Serum deprivation enhanced ethanol-induced toxic responses in A549, lung carcinoma cells

Aim: The current study explores the toxic consequences of ethanol on human lung carcinoma cell, A549 in serum-deprived condition. Methodology: Human lung carcinoma cells, A549, were cultured in complete and serum-deprived medium for 6 hr. Subsequently, they were exposed to 50 mM and 100 mM concentrations of ethanol. Cytotoxicity studies linked with cell viability, oxidative stress, cell cycle arrest and micronuclei formation were performed using various toxicological parameters, namely MTT assay, DCFDA based ROS generation, cell cycle analysis and micronuclei formation assay. The cytotoxicity of ethanol in complete and serum deprived medium were compared at similar doses and time duration. Results: The metabolic viability assay demonstrated that 50 mM and 100 mM concentration of ethanol did not induce significant levels of cytotoxic alteration in A549 lung carcinoma cells in complete medium. However, in serum-deprived conditions, 50 mM and 100 mM ethanol concentration significantly altered cell viability. Further, exposure of 50 mM and 100 mM concentration of ethanol enhanced reactive oxygen species levels in A549 cells more significantly in serum-deprived conditions than in complete medium. In addition to cytotoxicity and oxidative stress, 50 mM and 100 mM ethanol also arrested the cells at G0 phase more significantly in serum deprived conditions compared to complete medium. Interpretation: Both 50 mM and 100 mM ethanol concentration enhanced the cell cytotoxicity and reactive oxygen species, cell cycle arrest and micronuclei formation more severely in serum-deprived medium than in complete medium (containing 10% FBS) under similar treatment conditions.

Biosynthesis and Characterization of Extracellular Silver Nanoparticles from Streptomyces aizuneusis: Antimicrobial, Anti Larval, and Anticancer Activities

The ability of microorganisms to reduce inorganic metals has launched an exciting eco-friendly approach towards developing green nanotechnology. Thus, the synthesis of metal nanoparticles through a biological approach is an important aspect of current nanotechnology. In this study, Streptomyces aizuneusis ATCC 14921 gave the small particle of silver nanoparticles (AgNPs) a size of 38.45 nm, with 1.342 optical density. AgNPs produced by Streptomyces aizuneusis were characterized by means of UV-VIS spectroscopy and transmission electron microscopy (TEM). The UV-Vis spectrum of the aqueous solution containing silver ion showed a peak between 410 to 430. Moreover, the majority of nanoparticles were found to be a spherical shape with variables between 11 to 42 nm, as seen under TEM. The purity of extracted AgNPs was investigated by energy dispersive X-ray analysis (EDXA), and the identification of the possible biomolecules responsible for the reduction of Ag+ ions by the cell filtrate was carried out by Fourier Transform Infrared spectrum (FTIR). High antimicrobial activities were observed by AgNPs at a low concentration of 0.01 ppm, however, no deleterious effect of AgNPs was observed on the development and occurrence of Drosophila melanogaster phenotype. The highest reduction in the viability of the human lung carcinoma and normal cells was attained at 0.2 AgNPs ppm.

Dissection of function and recognition mechanism of M. tuberculosis ESX-1 secreted virulence factor EspC

Mycobacterium tuberculosis uses the ESAT-6 system-1/type VII (ESX-1) system for secretion of virulence proteins into the host cell, however the mechanism of virulence proteins secretion, molecular components and regulation of ESX-1 system are only partly understood. In the current study, we have analyzed the biological function and recognition mechanism between ESX-1 virulence EspC and EccA1 ATPase proteins. The EspC enters into A549 human lung carcinoma cells and exhibited cytotoxicity, as observed in MTT Assay. To understand the recognition mechanism between EspC and EccA1 ATPase, the EspC and EccA1 mutants were generated based on EspC~EccA1 interactions, as observed in molecular modeling. Binding analysis shows that EspC export arm interacts specifically to the b-hairpin insertion motif of the TPR domain of EccA1 ATPase. Mutations in these epitopes lead to significant decrease/or abolish the binding between EspC and EccA1 ATPase. Our study provides insight into biological function and recognition mechanism between EspC and EccA1 ATPase, which can be used as target to prevent EspC secretion/ or in general virulence factor secretion by mycobacterial ESX-1 system.

In Vitro Evaluation of Anti-Lung Cancer and Anti-COVID-19 Effects using Fermented Black Color Ginseng Extract

Ginseng is known as the “king” of herbal plants and has been used widely in Asia for centuries. Ginseng contains active saponins, including protopanaxadiols, protopanaxatriols, and other compounds. There are many methods for processing ginseng, such as steaming, fermentation, expansion, and conversion of active compounds, which can improve its biological activity. In this study, we investigated the cytotoxic and oxidative effects of fermented black color ginseng (FBCG), black ginseng (BG), and white ginseng (WG) on a human lung carcinoma cell line (A549). Moreover, we found that treatment with FBCG induced oxidative stress in the A549 cell line and increases the apoptosis percentage; these effects were linked to the stimulation of the caspase 3/mitogen-activated protein kinase (caspase 3/MAPK) pathway. We also evaluated the anti-coronavirus disease-2019 (COVID-19) effect of FBCG on a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected Vero E6 cell line. Our results suggest that FBCG not only inhibits the replication of this strain of virus in the cell but also reduces the number of viral RNA (vRNA) copies in the extracellular environment. Taken together, these data show that FBCG has both potential anti-lung cancer and anti-COVID-19 effects.

Natural Compounds Isolated from Stachybotrys chartarum Are Potent Inhibitors of Human Protein Kinase CK2

A large number of secondary metabolites have been isolated from the filamentous fungus Stachybotrys chartarum and have been described before. Fourteen of these natural compounds were evaluated in vitro in the present study for their inhibitory activity towards the cancer target CK2. Among these compounds, stachybotrychromene C, stachybotrydial acetate and acetoxystachybotrydial acetate turned out to be potent inhibitors with IC50 values of 0.32 µM, 0.69 µM and 1.86 µM, respectively. The effects of these three compounds on cell proliferation, growth and viability of MCF7 cells, representing human breast adenocarcinoma as well as A427 (human lung carcinoma) and A431 (human epidermoid carcinoma) cells, were tested using EdU assay, IncuCyte® live-cell imaging and MTT assay. The most active compound in inhibiting MCF7 cell proliferation was acetoxystachybotrydial acetate with an EC50 value of 0.39 µM. In addition, acetoxystachybotrydial acetate turned out to inhibit the growth of all three cell lines completely at a concentration of 1 µM. In contrast, cell viability was impaired only moderately, to 37%, 14% and 23% in MCF7, A427 and A431 cells, respectively.