The fruit of Rosa laevigata Michx. (FR), a traditional Chinese herb utilized for the treatment of a variety diseases, has notably diverse pharmacological activities including hepatoprotective, anti-oxidant, and anti-inflammatory effects. Despite ongoing research on illustrating the underlying anti-inflammatory mechanism of FR, the principal mechanism remained inadequately understood. In this study, we investigated in depth the molecular mechanism of the anti-inflammatory actions of the ethanol extract of FR (EFR) and its potential targets using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages in vitro. We showed that EFR effectively ameliorated the overproduction of inflammatory mediators and cytokines, as well as the expression of related genes. It was further demonstrated that LPS-induced activation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) were significantly inhibited by pretreatment with EFR, accompanied by a concomitant decrease in the nuclear translocation of the p65 subunit of NF-κB and activator protein 1 (AP-1). In addition, EFR pretreatment potently prevented LPS-induced decreased phosphorylation of adenosine monophosphate-activated protein kinase (AMPK). Our data also revealed that the activation of AMPK and subsequent inhibition of the mammalian target of the rapamycin (mTOR) signaling pathway was probably responsible for the inhibitory effect of EFR on LPS-induced inflammatory responses, evidenced by reverse changes observed under the condition of AMPK inactivation following co-treatment with the AMPK-specific inhibitor Compound C. Finally, the main components with an anti-inflammatory effect in EFR were identified as madecassic acid, ellagic acid, quinic acid, and procyanidin C1 by LC–MS and testified based on the inhibition of NO production and inflammatory mediator expression. Taken together, our results indicated that EFR was able to ameliorate inflammatory responses via the suppression of MAPKs/NF-κB signaling pathways following AMPK activation, suggesting the therapeutic potential of EFR for inflammatory diseases.
In traditional Chinese medicine, the root bark and leaves of Schima argentea are utilized to treat dysentery, parasitic infections, and digestive disorders. In this study, the n-butanol extract of S. argentea (NBA) exhibited potent antioxidant properties, protecting HaCaT cells from UVB-induced damage, and was abundant in phenolic and flavonoid compounds. Using UPLC-QTOF-MS analysis, several antioxidants within NBA were identified. Among these, 3,4-dihydroxybenzoic acid, (+)-catechin, and procyanidin B2 effectively reduced ROS levels after 1 h post-UVB treatment (225 mJ/cm2). Notably, all three compounds significantly decreased the phosphorylation of p38 and JNK in a dose-dependent manner. Additionally, the cell survival rate of these compounds was assessed after 12 h post-UVB treatment (225 mJ/cm2). Both 3,4-dihydroxybenzoic acid and (+)-catechin significantly prevented UVB-induced apoptosis in HaCaT cells, as evidenced by MTT, Hoechst, Calcein/PI staining, and flow cytometry analyses. Proteomic analysis revealed that 3,4-dihydroxybenzoic acid achieved photoprotection by downregulating c-Fos and Jun and modulating cell cycle proteins, while (+)-catechin promoted cell repair through the PI3K-Akt and Wnt signaling pathways. These results demonstrated that both compounds can directly absorb UVB, scavenge ROS, and provide cell photoprotection by modulating multiple signaling pathways. The n-butanol extract of S. argentea holds promising potential for future medical applications.
Background/Objectives: Esterases are widely used in various industrial fields. This study aimed to isolate and characterize esterase genes from Laceyella sacchari HS49-1, a thermophilic bacterium from a hot spring, which can survive at 45–60 °C and pH 5-10 with robust esterase activity. Methods: A genomic shotgun library was constructed to identify three esterase genes: two in family XII (Est2 and Est7) and one in family VIII (Est1). Sequence analysis revealed significant divergence from other genera. Only Est1 was successfully expressed in Escherichia coli. Its activity, optimal conditions, thermostability, and structure were investigated using p-NP butyrate, temperature/pH assays, heating pre-treatment, and fluorescence quenching. Results: Est1 demonstrated high activity (57.43 ± 0.04 U/mg) towards short-chain p-NP butyrate (C4). Molecular-docking analyses revealed that Est1’s catalytic motif (GXSXG) interacts with various p-NP esters, with binding energy and interaction types varying by acyl chain length. The optimal temperature was 60 °C, and the optimal pH was 8. Est1 exhibited excellent thermostability, retaining 90% of its activity after pre-treatment at 50 °C for 8 h and 69.8% after pre-treatment at 80 °C for the same duration. Fluorescence quenching showed that after 1 h at 80 °C, the fluorescence was reduced by only 16.6%, indicating remarkable heat resistance. Additionally, Est1 did not require metal ions as cofactors and maintained 74.8% of its activity in the presence of 0.1% SDS. Conclusions: The unique properties of Est1 from L. sacchari HS49-1 highlight its potential for industrial applications. Further exploration of this thermophilic bacterium could uncover more valuable genes.
Taxifolin, a natural flavonoid, consistently exerts cytoprotective effects against various oxidative stresses. In this study, we systematically evaluated its photoprotective efficacy and underlying mechanisms against ultraviolet B (UVB)-induced injury in human immortalized keratinocytes (HaCaT). Cell viability and apoptosis were assessed by MTT, fluorescence staining, and flow cytometry, while integrative transcriptomic and proteomic analyses were employed to identify core pathways and key mediators. Taxifolin exhibited antioxidant capacity comparable to that of ascorbic acid under identical in vitro radical-scavenging assays. Moreover, it displayed a strong absorption peak at 289 nm that overlaps the UVB spectrum (280–320 nm), enabling it to act as a chemical sunscreen. In UVB-challenged HaCaT cells, taxifolin markedly reduced intracellular reactive oxygen species (ROS) and attenuated JNK/p38 MAPK activation, as evidenced by Western blot, thereby breaking the ROS-MAPK vicious cycle. Multi-omics revealed that taxifolin was associated with attenuation of UVB-imposed G1/S arrest concomitant with restored Cyclin expression, while up-regulating MYC, FOXQ1, HMOX1 and AP-1 components c-Jun/c-Fos and thereby switching on a pro-survival transcriptional program. Consequently, apoptosis was suppressed and survival was significantly improved. Collectively, taxifolin integrated chemical filtration, ROS scavenging and signaling modulation to support a multi-target photoprotective network, which provides mechanistic insight into taxifolin-mediated cytoprotection and identifies candidate molecular nodes for further validation.