Biology subjects

Sengupta, T. K.

Publications and source records attributed to Sengupta, T. K..

6 recordsLinked to original sources

bioRxiv2025

Association of miR-181a-5p with Lantana camara leaf extract-mediated inhibition of proliferation, survival, and migration in luminal A-type MCF-7 cells and triple-negative type MDA-MB-231 cells

Ethnopharmacological relevanceBreast cancer has a high mortality with increasing chemoresistance and recurrence. Lantana camara has diverse medicinal properties, including anti-cancer potential; however, its role in breast cancer is not well-explored. Aim of the studyThe study aims to elucidate the role of Lantana camara leaf extract in miR-181a-5p-mediated control of proliferation, survival, and migration of breast cancer cells. Material and methodsReal-time PCR was employed for RNA expression studies. Bioinformatic tools were used for identifying miR-181a-5p target mRNAs and seed regions in the 3 prime untranslated region of target mRNAs. miR-181a-5p was overexpressed in cells using transfection method. Flow cytometry was employed for cell cycle and apoptosis assays. Scratch assay was performed to study cell migration. The 3 prime untranslated region of CDKN3 was cloned, and site-directed mutagenesis was employed to mutate miR-181a-5p seed region. Western blot analysis was employed for a reporter assay. ResultsL. camara leaf extract upregulated the expression of miR-181a-5p with concomitant decrease in mRNAs of BCL-2, MCL-1, and CDKN3 in breast cancer cells. Overexpression of miR-181a-5p induced cell death in MCF-7 and MDA-MB-231 cells, and cell death increased in the presence of leaf extract. miR-181a impeded migration in both cell lines in the presence of the extract. Reporter assay confirmed the interaction of miR-181a-5p with 3 prime untranslated region of the CDKN3 mRNA. ConclusionOur study suggests that the extract may play an important role in regulating miR-181a-5p in MCF-7 and MDA-MB-231 cells, and may have important therapeutic potential for breast cancer therapy.

cancer biology↗

bioRxiv2025

Antimicrobial and Biofilm-Inhibitory Potential of Green Synthesized Silver Nanoparticles from Lantana camara against Pseudomonas aeruginosa

BackgroundEmerging antimicrobial resistance poses serious threat to human well-being. Current therapeutics often fail to treat bacterial infections as pathogenic bacteria often attach to various surfaces and form biofilm. One such pathogen, Pseudomonas aeruginosa, can form biofilm for its survival in the presence of antibacterial agents. This study aimed to evaluate the antibacterial, antibiofilm, and mechanistic activities of Lantana camara leaf extract mediated silver nanoparticles (LCLE-Ag NPs) against Pseudomonas aeruginosa, where the extract contributes for the reduction of Ag+ to Ag0. MethodsLCLE-Ag NPs were synthesized and characterized by using UV visible spectroscopy, dynamic light scattering, and electron microscopy. Antibacterial and antibiofilm activities of the synthesized NPs were assessed against P. aeruginosa isolates KPW.1-S1 and HRW.1-S3. Extracellular polysaccharides (EPS), and extracellular DNA (eDNA) and reactive oxygen species (ROS) generation were visualized using epifluorescence microscopy. The ability of the nanoparticles to eradicate preformed biofilm was also evaluated. The expressions of quorum-sensing genes were analyzed using semi quantitative polymerase chain reaction. Cytotoxicity was tested on human kidney epithelial-like cells. ResultsThe synthesized LCLE-Ag NPs displayed an absorption peak at 416 nm and a size range of 30 to 35 nm. They exhibited significant antibacterial and antibiofilm activities correlating with decreased EPS and eDNA levels. LCLE-Ag NPs effectively disrupted both preformed and antibiotic-induced biofilms and such activities were found to be associated with increased ROS levels and decrease in lasI and pqsA expression. Cytotoxicity assays indicated no significant toxicity at effective concentrations. ConclusionsLCLE-Ag NPs displayed promising antibacterial and antibiofilm activities against P. aeruginosa, acting through biofilm matrix disruption, ROS generation, and quorum-sensing inhibition.

microbiology↗

bioRxiv2024

Salt-induced reduction of hyperswarming motility in Bacillus cereus MHS is associated with reduced flagellation, reduced nanotube formation and reduction in expression of quorum sensing regulator

Bacteria have been known to thrive in challenging environmental niches through diverse phenomena. Swarming is one such favourable adaptation that could help bacteria survive extreme conditions. Therefore, targeting swarming is crucial for improving our understanding of bacterial motility and preventing related infections. Bacillus cereus, which causes food poisoning, has been shown to perform swarming, and salts like NaCl can act as a food preservative to control bacterial growth. In order to explore the possible alterations in the swarming of Bacillus cereus in the presence of salt, the present study encompasses the effect of NaCl on the swarming characteristics of a natural bacterial isolate, Bacillus cereus MHS, with a hyperswarming phenotype. Here we report that the presence of an increased amount of NaCl in growth media could induce a reduction in swarming motility and swarming pattern of MHS on Luria agar plates and the observed reduction in swarming was associated with the reduced flagellation and reduction in bacterial nanotube formation. Gene expression studies supported the phenotypic and ultrastructure observations as the expressions of bfla and ymdb genes, involved in formations of flagella and nanotubes respectively, were found to be reduced in the swarming MHS cells in the presence of increased NaCl in swarm media. It was also observed that the salt-induced reduction in swarming of MHS is associated with the reduced expression of the quorum sensing regulator gene plcR. This study first time reports the bacterial nanotubes in a Bacillus cereus strain and indicates a possible link between the bacterial nanotube formation and hyperswarming phenotype in Bacillus cereus MHS.

microbiology↗

bioRxiv2024

Differentiating the mechanism of antibacterial activities of nano and ionic copper by using Escherichia coli as a model microorganism

In this study, the effect of polymer stabilized copper nanoparticles and ionic copper on the growth, nucleic acid pool, reactive oxygen species generation, cell surface lipopolysaccharide, outer membrane protein profile and cell surface morphology of Escherichia coli were investigated. Copper nanoparticles exhibited a superior bactericidal activity associated with increased nucleic acid degradation, reactive oxygen species generation and change in the outer membrane protein profile compared to ionic copper in a concentration dependent manner. Although, there was no change in the outer membrane lipopolysaccharide profile, inductively coupled plasma mass spectrometry analysis of nano- and ionic copper treated Escherichia coli cells revealed that more amounts of copper nanoparticles were transported inside the cells compared to the ionic counterpart up to 500 M concentrations. Interestingly, copper nanoparticles at 1000 M concentration could induce membrane pit formation whereas ionic copper failed to exhibit such property under the same experimental conditions. Based on these observations it can be concluded that both nano- and ionic copper exert their antibacterial action through the generation of reactive oxygen species, degradation of cellular nucleic acids and alteration of membrane protein profile, but with a significant difference in the effective concentration range due to the differential cellular transport.

microbiology↗

bioRxiv2023

Effect of Lantana camara ethanolic leaf extract on survival and migration of MDA-MB-231 triple negative breast cancer cell line

IntroductionBreast cancer is a leading cause of cancer-related death worldwide. Lantana camara has been reported to cure a number of ailments, with few studies showing its cytotoxic effects on breast cancer cells. However, the impact of Lantana camara on triple negative breast cancer cells is largely obscure to date. The present study investigated the effect of ethanolic extract of Lantana camara leaves on the triple negative breast cancer cell line, MDA-MB-231. MethodsCytotoxic effect of the extract on the cells was determined by cell survival assay. Cell cycle phase distribution was analysed using flow cytometry. To study the effect on nuclear morphology, nuclear stained cells were visualized using epifluorescence microscopy. The induction of apoptosis and generation of reactive oxygen species was conducted using flow cytometry. Cellular migration was studied by performing wound healing assay. Real-time polymerase chain reaction was done to determine the mRNA levels of some key genes. ResultsLantana camara leaf extract induced cytomorphological changes and growth inhibitory effect on MDA-MB-231 cells in a dose-dependent manner. The extract also induced G0/G1 cell cycle arrest and nuclear condensation. Flow cytometry analysis confirmed cell death by apoptosis. Lantana camara leaf extract also reduced the migration of MDA-MB-231 cells. mRNA expression levels also supported the above observations. ConclusionsThis study demonstrates the efficacy of the extract to induce growth-inhibitory and anti-migratory effects on MDA-MB-231 cells. Our results thus suggest that Lantana camara leaf extract can be considered as a potent source of chemotherapeutic agents for triple negative breast cancer.

cancer biology↗

bioRxiv2022

Antibiotic induced biofilm formations in Pseudomonas aeruginosa strains KPW.1-S1 and HRW.1-S3 are associated with increased production of eDNA and exoproteins, increased ROS generation, and increased cell surface hydrophobicity

Pseudomonas aeruginosa is a medically important bacteria due to its ability to form biofilm and is also an opportunistic pathogen. Pseudomonas aeruginosa has the intrinsic ability to form biofilm as one of the defense mechanisms for their survival. The fact that it can form biofilms on various medical implants makes it more harmful clinically. Although various antibiotics are used to treat Pseudomonas aeruginosa infections, previous studies have shown that sub-MIC levels of antibiotics cause biofilm formation in this type of bacteria. The present study thus deals with the effect of the aminoglycoside antibiotic gentamicin on the biofilm dynamics of two Pseudomonas aeruginosa strains KPW.1-S1 and HRW.1-S3. Biofilm formation was seen to be increasing with increased gentamicin concentrations in growth media. Confocal laser scanning microscopy and scanning electron microscopy accompanied with other biochemical tests deduced that biofilm-forming components like exoproteins, eDNA, and exolipids as exopolymeric substances in Pseudomonas aeruginosa biofilms were increased in the presence of gentamicin. An increase in reactive oxygen species generation along with increased cell surface hydrophobicity was also seen in both strains when treated with gentamicin. The observed increase in the adherence of the cells accompanied by an increase in exopolymeric substances, eDNA, and exolipids may have largely contributed to the increased biofilm production by the Pseudomonas aeruginosa strains KPW.1-S1 and HRW.1-S3 under the stress of the antibiotic treatment.

microbiology↗