Studies have shown that natural products can induce paraptosis in tumour cell lines. Paraptosis is characterized by cytoplasmic vacuolation arising from the endoplasmic reticulum (ER) and mitochondria. The mechanism of paraptosis is unclear; however, dysregulation of Ca homeostasis is believed to affect paraptosis induction.
View Article and Find Full Text PDFFolate receptor-targeted therapy has excellent prospects for the treatment of breast cancer. A non-toxic concentration of folate-conjugated palladium-based nanoparticles was used to target the overexpressed folate receptor on breast cancer cells. The folate-conjugated nanoparticles were tailored to accumulate selectively in cancer cells relative to normal cells via the folate receptor.
View Article and Find Full Text PDFUnderstanding the timing and trajectory of atmospheric oxygenation remains fundamental to deciphering its causes and consequences. Given its origin in oxygen-free photochemistry, mass-independent sulfur isotope fractionation (S-MIF) is widely accepted as a geochemical fingerprint of an anoxic atmosphere. Nevertheless, S-MIF recycling through oxidative sulfide weathering-commonly termed the crustal memory effect (CME)-potentially decouples the multiple sulfur isotope (MSI) record from coeval atmospheric chemistry.
View Article and Find Full Text PDFSignificanceThe permanent disappearance of mass-independent sulfur isotope fractionation (S-MIF) from the sedimentary record has become a widely accepted proxy for atmospheric oxygenation. This framework, however, neglects inheritance from oxidative weathering of pre-existing S-MIF-bearing sedimentary sulfide minerals (i.e.
View Article and Find Full Text PDFUnlabelled: Cannabis has been used for various medicinal applications including, but not limited to, cancer: most commonly to treat chemotherapy-associated side effects. Cannabis is often used for its palliative effects in the form of purified cannabinoids, or as extracts. This study was conducted using two breast cancer cell lines and aimed to evaluate potential anti-proliferative "intra-entourage effects" between purified phytocannabinoids resembling the THC and CBD ratios of medicinal and recreational cannabis strains, as well as to investigate potential "inter-entourage effects" between the different ratios and the phytochemicals found in a extract.
View Article and Find Full Text PDFEndoplasmic reticulum (ER) stress is an imbalance between the protein-folding load and capacity of ER. It can be induced by various physiological conditions, activating the unfolded protein response (UPR) to re-establish homeostasis, promoting cell survival. Under severe or chronic stress, apoptosis is induced.
View Article and Find Full Text PDFThis study evaluated the synergistic anti-cancer potential of cannabinoid combinations across the MDA-MB-231 and MCF-7 human breast cancer cell lines. Cannabinoids were combined and their synergistic interactions were evaluated using median effect analysis. The most promising cannabinoid combination (C6) consisted of tetrahydrocannabinol, cannabigerol (CBG), cannabinol (CBN), and cannabidiol (CBD), and displayed favorable dose reduction indices and limited cytotoxicity against the non-cancerous breast cell line, MCF-10A.
View Article and Find Full Text PDFThe Nconga Formation of the Mesoarchean (~2.96-2.84 Ga) Mozaan Group of the Pongola Supergroup of southern Africa contains the world's oldest known granular iron formation.
View Article and Find Full Text PDFOxygenic photosynthesis supplies organic carbon to the modern biosphere, but it is uncertain when this metabolism originated. It has previously been proposed that photosynthetic reaction centres capable of splitting water arose by about 3 billion years ago on the basis of the inferred presence of manganese oxides in Archaean sedimentary rocks. However, this assumes that manganese oxides can be produced only in the presence of molecular oxygen, reactive oxygen species or by high-potential photosynthetic reaction centres.
View Article and Find Full Text PDFβ-Cells contain a prominent endoplasmic reticulum (ER), disrupting ER homeostasis and function, activating the unfolded protein response (UPR). Currently, no direct protocols measure the UPR initiation. Current methods to measure ER stress include the quantification of nitric oxide (NO) (indirect method), Western blotting, and qRT-PCR of downstream components.
View Article and Find Full Text PDFThe marine nitrogen cycle is dominated by redox-controlled biogeochemical processes and, therefore, is likely to have been revolutionised in response to Earth-surface oxygenation. The details, timing, and trajectory of nitrogen cycle evolution, however, remain elusive. Here we couple nitrogen and carbon isotope records from multiple drillcores through the Rooihoogte-Timeball Hill Formations from across the Carletonville area of the Kaapvaal Craton where the Great Oxygenation Event (GOE) and its aftermath are recorded.
View Article and Find Full Text PDFWe document the discovery of the first granular iron formation (GIF) of Archaean age and present textural and geochemical results that suggest these formed through microbial iron oxidation. The GIF occurs in the Nconga Formation of the ca. 3.
View Article and Find Full Text PDFMolecular oxygen (O2) is, and has been, a primary driver of biological evolution and shapes the contemporary landscape of Earth's biogeochemical cycles. Although "whiffs" of oxygen have been documented in the Archean atmosphere, substantial O2 did not accumulate irreversibly until the Early Paleoproterozoic, during what has been termed the Great Oxygenation Event (GOE). The timing of the GOE and the rate at which this oxygenation took place have been poorly constrained until now.
View Article and Find Full Text PDFObjectives: The majority of research performed on cellular stress and apoptosis focuses on mitochondrial dysfunction; however, the importance of the endoplasmic reticulum dysfunction and the link to metabolic diseases has gained a substantial interest. This review focuses on the potential of terpenoids to influence endoplasmic reticulum stress and the possible role terpenoids play as the treatment of metabolic diseases.
Key Findings: Metabolic diseases develop as a result of a cascade of cellular pathways.
It is widely assumed that atmospheric oxygen concentrations remained persistently low (less than 10(-5) times present levels) for about the first 2 billion years of Earth's history. The first long-term oxygenation of the atmosphere is thought to have taken place around 2.3 billion years ago, during the Great Oxidation Event.
View Article and Find Full Text PDFThe synergistic interaction between various hemi/cellulolytic enzymes has become more important in order to achieve effective and optimal degradation of complex lignocellulose substrates for biofuel production. This study investigated the synergistic effect of three enzymes endoglucanase (EngE), mannanase (ManA) and xylanase (XynA) on the degradation of corn stalk, grass, and pineapple fruit pulp and determined the optimal degree of synergy between combinations of these enzymes. It was established that EngE was essential for degradation of all of the substrates, while the hemicellulases were able to contribute in a synergistic fashion to increase the activity on these substrates.
View Article and Find Full Text PDFThis aim of this study was to investigate the effect of ammonium hydroxide (NH(4)OH) and sodium hydroxide (NaOH) pre-treatment on the digestibility of sugarcane bagasse (SCB) by hemicellulase action. It was found that pre-treatment of SCB with NH(4)OH removed a larger percentage of the SCB lignin and effectively increased SCB digestibility 13.13 fold.
View Article and Find Full Text PDFAgricultural crop wastes are typically lignocellulosic in composition and thus partially recalcitrant to enzymatic degradation. The recalcitrant nature of plant biomass and the inability to obtain complete enzymatic hydrolysis has led to the establishment of various pre-treatment strategies. Alkaline pre-treatments increase the accessibility of the exposed surface to enzymatic hydrolysis through the removal of acetyl and uronic acid substituents on hemicelluloses.
View Article and Find Full Text PDFExtensive microbial mats colonize sandy tidal flats that form along the coasts of today's Earth. The microbenthos (mainly cyanobacteria) respond to the prevailing physical sediment dynamics by biostabilization, baffling and trapping, as well as binding. This biotic-physical interaction gives rise to characteristic microbially induced sedimentary structures (MISS) that differ greatly from both purely physical structures and from stromatolites.
View Article and Find Full Text PDFThe isolation of cellulosomes from clostridial sources has been extensively studied; however, the isolation of cellulosomes from facultative soil anaerobes of the family Bacillaceae is not as well characterized. The Bacillus cellulosome (celluloxylanosome) essentially consists of two complex components: C-I and C-II. This multi-component complex enables Bacillus to degrade a variety of carbonaceous compounds as it is composed of several enzymes, such as cellulases, xylanases and other degradative enzymes.
View Article and Find Full Text PDFSeveral lines of geological and geochemical evidence indicate that the level of atmospheric oxygen was extremely low before 2.45 billion years (Gyr) ago, and that it had reached considerable levels by 2.22 Gyr ago.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2000
Geological, geophysical, and geochemical data support a theory that Earth experienced several intervals of intense, global glaciation ("snowball Earth" conditions) during Precambrian time. This snowball model predicts that postglacial, greenhouse-induced warming would lead to the deposition of banded iron formations and cap carbonates. Although global glaciation would have drastically curtailed biological productivity, melting of the oceanic ice would also have induced a cyanobacterial bloom, leading to an oxygen spike in the euphotic zone and to the oxidative precipitation of iron and manganese.
View Article and Find Full Text PDFThe transition zone comprises Campbellrand microbialaminated (replacing "cryptalgalaminate") limestone and shale, with minor dolomite, conformably overlain by the Kuruman Iron Formation of which the basal part is characterized by siderite-rich microbanded iron-formation with minor magnetite and some hematite-containing units. The iron-formation contains subordinate intraclastic and microbialaminated siderite mesobands and was deposited in deeper water than the limestones. The sequence is virtually unaltered with diagenetic mineral assemblages reflecting a temperature interval of about 110 degrees to 170 degrees C and pressures of 2 kbars.
View Article and Find Full Text PDFA core drilled near Wolhaarkop in Griqualand West, South Africa, intersected highly oxidized Kuruman Iron Formation below red beds of the Gamagara Formation. The lateral equivalents of the Kuruman Iron Formation in this drill hole consist largely of siderite, ankerite, magnetite, greenalite, and quartz. The oxidation of the Kuruman Iron Formation in WOL 2 occurred almost certainly during weathering prior to the deposition of the Gamagara Formation.
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