Antioxidant and Antibacterial Activities of Nano-probiotics Versus Free Probiotics Against Gastrointestinal Pathogenic Bacteria.

Antibiotic-resistant pathogenic bacteria and the oxidative stress related to their infections are dangerous health problems. Finding new safe, effective antibacterial and antioxidant agents is an urgent global need. Probiotics are a strong candidate for possible antibacterial and antioxidant agents. The delivery of these probiotics without any effect on gastrointestinal digestion is the most important point for their application. The encapsulation of the probiotics on nanoparticles or other supports is a well-known method for the safe delivery of the probiotics. Little information is known about the effect of the probiotic encapsulation on its antibacterial and antioxidant activity. The present study tried to investigate the effect of probiotic encapsulation on nano-chitosan on its antioxidant activity and antibacterial activity against some pathogenic bacteria. We encapsulated some known probiotic species on nano-chitosan and investigated the antibacterial activity of the nano-probiotics and free probiotics against gastrointestinal pathogenic bacteria. The antioxidant characters of the free and encapsulated probiotics were investigated in terms of DPPH radicle scavenging activity, ferric ion chelating activity, hydroxyl radicle scavenging activity, superoxide anion radicle scavenging activity, and anti-lipid peroxidation activity. Results showed the superiority of the encapsulated probiotics as antibacterial and antioxidant agents over the free ones. The encapsulation improved the antibacterial activity of Sporolactobacillus laevolacticus against Bacteroides fragilis by 134% compared to the free one. Also, significantly, the encapsulation increased the hydroxyl radicle scavenging activity of Enterococcus faecium by about 180% compared to the free one. Nano-chitosan encapsulation synergistically increased the antioxidant and antibacterial activity of the studied probiotics. This can be promising for controlling pathogenic bacteria. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-023-01140-2.

Control the carcinogenic bacteria with new polysaccharides from agricultural wastes.

Agriculture activities industries produce a huge amount of waste every year. Agricultural wastes are a great source of natural polysaccharides characterized by accessibility, biocompatibility, and ease of modification. Finding new safe antibacterial agents has become one of the top priorities of health organizations worldwide. This priority emerged from the antibiotic resistance pathogenic bacteria hazard. Carcinogenic bacteria are one of the most dangerous antibiotic-resistant pathogenic bacteria. This study tries to investigate the antibacterial activity of polysaccharides from some agricultural wastes against carcinogenic bacteria related to gastrointestinal cancers. We determined the antibacterial activity (in terms of minimum inhibitory concentration (MIC)) and the biofilm reduction capacity. We studied the mechanism of the antibacterial activity by determining the effect of the MIC of the extracted polysaccharides on the plasma membrane permeability and the bacterial DNA content. All extracted polysaccharides showed effective antibacterial activity with low MICs ranging from 2 to 20 µg/mL. The barely straw polysaccharides showed the highest MIC (19.844 µg/mL) against Bacteroides fragilis, while the grape bagasse showed the lowest MIC (2.489 µg/mL) against Helicobacter pylori. The extracted polysaccharide showed high antibiofilm activity. Their capacity to reduce the formation of the pathogenic biofilm ranged from 75 to 95%. Regarding the antibacterial mechanism, the extracted polysaccharides showed destructive action on the DNA and the plasma membrane permeability. The bacterial DNA change percent after the treatment with the different polysaccharides ranged from 29% to -58%. The plasma membrane permeability increased by a high percentage, ranging from 92% to 123%. Agricultural waste polysaccharides are a promising antibacterial agent against antibiotic-resistant carcinogenic bacteria.

Antimicrobial synergism and antibiofilm activity of amoxicillin loaded citric acid-magnesium ferrite nanocomposite: Effect of UV-illumination, and membrane leakage reaction mechanism.

Magnesium ferrite nanoparticles (Mg Fe2O4 NPs) was synthesized by a chemical co-precipitation method and characterized via structural and optical properties. The surface of Mg Fe2O4 NPs was stabilized with citric acid (CA) by a direct addition method (CA-Mg Fe2O4 NPs), then Amoxicillin (AX) was loaded with CA-Mg Fe2O4 nanocomposites. Furthermore, their antimicrobial, and antibiofilm activities, growth curve, and effect of UV-illumination methods were examined against different pathogenic microbes. Based on XRD, HRTEM and SEM analyses, it is found that Mg Fe2O4 NPs are located at the core, while the CA and AX are coated this core. In-vitro zone of inhibition (ZOI) and minimum inhibitory concentration (MIC) results verified that AX-loaded CA-Mg Fe2O4 nanocomposites exhibited its encouraged antimicrobial activity against S. aureus, E. coli, and C. albicans (32.2, 22.0, and 19.0 mm ZOI, respectively) & (0.312, 0.625, and 1.25 µg/ml MIC, respectively). AX-CA-Mg Fe2O4 nanocomposites are showed antibiofilm percentage against S. aureus (95.34%), E. coli (93.93%), and C. albicans (76.23%). AX-CA-MgFe2O4 nanocomposites are an excellent disinfectant agents once they are excited by UV light. Membrane leakage assay explains the formation of holes on the surface of bacteria, and confirms SEM reaction mechanism. AX-loaded CA-Mg Fe2O4 NPs are promising for potential applications in biomedical uses.

Plant asparaginase versus microbial asparaginase as anticancer agent.

The considerable effect of enzymes on human health draws great attention to enzyme-based drugs (therapeutic enzymes), in recent times. L-asparaginase (ASNase) is a well-known therapeutic enzyme. It has varied applications and is a single molecule for the treatment of multiple diseases. This study tries to extract asparaginase from soybean debris (agricultural wastes) as a cheap plant source and compare this with microbial asparaginase as an agent in cancer chemotherapy. The asparaginase was extracted and purified from soybean debris (plant asparaginase) and Pseudomonas aeruginosa (microbial asparaginase), then the physiochemical characters were determined for the two enzymes, and the anticancer activity of plant and microbial asparaginase was determined against gastric cancer (CLS-145), pancreatic cancer (AsPC-1), colon cancer (HCT116), esophagus cancer (KYSE-410), liver cancer (HepG2), breast cancer (MCF-7), and cervical cancer (HELLA). The results showed that plant asparaginase was superior to microbial asparaginase in its physiochemical characters. Plant asparaginase showed higher stability and activity under the conditions of changing either the temperature or the pH; also plant asparaginase has a higher affinity to the asparagine than the microbial asparaginase; besides, this plant asparaginase did not show activity with glutamine as a substrate. The plant asparaginase showed higher anticancer activity than that of microbial asparaginase against all studied cancer cell lines. The present study introduces as the first time a comparative study between the plant and microbial asparaginase which proves that soybean debris asparaginase can be more efficient and safe than that of the microbial asparaginase as an anticancer agent.

Microbial Azurin Immobilized on Nano-Chitosan as Anticancer and Antibacterial Agent Against Gastrointestinal Cancers and Related Bacteria.

OBJECTIVES: To discover new natural effective anticancer agents and new antibacterial agents against antibiotic-resistant bacteria which are the most serious public health concern. Another important concern is drug delivery which is the transport of pharmaceutical compounds to have a therapeutic effect in organisms having a disease. Azurin is a promising anticancer agent produced from Pseudomonas aeruginosa. This study tried to test the effectiveness of the immobilization of azurin on nano-chitosan to enhance its anticancer and antibacterial activity against gastrointestinal cancer and its related bacteria. METHODS: We purified azurin protein from Pseudomonas aeruginosa and then immobilized it on nano-chitosan. The anticancer activity of the free and nano-azurin is tested against a gastric cancer cell line (CLS-145), pancreatic cancer cell line (AsPC-1), colon cancer cell line (HCT116), esophagus cancer cell line (KYSE-410), and liver cancer cell line (HepG2). The antibacterial activity of both free and immobilized azurin also is tested against bacterial species related to the gastrointestinal cancer biopsies: Helicobacter pylori, Bacteroides fragilis, Salmonella enterica, Fusobacterium nucleatum, and Porphyromonas gingivalis. RESULTS: Both free and nano-azurin showed high anticancer and antibacterial activity. Immobilization significantly increased the anticancer and antibacterial activity of the azurin CONCLUSION: Nano-azurin can be used as an effective anticancer and antibacterial agent against gastrointestinal cancer and bacterial species related to these cancers.

Nano-peroxidase a Promising Anti-inflammatory and Antibacterial Agent Against Bacteria and Inflammation Related to Colorectal Cancer.

BACKGROUND: Colorectal cancer (CRC) is one of the most common causes of cancer death in the world. Although genes are considered the most importantcauses that contribute to CRC, the intestinal microorganisms are an important player. Recently, various studies ensured the role of microbial infection and the ensuing inflammation in colon cancer initiation and progression. This present study tries to introduce a cheap nano-peroxidase (an antioxidant enzyme) produced from natural sources as efficient and safe antibacterial and anti-inflammatory agent against bacteria and inflammation related to colorectal cancer. METHODS: Silica nanoparticles were prepared from rice straw. Peroxidase extracted from the dry onion scales was then immobilized on the prepared nanosilica (nano-peroxidase). The antibacterial activity of the prepared nano-peroxidase was tested against the four horsemen bacteria in CRC, Fusobacterium nucleatum, Escherichia coli, Bacteroides fragilis, and Salmonella enterica. The in vitro anti-inflammatory activity of the prepared nano-peroxidase also tests through performing inhibition of albumin denaturation test. RESULTS: The prepared nano-peroxidase showed high antibacterial activity against the tested bacteria in presence of very low concentration of H2O2. Immobilization increased the peroxidase stability and protected it from hydrolysis enzymes produced by the bacteria. The prepared nano-peroxidase interestingly showed significant higher anti-inflammatory activity than that of the standard (Aspirin). CONCLUSION: Nano-peroxidase can be considered a promising safe anti-inflammatory and antibacterial agent against bacteria and inflammation related to colorectal cancer.

Gum Arabic polymer-stabilized and Gamma rays-assisted synthesis of bimetallic silver-gold nanoparticles: Powerful antimicrobial and antibiofilm activities against pathogenic microbes isolated from diabetic foot patients.

In this research, irradiation by gamma rays was employed as an eco-friendly route for the construction of bimetallic silver-gold nanoparticles (Ag-Au NPs), while Gum Arabic polymer was used as a capping agent. Ag-Au NPs were characterized through UV-Vis., XRD, EDX, HR-TEM, FTIR, SEM/mapping and EDX analysis. Antibiofilm and antimicrobial activities were examined against some bacteria and Candida sp. isolates from diabetic foot patients. Our results revealed that the synthesis of Ag-Au NPs depended on the concentrations of tetra-chloroauric acid and silver nitrate. HR-TEM analysis confirmed the spherical nature and an average diameter of 18.58 nm. FTIR results assured many functional groups in Gum Arabic which assisted in increasing the susceptibility of incorporation with Ag-Au NPs. Our results showed that, Ag-Au NPs exhibited the highest antimicrobial performance against B. subtilis (14.30 mm ZOI) followed by E. coli (12.50 mm ZOI) and C. tropicalis (11.90 mm ZOI). In addition, Ag-Au NPs were able to inhibit the biofilm formation by 99.64%, 94.15%, and 90.79% against B. subtilis, E. coli, and C. tropicalis, respectively. Consequently, based on the promising properties, they showed superior antimicrobial potential at low concentration and continued-phase durability, they can be extensively-used in many pharmaceutical and biomedical applications.

Biogenic synthesis of copper nanoparticles by natural polysaccharides and Pleurotus ostreatus fermented fenugreek using gamma rays with antioxidant and antimicrobial potential towards some wound pathogens.

Mono-dispersed copper nanoparticles (CuNPs) were constructed using cheap polysaccharides (citrus pectin, chitosan, and sodium alginate), and by appropriating aqueous fermented fenugreek powder (FFP) under the action of Pleurotus ostreatus (as reducing and preserving means), through the influence of gamma irradiation. The synthesized CuNPs are described by UV-Vis. spectroscopy TEM, DLS, XRD, and FT-IR. XRD study of the CuNPs confirmed the generation of metallic CuNPs. The nucleation and the production mechanism of CuNPs are moreover explained. TEM unveiled that, the ordinary diameter of CuNPs incorporated by various polysaccharides, and FFP taken in the range of 31.0 and 36.0 nm respectively. CuNPs size is influenced by many parameters such as the variety of stabilizer, pH within the organization and applied gamma dose. Evaluation of the antioxidant and antimicrobial activities of CuNPs was performed against some selected wound pathogens. The results showed that, CuNPs were a strong antimicrobial agents against microbes caused burn skin infection such as Klebsiella pneumoniae, Staphylococcus aureus, and Candida albicans (16.0, 15.0, and 15.0 mm ZOI, respectively). Additionally, CuNPs have a strong antioxidant with 70% scavenging activity against DPPH. So, due to unique characteristics of CuNPs (cost-effective with continued-term stabilization and effective features), they can recover reasonable potential in biomedical, industrial, agricultural, cosmetics, dermal products and pharmaceutical purposes.