Search

Purpose: This article details the application of pristine nitrogen and sulfur doped carbon quantum dots (CQDs) as a novel fluorescence biosensor for the detection of glutathione. The second object of this study is to evaluate reduction of cellular nitric oxide in microglial cells. Methods: Microwave assisted hydrothermal method was used for the fabrication of CQDs. Unlike conventional methods which utilize metallic or transition metal coating over CQDs for the fabrication of fluorescence switch on/off probes, our simple yet efficient CQDs itself performed as a biosensor that is both selective and sensitive towards glutathione (GSH). Particle size analyzer, scanning electron microscope, atomic force microscopy, high-performance X-ray photoelectron spectroscopy, fourier-transform infrared spectroscopy were used for physicochemical characterization of developed CQDs. Photoluminescence properties of CQDs were analyzed using photoluminescence spectroscope for glutathione detection. Furthermore, microglial cells were used to evaluate reduction of cellular nitric oxide. Results: The developed biosensor was able to detect GSH within a short time of 2 min. Hemolysis assay confirmed negligible red blood cell lysis even at a higher concentration of 0.2 mg/mL. Furthermore, the developed CQDs demonstrated enhanced cellular uptake, which resulted in generating fluorescence from the BV-2 microglial cells. Interestingly, the developed CQDs were able to mitigate the secretion of toxic pro-inflammatory cytokine, nitric oxide (NO) from the lipopolysaccharide (LPS) insulted BV-2 microglial cells. A 50% reduction in the secretion of NO was observed after treating with CQDs in the LPS treated BV-2 cells. Conclusion: These novel fluorescent CQDs with low manufacturing costs, high selectivity and sensitivity towards GSH and shorter detection time manifest them as a promising nanomaterial for diverse biomedical applications.

Common features of neurodegenerative diseases (NDDs) include progressive dysfunctions and neuronal injuries leading to deterioration in normal brain functions. At present, ginseng is one of the most frequently used natural products. Its use has a long history as a cure for various diseases because its extracts and active compounds exhibit several pharmacological properties against several disorders. However, the pathophysiology of NDDs is not fully clear, but researchers have found that various ion channels and specific signaling pathways might have contributed to the disease pathogenesis. Apart from the different pharmacological potentials, ginseng and its active compounds modulate various ion channels and specific molecular signaling pathways related to the nervous system. Here, we discuss the signal modulating potential of ginseng and its active compounds mainly focusing on those relevant to NDDs.

Oxidative stress during sepsis pathogenesis remains the most-important factor creating imbalance and dysregulation in immune-cell function, usually observed following initial infection. Hydrogen peroxide (H2O2), a potentially toxic reactive oxygen species (ROS), is excessively produced by pro-inflammatory immune cells during the initial phases of sepsis and plays a dominant role in regulating the pathways associated with systemic inflammatory immune activation. In the present study, we constructed a peroxide scavenger mannosylated polymeric albumin manganese dioxide (mSPAM) nanoassembly to catalyze the decomposition of H2O2responsible for the hyper-activation of pro-inflammatory immune cells. In a detailed manner, we investigated the role of mSPAM nanoassembly in modulating the expression and secretion of pro-inflammatory markers elevated in bacterial lipopolysaccharide (LPS)-mediated endotoxemia during sepsis. Through a facile one-step solution-phase approach, hydrophilic bovine serum albumin reduced manganese dioxide (BM) nanoparticles were synthesized and subsequently self-assembled with cationic mannosylated disulfide cross-linked polyethylenimine (mSP) to formulate mSPAM nanoassembly. In particular, we observed that the highly stable mSPAM nanoassembly suppressed HIF1α expression by scavenging H2O2in LPS-induced macrophage cells. Initial investigation revealed that a significant reduction of free radicals by the treatment of mSPAM nanoassembly has reduced the infiltration of neutrophils and other leukocytes in a local endotoxemia animal model. Furthermore, therapeutic studies in a systemic endotoxemia model demonstrated that mSPAM treatment reduced TNF-α and IL-6 inflammatory cytokines in serum, in turn circumventing organ damage done by the inflammatory macrophages. Interestingly, we also observed that the reduction of these inflammatory cytokines by mSPAM nanoassembly further prevented IBA-1 immuno-positive microglial cell activation in the brain and consequently improved the cognitive function of the animals. Altogether, the administration of mSPAM nanoassembly scavenged H2O2and suppressed HIF1α expression in LPS-stimulated macrophages and thereby inhibited the progression of local and systemic inflammation as well as neuroinflammation in an LPS-induced endotoxemia model. This mSPAM nanoassembly system could serve as a potent anti-inflammatory agent, and we further anticipate its successful application in treating various inflammation-related diseases.

Polyphenol contents and antiradical scavenging activities of nanopowdered peanut sprout (NPPS) and powdered peanut sprout (PPS) were compared using various antiradical scavenging assays such as α-diphenyl-β-picryl-hydrazyl free radical (DPPH·) scavenging, 2, 2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging activity, reducing power, and superoxide dismutase. The size of NPPS ranged from 300–350 nm as observed by the particle size analyzer, much smaller than that of PPS ranging from 50 to 150 μm. Total polyphenol contents in NPPS (455.05±18.69 μg/mL) were relatively higher than those of PPS (421.99±14.94 mg/mL). NPPS showed higher antioxidant activity than PPS at all concentrations (2.5, 5, 10, 15 and 20 mg/mL). Overall, the antiradical scavenging activity was much higher in NPPS and nanogrinding increases the surface area of polyphenol with higher functional site.