As the greatest defense organ of the body, the skin is exposed to endogenous and external stressors that produce reactive oxygen species (ROS). When the antioxidant system of the body fails to ...eliminate ROS, oxidative stress is initiated, which results in skin cellular senescence, inflammation, and cancer. Two main possible mechanisms underlie oxidative stress-induced skin cellular senescence, inflammation, and cancer. One mechanism is that ROS directly degrade biological macromolecules, including proteins, DNA, and lipids, that are essential for cell metabolism, survival, and genetics. Another one is that ROS mediate signaling pathways, such as MAPK, JAK/STAT, PI3K/AKT/mTOR, NF-κB, Nrf2, and SIRT1/FOXO, affecting cytokine release and enzyme expression. As natural antioxidants, plant polyphenols are safe and exhibit a therapeutic potential. We here discuss in detail the therapeutic potential of selected polyphenolic compounds and outline relevant molecular targets. Polyphenols selected here for study according to their structural classification include curcumin, catechins, resveratrol, quercetin, ellagic acid, and procyanidins. Finally, the latest delivery of plant polyphenols to the skin (taking curcumin as an example) and the current status of clinical research are summarized, providing a theoretical foundation for future clinical research and the generation of new pharmaceuticals and cosmetics.
Reactive oxygen species (ROS) levels largely determine pulmonary fibrosis. Antioxidants have been found to ameliorate lung fibrosis after long-term paraquat (PQ) exposure. The effects of ...antioxidants, however, on the signalling pathways involved in PQ-induced lung fibrosis have not yet been investigated sufficiently. Here, we examined the impacts of ligustrazin on lung fibrosis, in particular ROS-related autophagy and pro-fibrotic signalling pathways, using a murine model of PQ-induced lung fibrosis.
We explored the effects of microRNA-193 (miR-193a) on Hedgehog (Hh) and PI3K/Akt/mTOR signalling and oxidative stress in lung tissues. Levels of miR-193a, protein kinase B (Akt), phosphoinositide 3-Kinase (PI3K), ceclin1, mammalian target of rapamycin (mTOR), sonic hedgehog (SHH), myosin-like Bcl2 interacting protein (LC3), smoothened (Smo), and glioma-associated oncogene-1 (Gli-1) mRNAs were determined with quantitative real-time PCR. Protein levels of PI3K, p-mTOR, p-Akt, SHH, beclin1, gGli-1, LC3, smo, transforming growth factor-β1 (TGF-β1), mothers against DPP homologue-2 (Smad2), connective tissue growth factor (CTGF), collagen I, collagen III, α-smooth muscle actin (α-SMA) nuclear factor erythroid 2p45-related factor-2 (Nrf2), and p-Smad2 were detected by western blotting. In addition, α-SMA, malondialdehyde, ROS, superoxide dismutase (SOD), oxidised and reduced glutathione, hydroxyproline, and overall collagen levels were identified in lung tissues using immunohistochemistry.
Long-term PQ exposure blocked miR-193a expression, reduced PI3K/Akt/mTOR signalling, increased oxidative stress, inhibited autophagy, increased Hh signalling, and facilitated the formation of pulmonary fibrosis. Ligustrazin blocked PI3K/Akt/mTOR and Hh signalling as well as reduced oxidative stress via increasing miR-193a expression and autophagy, all of which reduced pulmonary fibrosis. These effects of ligustrazin were accompanied by reduced TGF-β1, CTGF, and Collagen I and III expression.
Ligustrazin blocked PQ-induced PI3K/Akt/mTOR and Hh signalling by increasing miR-193a expression, thereby attenuating PQ-induced lung fibrosis.
Wnt/β-catenin signaling is upregulated in triple-negative breast cancer (TNBC) compared to other breast cancer subtypes and normal tissues. Current Wnt/β-catenin inhibitors, such as niclosamide, ...target the pathway nonspecifically and exhibit poor pharmacokinetics/pharmacodynamics in vivo. Niclosamide targets other pathways, including mTOR, STAT3 and Notch. Novel benzimidazoles have been developed to inhibit Wnt/β-catenin signaling with greater specificity. The compounds SRI33576 and SRI35889 were discovered to produce more cytotoxicity in TNBC cell lines than in noncancerous cells. The agents also downregulated Wnt/β-catenin signaling mediators LRP6, cyclin D1, survivin and nuclear active β-catenin. In addition, SRI33576 did not affect mTOR, STAT3 and Notch signaling in TNBC and noncancerous cells. SRI35889 inhibited mTOR signaling less in noncancerous than in cancerous cells, while not affecting STAT3 and Notch pathways. Compounds SRI32529, SRI35357 and SRI35361 were not selectively cytotoxic against TNBC cell lines compared to MCF10A cells. While SRI32529 inhibited Wnt/β-catenin signaling, the compound also mitigated mTOR, STAT3 and Notch signaling. SRI33576 and SRI35889 were identified as cytotoxic and selective inhibitors of Wnt/β-catenin signaling with therapeutic potential to treat TNBC in vivo.
In this study, ultrasonic-assisted cellulase extraction (UCE) was applied to extract flavonoids and polyphenols from the
flower. The extraction conditions were optimized using the response surface ...method (RSM) coupled with a Box-Behnken design. The crude extract of
(NHE) was further purified using AB-8 macroporous resins, and the purified extract (NHEP) was characterized by FTIR and HPLC. In vitro activity determination by chemical method showed that NHEP displayed strong free radical scavenging abilities against the DPPH and ABTS radicals, good reduction power, and hyaluronidase inhibition. The cell viability by CCK-8 assays showed that NHEP had no significant cytotoxicity for B16 and HaCaT cells when the concentration was below 100 μg/mL and 120 μg/mL, respectively. NHEP with a concentration of 20-160 μg/mL can more effectively reduce the ROS level in H
O
damaged HaCaT cells compared with 10 μg/mL of VC. The 40 μg/mL of NHEP had similar activity against intracellular melanin production in the B16 melanoma cells compared with 20 μg/mL Kojic acid. Good activities of antioxidation, whitening and protective effect against H
O
-induced oxidative damage promote the potential for NHEP as a functional raw material in the field of cosmetics and medicine.
Several chemical changes in soil are associated with plant growth-promoting rhizobacteria (PGPR). Some bacterial strains directly regulate plant physiology by mimicking synthesis of plant hormones, ...whereas others increase mineral and nitrogen availability in the soil as a way to augment growth. Identification of bacterial chemical messengers that trigger growth promotion has been limited in part by the understanding of how plants respond to external stimuli. With an increasing appreciation of how volatile organic compounds signal plants and serve in plant defense, investigations into the role of volatile components in plant-bacterial systems now can follow. Here, we present chemical and plant-growth data showing that some PGPR release a blend of volatile components that promote growth of Arabidopsis thaliana. In particular, the volatile components 2,3-butanediol and acetoin were released exclusively from two bacterial strains that trigger the greatest level of growth promotion. Furthermore, pharmacological applications of 2,3-butanediol enhanced plant growth whereas bacterial mutants blocked in 2,3-butanediol and acetoin synthesis were devoid in this growth-promotion capacity. The demonstration that PGPR strains release different volatile blends and that plant growth is stimulated by differences in these volatile blends establishes an additional function for volatile organic compounds as signaling molecules mediating plant-microbe interactions.
A practical one-pot and regiospecific three-component process for the synthesis of 2,3-disubstituted indoles from 2-bromoanilides was developed via consecutive palladium-catalyzed Sonogashira ...coupling, amidopalladation, and reductive elimination.
A practical one-pot, regiospecific three-component process for the synthesis of 2,3-disubstituted indoles was developed via consecutive Pd-catalyzed Sonogashira coupling, amidopalladation, and ...reductive elimination.
Concrete repair and rehabilitation prolong the effective service lives of structures and are important topics in the building field worldwide. Epoxy latex-modified cementitious materials have shown ...promise for a number of applications in building and construction, but the mix design processes remain arbitrary because their pore structures are not well understood. Porosity and pore size distributions are pore structure parameters that have direct effects on the mechanical properties and durability of concrete. In this paper, mercury intrusion porosimetry (MIP) was used to analyze the porosities and pore size distributions of epoxy latex-modified mortars. The effects of the polymer-to-cement ratio on the pore structures of epoxy latex-modified mortars were investigated. Mortars with polymer-to-cement ratios of 0%, 5%, 10%, 15%, and 20% were cured for 7, 28, 60, and 90 days in this study. Images of specimen microstructures were obtained by scanning electron microscopy (SEM), which showed that increases in the amount of epoxy latex added caused the proportion of micropores in the mortar to decrease, while the proportion of macropores and gel pores increased. The pore size distribution of epoxy latex-modified mortar was described with a composite logarithmic model. Relationships between the pore size distribution and the polymer-to-cement ratio and the curing age were obtained. The method described herein might be sufficiently accurate and convenient to evaluate or predict the pore size distribution of an epoxy latex-modified mortar, i.e., by determining the statistical distribution and analyzing the probability. The process for design of the polymer concrete mix ratio will be facilitated by methods that accurately describe the structure of the epoxy latex-modified mortar.
The rapid development of wireless communication systems demands extremely high reliability in transmission links. However, non-ideal characteristics of RF links, such as carrier frequency offset ...(CFO) and IQ mismatch (IQM), can lead to RF impairments, severely affecting system performance. Advanced signal processing techniques are indispensable to mitigate the non-ideal characteristics of RF links. Within signal processing, synchronization issues, including CFO estimation schemes for frequency synchronization, should be prioritized. However, the traditional CFO estimation schemes are susceptible to interference from the harmonics caused by IQM, resulting in severe performance degradation. Therefore, based on the least squares (LS) interpolation method, we develop a CFO estimation scheme robust to IQM by using <inline-formula> <tex-math notation="LaTeX">2l _{0}+1 </tex-math></inline-formula> (<inline-formula> <tex-math notation="LaTeX">l _{0}\geqslant ~3 </tex-math></inline-formula>) discrete Fourier transform (DFT) coefficients. The proposed estimator combines a coarse estimation and a fine estimation. In the first stage, the peak position of the signal amplitude spectrum is detected to provide a rough frequency estimation. In the second stage (fine estimation), an LS equation relationship between the observation vector and the observation matrix is established with observed DFT samples and DFT rotation factors. The precise frequency is extracted using the LS principle from the equation, utilizing <inline-formula> <tex-math notation="LaTeX">2l _{0}+1 </tex-math></inline-formula> (<inline-formula> <tex-math notation="LaTeX">l _{0}\geqslant ~3 </tex-math></inline-formula>) DFT sample points. Because the IQM interference structure is considered in the equation, the proposed method can combat IQI. Test results based on the RF verification platform indicate that the proposed method improves accuracy by at least 20 dB at an input power of −45 dBm. Accuracy improves by at least 9 dB at an input power of −65 dBm. Complexity analysis shows that the proposed method increases by at most 10.74% compared to the traditional LS-based methods.
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