Other affiliations: Indian Institute of Technology Kanpur, Durban University of Technology, University of KwaZulu-Natal ...read more
Bio: Krishnan Anand is an academic researcher from University of the Free State. The author has contributed to research in topics: Drug delivery & Medicine. The author has an hindex of 16, co-authored 72 publications receiving 1180 citations. Previous affiliations of Krishnan Anand include Indian Institute of Technology Kanpur & Durban University of Technology.
TL;DR: Stable gold nanoparticles (AuNPs) were synthesized from aqueous 1M chloroauric acid and Moringa oleifera flower extract.
Abstract: Stable gold nanoparticles (AuNPs) were synthesised from aqueous 1 M chloroauric acid and Moringa oleifera flower aqueous extract. The UV–vis spectrum of AuNPs displays the surface plasmon resonance at 540 nm. The AuNPs were characterized using transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray analysis and dynamic light scattering whilst Fourier transform infrared and 1 H-NMR spectroscopy were used to probe the type of capping agents. The AuNPs were assessed for their catalytic reduction of nitrophenol and nitroaniline by UV–vis and showed a rapid reduction within 3 min thereby indicating degradation of industrial effluents. Furthermore, the AuNPs may possess good anti-cancer properties.
TL;DR: Stable AgNPs were formed in vitro by reacting AgNO3 (aq) solution with the aqueous plant leaf extract and the surface plasmon resonance λmax at 448 nm and the absorbance steadily increased in intensity as a function of reaction time.
Abstract: Stable AgNPs were formed in vitro by reacting AgNO3 (aq) solution with the aqueous plant leaf extract. UV-vis revealed the surface plasmon resonance λmax at 448 nm and the absorbance steadily increased in intensity as a function of reaction time. Transmission electron microscope (TEM) and XRD studies were used to characterize the AgNPs; the size was 4-35 nm. Dynamic light scattering (DLS) was used as supporting evidence to determine hydrodynamic size and zeta potential recorded as 80.27 nm and -24.7 mV, respectively. FT-IR spectra suggest that AgNPs are capped with protein molecules and other water soluble phytocompounds such as saponins and glycosides which also behave as stabilizing agents; TEM images indicate a visible layer surrounding the AgNPs. Prominent absorption bands at 3380 and 1642 cm(-1) are assigned to alcohol and carbonyl groups, respectively. (1)H NMR of the neat aqueous plant extract indicates presence of a complex mixture of compounds; however the chemical shift at δ 6.0-8.0 and 1.0-4.0 ppm indicates the presence of few aromatic but abundant aliphatic compounds, respectively. Toxicity of AgNPs on lung cancer cells (A549) and normal healthy peripheral lymphocytes (PLs) at 10 μg/ml and 50 μg/ml was assessed using the MTT, ATP and lactate dehydrogenase assays. Viability data for A549 cells showed a 21% (10 μg/ml) and 73% (50 μg/ml) cell viability after 6h exposure to AgNPs compared to 117% (10 μg/ml) and 109% (50 μg/ml) cell viability of normal peripheral lymphocytes. Lactate dehydrogenase was only significantly altered at 50 μg/ml AgNPs treated cells from 2.43±0.04 units to 0.77±0.04 units.
TL;DR: In this paper, different morphological silver nanoparticles were synthesized using Dodonaea viscosa leaves, extracted using different polar and non-polar solvents, which attributed to obtaining nanoparticles with different physical, chemical, antibacterial and cytotoxic properties.
Abstract: Distinct morphological silver nanoparticles were synthesized using Dodonaea viscosa leaves, extracted using different polar and non-polar solvents. Petroleum ether, methanol, acetone, acetonitrile and water were used for the extraction of active ingredients from the leaves of Dodonaea viscosa which attributed to obtaining nanoparticles with different physical, chemical, antibacterial and cytotoxic properties. The synthesized nanoparticles were characterized by UV–vis, FT-IR, XRD, HR-SEM with EDX and HR-TEM with SAED patterns. The XRD, HR-SEM and HR-TEM results reveal different nano sizes (15, 18, 12 and 20 nm) with different surface morphology (worm-like, irregular flower, spherical and dendritic structures) of the nanoparticles prepared using different solvent extracts (methanol, acetone, acetonitrile and water). The antibacterial results show significant zone of inhibition (20, 16, 13, 18 mm) against the test bacterium Streptococcus pyogenes for AgNPs synthesized by methanol, acetone, acetonitrile and water extracts, respectively. The cytotoxicity of synthesized silver nanoparticles in A549 NSCLC cells using the MTT assay were found to be 14, 3, 80, and 4 μg/mL for AgNPs synthesized using leaf extracts obtained from methanol, acetone, acetonitrile and water, respectively. The results revealed that the synthesized AgNPs were effective in inhibiting the growth of A549 NSCLC cells.
TL;DR: Data suggests that AAAgNP induces cell death in the A549 lung cells via the mt mediated intrinsic apoptotic program, and further investigation is required to potentiate the use of this novel compound in cancer therapy trials.
Abstract: Silver nanoparticles (AgNP), the most popular nano-compounds, possess unique properties. Albizia adianthifolia (AA) is a plant of the Fabaceae family that is rich in saponins. The biological properties of a novel AgNP, synthesized from an aqueous leaf extract of AA (AAAgNP), were investigated on A549 lung cells. Cell viability was determined by the MTT assay. Cellular oxidative status (lipid peroxidation and glutathione (GSH) levels), ATP concentration, caspase-3/-7, -8 and −9 activities were determined. Apoptosis, mitochondrial (mt) membrane depolarization (flow cytometry) and DNA fragmentation (comet assay) were assessed. The expression of CD95 receptors, p53, bax, PARP-1 and smac/DIABLO was evaluated by flow cytometry and/or western blotting. Silver nanoparticles of AA caused a dose-dependent decrease in cell viability with a significant increase in lipid peroxidation (5-fold vs. control; p = 0.0098) and decreased intracellular GSH (p = 0.1184). A significant 2.5-fold decrease in cellular ATP was observed upon AAAgNP exposure (p = 0.0040) with a highly significant elevation in mt depolarization (3.3-fold vs. control; p < 0.0001). Apoptosis was also significantly higher (1.5-fold) in AAAgNP treated cells (p < 0.0001) with a significant decline in expression of CD95 receptors (p = 0.0416). Silver nanoparticles of AA caused a significant 2.5-fold reduction in caspase-8 activity (p = 0.0024) with contrasting increases in caspase-3/-7 (1.7-fold vs. control; p = 0.0180) and −9 activity (1.4-fold vs. control; p = 0.0117). Western blots showed increased expression of smac/DIABLO (4.1-fold) in treated cells (p = 0.0033). Furthermore, AAAgNP significantly increased the expression of p53, bax and PARP-1 (1.2-fold; p = 0.0498, 1.6-fold; p = 0.0083 and 1.1-fold; p = 0.0359 respectively). Data suggests that AAAgNP induces cell death in the A549 lung cells via the mt mediated intrinsic apoptotic program. Further investigation is required to potentiate the use of this novel compound in cancer therapy trials.
TL;DR: PdNPs displayed potential for further anticancer studies via tumour cell lines and showed antibacterial activity against Enterococcus faecalis among the different tested strains, including Bacillus cereus, Staphylococcus aureus, Esherichia coli and Candida albicans, Candida utilis.
Abstract: The biosynthesis of nanostructured biopalladium nanoparticles (PdNPs) from an aqueous solution of crystalline palladium acetate is reported. For the synthesised PdNPs in solution, an agroforest biomass waste petal of Moringa oleifera derived bis-phthalate was used as natural reducing and biocapping agents. Continuous absorption in the UV region and subsequent brown colour change confirmed the formation of PdNPs. A strong surface plasmon peak for PdNPs occurred at 460nm. PdNPs were characterized by SEM with EDX, FTIR, TEM and DLS. The chemical composition of the aqueous extract was determined by GC-MS coupled with FTIR and 1NMR. The catalytic degradation effect by PdNPs on industrial organic toxic effluents p-nitrophenol (PNP) and methylene blue dye was monitored by UV Spectroscopy. On the other hand PdNPs catalysed the base mediated suzuki coupling reaction for biphenyl synthesis, in water. Moreover, PdNPs were found to be reusable catalysts. Toxicity studies of PdNPs showed that the death of brine shrimp to be <50%. Therefore, PdNPs displayed potential for further anticancer studies via tumour cell lines. The in vitro cytotoxicity evaluation of the extract capped nanoparticles was carried out using human lung carcinoma cells (A549) and peripheral lymphocytes normal cells by MTT cell viability assay. Also, PdNPs showed antibacterial activity against Enterococcus faecalis among the different tested strains, including Bacillus cereus, Staphylococcus aureus, Esherichia coli and Candida albicans, Candida utilis.
01 Jan 2015
01 Jan 1999
TL;DR: Caspases, a family of cysteine-dependent aspartate-directed proteases, are prominent among the death proteases as discussed by the authors, and they play critical roles in initiation and execution of this process.
Abstract: ■ Abstract Apoptosis is a genetically programmed, morphologically distinct form of cell death that can be triggered by a variety of physiological and pathological stimuli. Studies performed over the past 10 years have demonstrated that proteases play critical roles in initiation and execution of this process. The caspases, a family of cysteine-dependent aspartate-directed proteases, are prominent among the death proteases. Caspases are synthesized as relatively inactive zymogens that become activated by scaffold-mediated transactivation or by cleavage via upstream proteases in an intracellular cascade. Regulation of caspase activation and activity occurs at several different levels: ( a) Zymogen gene transcription is regulated; ( b) antiapoptotic members of the Bcl-2 family and other cellular polypeptides block proximity-induced activation of certain procaspases; and ( c) certain cellular inhibitor of apoptosis proteins (cIAPs) can bind to and inhibit active caspases. Once activated, caspases cleave a variety of intracellular polypeptides, including major structural elements of the cytoplasm and nucleus, components of the DNA repair machinery, and a number of protein kinases. Collectively, these scissions disrupt survival pathways and disassemble important architectural components of the cell, contributing to the stereotypic morphological and biochemical changes that characterize apoptotic cell death.
TL;DR: Future prospects for targeting CSCs for cancer therapies by using a variety of nanomaterials are highlighted and it remains an open question how nanommaterials can meet future demands for targeting and eradicating of C SCs.
Abstract: Cancer stem cells (CSCs) have been identified in almost all cancers and give rise to metastases and can also act as a reservoir of cancer cells that may cause a relapse after surgery, radiation or chemotherapy. Thus they are obvious targets in therapeutic approaches and also a great challenge in cancer treatment. The threat presented by CSCs lies in their unlimited proliferative ability and multidrug resistance. These findings have necessitated an effective novel strategy to target CSCs for cancer treatment. Nanomaterials are on the route to providing novel methods in cancer therapies. Although there have been a large number of excellent work in the field of targeted cancer therapy, it remains an open question how nanomaterials can meet future demands for targeting and eradicating of cancer stem cells. In this review, we summarized recent and highlighted future prospects for targeting CSCs for cancer therapies by using a variety of nanomaterials.