METHODS: Postbiotic metabolites (PM) produced by six strains of L. plantarum were determined for their antiproliferative and cytotoxic effects on normal human primary cells, breast, colorectal, cervical, liver and leukemia cancer cell lines via MTT assay, trypan blue exclusion method and BrdU assay. The toxicity of PM was determined for human and various animal red blood cells via haemolytic assay. The cytotoxicity mode was subsequently determined for selected UL4 PM on MCF-7 cells due to its pronounced cytotoxic effect by fluorescent microscopic observation using AO/PI dye reagents and flow cytometric analyses.
RESULTS: UL4 PM exhibited the lowest IC50 value on MCF-7, RG14 PM on HT29 and RG11 and RI11 PM on HL60 cell lines, respectively from MTT assay. Moreover, all tested PM did not cause haemolysis of human, dog, rabbit and chicken red blood cells and demonstrated no cytotoxicity on normal breast MCF-10A cells and primary cultured cells including human peripheral blood mononuclear cells, mice splenocytes and thymocytes. Antiproliferation of MCF-7 and HT-29 cells was potently induced by UL4 and RG 14 PM respectively after 72 h of incubation at the concentration of 30% (v/v). Fluorescent microscopic observation and flow cytometric analyses showed that the pronounced cytotoxic effect of UL4 PM on MCF-7 cells was mediated through apoptosis.
CONCLUSION: In conclusion, PM produced by the six strains of L. plantarum exhibited selective cytotoxic via antiproliferative effect and induction of apoptosis against malignant cancer cells in a strain-specific and cancer cell type-specific manner whilst sparing the normal cells. This reveals the vast potentials of PM from L. plantarum as functional supplement and as an adjunctive treatment for cancer.
METHODS: The analysis was done using BLASTP to detect peptides catalytic domains. Many peptides that are related to several phage proteins were revealed.
RESULTS: UPMK_1 and UPMK_2 custom sequence database were used for peptide identification. The biofilm-degrading proteins in the bacteriophage UPMK_2 revealed the same lytic activity towards polysaccharide intercellular adhesin-dependent and independent of Methicillin-resistant Staphylococcus aureus (MRSA) biofilm producers in comparison to UPMK_1, which had lytic activity restricted solely to its host.
CONCLUSION: Both bacteriophage enzymes were involved in MRSA biofilm degradation during phage infection and they have promising enzybiotics properties against MRSA biofilm formation.
METHODS: We conducted a retrospective observational study, reviewing medical records of patients treated for mangrove pit viper bites between 1st July 2020 to 30th June 2023. Data on patient demographics, clinical characteristic, laboratory findings, treatment modalities and clinical outcomes were collected and analyzed.
RESULTS: A total of 25 patients were included in this study. The majority of the patients were male (n=23, 92%) with the mean age of 38.7±17.6 years. Most frequent anatomical region involved is foot (n=12, 48%). Common clinical presentation included localized pain (n=xx, 96%), swelling (n=22, 88%) and fang mark (n=22, 88%). Systemic symptoms were less common, with 1 patient exhibit coagulopathy with clinical bleeding at 28 hours post bite. Antivenom was administered to 68% (n=17) of the patients. The majority of the patients (n=23, 92%) recovered without significant morbidity while 8% (n=2) of the patients developed skin infection that required antibiotic therapy. No fatalities were reported.
CONCLUSION: Mangrove pit viper envenomation encounter in these regions predominantly causes local symptoms while systemic symptoms were less common. This study provides a glimpse to the clinical characteristics and management of mangrove pit viper envenomation, coagulopathy may be delayed due to characteristic of the snake venom and patient's preexisting illness. Further research is needed to enhance our understanding of this snakebite envenomation.
Methods: In this study, the region spanning exon 2 from the 4th to 18th codon within the peptide sequence of wtKRAS was chosen for sequence manipulation. Mutated G12V and G13D K-ras controls were generated in silico, along with additional single amino acid substitutions flanking the original codon 12/13 mutations. IEDB was used for assessing human and mouse MHC class I/II epitope predictions, as well as linear B-cell epitopes predictions, while RNA secondary structure prediction was performed via CENTROIDFOLD. A scoring and ranking system was established in order to shortlist top mimotopes whereby normalized and reducing weighted scores were assigned to peptide sequences based on seven immunological parameters. Among the top 20 ranked peptide sequences, peptides of three mimotopes were synthesized and subjected to in vitro and in vivo immunoassays. Mice PBMCs were treated in vitro and subjected to cytokine assessment using CBA assay. Thereafter, mice were immunized and sera were subjected to IgG-based ELISA.
Results: In silico immunogenicity prediction using IEDB tools shortlisted one G12V mimotope (68-V) and two G13D mimotopes (164-D, 224-D) from a total of 1,680 candidates. Shortlisted mimotopes were predicted to promote high MHC-II and -I affinities with optimized B-cell epitopes. CBA assay indicated that: 224-D induced secretions of IL-4, IL-5, IL-10, IL-12p70, and IL-21; 164-D triggered IL-10 and TNF-α; while 68-V showed no immunological responses. Specific-IgG sera titers against mutated K-ras antigens from 164-D immunized Balb/c mice were also elevated post first and second boosters compared to wild-type and G12/G13 controls.
Discussion: In silico-guided predictions of mutated K-ras T- and B-cell epitopes were successful in identifying two immunogens with high predictive scores, Th-bias cytokine induction and IgG-specific stimulation. Developments of such immunogens are potentially useful for future immunotherapeutic and diagnostic applications against KRAS(+) malignancies, monoclonal antibody production, and various other research and development initiatives.