Determination of Toxic Pyrrolizidine Alkaloids in Traditional Chinese Herbal Medicines by UPLC-MS/MS and Accompanying Risk Assessment for Human Health.

Pyrrolizidine alkaloids (PAs) are a class of natural toxins with hepatotoxicity, genotoxicity and carcinogenicity. They are endogenous and adulterated toxic components widely found in food and herbal products. In this study, a sensitive and efficient ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was used to detect the PAs in 386 kinds of Chinese herbal medicines recorded in the Chinese Pharmacopoeia (2020). The estimated daily intake (EDI) of 0.007 µg/kg body weight (bw)/day was adopted as the safety baseline. The margin of exposure (MOE) approach was applied to evaluate the chronic exposure risk for the genotoxic and carcinogenic potential of PAs. Results showed that PAs was detected in 271 out of 386 samples with a content of 0.1-25,567.4 µg/kg, and there were 20 samples with EDI values above the baseline, 0.007 µg/kg bw/day. Beyond that, the MOE values for 10 out of 271 positive samples were below 10,000. Considering the actual situation, Haber's rule was used to assume two weeks exposure every year during lifetime, and still the MOE values for four out of 271 positive samples were under 10,000, indicating these products may have potential health risk. The developed method was successfully applied to detect the PAs-containing Chinese herbal medicines. This study provides convincing data that can support risk management actions in China and a meaningful reference for the rational and safe use of Chinese herbal medicines.

Simultaneous Determination and Risk Assessment of Pyrrolizidine Alkaloids in Artemisia capillaris Thunb. by UPLC-MS/MS Together with Chemometrics.

Pyrrolizidine alkaloids (PAs) are natural toxins found in some genera of the family Asteraceae. However, it has not been reported whether PAs are present in the widely used Asteraceae plant Artemisia capillaris Thunb. (A. capillaris). The purpose of this study was to establish a sensitive and rapid UPLC-MS/MS method together with chemometrics analysis for simultaneous determination and risk assessment of PAs in A. capillaris. The developed UPLC-MS/MS method was validated and was confirmed to display desirable high selectivity, precision and accuracy. Risk assessment was conducted according to the European Medicines Agency (EMA) guideline. Chemometrics analysis was performed with hierarchical clustering analysis and principal component analysis to characterize the differences between PAs of A. capillaris. Finally, PAs were found in 29 out of 30 samples and at least two were detected in each sample, besides, more than half of the samples exceeded the EMA baseline. Nevertheless, the chemometrics results suggested that the PAs contents of A. capillaris from different sources varied significantly. The method was successfully applied to the detection and risk evaluation of PAs-containing A. capillaris for the first time. This study should provide a meaningful reference for the rational and safe use of A. capillaris.

Microbe-mediate transformation of echinocystic acid by whole cells of filamentous fungus Cunninghamella blakesleana CGMCC 3.910.

Structural modification of echinocystic acid (EA), a pentacyclic triterpenoid with wide spread biological activities was investigated by microbial transformation. Microbe-mediate transformation of EA was carried out by filamentous fungus Cunninghamella blakesleana CGMCC 3.910. Four metabolites 3ß, 7ß, 16α-trihydroxy-olean-12-en-28-oic acid (EA-2); 3ß, 7ß, 16ß,19ß-tetrahydroxy-olean-12-en-28-oic acid (EA-3); 3ß, 7ß, 16α, 21ß-tetrahydroxy-olean-12-en-28-oic acid (EA-4); 3ß, 7ß, 16α-trihydroxy-olean-11, 13(18)-dien-28-oic acid (EA-5) were produced. Structures of transformed products were elucidated by 1D and 2D NMR and HR-MS data. EA-3 and EA-4 were new compounds.

Microbial transformation of pseudoprotodioscin by Gibberella fujikuroi.

Three new (6, 9, and 12) and nine known steroidal saponins were obtained from the fermentation broth of pseudoprotodioscin (PPD) incubated with a fungus Gibberella fujikuroi CGMCC 3.4663. Structures of the metabolites were elucidated by 1-D (1H, 13C), 2-D (HMBC, HSQC, NOESY) NMR, and HR-MS analyses. The biotransformation pathway of pseudoprotodioscin by Gibberella fujikuroi CGMCC 3.4663 was proposed. Compounds 1-11 were tested in vitro for their cytotoxic activities against two human cancer cell lines (HepG2 and Hela). Compounds 1, 6, 9, and 10 exhibited cytotoxic activity against HepG2 cells. Compound 10 exhibited cytotoxicity to Hela cells.

Serum Thyroglobulin-A Sensitive Biomarker of Iodine Nutrition Status and Affected by Thyroid Abnormalities and Disease in Adult Populations.

OBJECTIVE: To evaluate the usefulness of the thyroglobulin (Tg) level in adults as a nutritional biomarker of iodine status and to identify the factors related to the serum Tg level. METHODS: A cross-sectional study was conducted in adult populations of areas differing in iodine nutrition from three provinces (Autonomous Region) in China. Serum levels of thyroid hormones and Tg as well as thyroid autoantibodies were measured. The thyroid volume and nodule were measured by ultrasound. A multivariate linear regression analysis was used to assess iodine intake and other indeterminate factors associated with the serum Tg level. RESULTS: A total of 573 adults were recruited for this study. The serum Tg levels differed significantly among the three groups (22.27 µg/L, 9.73 µg/L and 15.77 µg/L in the excess, more-than-adequate, and deficient groups, respectively). The results of multivariate linear regression analysis indicate that excess and deficient iodine intake, goiter, thyroid nodule, hypothyroidism are significantly related with higher Tg level, and TgAb positivity is significantly related with lower serum Tg. CONCLUSION: The serum Tg level reflects abnormal thyroid function and is a sensitive functional biomarker of iodine nutrition status.

Generation and analysis of the Rett syndrome-associated MeCP2- null rat model.

MeCP2 mutations are associated with the Rett syndrome (RTT). Currently, there is an urgent need for new animal models for RTT as the existing MeCP2 knockout mouse models fail to fully mimic the pathogenesis and symptoms of RTT patients. In order to investigate the role of MeCP2 in brain development and RTT pathogenesis, we aimed to set up the MeCP2-null rat model using the CRISPR/Cas9 technology. Firstly we constructed the MeCP2 targeting vector and then microinjected Cas9 mRNA and sgRNA mixtures into fertilized ova of SD rats. The sgRNA was designed to target the exon 2 of MeCP2. Next, knockout rats were confirmed using DNA sequencing and Western blotting. Lastly, phenotypes including growth and behaviors of MeCP2 knockout rats were analyzed. The results indicated that the MeCP2 knockout rats showed body weight loss, anxiety tendency and cognitive deficits. The MeCP2-null rat model established in this study recapitulates the major symptoms of RTT patients and provides an alternative tool for future studies of MeCP2 functions.

B7-H3 promotes aggression and invasion of hepatocellular carcinoma by targeting epithelial-to-mesenchymal transition via JAK2/STAT3/Slug signaling pathway.

BACKGROUND: B7-homologue 3 (B7-H3), a recently identified immunoregulatory protein, has been shown to be overexpressed in human hepatocellular carcinoma (HCC). However, whether the dynamic expression pattern of B7-H3 contributes to early invasion of HCC is largely unknown. In addition, the biological roles of B7-H3 in HCC are still unclear. Herein, we are going to examine B7-H3 expression profile and its clinicopathological significance in primary and metastatic HCC, and further determine whether B7-H3 knockdown simulates different pathological states of HCC progression and metastasis. METHODS: Using immunohistochemistry, B7-H3 expression was studied on 116 HCC containing primary and metastatic HCCs. Survival curves and log-rank tests were used to test the association of B7-H3 expression with survival. HCC cells with B7-H3 depletion were established by RNA interference to investigate the effect of B7-H3 on cell proliferation, apoptosis, migration and invasion in vitro. RESULTS: Statistical analysis of clinical cases revealed that B7-H3 high expression group had inclinations towards late TNM stage, the presence of vascular invasion, lymph metastasis, and the formation of microsatellite tumors. Increased intensity of tumor B7-H3 staining was detected more significantly in metastatic HCC tumors. Consistently in experiments performed in vitro, B7-H3 was able to stimulate the wound healing, metastasis and invasion of hepatoma cells by targeting epithelial-to-mesenchymal transition (EMT) via JAK2/Stat3/Slug signaling pathway, while no obvious influence on cell growth and apoptosis. CONCLUSION: B7-H3 in the regulation of the metastatic capacity of HCC cells makes itself a promising therapeutic target for anti-metastasis therapy.

Unusual microbial lactonization and hydroxylation of asiatic acid by Umbelopsis isabellina.

Asiatic acid (1) is a natural triterpenoid isolated from Centella asiatica. This paper reports the microbial transformation of asiatic acid by an endophytic fungus Umbelopsis isabellina to obtain derivatives potentially useful for further studies. Incubation of asiatic acid with U. isabellina afforded two derivatives 2α,3ß,7ß, 23-tetrahydroxyurs-12-ene-28-oic acid (2) and 2α,3ß,7ß,23-tetrahydroxyurs-11-ene-28,13-lactone (3). The structures of these compounds were elucidated by spectral data. Compound 3 has formed an unusual lactone. These two products are new compounds. The possible transformation passway was also discussed.

Low Selenium and Low Protein Exacerbate Myocardial Damage in Keshan Disease by Affecting the PINK1/Parkin-mediated Mitochondrial Autophagy Pathway.

OBJECTIVE: Keshan disease (KD) is a myocardial mitochondrial disease closely related to insufficient selenium (Se) and protein intake. PTEN induced putative kinase 1 (PINK1)/Parkin mediated mitochondrial autophagy regulates various physiological and pathological processes in the body. This study aimed to elucidate the relationship between PINK1/Parkin-regulated mitochondrial autophagy and KD-related myocardial injury. METHODS: A low Se and low protein animal model was established. One hundred Wistar rats were randomly divided into 5 groups (control group, low Se group, low protein group, low Se + low protein group, and corn from KD area group). The JC-1 method was used to detect the mitochondrial membrane potential (MMP). ELISA was used to detect serum creatine kinase MB (CK-MB), cardiac troponin I (cTnI), and mitochondrial-glutamicoxalacetic transaminase (M-GOT) levels. RT-PCR and Western blot analysis were used to detect the expression of PINK1, Parkin, sequestome 1 (P62), and microtubule-associated proteins1A/1B light chain 3B (MAP1LC3B). RESULTS: The MMP was significantly decreased and the activity of CK-MB, cTnI, and M-GOT significantly increased in each experimental group (low Se group, low protein group, low Se + low protein group and corn from KD area group) compared with the control group (P<0.05 for all). The mRNA and protein expression levels of PINK1, Parkin and MAP1LC3B were profoundly increased, and those of P62 markedly decreased in the experimental groups compared with the control group (P<0.05 for all). CONCLUSION: Low Se and low protein levels exacerbate myocardial damage in KD by affecting the PINK1/Parkin-mediated mitochondrial autophagy pathway.

LPI-SKMSC: Predicting LncRNA-Protein Interactions with Segmented k-mer Frequencies and Multi-space Clustering.

 Long noncoding RNAs (lncRNAs) have significant regulatory roles in gene expression. Interactions with proteins are one of the ways lncRNAs play their roles. Since experiments to determine lncRNA-protein interactions (LPIs) are expensive and time-consuming, many computational methods for predicting LPIs have been proposed as alternatives. In the LPIs prediction problem, there commonly exists the imbalance in the distribution of positive and negative samples. However, there are few existing methods that give specific consideration to this problem. In this paper, we proposed a new clustering-based LPIs prediction method using segmented k-mer frequencies and multi-space clustering (LPI-SKMSC). It was dedicated to handling the imbalance of positive and negative samples. We constructed segmented k-mer frequencies to obtain global and local features of lncRNA and protein sequences. Then, the multi-space clustering was applied to LPI-SKMSC. The convolutional neural network (CNN)-based encoders were used to map different features of a sample to different spaces. It used multiple spaces to jointly constrain the classification of samples. Finally, the distances between the output features of the encoder and the cluster center in each space were calculated. The sum of distances in all spaces was compared with the cluster radius to predict the LPIs. We performed cross-validation on 3 public datasets and LPI-SKMSC showed the best performance compared to other existing methods. Experimental results showed that LPI-SKMSC could predict LPIs more effectively when faced with imbalanced positive and negative samples. In addition, we illustrated that our model was better at uncovering potential lncRNA-protein interaction pairs.

Oral exposure to the herbicide simazine induces mouse spleen immunotoxicity and immune cell apoptosis.

The authors investigated the toxic effects of simazine on mice spleen immune cells and the underlying mechanisms. Mice were given simazine at 0, 90, 200, or 400 mg/kg by gastric gavage for 3 weeks. The authors then measured immune cell proliferation and the expressions of apoptosis-related proteins (Bcl-2, Bax, Fas, and caspase-3), spleen cell intracellular [Ca(2+)], cellular oxidative stress level, and immune functions. After 3 weeks, mice exposed to simazine had reduced proliferation of both spleen T and B cells. The number of spleen CD4(+) T lymphocytes decreased with simazine exposure, while CD8(+) T cells remained unchanged. Exposure to simazine resulted in reduced immune function, higher intracellular [Ca(2+)], and oxidative stress. Finally, simazine induced spleen immune cells apoptosis by reducing Bcl-2, while increasing Fas and Caspase-3 level. Overall, the immunotoxicity of simazine may involve the induction of immune cell apoptosis and alterations in the immune and physiological functions of spleen cells.

[Study of using an individualized treatment strategy to treat patients with chronic hepatitis C].

OBJECTIVE: To investigate the outcomes of chronic hepatitis C (CHC) patients treated with antiviral regimens of interferon (IFN) plus ribavirin (RBV) using individualized doses and durations. METHODS: This study was designed as an open-label, prospective clinical trial to analyze the virological responses of 169 CHC patients who received individualized dosages of IFNa-2b or pegylated (Peg)IFNa-2a combined with RBV based on their weight ( less than 60 kg or more than or equal to 60 kg), age (less than 65 years or 65-75 years), morbid state (liver cirrhosis or not), and complications (such as heart disease, diabetes, thyroid disorder). Treatment duration was calculated using the time required to induce HCV RNA negativity. The rates of virological response and adverse effects among the different groups were compared. RESULTS: The IFNa-2b treatment was given to 116 patients, and PegIFNa-2a was given to 53 patients. Compared to the IFNa-2b group, the PegIFNa-2a group showed significantly higher rates of complete early virological response (cEVR; 76.7% vs. 92.5%, P less than 0.05) and sustained virological response (SVR; 53.6% vs. 92.3%, P less than 0.05) among the patients who had completed their course of treatment; the rapid virological response (RVR) rate was also higher for the PegIFNa-2a group but the difference did not reach statistical significance (48.7% vs. 60.4%, P more than 0.05). Seventy-eight patients received the routine dose, and 91 patients received the low dose; there were no significant differences between these two groups for RVR (53.8% vs. 58.9%, P more than 0.05), cEVR (78.0% vs. 80.8%, P more than 0.05), or SVR (65.5% vs. 58.3%, P more than 0.05). CONCLUSION: Use of an individualized antiviral treatment strategy designed according to the patient's baseline condition, early viral kinetics, and tolerability to adverse reactions can achieve a high rate of SVR, as well as improve the safety, prognosis, and cost-effectiveness associated with treating CHC patients.

[Relation of IL-17 polymorphisms and serum levels in patients with chronic HCV infection].

OBJECTIVE: To investigate the association of single nucleotide polymorphisms (SNPs) in the interleukin 17 (IL-17) gene and serum protein levels in patients with chronic hepatitis C virus (HCV) infection. METHODS: A total of 228 patients with chronic HCV infection and 81 healthy controls were enrolled in the study. The frequencies of IL-17 rs8193036 and rs2275913 polymorphisms were detected by the TaqMan SNP genotyping assay. Serum levels of IL-17 protein were detected by ELISA. Pairwise comparisons were made by the Chi-square test, and the significance of between-group differences was assessed by the Student's t-test with P less than 0.05. RESULTS: The patients with chronic HCV infection and the healthy controls showed similar frequencies of the rs8193036 C/T allele (x2 = 1.428, P = 0.232) and the rs2275913 A/G allele (x2 = 0.106, P = 0.744). In addition, the two groups showed similar distribution of the rs8193036 CC (chronic HCV infection: 46.49% vs. healthy controls: 41.98%), CT (45.61% vs. 44.44%) and TT (7.89% vs. 13.58%) genotypes (x2 = 2.346, P = 0.309), and of the rs2275913 AA (16.23% vs. 13.58%), AG (48.25% vs. 50.62%) and GG (35.53% vs. 35.80%) genotypes (x2 = 0.340, P = 0.844). Subgroup analysis of chronic HCV infection patients stratified according to HCV genotypes 1 and 2 showed no differences in the distribution of rs8193036 and rs2275913 alleles (x2 = 1.127, P = 0.288; x2 = 1.088, P = 0.297) and genotypes (x2 = 2.825, P = 0.246; x2 = 0.970, P = 0.616). However, the chronic HCV infection group did show significantly higher levels of serum IL-17 than the controls (97.67+/-39.68 vs. 71.60+/-19.78 pg/ml, t = 2.414, P = 0.033). CONCLUSION: Chronic HCV infection is associated with increased serum IL-17; however, the IL-17 polymorphisms rs8193036 and rs2275913 were not associated with chronic HCV infection susceptibility in this study's Chinese cohort.

Circ-100290 Regulates Autophagy-Mediated Angiogenesis of Human Umbilical Vein Endothelial Cells Induced by Conditioned Medium of Human Amniotic Mesenchymal Stem Cells.

BACKGROUND: Conditioned medium (CM) from human amnion-derived mesenchymal stem cells (hAMSCs) exhibits excellent pro-angiogenic capacity, and circ-100290 participates in this process. Autophagy is involved in the relevant mechanisms of angiogenesis, but it is unclear whether autophagy is related to the pro-angiogenesis effect of hAMSCs. This research sought to determine whether autophagy involved in the process of pro-angiogenesis induced by hAMSCs might be regulated by circ-100290. METHODS: Upon treatment with CM from hAMSC or 3-methyladenine (3-MA), autophagosomes in human umbilical vein endothelial cells (HUVECs) were observed by transmission electron microscopy. HUVECs' angiogenic ability was evaluated by in vitro assays (transwell, wound healing, tube formation) and an in vivo Matrigel plug assay. Specific small interfering RNAs (siRNA) or inhibitors were used to regulate circ-100290 expression. Additionally, western blot and quantitative reverse transcription-polymerase chain reaction (RT-qPCR) were used to evaluate expression of the following indicators: Beclin-1, LC3-II, matrix metalloproteinase 2 (MMP2), MMP9, vascular endothelial growth factor (VEGF)-A, and endothelial nitric oxide synthase (eNOS). RESULTS: Incubation with hAMSC-CM increased autophagy, angiogenesis and the expressions of VEGF-A and eNOS in HUVECs, all of which were inhibited by 3-MA. Knocking down circ-100290 in hAMSC-CM-treated HUVECs reduced Beclin-1 expression and inhibited autophagy. This resulted in lower angiogenesis in the Matrigel plug assay showing that reduced angiogenesis occurred after circ-100290 silencing in hAMSC-CM-treated HUVECs. CONCLUSIONS: Circ-100290 promotes autophagy-mediated angiogenesis in hAMSC-CM-treated HUVECs.

Bioactive secondary metabolites from endophytic strains of Neocamarosporium betae collected from desert plants.

Endophytic fungi from desert plants belong to a unique microbial community that has been scarcely investigated chemically and could be a new resource for bioactive natural products. In this study, 13 secondary metabolites (1-13) with diverse carbon skeletons, including a novel polyketide (1) with a unique 5,6-dihydro-4H,7H-2,6-methanopyrano[4,3-d][1,3]dioxocin-7-one ring system and three undescribed polyketides (2, 7, and 11), were obtained from the endophytic fungus Neocamarosporium betae isolated from two desert plant species. Different approaches, including HR-ESI-MS, UV spectroscopy, IR spectroscopy, NMR, and CD, were used to determine the planar and absolute configurations of the compounds. The possible biosynthetic pathways were proposed based on the structural characteristics of compounds 1-13. Compounds 1, 3, 4, and 9 exhibited strong cytotoxicity toward HepG2 cells compared with the positive control. Several metabolites (2, 4-5, 7-9, and 11-13) were phytotoxic to foxtail leaves. The results support the hypothesis that endophytic fungi from special environments, such as desert areas, produce novel bioactive secondary metabolites.

The Raf-1 inhibitor GW5074 and the ERK1/2 pathway inhibitor U0126 ameliorate PC12 cells apoptosis induced by 6-hydroxydopamine.

6-Hydroxydopamine (6-OHDA) is a widely used dopaminergic neurotoxin that leads to cell apoptosis in vivo and in vitro, and is a widely accepted experimental model of neurodegeneration in Parkinson's disease. However, the molecular mechanisms responsible for 6-OHDA-induced cell apoptosis are unclear. We found that the treatment of PC12 cells with 6-OHDA resulted in a significant decrease in cell viability and elevated apoptosis as detected by MTT assay, Hoechst 33258 staining, and flow cytometry. In addition, 6-OHDA induced a time-dependent phosphorylation of ERK1/2 at Thr-202/Tyr-204 and of Raf-1 at Ser-338, but a decreased level of Raf-1 phosphorylation at Ser-259. Phosphorylation of ERK1/2 at Thr-202/Tyr-204 and Raf-1 at Ser-338 were inhibited by the Raf-1 inhibitor GW5074, while the ERK1/2 pathway inhibitor U0126 decreased phosphorylation of ERK1/2. Furthermore, 6-OHDA-induced PC12 cells apoptosis was suppressed by GW5074 and U0126. Our results suggest that GW5074 and U0126 act as neuroprotants against 6-OHDA toxicity in PC12 cells by modulating Raf-1/ERK1/2 signaling systems.

Biotransformation of ursolic acid by an endophytic fungus from medicinal plant Huperzia serrata.

Endophytic fungi were used not only for their producing bioactive products but also for their ability to transform natural compounds. An endophytic fungus, isolated from medicinal plant Huperzia serrata, was identified as Umbelopsis isabellina based on the internal transcribed spacer of ribosomal DNA (rDNA-ITS) region. It was used to transform ursolic acid (1), a pentacyclic triterpene. Incubation of ursolic acid with U. isabellina afforded three products, 3ß-hydroxy-urs-11-en-28,13-lactone (2), 3ß,7ß-dihydroxy-urs-11-en-28,13-lactone (3), 1ß,3ß-dihydroxy-urs-11-en-28,13-lactone (4). Although product 2 was a known compound, it was first obtained by microbial transformation. Products 3 and 4 were new compounds. The structural elucidation of the three compounds was achieved mainly by the 1D- and 2D-NMR, MS, IR data. The endophytic fungus U. isabellina can hydroxyate the C12-C13 double bond at position 13 of ursolic acid 1 and form a five-member lactone effectively. In the meantime, this fungus can also introduce the hydroxyl group at C-1 or C-7 of ursolic acid 1.

Microbial transformation of diosgenin by filamentous fungus Cunninghamella echinulata.

Microbial transformation of diosgenin (1) by suspended-cell cultures of the filamentous fungus Cunninghamella echinulata CGMCC 3.2000 was investigated. Incubation of the substrate diosgenin (1) with this fungus led to the isolation of three products: two known compounds, (25R)-spirost-5-en-3ß,7ß,12ß-triol and (25R)-spirost-5-en-3ß,7ß,11α-triol, and a new compound (25R)-spirost-5-en-3ß,7α,11α-triol. The structural elucidations of the three compounds were achieved mainly by the MS, 1D and 2D NMR spectroscopic methods and comparison with known compounds. C. echinulata CGMCC 3.2000 has not been used before in the biotransformation of diosgenin.

Diaqua-bis-[8-ethyl-5-oxo-2-(piperazin-4-ium-1-yl)-5,8-dihydro-pyrido[2,3-d]pyrimidine-6-carboxyl-ato]copper(II) bis[4-(4-carboxyphenoxy)benzoate].

In the title compound, [Cu(C(14)H(17)N(5)O(3))(2)(H(2)O)(2)](C(14)H(9)O(5))(2), the Cu(2+) atom, located on an inversion centre, exhibits a distorted octa-hedral geometry, coordinated by four O atoms from two pipemidic acid ligands in equatorial positions and two water mol-ecules in axial positions. The pipemidic acid ligand acts a bidentate ligand and the single deprotonated 4,4'-oxydibenzoic acid acts as an anion. Classical N-H⋯O and O-H⋯O hydrogen bonds are present in the crystal structure.