Morus alba L. (Sangzhi) alkaloids (SZ-A) exert anti-inflammatory effects via regulation of MAPK signaling in macrophages.

ETHNOPHARMACOLOGICAL RELEVANCE: Morus alba L. (Sangzhi) alkaloids (SZ-A) tablets have been approved by the China National Medical Products Administration for T2DM treatment. Our previous study (Liu et al., 2021) revealed that SZ-A protected against diabetes and inflammation in KKAy mice. However, the mechanism and components in SZ-A exerting anti-inflammatory effects are unclear. AIM OF THE STUDY: Investigate the effects and molecular mechanisms of SZ-A on inflammation, and identify anti-inflammatory active components in SZ-A. MATERIALS AND METHODS: The major ingredients in SZ-A were analyzed by HPLC and sulfuric acid - anthrone spectrophotometry. The inhibitory activities of SZ-A on lipopolysaccharide (LPS)-stimulated inflammation were determined in bone marrow-derived macrophage (BMDM) and RAW264.7 cells. The cytokine levels of IL-6 and TNF-α in cell culture supernatant were measured by enzyme-linked immunosorbent assay (ELISA). Gene expression levels of IL-6 and TNF-α were detected by qRT-PCR. The levels of protein phosphorylation of p38 MAPK, ERK, and JNK were analyzed by Western blot. RESULTS: The main components in SZ-A were found to be 1-deoxynojirimycin (DNJ), 1,4-dideoxy-1,4-imino-D-arabinitol (DAB), fagomine (FAG), polysaccharide (APS), and arginine (ARG). SZ-A reduced the levels of IL-6 and TNF-α secreted by LPS-induced RAW264.7 and BMDM cells. Simultaneously, the mRNA expression levels of IL-6 and TNF-α were all significantly suppressed by SZ-A in a concentration-dependent manner. Furthermore, SZ-A inhibited the phosphorylation of p38 MAPK, ERK, and JNK in BMDM and the activation of ERK and JNK signaling in RAW264.7 cells. We also observed that DNJ, DAB, FAG, and ARG markedly downregulated IL-6 and TNF-α cytokine levels, while APS did not have an obvious effect. CONCLUSIONS: SZ-A attenuates inflammation at least partly by blocking the activation of p38 MAPK, ERK, and JNK signaling pathways. DNJ, FAG, DAB, and ARG are the main constituents in SZ-A that exert anti-inflammatory effects.

Ramulus Mori (Sangzhi) Alkaloids (SZ-A) Ameliorate Glucose Metabolism Accompanied by the Modulation of Gut Microbiota and Ileal Inflammatory Damage in Type 2 Diabetic KKAy Mice.

The novel Traditional Chinese Medicine Ramulus Mori (Sangzhi) alkaloid tablets (SZ-A) are approved by The China National Medical Products Administration for the treatment of type 2 diabetes mellitus (T2DM). However, the extensive pharmacological characteristics and the underlying mechanism are unknown. This study investigated the mechanisms by which SZ-A ameliorates glucose metabolism in KKAy mice, an animal model of T2DM. Diabetic KKAy mice were treated intragastrically with SZ-A once daily for 8 weeks, after which glucose levels, lipid metabolism, gut microbiome, systemic inflammatory factors, luminal concentrations of short-chain fatty acids (fecal samples), and ileal proteomic changes were evaluated. The ileum tissues were collected, and the effects of SZ-A on pathological inflammatory damage were evaluated by hematoxylin and eosin staining, immunofluorescence, and immunohistochemistry. The mRNA and protein expression levels of various inflammatory markers, including monocyte chemoattractant protein-1 and phosphorylated nuclear factor kappa B p65, were detected in the ileum tissues. SZ-A improved glucose metabolism with enhanced insulin response and elevated glucagon-like peptide 1 (GLP-1) nearly 2.7-fold during the glucose tolerance test in diabetic KKAy mice. Gut microbiota analysis demonstrated that SZ-A administration elevated the abundance of Bacteroidaceae and Verrucomicrobia, reduced the levels of Rikenellaceae and Desulfovibrionaceae; and increased the concentrations of fecal acetic and propionic acids compared to the diabetic model group. Additionally, SZ-A markedly improved ileal inflammatory injury and pro-inflammatory macrophage infiltration and improved intestinal mucosal barrier function in diabetic KKAy mice. SZ-A also attenuated the levels of circulating endotoxin, pro-inflammatory cytokines, and chemokines in the mice sera. Collectively, SZ-A ameliorated the overall metabolic profile including glucose and lipid metabolism in KKAy mice, which may be associated with an improvement in GLP-1 and insulin secretion, at least in part by modulating the gut microbiome and relieving the degree of ileal and systemic inflammation.

Fluorescence-enhanced covalent organic framework nanosystem for tumor imaging and photothermal therapy.

Fluorescent dyes, as a key factor in fluorescence imaging, usually exhibit a low signal-to-noise ratio (SNR) due to the limited loading capacities of delivery systems (usually less than 10.0 wt%) and their uncontrolled release. Herein, we developed a type of pH-responsive nanoplatform (MnO2/ZnCOF@Au&BSA) based on a zinc porphyrin covalent organic framework (COF), in which the zinc porphyrin (ZnPor) loading rate is 22.5 wt%. At pH = 7.4, the interlinked ZnPor in the assembly state did not show a fluorescence signal ("off" state). Together with the pH-triggered disintegration of ZnCOF in tumor cells (pH = 5.5), the scattered ZnPor displayed an obvious fluorescence signal recovery ("on" state). Simultaneously, the shed BSA-coated gold nanoparticles ingeniously caused the fluorescence signal to be further amplified through the metal-enhanced fluorescence effect, which was about 3.0-fold higher in vivo than in the free ZnPor group. Combined with the excellent photothermal therapy effect by the nanoplatform itself with the tumor inhibition rate of 79.5%, this nanosystem effectively solves the problem of low loading capacities and imaging SNR by traditional delivery systems, and successfully develops the potential of COFs for fluorescence imaging, achieving the purpose of integration of diagnosis and treatment.

Near-infrared-light induced nanoparticles with enhanced tumor tissue penetration and intelligent drug release.

Tumor tissue presents much denser and stiffer extracellular matrix (ECM), which can hinder the penetration of most nanoparticles (NPs) and contribute to the tumor cell proliferation. Here, NIR-activated losartan was encapsulated in hollow mesoporous prussian blue nanoparticles (HMPBs) to degrade ECM. The results showed that losartan enhanced the penetration of DOX, 1.47% of the injected dose (ID) of DOX reached the tumor tissues, which was 3.00-fold higher than the control group (0.49%). In addition, as the existence of thermo-sensitive lauric acid, (Losartan + DOX)@HMPBs could achieve near "zero drug leakage" during blood circulation, so as to reduce the damage of DOX to normal tissues. Furthermore, the animal experiments proved tumor inhibition ability of (Losartan + DOX)@HMPBs in synergistic of photothermal/chemotherapy, with the tumor growth inhibition rate of 81.3%. Taken together, these findings can be a candidate for developing vectors with enhanced tumor penetration and therapeutic effect in future clinical application. STATEMENT OF SIGNIFICANCE: Due to the existence of denser extracellular matrices (ECM), only 0.7% of the administered nanoparticles dose is delivered to tumor, which will limit the tumors' therapeutic effect. Degradation of ECM can improve the penetration of nanoparticles in tumors. However, no researchers has encapsulated losartan in nanoparticles to degrade ECM. Herein, we developed a NIR induced losartan and DOX co-delivery system based on hollow mesoporous prussian blue nanoparticles (HMPBs) to degrade ECM and improve the penetration of nanoparticles in tumors. The prepared nanoparticles can also acheive near "zero drug leakage" during blood circulation and "fixed-point drug release" in tumor, so as to reduce the damage of DOX to normal tissues. We believe the prepared nanoparticles provide a new platform for cancer treatment.

Hypoglycemic effect and mechanism of honokiol on type 2 diabetic mice.

BACKGROUND: Honokiol is one of the main bioactive constituents of the traditional Chinese herbal drug Magnolia bark (Cortex Magnoliae officinalis, Hou Po). The aim of this study was to probe its anti-type 2 diabetes mellitus effects and the underlying mechanism. METHODS: Type 2 diabetic mouse model was established by intraperitoneally injecting with streptozotocin. Fasting blood glucose, body weight, and lipid profile were measured. The subcutaneous adipose tissue, skeletal muscle, and liver were isolated as well as homogenized. The phospho-insulin receptor ß-subunit (IRß), IRß, phospho-AKT, AKT, phospho-ERK1/2, ERK1/2, phosphotyrosine, and actin were examined by Western blot assay. Cell viability or cytotoxicity was analyzed by using MTT method. The inhibitory potencies of honokiol on the protein tyrosine phosphatase 1B (PTP1B) activity were performed in reaction buffer. Molecular docking and dynamic simulation were also analyzed. RESULTS: In in vivo studies, oral treatment with 200 mg/kg honokiol for 8 weeks significantly decreases the fasting blood glucose in type 2 diabetes mellitus mice. The phosphorylations of the IRß and the downstream insulin signaling factors including AKT and ERK1/2 significantly increase in adipose, skeletal muscle, and liver tissue of the honokiol-treated mice. Moreover, honokiol enhanced the insulin-stimulated phosphorylations of IRß, AKT, and ERK1/2 in a dose-dependent manner in C2C12 myotube cells. Meanwhile, honokiol enhanced insulin-stimulated GLUT4 translocation. Importantly, honokiol exhibited reversible competitive inhibitory activity against PTP1B with good selectivity in vitro and in vivo. Furthermore, using molecular docking and dynamic simulation approaches, we determined the potential binding mode of honokiol to PTP1B at an atomic level. CONCLUSION: These findings indicated the hypoglycemic effects of honokiol and its mechanism that honokiol improved the insulin sensitivity by targeting PTP1B. Therefore, our study may highlight honokiol as a promising insulin sensitizer for the therapy of type 2 diabetes.

A stomatin-like protein encoded by the slp gene of Rhizobium etli is required for nodulation competitiveness on the common bean.

Rhizobium etli strain TAL182 is a competitive strain for effective nodulation of beans. From this strain, a novel gene was isolated, slp, which is 669 bp in size and required for nodulation competition on the common bean. The slp knockout mutant of TAL182 is defective in nodulation competition, shows reduced growth in the presence of 200 mM NaCl, KCl or LiCl and is complemented by the cloned slp gene. The deduced amino acid sequence of slp shows 66-72% similarity to stomatin proteins of Homo sapiens, Mus musculus and Caenorhabditis elegans. Expression of slp in Escherichia coli from a T7 promoter shows a 26 kDa protein which cross-reacts with human-stomatin-specific polyclonal antibody. Like the human stomatin protein, the slp-deduced protein, Slp, is very hydrophilic except for a single hydrophobic membrane-spanning domain. Among various bean-nodulating rhizobia, slp is present in R. etli, Rhizobium leguminosarum bv. phaseoli and Rhizobium tropici type A strains but is absent in R. tropici type B strains. It is also absent in Bradyrhizobium and several other Rhizobium spp.