Biosurfactants are surface-active compounds produced by a wide range of microorganisms. They have both hydrophobic and hydrophilic domains and can decrease the surface tension and the interfacial tension of growth medium. Biosurfactants have different chemical structures like-lipopeptides, glycolipids, neutral lipids and fatty acids. They are biodegradable non-toxic biomolecules that show strong emulsification of hydrophobic compounds. They have the ability to form stable emulsions. The low water-solubility of these compounds restricts their availability to microorganisms. Surfactants secreted by microbes enhance the bioavailability of such hydrophobic compounds for bioremediation. Therefore, biosurfactant-enhanced solubility of pollutants has prospective applications in bioremediation. Biosurfactants are useful in a variety of industrial processes, and are also of vital importance to the microbes in adhesion, emulsification, and bioavailability, desorption and defense strategy. Therefore, it is of interest to identify biosurfuctant producing strain of bacteria from brackish water. The microbial samples were isolated from the Chilika Lake, odisha, India and were tested for its biosurfactant property by various biochemical methods. 16S rRNA was sequenced using Sanger dideoxy sequencing method to characterize the biosurfuctant producing strain. The new Bacillus subtilis strain ANSKLAB03 isolated from 40 samples was deposited in GenBank with Accession number KU523257.
β-Sitosterol (BS), a major bioactive constituent present in plants and vegetables has shown potent anticancer effect against many human cancer cells, but the underlying mechanism remain elusive on NSCLC cancers. We found that BS significantly inhibited the growth of A549 cells without harming normal human lung and PBMC cells. Further, BS treatment triggered apoptosis via ROS mediated mitochondrial dysregulation as evidenced by caspase-3 & 9 activation, Annexin-V/PI positive cells, PARP inactivation, loss of MMP, Bcl-2-Bax ratio alteration and cytochrome c release. Moreover, generation of ROS species and subsequent DNA stand break were found upon BS treatment which was reversed by addition of ROS scavenger (NAC). Indeed BS treatment increased p53 expression and its phosphorylation at Ser15, while silencing the p53 expression by pifithrin-α, BS induced apoptosis was reduced in A549 cells. Furthermore, BS induced apoptosis was also observed in NCI-H460 cells (p53 wild) but not in the NCI-H23 cells (p53 mutant). Down-regulation of Trx/Trx1 reductase contributed to the BS induced ROS accumulation and mitochondrial mediated apoptotic cell death in A549 and NCI-H460 cells. Taken together, our findings provide evidence for the novel anti-cancer mechanism of BS which could be developed as a promising chemotherapeutic drug against NSCLC cancers.
Zika virus is a mosquito-transmitted flavivirus that causes devastating fetal outcomes in the context of maternal infection during pregnancy. An important target for drugs combatting Zika virus pathogenicity is NS2B-NS3 protease, which plays an essential role in hydrolysis and maturation of the flavivirus polyprotein. We identify hydroxychloroquine, a drug that already has approved uses in pregnancy, as a possible inhibitor of NS2B-NS3 protease by using a Food and Drug Administration-approved drug library, molecular docking, and molecular dynamics simulations. Further, to gain insight into its inhibitory potential toward NS2B-NS3 protease, we performed enzyme kinetic studies, which revealed that hydroxychloroquine inhibits protease activity with an inhibition constant (Ki) of 92.34 ± 11.91 μM. Additionally, hydroxychloroquine significantly decreases Zika virus infection in placental cells.
1 November 2017 in International Journal of Biological Macromolecules