[Protective effect of salidroside on renal damage in diabetic nephropathy mice by regulating RAGE/JAK1/STAT signaling pathway].

This study aims to investigate the protective effect of salidroside(SAL) on renal damage in diabetic nephropathy(DN) mice based on the receptor for advanced glycation end products/janus activated kinase 1/signal transduction and activator of transcription 3(RAGE/JAK1/STAT3) signaling pathway. The mouse DN model was established by high-fat/high-sucrose diets combined with intraperitoneal injection of streptozocin(STZ). Mice were randomly divided into normal group, model group, low-dose SAL group(20 mg·kg~(-1)), high-dose SAL group(100 mg·kg~(-1)), and metformin group(140 mg·kg~(-1)), with 12 mice in each group. After establishing the DN model, mice were given drugs or solvent intragastrically, once a day for consecutive 10 weeks. Body weight, daily water intake, and fasting blood glucose(FBG) were measured every two weeks. After the last dose, the glucose tolerance test was performed, and the samples of 24-hour urine, serum, and kidney tissue were collected. The levels of 24 hours urinary total protein(24 h-UTP), serum creatinine(Scr), blood urea nitrogen(BUN), triglyceride(TG), total cholesterol(TC), low density lipoprotein cholesterol(LDL-C), and high density lipoprotein cholesterol(HDL-C) were detected by biochemical tests. Periodic acid-schiff(PAS) staining was used to observe the pathological changes in the kidney tissue. The protein expressions of α-smooth muscle actin(α-SMA), vimentin, and advanced glycation end products(AGEs) in kidneys were detected by immunohistochemical staining. The activities of superoxide dismutase(SOD), catalase(CAT), glutathione peroxidase(GSH-PX), and the level of malondialdehyde(MDA) in kidneys were detected by using a corresponding detection kit. Enzyme-linked immunosorbent assay(ELISA) was used to detect the levels of AGEs, carboxymethyllysine(CML), and carboxyethyllysine(CEL) in serum. The protein expressions of RAGE and the phosphorylation level of JAK1 and STAT3 in kidneys were detected by Western blot. Compared with the normal group, the levels of FBG, the area under the curve of glucose(AUCG), water intake, kidney index, 24 h-UTP, tubular injury score, extracellular matrix deposition ratio of the renal glomerulus, the serum levels of Scr, BUN, TG, LDL-C, AGEs, CEL, and CML, the level of MDA, the protein expressions of α-SMA, vimentin, AGEs, and RAGE, and the phosphorylation level of JAK1 and STAT3 in kidney tissue were increased significantly(P<0.01), while the level of HDL-C in serum and the activity of SOD, CAT, and GSH-PX in kidney tissue were decreased significantly(P<0.01). Compared with the model group, the above indexes of the high-dose SAL group were reversed significantly(P<0.05 or P<0.01). In conclusion, this study suggests that SAL can alleviate oxidative stress and renal fibrosis by inhibiting the activation of AGEs-mediated RAGE/JAK1/STAT3 signaling axis, thus playing a potential role in the treatment of DN.

A novel p55PIK signaling peptide inhibitor alleviates neuroinflammation via the STAT3/NF-kB signaling pathway in experimental stroke.

BACKGROUND: Ischemic stroke remains the predominant contributor to mortality and disability globally. Microglia undergo rapid activation and initiate inflammatory cascade reactions by phenotypic polarization, participating in the regulation of inflammatory injury and tissue repair post-ischemic stroke. Regulating microglia-mediated neuroinflammation is a promising therapeutic strategy for ischemic stroke. Previously, we designed and synthesized a novel p55PIK inhibitor, TAT-N15 polypeptide, which presents inhibitive activity on NF-κB signaling-mediated inflammation in acute conjunctivitis and allergic rhinitis. The present study aimed to explore the therapeutic effect and mechanism of TAT-N15 on ischemia stroke. METHODS: The mouse model of transient cerebral ischemia was made using the intraluminal filament method. After being treated with daily intraperitoneal injections of TAT-N15 (10 mg/kg) for 7 d, the neurological outcomes and the cerebral infarction volume were evaluated. Histopathology of the ischemia cerebral hemisphere was observed by H&E and Nissl staining. Neuronal survival, astrogliosis, and co-labeling of CD86/Iba1 and CD206/Iba1 were detected by immunofluorescence. The cell apoptosis was estimated by TUNEL staining. The expression levels of apoptosis-associated proteins, proinflammatory cytokines, protein markers of M1 and M2 microglia, and the phosphorylation of NF-κB and STAT3 proteins in the ischemic penumbra were detected by Western blot. RESULTS: TAT-N15 treatment significantly decreased the infarct volume and alleviated neurological functional impairment, neuronal injury, and neuron apoptosis. Meanwhile, TAT-N15 treatment restrained the activation of microglia and astrocytes as well as the protein expression of proinflammatory cytokine in ischemic penumbra. Additionally, the administration of TAT-N15 treatment resulted in a significant reduction in the density of M1 phenotype microglia while concurrently increasing the density of M2 phenotype microglia within the ischemic penumbra. Finally, mechanical analysis unveiled that TAT-N15 exerted a substantial inhibitory effect on the protein expression of phosphorylated STAT3 and NF-κB. CONCLUSION: TAT-N15 may inhibit neuroinflammation via regulating microglia activation and polarization through the STAT3/NF-κB pathway, which exhibits the neuroprotection effect in ischemic stroke.

A novel lysosome-targeted fluorescent probe for precise formaldehyde detection in water samples, living cells and breast cancer tumors.

This study investigated the potential ability of the fluorescent probe Ly-CHO to detect formaldehyde (FA) in living cells and tumor-bearing mice. Ly-CHO exhibited great selectivity, excellent sensitivity, and rapid response to FA, making it a valuable tool for tracking FA concentration changes. The probe was also found to target lysosomes specifically. Furthermore, Ly-CHO showed an obvious fluorescence increase in endogenous CHO detection after adding tetrahydrogen folic acid (THFA). This study validated Ly-CHO's possibility for FA imaging in vivo, with potential applications in understanding formaldehyde-related diseases.

Discovery of sesquiterpene from Youngia japonica with antitumor effect.

Fourteen sesquiterpenes, including one undescribed sesquiterpene lactone, were isolated from Youngia japonica, and their structures were identified by NMR, HRESIMS, ECD and calculated ECD. Cytotoxic activities of all isolates against A549, HeLa, and 4 T1 cell lines were detected by CCK8 assay. Among them, 2 showed obvious cytotoxic activity against A549 cells. Subsequently, the production of ROS, and apoptosis of A549 cells treated with 2 were evaluated. The result showed that 2 distinctly increased the ROS level, and induced the apoptosis of A549 cells. Further anticancer mechanism studies showed that 2 increased the expression of cleaved caspase 3. Taken together, our results demonstrated that 2 might become potential leading compounds for the treatment of lung cancer.

Four undescribed coumarin derivatives, with ten amides from the roots of Ficus hirta and their cytotoxic activities.

Four undescribed coumarin derivatives, ficusalt A (1) and ficusalt B (2), a pair of racemic coumarins, (±) ficudimer A (3a/3b), along with ten known amides, were isolated from the roots of Ficus hirta. Their structures were elucidated by several spectroscopic data analyses, including HRESIMS, NMR, and X-ray single-crystal diffraction. The cytotoxic activities of all compounds against HeLa, HepG2, MCF-7, and H460 cell lines were detected using the MTT assay. Among these, 5 showed the highest activity against HeLa cells. Subsequently, the apoptotic, anti-invasive, and anti-migration effects of 5 on HeLa cells were determined by flow cytometer, transwell invasion assay, and wound-healing assay, respectively. The result suggested that 5 distinctly induced the apoptosis in HeLa cells and inhibited their invasion and migration. Further studies on anticancer mechanisms were conducted using Western blotting. As a result, 5 increased the cleavage of PARP and the expression of pro-apoptotic protein Bax. Moreover, 5 notably upregulated the phosphorylation of p38 and JNK, whereas inhibited the expression of p-ERK and p-AKT. Our results demonstrated that 5 could be a potential leading compound for further application in the treatment of cervical cancer.

Correction: Sun et al. Ergosterol Isolated from Antrodia camphorata Suppresses LPS-Induced Neuroinflammatory Responses in Microglia Cells and ICR Mice. Molecules 2023, 28, 2406.

The original version of this article unfortunately contains an error in Figures 4B,C,H-J and 5C,D [...].

Ergosterol Isolated from Antrodia camphorata Suppresses LPS-Induced Neuroinflammatory Responses in Microglia Cells and ICR Mice.

Inflammation caused by microglial activation is important in neurodegenerative diseases. In this research, we tried to identify safe and effective anti-neuroinflammatory agents by screening a natural compounds library and found that Ergosterol can inhibit the nuclear factor kappa-light-chain enhancer of the activated B cells (NF-κB) pathway induced by lipopolysaccharide (LPS) in microglia cells. Ergosterol has been reported to be an effective anti-inflammatory agent. Nevertheless, the potential regulatory role of Ergosterol in neuroinflammatory responses has not been fully investigated. We further investigated the mechanism of Ergosterol that regulates LPS-induced microglial activation and neuroinflammatory reactions both in vitro and in vivo. The results showed that Ergosterol can significantly decrease the pro-inflammatory cytokines induced by LPS in BV2 and HMC3 microglial cells, possibly by inhibiting the NF-κB, protein kinase B (AKT), and mitogen-activated protein kinase (MAPK) signaling pathways. In addition, we treated Institute of Cancer Research (ICR) mice with a safe concentration of Ergosterol following LPS injection. Ergosterol treatment significantly decreased microglial activation-associated ionized calcium-binding adapter molecule-1 (IBA-1), NF-κB phosphorylation, and pro-inflammatory cytokine levels. Moreover, Ergosterol pretreatment clearly reduced LPS-induced neuron damage by restoring the expression of synaptic proteins. Our data may provide insight into possible therapeutic strategies for neuroinflammatory disorders.

Ethyl-acetate fraction from a cinnamon-cortex extract protects pancreatic ß-cells from oxidative stress damage.

Background: The pathogenesis of diabetes mellitus is mediated mainly by oxidative stress produced by damaged pancreatic ß-cells. We identified that an ethyl-acetate fraction (EA) from a cinnamon-cortex extract (CCE) is rich in flavonoid, and showed no toxicity to ß cells. Objective: In this study, we evaluated the pharmacologic activities of EA on pancreatic ß cells using a model of oxidative stress induced by H2O2 or alloxan. Results: The results showed that EA could significantly reduce reactive oxygen (ROS) accumulation to improve the survival of cells. Western blot showed that EA treatment upregulated expression of nuclear factor erythroid 2 related factor 2, heme oxygenase-1, and gamma glutamylcysteine synthetase. The same model study found that EA also can protect ß cells against the apoptosis induced by oxidative stress. Furthermore, EA can enhance insulin secretion in rat and mouse ß cell lines treated or not with alloxan or H2O2. The expression of the insulin transcription factor PDX-1 increased in an EA concentration-dependent manner. At last, the major functional compounds of EA analysis showed that three compounds, cinnamyl alcohol, coumarin, and cinnamic acid, had similar effects as EA. Conclusions: In sum, our data suggested that EA fraction from CCE can protect ß cells from oxidative stress, and increase insulin secretion to improve the function of ß cells. This function might be due to these three compounds found in EA. Our findings provide a theoretical basis and functional molecules for the use of CCE against diabetes mellitus.

Two Resveratrol Oligomers Inhibit Cathepsin L Activity to Suppress SARS-CoV-2 Entry.

Cell entry of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) depends on specific host cell proteases, which are the key targets for preventing and treating viral infections. Herein, we describe miyabenol C and trans-ε-viniferin, two resveratrol oligomers that specifically inhibit SARS-CoV-2 entry by targeting host protease cathepsin L. Several cell-based assays were used to demonstrate the effect of resveratrol oligomers, and their target was identified via screening of antiviral targets. Molecular docking analysis suggested that the oligomers could occupy the active cavity of cathepsin L. The surface plasmon resonance assay showed that the equilibrium dissociation constant (KD) values of miyabenol C-cathepsin L and trans-ε-viniferin-cathepsin L were 5.54 and 8.54 µM, respectively, indicating their excellent binding ability for cathepsin L. Our study demonstrated the potential application of resveratrol oligomers as lead compounds in controlling SARS-CoV-2 infection by targeting cathepsin L.

Chebulic Acid Prevents Hypoxia Insult via Nrf2/ARE Pathway in Ischemic Stroke.

Excessive reactive oxygen species (ROS) production contributes to brain ischemia/reperfusion (I/R) injury through many mechanisms including inflammation, apoptosis, and cellular necrosis. Chebulic acid (CA) isolated from Terminalia chebula has been found to have various biological effects, such as antioxidants. In this study, we investigated the mechanism of the anti-hypoxic neuroprotective effect of CA in vitro and in vivo. The results showed that CA could protect against oxygen-glucose deprivation/reoxygenation (OGD/R) induced neurotoxicity in SH-SY5Y cells, as evidenced by the enhancement of cell viability and improvement of total superoxide dismutase (T-SOD) in SH-SY5Y cells. CA also attenuated OGD/R-induced elevations of malondialdehyde (MDA) and ROS in SH-SY5Y cells. Nuclear factor-E2-related factor 2 (Nrf2) is one of the key regulators of endogenous antioxidant defense. CA acted as antioxidants indirectly by upregulating antioxidant-responsive-element (ARE) and Nrf2 nuclear translocation to relieve OGD/R-induced oxidative damage. Furthermore, the results showed that CA treatment resulted in a significant decrease in ischemic infarct volume and improved performance in the motor ability of mice 24 h after stroke. This study provides a new niche targeting drug to oppose ischemic stroke and reveals the promising potential of CA for the control of ischemic stroke in humans.

Inhibitory effects of phenolic glycosides from Trollius chinensis Bunge on α-glucosidase: inhibition kinetics and mechanisms.

Two undescribed phenolic glycosides, trochinenols B and C (1 and2), together with four known analogues (3-6), were isolated from the functional tea Trollius chinensis Bunge and their α-glucosidase inhibitory kinetics and mechanisms were investigated. It was found that 1 inhibited α-glucosidase in a noncompetitive manner with an IC50 value of 25.96 µM, while 3 showed a notable inhibitory effect against α-glucosidase in an uncompetitive manner with an IC50 value of 3.14 µM. Analysis of synchronous fluorescence and circular dichroism spectroscopy indicated that the binding of 1 to α-glucosidase led to the rearrangement and conformational alteration of the α-glucosidase enzyme. Furthermore, molecular docking indicated that 1 had a high affinity close to the active site pocket of α-glucosidase and indirectly inhibited the catalytic activity of the enzyme. However, 3 was bound to the entrance part of the active center of α-glucosidase and could hinder the release of the substrate as well as the catalytic reaction product, eventually suppressing the catalytic activity of α-glucosidase.

A new phenolic glycoside from Trollius chinensis Bunge with anti-inflammatory and antibacterial activities.

A undescribed phenolic glycoside, trochinenol A (1), was isolated from the flowers of Trollius chinensis Bunge and the structure was identified by spectroscopic methods. Its anti-inflammatory and antibacterial effects were investigated by broth microdilution and NF-κB reporter gene assays. Consequently, compound 1 exhibited an appreciable effect against Staphylococcus aureus with the MIC value of 6.25 µg/mL. Besides, it showed moderate effect against TNFα-induced activation of NF-κB pathway.

Lignans and phenylpropanoids from the roots of Ficus hirta and their cytotoxic activities.

One undescribed lignan, one new natural product, along with fourteen known compounds, were isolated from the roots of Ficus hirta. The structures of the isolates were elucidated by comprehensive spectroscopic technologies, including UV, IR, HRESIMS, and NMR. The absolute configuration of 1 was determined by comparison of experimental and calculated ECD data. The cytotoxicity of all the compounds against HeLa and HepG2 cell lines was evaluated and compound 7 showed considerable cytotoxic effect towards HepG2 cells. Also, the apoptotic effect of 7 on HepG2 cells and the effect of 7 on the key proteins (p-JNK and p-p38) in MAPK (Mitogen-activated protein kinases) pathways were studied by flow cytometry and western blotting experiment. As a result, compound 7 induced the apoptosis of HepG2 cells, and dose-dependently increased the phosphorylation of JNK and p38. Thus, 7 might trigger HepG2 cells apoptosis via JNK/p38 MAPK signaling pathway.

Secoiridoid dimers and their biogenetic precursors from the fruits of Cornus officinalis with potential therapeutic effects on type 2 diabetes.

Cornusdiridoid A-F (1-6), six unusual cornuside-morroniside secoiridoid dimers, and their possible new biogenetic precursor, 3″,5″-dehydroxycornuside (7), together with four known secoiridoids (8-11), were obtained from the fruits of Cornus officinalis. Their structures were elucidated on the basis of various spectroscopic and chemical methods. A plausible biosynthetic pathway of compounds 1-11 was proposed. The α-glucosidase inhibitory, antioxidant and anti-inflammatory activities of these isolates were evaluated. Some of them emerged out as potent antidiabetic, anti-inflammatory and free radical scavenging agents. Molecular docking was also carried out for antidiabetic target α-glucosidase to investigate the possible binding modes of the most potent α-glucosidase inhibitor, vincosamide (9). These results revealed that the secoiridoids from C. officinalis fruits may be served as new potential antidiabetic agents to prevent and treat type 2 diabetes.

Prenylated flavonoids from Ficus hirta induces HeLa cells apoptosis via MAPK and AKT signaling pathways.

A pair of undescribed enantiomers, (±) ficusflavonid A (1a/1b), along with five known analogues, were isolated from the roots of Ficus hirta. Their structures were determined by the analysis of extensive spectroscopic data (including UV, IR, HRESIMS and NMR). Two enantiomers (1a and 1b) were successfully separated by chiral chromatographic column and their absolute configurations were assigned by the comparison of experimental and calculated ECD data. The cytotoxicity of all the isolates against HeLa, MCF-7, HepG2 and H460 cell lines were evaluated by MTT assay. Among them, 4 suppressed the proliferation of HeLa cells with the IC50 value of 28.88 µM. Furthermore, the apoptotic effect of 4 on HeLa cells and the level of several crucial proteins in AKT/MAPKs signaling pathways were analyzed by flow cytometer and western blot assay. As a result, 4 induced HeLa cell apoptosis in a dose dependent manner and significantly increased the protein levels of p-JNK and p-p38, whereas distinctly reduced the expression of p-AKT, and p-ERK. Thus, compound 4 might induce HeLa cells apoptosis via MAPK and AKT signaling pathways, which could be considered as a potential leading compound for the development of anticancer drugs.

Jatrophane Diterpenoids from Euphorbia peplus as Multidrug Resistance Modulators with Inhibitory Effects on the ATR-Chk-1 Pathway.

Twelve undescribed jatrophane diterpenoids, euphpepluones A-L (1-12), together with seven known analogues (13-19), were isolated from the whole plant of Euphorbia peplus, and their structures were elucidated by spectroscopic studies. The absolute configurations of 1 and 4 were assigned by X-ray crystallographic analysis. All isolates were investigated for their inhibitory effects against the ATR-Chk1 pathway using a Western blotting assay. As a result, 1, 2, 5, 8, 10, and 16 were found to suppress the camptothecin (CPT)-induced phosphorylation of Chk1, indicating that these compounds inhibit the activation of the ATR-Chk1 pathway. A preliminary structure-activity relationship (SAR) study of the isolates was conducted. When compound 10 and CPT were combined, apoptosis was induced in A549 cells with PARP cleavage, while there was no apoptotic effect by treatment with CPT or 10 alone. The data obtained indicate that 10 potentiates the chemotherapeutic sensitivity of A549 cells to CPT.

Cytotoxic compound triacremoniate from Marine Fungus Acremonium citrinum. MMF4.

Two new compounds, triacremoniate (1) and dietziamide C (2) along with known compounds ß-Adenosine (3) and acrepyrone A (4) were obtained from the mangrove-derived fungus Acremonium citrinum. MMF4. Their structures were unambiguously determined by extensive spectroscopic methods, including UV, IR, HRESIMS and NMR. Triacremoniate (1) can promote apoptosis of HeLa cells by increasing the PARP cleavage and the phosphorylation of JNK and p38.

Phenolic Glycosides from the Roots of Ficus hirta Vahl. and Their Antineuroinflammatory Activities.

Ficus hirta Vahl. (Wuzhimaotao) is an edible functional food used for the soup cooking and health products. Seven undescribed phenolic glycosides (1-7), along with 20 analogues, were isolated from the roots of Ficus hirta. Their structures were determined by comprehensive spectroscopic methods (UV, IR, HRESIMS, and NMR), while the absolute configuration of 1 was established by comparison of the experimental and calculated ECD data. The antineuroinflammatory effects of all the compounds were examined by Western blot. Compounds 1 and 11 attenuated the phosphorylation of AKT, JNK, and ERK1/2. In addition, compound 11 inhibited the NF-κB p65 phosphorylation. Our results indicated that compounds 1 and 11 decreased the occurrence of neuroinflammation in BV2 microglia cells, which might be regulated by inhibiting the activity of proteins in NF-κB, MAPK (JNK and ERK1/2), or AKT signaling pathways. Thus, 1 and 11 might exhibit antineuroinflammatory activities and show promise in treating neurodegenerative diseases.

Undescribed morroniside-like secoiridoid diglycosides with α-glucosidase inhibitory activity from Corni Fructus.

Corni Fructus, also known as the fruit of Cornus officinalis Sieb. et Zucc., has long been used as a traditional Chinese medicine and is widely consumed as a nutritional food in the form of function drink and wine. Recently, Corni Fructus has attracted considerable interest because of its anti-diabetic effects. A systematic phytochemical investigation of Corni Fructus was performed to find anti-diabetic components, which led to the isolation of 10 unreported iridoid glycosides, cornusdiglycosides A-J (1-8, 9a/9b and 10a/10b). Their chemical structures were determined through spectroscopic analysis (ultraviolet [UV], infrared [IR], high-resolution electrospray ionisation mass spectroscopy [HRESIMS], one-dimensional [1D] and two-dimensional [2D] nuclear magnetic resonance [NMR]). Such morroniside-type diglycosides were first reported from natural sources, and all isolates were evaluated for α-glucosidase inhibitory activity. The results showed that all compounds (1-10) exhibited α-glucosidase (from Saccharomyces cerevisiae) inhibitory activities with IC50 values ranging from 78.9 ± 4.09 to 162.2 ± 9.17 µM, whereas acarbose, the positive control, displayed α-glucosidase inhibitory activity with IC50 value of 118.9 ± 7.89 µM.

Cornusglucosides A and B, Two New Iridoid Glucosides from the Fruit of Cornus officinalis.

Phytochemical study on the fruit of Cornus officinalis Sieb. et Zucc. yielded two new iridoid glucosides, named cornusglucoside A (1) and cornusglucoside B (2). The structures of 1 and 2 were elucidated via comprehensive NMR and HR-ESI-MS data analysis. Additionally, their inhibitory effects on IL-6-induced STAT3 activation were assessed.