A squalene analog 4,4'-diapophytofluene from coconut leaves having antioxidant and anti-senescence potentialities toward human fibroblasts and keratinocytes.

Coconut (Cocos nucifera) leaves, an unutilized resource, enriched with valuable bioactive compounds. Spectral analysis of purified pentane fraction of coconut leaves revealed the presence of a squalene analog named 4,4'-diapophytofluene or in short 4,4'-DPE (C30H46). Pure squalene standard (PSQ) showed cytotoxicity after 8 µg/ml concentration whereas 4,4'-DPE exhibited no cytotoxic effects up to 16 µg/ml concentration. On senescence-induced WI38 cells, 4,4'-DPE displayed better percentage of cell viability (164.5% at 24 h, 159.4% at 48 h and 148% at 72 h) compared to PSQ and BSQ (bio-source squalene) with same time duration. Similar trend of result was found in HaCaT cells. SA-ß-gal assay showed that number of ß-galactosidase positive cells were significantly decreased in senescent cells (WI38 and HaCaT) after treated with 4,4'-DPE than PSQ, BSQ. Percentage of ROS was increased to 60% in WI38 cells after olaparib treatment. When PSQ, BSQ and 4,4'-DPE were applied separately on these oxidative-stress-induced cells for 48 h, the overall percentage of ROS was decreased to 39.3%, 45.6% and 19.3% respectively. This 4,4'-DPE was found to be more effective in inhibiting senescence by removing ROS as compared to squalene. Therefore, this 4,4'-DPE would be new potent senotherapeutic agent for pharmaceuticals and dermatological products.

Enhancement of Fluorescence Mediated by Silver Nanoparticles: Implications for Cell Imaging.

In this study, we report the surface enhanced fluorescence (SEF) of a biologically important organic dye, fluorescein (FL), by silver nanoparticles (Ag NPs) in an aqueous medium and its implications for human cell imaging. The as-synthesized Ag NPs were characterized by dynamic light scattering (DLS), zeta potential, transmission electron microscopy (TEM), and UV-vis absorption spectroscopic studies. The interaction and aggregation of FL dye with Ag NPs and a cationic surfactant, namely, cetyltrimethylammonium bromide (CTAB), were explored by UV-vis absorption and steady-state and time-resolved fluorescence spectroscopic methods. The distance-dependent fluorescence enhancement of FL due to Ag NPs in the solution was also theoretically correlated by three-dimensional finite-difference time-domain (3D-FDTD) simulation. The plasmonic coupling between neighboring NPs facilitated the augmentation of the local electric field, thereby producing various "hotspots" that influence the overall fluorescence of the emitter. J-type aggregates of FL in the presence of the CTAB micelles and Ag NP mixed solution were confirmed by electronic spectroscopy. The density functional theoretical (DFT) study revealed the electronic energy levels associated with different forms of FL dye in the aqueous solution. Most interestingly, the Ag NP/FL mixed system used in fluorescence imaging of human lung fibroblast cells (WI 38 cell line) showed a significantly stronger green fluorescence signal compared to that of FL after an incubation period of only 3 h. This study confirms that the Ag NP mediated SEF phenomenon of the FL dye is also manifested in the intracellular medium of human cells giving a brighter and more intense fluorescence image. The cell viability test after exposure to the Ag NP/FL mixed system was confirmed by the MTT assay method. The proposed study may have an implication as an alternate approach for human cell imaging with higher resolution and more contrast.

Drugging non-coding RNAs-A new light of hope in senescence-related cancer therapy.

Cancer is the most prevalent disease of concern worldwide for several decades. Diverse therapeutic aspects are in applications to control this phenomenal disease and also for decennaries. Among many causes and consequences of cancer, senescence has gained much interest in recent times. Senescence, also termed aging, is the natural process that induces cancer in neighboring cells through Senescence-Associated-Secretory Phenotypes (SASPs) production. As a cure or preventive measure of cancer progression, studies already light upon multiple proteins and their roles in associated pathways but the aspect of different non-coding RNAs (ncRNAs) is emerging recently and is under extensive research. Different approaches toward controlling senescence and inhibiting senescent cell accumulation are other aspects of cancer procurement. Thus, the role of ncRNA molecules in senescence and aging is getting much more interest as an alternate therapy for cancer treatment. In this review, at first, the roles of different ncRNAs related to several cellular processes are described. Then we tried to highlight the roles of different non-coding RNAs in senescence-induced cancer formation that extends with increasing age and emphasized non-coding RNAs as a therapeutic target solely or in combination with small molecules where drugging of small molecules targeting these non-coding RNAs can control cancer development.