Appl. Biosci., Volume 1, Issue 3 (December 2022) – 6 articles

The zebrafish model is an emerging model for the study of the complex behavioural patterns noted in depression and neurological disorders. Confinement and memory loss are linked with cognition and mental health impairment, where confinement paradigms are assessed using other behavioural responses based on novel tanks or T tanks. Since zebrafish are exploratory animals, the impact during confinement cannot be evaluated using a novel tank or T tank. The present study investigates the response of the zebrafish to acute confinement and assesses its memory-based learning behaviour through parameters such as movement, swimming speed, and time spent inside the confined space. The movement and swimming speed of the fishes in confinement showed no significant difference. When confined inside a space, the fish showed their anxiety with erratic movements or bouts of freezing, which declined by 83%, during the six days of confinement and the escape time from the confinement space also decreased by 58%. The impact of anxiety, resulting in clockwise and counter-clockwise movement, also reduced after three days. Our results summarise that the decrease in anxiety can help the fish in habituating itself to a forced condition. This experiment on zebrafish behavioural biology is used to assess the cognitive behaviour against confinement, and it emphasizes the learning of behavioural adaptions under both crowded and solitary conditions. Full article

Fish are marketed as a food and consumed worldwide. During the production of food, contamination by microorganisms is possible through the air, soil, water, surfaces, food handlers, etc. The air does not have a natural microbial composition, but it is a vehicle for the transmission of microorganisms of economic and health interest because they are associated with food spoilage and human diseases. The objective of this study was the microbiological analysis of the air in an area popular for the processing and marketing of fish products in the city of Tepic Nayarit. Using the passive or sedimentation method to collect microorganisms present in the air, the proportion of aerobic mesophile bacteria, coliform bacteria, fungi and yeast was determined at different locations in the fish processing and marketing area for four weeks. The results indicated that the aerobic mesophiles had the highest counts among all the microbial groups analyzed at the twelve different sampling points during the four weeks of the study; their numbers ranged from 2.44 to 2.95 log CFU/m³/h, followed by molds with counts from 1.44 to 2.75 log CFU/m³/h, yeasts with counts from 0.7 to 2.01 log CFU/m³/h and coliforms with counts that ranged from 0.7 to 1.68 log CFU/m³/h. We determined the proportion of the viable microbiological population present in the air at the different sampling points of the study area; several of these sampling points presented values above those recommended by various agencies around the world. Knowledge of the biological hazards transported through the air is important to establish and reduce the risk to the health of occupants and the contamination pathways of processed and marketed fishery products that may be associated with spoilage and foodborne diseases. Full article

Quaternary ammonium compounds (QACs) are routinely used as disinfectants in a variety of settings. They are generally effective against a wide range of microbes but often exhibit undesirable toxicity. Consequently, companies are constantly seeking alternatives to QACs that are just as effective but with reduced health and environmental hazards. Two boronium salt derivatives were tested against influenza A and SARS-CoV-2 viruses. One salt possessed a terminal benzyl group, while the other lacked the same terminal benzyl group. Both salts demonstrated virus inactivation similar to a commercial QAC disinfectant. The non-benzylated form exhibited the same cell toxicity profile as the QAC. However, the benzylated form displayed less cell toxicity than both the non-benzylated form and QAC. These results suggest that the boronium salts may be suitable for use as a disinfecting agent against enveloped viruses in lieu of using a QAC. Continued evaluation of the boronium salts is warranted to determine the lowest effective concentration capable of effectively controlling influenza A and SARS-CoV-2 viruses that also demonstrates low cytotoxicity. Full article

Due to the aromatase enzyme’s involvement in estrogen biosynthesis, aromatase inhibitors have emerged as the preferred treatment for postmenopausal women with ER+ breast cancer. Using computational chemistry tools, we investigate how the human placental aromatase cytochrome P450 interacts with various phorbols with distinct chains at C-12, C-13, and C-20, as well as the well-known aromatase inhibitors anastrozole, exemestane, and letrozole. To identify phorbol-aromatase interactions, we performed a protein–ligand docking using the structures of our ligands and proteins using the Flare software (version 2.0, Cresset Software, Litlington, UK). These preliminary findings show that the phorbols considered (P-12,13-diAcPh, P-12,13-diiBu, P-12AcPh-13iBu, P-12Ang-13iBu, P-20Ac-12AcPh-13iBu and P-20Ac-12Ang-13iBu) had the highest binding energies in comparison with the commercially available aromatase inhibitors (anastrozole, letrozole, exemestane) used in this study. A subset of the previously described binding residues of testosterone (TST), the endogenous ligand, were also found to be responsible for the phorbol diesters’ binding to the aromatase enzyme, as demonstrated by the findings. This further suggests that the phorbol diesters can bind efficiently to CYP19A1 and may be able to alter its activity because they had higher binding energies than the commercially available drugs. Full article

Films made from cellulose nanocrystals (CNCs) may have iridescent structural colours (pure or in combination with other materials). Numerous fields might benefit from understanding how CNC self-assembly constructs these periodic structures. Herein, we looked at the colloidal characteristics of CNC particles as well as the development and behaviour of liquid crystals (LCs). We conducted a very brief literature analysis on the main issues related to the chiral structure creation of CNC LCs, including the origins of chirality, orientation, as well as its mechanical properties. Finally, by altering the pitch size, applications such as energy storage, humidity sensing, and photonic crystals were studied in a case-by-case manner. The manuscript, it is observed that the rational design of metamaterials built on CNCs allows for the reversible changing of colours through physical and chemical modifications by adding chemical or changing environmental factors. Examples of this alteration include the use of solvents, chemical penetration in applied fields (magnetic and electric), deflection, light, temperature change, acidity change, and molecular interaction detection. Reversible colours may be produced by altering the spacing between the particles, the filler materials, or the structural elements of the system’s refractive indices. This article briefly discusses the inner workings of CNCs, potential barriers to developing photonic structures, and several techniques and processes for achieving changeable colours. Full article

Insects and ectoparasites are causes for major concern throughout the world due to their economic and welfare impacts on livestock agriculture. Current control measures involve chemicals such as acaricides which pose challenges like chemical resistance and longer withholding periods. To enable more sustainable agriculture practices, it is important to develop technologies that combine targeted effectiveness with minimal environmental footprint. RNA interference (RNAi) is a eukaryotic process in which transcript expression is reduced in a sequence-specific manner. This makes it a perfect tool for developing efficient and effective biological control against pests and pathogens. Double-stranded RNA (dsRNA) is the key trigger molecule for inducing RNAi; this concept is widely studied for development of RNA-based biopesticides as an alternative to chemical controls in crop protection for targeting pests and pathogens with accuracy and specificity. In this review, we discuss key advances made using RNAi technology and how they can be applied to improve health in livestock industries. This includes research focused on different delivery mechanisms of dsRNA, important developments in regulatory frameworks, and risk identification, that will enable the future adoption of RNAi technologies to improve animal health. Full article