Bacteriocins are a large group of antimicrobial compounds that are synthesized by representatives of the genus Bacillus and lactic acid bacteria. They are used extensively in the food industry as biopreservatives. Incorporated in the composition of edible coatings, bacteriocins can reduce microbial growth and decay incidence in perishable fruits, thus improving product shelf-life and commercial appearance. The present study aims to investigate the effect of edible coatings of 0.5 % carboxymethyl cellulose (CMC) enriched with a purified bacteriocin from Bacillus methylotrophicus BM47 on the shelf-life extension of fresh strawberries. During storage at 4 °C and 75 % relative humidity for 16 days, the measurements of mass loss, decay percentage, total soluble solids (TSS), titratable acidity (TA), pH, organic acids, total phenolic and anthocyanin contents and antioxidant activity were made. The results demonstrate that the application of edible coatings with 0.5 % CMC and 0.5 % CMC with bacteriocin (CMC+B) led to a significant decrease of mass loss in the treated strawberries compared to the uncoated fruit. After the 8th day of storage, significant reductions in decay percentage along with the absence of fungal growth in CMC+B-coated fruit were observed in comparison with the CMC-coated and control strawberries. During the second half of the storage period, CMC and CMC+B treatments reduced TSS amount in the coated fruit compared to the control, but did not affect the increase of TA and decrease of pH values that are normally associated with postharvest changes. The CMC and CMC+B coatings did not prevent the decrease of ascorbic acid, and total phenolic and anthocyanin contents during cold storage. The application of CMC and CMC+B coatings had a significant inhibitory effect on decreasing the antioxidant activity throughout the storage period and maintained the antioxidant levels in both treatments close to the initial value of 76.8 mmol Trolox equivalents per 100 g of fresh mass.

The present article focuses on the synthesis and biological evaluation of a novel anthranilic acid hybrid and its diamides as antispasmodics. Methods: Due to the predicted in silico methods spasmolytic activity, we synthesized a hybrid molecule of anthranilic acid and 2-(3-chlorophenyl)ethylamine. The obtained hybrid was then applied in acylation with different acyl chlorides. Using in silico analysis, pharmacodynamic profiles of the compounds were predicted. A thorough biological evaluation of the compounds was conducted assessing their in vitro antimicrobial, cytotoxic, anti-inflammatory activity, and ex vivo spasmolytic activity. Density functional theory (DFT) calculation, including geometry optimization, molecular electrostatic potential (MEP) surface, and HOMO-LUMO analysis for the synthesized compounds was conducted using the B3LYP/6–311G(d,p) method to explore the electronic behavior, reactive regions, and stability and chemical reactivity of the compounds. Furthermore, molecular docking simulation along with viscosity measurement indicated that the newly synthesized compounds interact with DNA via groove binding mode. The obtained results from all the experiments demonstrate that the hybrid molecule and its diamides inherit spasmolytic, antimicrobial, and anti-inflammatory capabilities, making them excellent candidates for future medications.

Anticoagulants prevent the blood from developing the coagulation process, which is the primary cause of death in thromboembolic illnesses. Phenindione (PID) is a well-known anticoagulant that is rarely employed because it totally prevents coagulation, which can be a life-threatening complication. The goal of the current study is to synthesize drug-loaded Ag NPs to slow down the coagulation process. Methods: A rapid synthesis and stabilization of silver nanoparticles as drug-delivery systems for phenindione (PID) were applied for the first time. Results: Several methods are used to determine the size of the resulting Ag NPs. Additionally, the drug-release capabilities of Ag NPs were established. Density functional theory (DFT) calculations were performed for the first time to indicate the nature of the interaction between PID and nanostructures. DFT findings supported that galactose-loaded nanostructure could be a proper delivery system for phenindione. The drug-loaded Ag NPs were characterized in vitro for their antimicrobial, cytotoxic, and anticoagulant activities, and ex vivo for spasmolytic activity. The obtained data confirmed the drug-release experiments. Drug-loaded Ag NPs showed that prothrombin time (PT, sec) and activated partial thromboplastin time (APTT, sec) are approximately 1.5 times longer than the normal values, while PID itself stopped coagulation at all. This can make the PID-loaded Ag NPs better therapeutic anticoagulants. PID was compared to PID-loaded Ag NPs in antimicrobial, spasmolytic activity, and cytotoxicity. All the experiments confirmed the drug-release results.

Anti-inflammatory drugs are used to relieve pain, fever, and inflammation while protecting the cardiovascular system. However, the side effects of currently available medications have limited their usage. Due to these adverse effects, there is a significant need for new drugs. The current trend of research has shifted towards the synthesis of novel anthranilic acid hybrids as anti-inflammatory agents. Phenyl- or benzyl-substituted hybrids exerted very good anti-inflammatory effects in preventing albumin denaturation. To confirm their anti-inflammatory effects, additional ex vivo tests were conducted. These immunohistochemical studies explicated the same compounds with better anti-inflammatory potential. To determine the binding affinity and interaction mode, as well as to explain the anti-inflammatory activities, the molecular docking simulation of the compounds was investigated against human serum albumin. The biological evaluation of the compounds was completed, assessing their antimicrobial activity and spasmolytic effect. Based on the experimental data, we can conclude that a collection of novel hybrids was successfully synthesized, and they can be considered anti-inflammatory drug candidates—alternatives to current therapeutics.

Members of the bacterial genus Bacillus are known as producers of a broad spectrum of antibiotic compounds of proteinaceous nature that possess inhibitory activity against different saprophytic and pathogenic microorganisms. In the current research, a peptide synthesized by Bacillus methylotrophicus strain BM47, previously isolated from a natural thermal spring in Bulgaria, was identified and characterized as a bacteriocin. In vitro antimicrobial screening of the crude bacteriocin substance of B. methylotrophicus BM47 showed activity against the plant pathogenic fungi Fusarium moniliforme, Aspergillus awamori, Penicillium sp., Aspergillus niger and Gram-negative bacterium Pseudomonas aeruginosa. The antimicrobial activity of the crude bacteriocin substance was partially inhibited by the enzymes trypsin, Alcalase®, Savinase®, proteinase K, papain and Esperase®, while catalase was not effective. The crude bacteriocin substance was relatively pH resistant, but sensitive to the action of heat and most organic solvents and detergents tested. To obtain the active protein fractions, crude bacteriocin substance was purified by fast protein liquid chromatography (FPLC) using a strong anion exchange column. Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis demonstrated that the purified bacteriocin had molecular mass of 19 578 Da. The amino acid analysis performed by high-performance liquid chromatography (HPLC) revealed that the isolated bacteriocin consisted of 17 types of amino acids, with the highest mol fraction expressed as percent of serine (29.3), valine (10.3), alanine (9.8) and tyrosine (7.1).

Background/objectives: Propolis (bee glue) is a valuable bee product widely used as a natural remedy, a cosmetic ingredient, a nutritional value enhancer and a food biopreservative. The present research aims to investigate the phenolic content, antioxidant activity and in vitro anti-inflammatory and antitumor potential of six propolis samples from three regions of Bulgaria (Vidin, Gabrovo and Lovech). Methods: the analysis of propolis phenolic compounds was determined by high-performance liquid chromatography (HPLC); the antioxidant activity of ethanolic propolis extracts was assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and ferric-reducing antioxidant power (FRAP) assay; the in vitro anti-inflammatory activity was assessed by the inhibition of albumin denaturation method; the in vitro antitumor activity was determined in human metastatic breast cancer cell line MDA-MB-231 using 3-(4,5-Dimethyl -2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Results: The ethanolic propolis extracts exhibited the total phenolic content from 190.4 to 317.0 mg GAE/g, total flavonoid content from 53.4 to 79.3 mg QE/g and total caffeic acid derivatives content from 5.9 to 12.1 mg CAE/g. The studied propolis extracts showed significant antioxidant capacity (between 1000.3 and 1606.0 mM TE/g determined by the DPPH assay, and between 634.1 and 1134.5 mM TE/g determined by the FRAP assay). The chemical composition analysis indicated high concentrations of caffeic acid benzyl ester, chrysin, pinocembrin and pinobanksin-3-O-propionate, predominantly in three of the propolis samples originating from Gabrovo and Lovech regions. All propolis samples demonstrated promising in vitro anti-inflammatory activity, expressed as the inhibition of thermally induced albumin denaturation by 73.59% to 78.44%, which was higher than that of the conventional anti-inflammatory drugs Aspirin (58.44%) and Prednisolone Cortico (57.34%). The propolis samples exhibited high in vitro cytotoxicity against cancer cells MDA-MB-231 with IC₅₀ values ranging between 9.24 and 13.62 µg/mL as determined by MTT assay. Conclusions: Overall, we can suggest that the high phenolic content of Bulgarian propolis from respective areas contributes to its enhanced antioxidant, anti-inflammatory and antitumor activity. Taken together, our results support the beneficial properties of Bulgarian propolis, with potential application as a promising therapeutic agent.