Selection and Evaluation of Probiotic and Functional Characteristics of Autochthonous Lactic Acid Bacteria Isolated from Fermented Wheat Flour Dough Babroo

Probiotics and Antimicrobial Proteins - The present study aimed to isolate and identify the potential probiotic lactic acid bacteria (LAB) from traditionally fermented wheat flour dough known as...     

Novel Pactamycin Analogs Induce p53 Dependent Cell-Cycle Arrest at S-Phase in Human Head and Neck Squamous Cell Carcinoma (HNSCC) Cells

Pactamycin, although putatively touted as a potent antitumor agent, has never been used as an anticancer drug due to its high cytotoxicity. In this study, we characterized the effects of two novel biosynthetically engineered analogs of pactamycin, de-6MSA-7-demethyl-7-deoxypactamycin (TM-025) and 7-demethyl-7-deoxypactamycin (TM-026), in head and neck squamous cell carcinoma (HNSCC) cell lines SCC25 and SCC104. Both TM-025 and TM-026 exert growth inhibitory effects on HNSCC cells by inhibiting cell proliferation. Interestingly, unlike their parent compound pactamycin, the analogs do not inhibit synthesis of nascent protein in a cell-based assay. Furthermore, they do not induce apoptosis or autophagy in a dose- or a time-dependent manner, but induce mild senescence in the tested cell lines. Cell cycle analysis demonstrated that both analogs significantly induce cell cycle arrest of the HNSCC cells at S-phase resulting in reduced accumulation of G₂/M-phase cells. The pactamycin analogs induce expression of cell cycle regulatory proteins including master regulator p53, its downstream target p21^Cip1/WAF1, p27^kip21, p19, cyclin E, total and phospho Cdc2 (Tyr15) and Cdc25C. Besides, the analogs mildly reduce cyclin D1 expression without affecting expression of cyclin B, Cdk2 and Cdk4. Specific inhibition of p53 by pifithrin-α reduces the percentage of cells accumulated in S-phase, suggesting contribution of p53 to S-phase increase. Altogether, our results demonstrate that Pactamycin analogs TM-025 and TM-026 induce senescence and inhibit proliferation of HNSCC cells via accumulation in S-phase through possible contribution of p53. The two PCT analogs can be widely used as research tools for cell cycle inhibition studies in proliferating cancer cells with specific mechanisms of action.     

Biosorption of Pb<Superscript>2+</Superscript> and Zn<Superscript>2+</Superscript> by Non-Living Biomass of <Emphasis Type="Italic">Spirulina</Emphasis> sp.

Removal of heavy metals (Pb²⁺, Zn²⁺) from aqueous solution by dried biomass of Spirulina sp. was investigated. Spirulina rapidly adsorbed appreciable amount of lead and zinc from the aqueous solutions within 15 min of initial contact with the metal solution and exhibited high sequestration of lead and zinc at low equilibrium concentrations. The specific adsorption of both Pb²⁺ and Zn²⁺ increased at low concentration and decreased when biomass concentration exceeded 0.1 g l⁻¹. The binding of lead followed Freundlich model of kinetics where as zinc supported Langmuir isotherm for adsorption with their r ² values of 0.9659 and 0.8723 respectively. The adsorption was strongly pH dependent as the maximum lead biosorption occurred at pH 4 and 10 whereas Zn²⁺ adsorption was at pH 8 and 10.     

Induction of Systemic Acquired Resistance in Arachis hypogaea L. by Sclerotium rolfsii Derived Elicitors

Plants evolve a strategy to survive the attacks of potential pathogens by inducing the microbial signal molecules. In this study, plant defence responses were induced in four different varieties of Arachis hypogaea (J‐11, GG‐20, TG‐26 and TPG41) using the fungal components of Sclerotium rolfsii in the form of fungal culture filtrate (FCF) and mycelial cell wall (MCW), and the levels of defence‐related signal molecule salicylic acid (SA), marker enzymes such as peroxidase (POX), phenylalanine ammonia lyase (PAL), β‐1,3‐glucanase and lignin were determined. There was a substantial fold increase in POX, PAL, SA, β‐1,3‐glucanase and lignin content in FCF‐ and MCW‐treated plants of all varieties of groundnut when compared to that of control plants. The enzyme activities were much higher in FCF‐treated plants than in MCW‐treated plants. The increase in fold activity of enzymes and signal molecule varied between different varieties. These results indicate that the use of fungal components (FCF and MCW) had successfully induced systemic resistance in the four different varieties of groundnut plants against Sclerotium rolfsii.     

Variability of azadirachtin inAzarirachta indica (neem) and batch kinetics studies of cell suspension culture

Seeds of neem were collected from different parts of India and analyzed for their azadirachtin content by High Performance Liquid Chromatography (HPLC). In order to assess the effects of genotypic and geographical variation on azadirachtin content in cell cultures, callus development was attempted in the seeds containing high and low concentration of azadirachtin. The concentration of azadirachtin in callus cultures was significantly affected by the explant source. Seed kernels with higher azadirachtin content produced higher azadiractin content in callus cultures and lower azadirachtin content was seen in callus cultures produced from seed kernels with low azadiractin content. The protocol for development of elite stock culture ofAzadirachta indica was established with the objective of selecting a high azadirachtin-producing cell line. The highest azadirachtin-producing cell line was selected and the effects of different media and illumination conditions on growth and azadirachtin production were studied in shake flask suspension culture. Detailed batch growth kinetics was also established. These studies provided elite starter culture and associated protocols for cultivation ofA. indica plant cell culture in the bioreactor.     

Changes in surface topologies of chondrocytes subjected to mechanical forces: an AFM analysis

The cartilage is composed of chondrocytes embedded in a matrix of collagen fibrils interspersed within a network of proteoglycans and is constantly exposed to biomechanical forces during normal joint movement. Characterization of the surface morphology, cytoskeletal structure, adherance and elastic properties of these mechanosensitive cells are crucial in understanding the effects of mechanical forces around a cell and how a cell responds to changes in its physical environment. In this work, we employed the atomic force microscope (AFM) to image cultured chondrocytes before and after subjecting them to mechanical forces in the presence or absence of interleukin-1β to mimic inflammatory conditions. Nanoscale imaging and quantitative measurements from AFM data revealed that there are distinct changes in cell-surface topology and cytoskeleton arrangement in the cells following treatment with mechanical forces, IL-1β or both. Our findings for the first time demonstrate that cultured chondrocytes are amenable to high-resolution AFM imaging and dynamic tensile forces may help overcome the effect of inflammatory factors on chondrocyte response.