Enhancing Osteoblastic Cell Cultures with Gelatin Methacryloyl, Bovine Lactoferrin, and Bioactive Mesoporous Glass Scaffolds Loaded with Distinct Parsley Extracts.

The increasing interest in innovative solutions for addressing bone defects has driven research into the use of Bioactive Mesoporous Glasses (MBGs). These materials, distinguished by their well-ordered mesoporous structure, possess the capability to accommodate plant extracts with well-established osteogenic properties, including bovine lactoferrin (bLF), as part of their 3D scaffold composition. This harmonizes seamlessly with the ongoing advancements in the field of biomedicine. In this study, we fabricated 3D scaffolds utilizing MBGs loaded with extracts from parsley leaves (PL) and embryogenic cultures (EC), rich in bioactive compounds such as apigenin and kaempferol, which hold potential benefits for bone metabolism. Gelatin Methacryloyl (GelMa) served as the polymer, and bLF was included in the formulation. Cytocompatibility, Runx2 gene expression, ALP enzyme activity, and biomineralization were assessed in preosteoblastic MC3T3-E1 cell cultures. MBGs effectively integrated PL and EC extracts with loadings between 22.6 ± 0.1 and 43.6 ± 0.3 µM for PL and 26.3 ± 0.3 and 46.8 ± 0.4 µM for EC, ensuring cell viability through a release percentage between 28.3% and 59.9%. The incorporation of bLF in the 3D scaffold formulation showed significant differences compared to the control in all assays, even at concentrations below 0.2 µM. Combinations, especially PL + bLF at 0.19 µM, demonstrated additive potential, with superior biomineralization compared to EC. In summary, this study highlights the effectiveness of MBGs in incorporating PL and EC extracts, along with bLF, into 3D scaffolds. The results underscore cytocompatibility, osteogenic activity, and biomineralization, offering exciting potential for future in vivo applications.

Antimicrobial and antioxidant activity of proteins isolated from Melipona beecheii honey.

Proteins from Melipona beecheii honey were purified by concanavalin A (conA) affinity chromatography and eluted with a stepwise glucose gradient into fractions named F2-F5. The conA-unbound fraction (F1) was further separated by molecular exclusion into fractions named MbF1-1,2 and MbF1-3. All fractions were evaluated for antibacterial activity against foodborne pathogens and antioxidant capacity. F1 fraction possessed highest antimicrobial activity against S. aureus, L. monocytogenes, S. Typhimurium, E. coli and P. aeruginosa with MIC's 1.4 ± 0.2, 15 ± 1, 39 ± 2, 1 ± 0.1, and 75 ± 2 µg/mL, respectively. F1, MbF1-1,2 and MbF1-3 had bactericidal effect except against P. aeruginosa. When the antioxidant capacity of the fractions was determined, F2 had the highest antioxidant activity measured by DPPH radical scavenging activity (IC50 = 2.4 ± 0.4 µg/µL) and reducing power of Fe(III) (IC50 = 1.8 ± 0.2 µg/µL). We provide evidence that M. beecheii honey proteins possess broad spectrum antibacterial and antioxidant activity, the latter probably through their reducing agent and free radical scavenger properties.

Effect of plant growth-promoting bacteria on the growth and fructan production of Agave americana L

ABSTRACT The effect of plant growth-promoting bacteria inoculation on plant growth and the sugar content in Agave americana was assessed. The bacterial strains ACO-34A, ACO-40, and ACO-140, isolated from the A. americana rhizosphere, were selected for this study to evaluate their phenotypic and genotypic characteristics. The three bacterial strains were evaluated via plant inoculation assays, and Azospirillum brasilense Cd served as a control strain. Phylogenetic analysis based on the 16S rRNA gene showed that strains ACO-34A, ACO-40 and ACO-140 were Rhizobium daejeonense, Acinetobacter calcoaceticus and Pseudomonas mosselii, respectively. All of the strains were able to synthesize indole-3-acetic acid (IAA), solubilize phosphate, and had nitrogenase activity. Inoculation using the plant growth-promoting bacteria strains had a significant effect (p < 0.05) on plant growth and the sugar content of A. americana, showing that these native plant growth-promoting bacteria are a practical, simple, and efficient alternative to promote the growth of agave plants with proper biological characteristics for agroindustrial and biotechnological use and to increase the sugar content in this agave species.

Effect of plant growth-promoting bacteria on the growth and fructan production of Agave americana L.

The effect of plant growth-promoting bacteria inoculation on plant growth and the sugar content in Agave americana was assessed. The bacterial strains ACO-34A, ACO-40, and ACO-140, isolated from the A. americana rhizosphere, were selected for this study to evaluate their phenotypic and genotypic characteristics. The three bacterial strains were evaluated via plant inoculation assays, and Azospirillum brasilense Cd served as a control strain. Phylogenetic analysis based on the 16S rRNA gene showed that strains ACO-34A, ACO-40 and ACO-140 were Rhizobium daejeonense, Acinetobacter calcoaceticus and Pseudomonas mosselii, respectively. All of the strains were able to synthesize indole-3-acetic acid (IAA), solubilize phosphate, and had nitrogenase activity. Inoculation using the plant growth-promoting bacteria strains had a significant effect (p<0.05) on plant growth and the sugar content of A. americana, showing that these native plant growth-promoting bacteria are a practical, simple, and efficient alternative to promote the growth of agave plants with proper biological characteristics for agroindustrial and biotechnological use and to increase the sugar content in this agave species.

Oxidative stress response of Mycosphaerella fijiensis, the causal agent of black leaf streak disease in banana plants, to hydrogen peroxide and paraquat.

Mycosphaerella fijiensis causes black leaf streak disease in banana and plantain. This fungus is usually attacked by reactive oxygen species secreted by the plant or during exposure to fungicide, however, little is known about the antioxidant response of the fungus. In this study, mycelia were observed to totally decompose 30 mmol/L of hydrogen peroxide (H2O2) within 120 min, liberating oxygen bubbles, and also to survive in concentrations as high as 100 mmol/L H2O2. The oxidative stress responses to H2O2, paraquat, and hydroquinone were characterized in terms of the activities of catalase and superoxide dismutase (SOD). Two active catalase bands were seen in native PAGE induced by H2O2. Band I had monofunctional activity and band II had bifunctional catalase-peroxidase activity. Two isozymes of SOD, distinguishable by their cyanide sensitivity, were found; CuZnSOD was the main one. The combination of H2O2 and 3-aminotriazole reduced the accumulation of biomass up to 40% compared with exposure to H2O2 alone, suggesting that catalase is important for the rapid decomposition of H2O2 and has a direct bearing on cell viability. The results also suggest that the superoxide anion formed through the redox of paraquat and hydroquinone has a greater effect than H2O2 on the cellular viability of M. fijiensis.

Identification of Actinobacillus pleuropneumoniae biovars 1 and 2 in pigs using a PCR assay.

Actinobacillus pleuropneumoniae causes swine pleuropneumonia worldwide. Previously, we described a gene sequence of approximately 800bp in A. pleuropneumoniae serotype 1 that encodes a metalloprotease of 24kDa, (Genbank accession no. AY217757). We selected primers carrying the forward and reverse 5'-terminal sequences of this region of the gene for the development of a species-specific PCR assay. The primers amplified an 800bp sequence from isolated DNA and lysed bacteria of the 13 A. pleuropneumoniae biovar 1 serotypes, with the exception of subtype 1b. The primers also amplified the sequence in nasal secretion cultures from pigs with chronic and acute experimental pleuropneumonia. No PCR products were detected when A. pleuropneumoniae serotypes of biovar 2 were used. Internal primers from this gene sequence detected biovar 2 and subtype 1b, leading to the production of a 350bp PCR product. The primers did not amplify DNA from other related species from the Pasteurellaceae family. The 800bp PCR assay was sensitive in vitro, with a detection limit of 5.5pg of extracted DNA, and an average of 120CFU. The specificity and sensitivity of this PCR assay make it a useful method for the rapid identification and diagnosis of A. pleuropneumoniae.

Aqueous crude extract of Rhoeo discolor, a Mexican medicinal plant, decreases the formation of liver preneoplastic foci in rats.

There are many plants in Mexico with medicinal properties, some of them used in alternative medicine to treat cancer, such is the case of Rhoeo discolor L. Hér Hance (Commelinaceae family); however, there are not scientific reports that validate their antitumoral property. The present study shows the protective effects of the Rhoeo discolor aqueous crude extract (ACE) against rat liver cancer using the resistant-hepatocyte model. The carcinogenesis protocol consisted on the initiation with N-diethylnitrosamine, followed by the promotion with 2-acetylaminofluorene and a partial hepatectomy. After 24 days, the gamma-glutamyl transpeptidase positive, corresponding to altered hepatocytes foci (AHF), were quantified. Additionally to discard a possible carcinogenic effect of ACE, it was first tested as promoting agent instead 2-acetylaminofluorene, and second, ACE was administered as initiator and promoter instead of the whole carcinogenic treatment. In summary, firstly, ACE administration reduced the number and area of preneoplastic lesions with dose below 20mg/kg body weight and secondly, ACE administration neither presented a promoting or initiator effects nor induced the development of AHF. Results of this investigation justify continuing with further studies of Rhoeo discolor components to develop chemoprevention strategies as an option in the treatment of cancer.