Viện Khoa học Công nghệ ứng dụng (IAST) 

Abstract: 

Leishmaniasis, an infectious disease caused by pathogenic Leishmania parasites, affects millions of people in developing countries, and its re-emergence in developed countries, particularly in Europe, poses a growing public health concern. The limitations of current treatments and the absence of effective vaccines necessitate the development of novel therapeutics. In this study, we focused on identifying small molecule inhibitors which prevents the interaction between peroxin 5 (PEX5) and peroxisomal targeting signal 1 (PTS1), pivotal for kinetoplastid parasite survival. The Leishmania donovani PEX5, containing a C-terminal tetratricopeptide repeat (TPR) domain, was expressed and purified, followed by the quantification of kinetic parameters of PEX5-PTS1 interactions. A fluorescence polarization-based high-throughput screening assay was developed and small molecules inhibiting the LdPEX5-PTS1 interaction were discovered through the screening of a library of 51,406 compounds. Based on the confirmatory assay, nine compounds showed half maximal inhibitory concentration (IC50) values ranging from 3.89 to 24.50 µM. In silico docking using a homology model of LdPEX5 elucidated that the molecular interactions between LdPEX5 and the inhibitors share amino acids critical for PTS1 binding. Notably, compound P20 showed potent activity against the growth of L. donovani promastigotes, L. major promastigotes, and Trypanosoma brucei blood stream form, with IC50 values of 12.16, 19.21, and 3.06 μM, respectively. The findings underscore the potential of targeting LdPEX5-PTS1 interactions with small molecule inhibitors as a promising strategy for the discovery of new anti-parasitic compounds. 

Abstract: 

Enrofloxacin has been widely and increasingly used in veterinary medicine to treat infection on animals which could lead to antibiotic resistance for the consumer. Among the available detection techniques for Enrofloxacin, immunoassay lateral flow test strip is realised to be a rapid and accurate detection method for on-site analysis of Enrofloxacin antibiotic. The current study aims to analyse the application of inkjet printing technology on the immobilisation of biological substances at the test line and control line position of the test strip. With the printing parameters value at 35 °C, 35 °C, 7 layers and 15 μm for cartridge temperature, substrate temperature, printing layers and drop spacing, respectively, the fabricated test strips show correlation coefficient R2 at 0.993 for the test with Enrofloxacin samples in the concentration range from 0 to 100 ppb. Compared to conventional fabrication method, the immobilisation process utilising inkjet printing technology is considered to be superior in printing patterns with a simple and material-saving process, which holds a potential of innovative and financially beneficial approach for on-site detection of Enrofloxacin antibiotic. 

Abstract: 

Postharvest quality plays a crucial role in marketability, consumer acceptability, and shelf life of avocados. This study investigates the efficacy of nitric oxide (NO) on postharvest physiology and quality of Booth 7 avocadostreated with different concentrations of sodium nitroprusside (SNP) - a nitric oxide-releasing compound. Booth 7avocados were immersed in SNP solutions (0.5 mM, 1.0 mM, and 1.5 mM), while the control fruit was immersedin distilled water for 15 min. After treatment, the fruit was stored at a temperature (T) of 8 ± 1 ◦C and relative humidity (RH) of 90 ± 5% for 35 days, during which the control fruit exhibited complete deterioration. The results revealed that Booth 7 avocados treated with 1.5 mM SNP concentration exhibited delayed quality changes during storage, reduced ethylene production and respiration rate, reduced alterations in soluble solids and acid content of the fruit flesh, as well as delayed changes in flesh and peel color. Additionally, the activity of total phenolic compounds (TPC), polygalacturonase (PG), and polyphenol oxidase (PPO) enzymes increased significantly, while the activity of the pectin methyl esterase (PME) enzyme was reduced. In conclusion, SNP treatment improved the quality and can be utilized as a potential postharvest preservative for Booth 7 avocados. For producers and distributors, the use of SNP in avocado postharvest management offers the potential to extend shelf life without compromising fruit quality.