The use of natural products for the treatment of various diseases has a long history.In the present study, the anti-oxidative, cytotoxic and phytochemical properties of ethanol extract of a local variety of Piper betle leaves cultivated in Potia, Bangladesh has been investigated.The antioxidant and cytotoxic activity of the Piper betle ethanol extract were evaluated by DPPH (1, 1-diphenyl-2picrylhydrazyl) free radical scavenging method and brine shrimp lethality bioassay method, respectively.Preliminary phytochemical group tests were also done to investigate the phytochemical properties of the extract.Leaf extract showed significant DPPH free radical scavenging effect compared to standard antioxidant ascorbic acid.IC 50 value of ascorbic acid and leaf extract was found 1.81μg/ml and 151.36μg/ml respectively.In brine shrimp lethality bioassay LC 50 value of Piper betle ethanol extract was found 274.63862µg/ml with 95% confidence limit where the lower and upper limits were 198.39 µg/ml and 387.18µg/ml respectively, which indicates that the Piper betle leaf extract has promising cytotoxic effect.Phytochemical analysis was found to be positive for alkaloid, glycosides, terpenoids, flavonoids, tannins and saponins.The present study demonstrates that ethanol extract of Piper betle Linn.Leaf has significant antioxidant and cytotoxic effect. INTRODUCTION:Piper betle commonly called betel leaf is a climbing shrub or small tree indigenous to tropical Asia, Australasia, and the Pacific and grown mostly in Bangladesh, India, China, Bhutan, and Malaysia 1-3 .The betel plant is an evergreen and perennial creeper, with glossy heart-shaped leaves and white catkin.The medicinal properties of betel leaf are well known since time immemorial.Traditionally the leaves are used to treat various diseases like halitosis, boils and abscesses, conjunctivitis, constipation, swelling of gums, cuts and injuries.The essential oil contained in the leaves is known to possess antibacterial, anti-protozoan and anti-fungal properties.
An OmpA family protein (FopA) previously reported as one of the major outer membrane proteins of an acidophilic iron-oxidizing bacterium Acidithiobacillus ferrooxidans was characterized with emphasis on the modification by heat and the interaction with peptidoglycan. A 30-kDa band corresponding to the FopA protein was detected in outer membrane proteins extracted at 75°C or heated to 100°C for 10 min prior to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). However, the band was not detected in outer membrane proteins extracted at ≤40°C and without boiling prior to electrophoresis. By Western blot analysis using the polyclonal antibody against the recombinant FopA, FopA was detected as bands with apparent molecular masses of 30 and 90 kDa, suggesting that FopA existed as an oligomeric form in the outer membrane of A. ferrooxidans. Although the fopA gene with a sequence encoding the signal peptide was successfully expressed in the outer membrane of Escherichia coli, the recombinant FopA existed as a monomer in the outer membrane of E. coli. FopA was detected in peptidoglycan-associated proteins from A. ferrooxidans. The recombinant FopA also showed the peptidoglycan-binding activity.
Sulfide:quinone oxidoreductase (SQR) was purified from membrane of acidophilic chemolithotrophic bacterium Acidithiobacillus ferrooxidans NASF-1 cells grown on sulfur medium. It was composed of a single polypeptide with an apparent molecular mass of 47 kDa. The apparent K(m) values for sulfide and ubiquinone were 42 and 14 muM respectively. The apparent optimum pH for the SQR activity was about 7.0. A gene encoding a putative SQR of A. ferrooxidans NASF-1 was cloned and sequenced. The gene was expressed in Escherichia coli as a thioredoxin-fusion protein in inclusion bodies in an inactive form. A polyclonal antibody prepared against the recombinant protein reacted immunologically with the purified SQR. Western blotting analysis using the antibody revealed an increased level of SQR synthesis in sulfur-grown A. ferrooxidans NASF-1 cells, implying the involvement of SQR in elemental sulfur oxidation in sulfur-grown A. ferrooxidans NASF-1 cells.
Mpox (formerly known as monkeypox) virus and some related poxviruses including smallpox virus pose a significant threat to public health, and effective prevention and treatment strategies are needed. This study utilized a reverse vaccinology approach to retrieve conserved epitopes for monkeypox virus and construct a vaccine that could provide cross-protection against related viruses with similar antigenic properties. The selected virulent proteins of monkeypox virus, MPXVgp165, and Virion core protein P4a, were subjected to epitope mapping for vaccine construction. Two vaccines were constructed using selected T cell epitopes and B cell epitopes with PADRE and human beta-defensins adjuvants conjugated in the vaccine sequence. Both constructs were found to be highly antigenic, non-allergenic, nontoxic, and soluble, suggesting their potential to generate an adequate immune response and be safe for humans. Vaccine construct 1 was selected for molecular dynamic simulation studies. The simulation studies revealed that the TLR8-vaccine complex was more stable than the TLR3-vaccine complex. The lower RMSD and RMSF values of the TLR8 bound vaccine compared to the TLR3 bound vaccine suggested better stability and consistency of hydrogen bonds. The Rg values of the vaccine chain bound to TLR8 indicated overall stability, whereas the vaccine chain bound to TLR3 showed deviations throughout the simulation. These results suggest that the constructed vaccine could be a potential preventive measure against monkeypox and related viruses however, further experimental validation is required to confirm these findings.
Gastrointestinal episodes associated with Vibrio species have been rising worldwide in the last few years. In this study, toxicities of two very well characterized V. fluvialis and V. furnissii strains, isolated from environmental samples, were used to investigate the comparative pathogenicity of these strains. The results showed that there is a positive relationship between toxin production as well as a high interspecies correlation. In the analysis of toxicity, both species showed positive results with close similarity in cell death on BHK-21 cell line and destruction of RBC, which were indicative of cytotoxic and hemolytic activity, respectively. Besides, molecular analysis showed the absence of ctx, tdh, trh, stx1 and stx2 genes. On the other hand, reduced fluid accumulation ratio in rabbit ileal loop assay and paralysis of hind legs of Swiss Albino mice were observed for V. furnissi strain, which indicates the differences in pathogenicity between the two species.
Bangladesh J Microbiol, Volume 38, Number 2, December 2021, pp 73-77
The Varicella Zoster Virus (VZV) presents a global health challenge due to its dual manifestations of chickenpox and shingles. Despite vaccination efforts, incomplete coverage, and waning immunity lead to recurrent infections, especially in aging and immunocompromised individuals. Existing vaccines prevent chickenpox but can trigger the reactivation of shingles. To address these limitations, we propose a polyvalent multiepitope subunit vaccine targeting key envelope glycoproteins of VZV. Through bioinformatics approaches, we selected six glycoproteins that are crucial for viral infection. Epitope mapping led to the identification of cytotoxic T lymphocyte (CTL), helper T lymphocyte (HTL), and B cell linear (LBL) epitopes. Incorporating strong immunostimulants, we designed two vaccine constructs, demonstrating high antigenicity, solubility, stability, and compatibility with Toll-like receptors (TLRs). Molecular docking and dynamics simulations underscored the stability and affinity of the vaccine constructs with TLRs. These findings lay the foundation for a comprehensive solution to VZV infections, addressing the challenges of incomplete immunity and shingles reactivation. By employing advanced immunoinformatics and dynamics strategies, we have developed a promising polyvalent multiepitope subunit vaccine candidate, poised to enhance protection against VZV and its associated diseases. Further validation through in vivo studies is crucial to confirm the effectiveness and potential of the vaccine to curb the spread of VZV. This innovative approach not only contributes to VZV control but also offers insights into tailored vaccine design strategies against complex viral pathogens.
