PARG inhibitor treatment is ineffective on HNSCC cells that overexpress Polβ, implying that the PARG inhibitor-induced PAR and apoptotic response is dependent on the level of Polβ. Further, our in vitro experiments demonstrate that combining PARG and ATR/CHK1 inhibitors overcomes Polβ-mediated treatment resistance in HNSCC cells, producing enhanced effects as compared to the individual treatment conditions. Our findings suggest a possible treatment paradigm for HNSCC, employing ATR or CHK1 inhibitors in combination with PARG inhibitors. This strategy offers a promising path for more effective HNSCC treatments, potentially overcoming Polβ-related resistance.