Directed evolution of Baeyer-Villiger monooxygenase for highly secretory expressed in Pichia pastoris and efficient preparation of chiral pyrazole sulfoxide.

The methylotrophic yeast Pichia pastoris (Komagataella phaffii) is a highly distinguished expression platform for the excellent synthesis of various heterologous proteins in recent years. With the advantages of high-density fermentation, P. pastoris can produce gram amounts of recombinant proteins. While not every protein of interest can be expressed to such high titers, such as Baeyer-Villiger monooxygenase (BVMO) (AcPSMO) which is responsible for pyrazole sulfide asymmetric oxidation. In this work, an excellent yeast expression system was established to facilitate efficient AcPSMO expression, which exhibited 9.5-fold enhanced secretion. Subsequently, an ultrahigh throughput screening method based on fluorescence-activated cell sorting by fusing super folder green fluorescent protein (sfGFP) in the C-terminal of AcPSMO was developed, and directed evolution was performed. The protein expression level of the superior mutant AcPSMOP1 (S58T/T252P/E336N/H456D) reached 84.6 mg/L at 100 mL shaking flask, which was 4.7 times higher than the levels obtained with the wild-type. Finally, the optimized chassis cells were used for high-density fermentation on a 5-L scale, and AcPSMOP1 protein yield of 3.4 g/L was achieved, representing approximately 85% of the total protein secreted. By directly employing the pH-adjusted supernatant as a biocatalyst, 20 g/L pyrmetazole sulfide was completely transformed into the corresponding (S)-sulfoxide, with a 78.8% isolated yield. This work confers dramatic benefits for efficient secretion of other BVMOs in P. pastoris.

Quercetin protects against diabetic encephalopathy via SIRT1/NLRP3 pathway in db/db mice.

Epidemiological studies have found that diabetes and cognitive dysfunction are closely related. Quercetin has been certified with the effect on improving diabetes mellitus (DM) and cognitive impairment. However, the effect and related mechanism of quercetin on diabetic encephalopathy (DE) are still ambiguous. In this study, we used the db/db mice (diabetic model) to discover whether quercetin could improve DE through the Sirtuin1/NLRP3 (NOD-, LRR- and pyrin domain-containing 3) pathway. Behavioural results (Morris water maze and new object recognition tests) showed that quercetin (70 mg/kg) improved the learning and memory. Furthermore, quercetin alleviated insulin resistance and the level of fasting blood glucose. Besides, Western blot analysis also showed that quercetin increased the protein expressions of nerve- and synapse-related protein, including postsynapticdensity 93 (PSD93), postsynapticdensity 95 (PSD95), brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the brain of db/db mice. Quercetin also increased the protein expression of SIRT1 and decreased the expression of NLRP3 inflammation-related proteins, including NLRP3, the adaptor protein ASC and cleaved Caspase-1, the pro-inflammatory cytokines IL-1ß and IL-18. In conclusion, the present results indicate that the SIRT1/NLRP3 pathway may be a crucial mechanism for the neuroprotective effect of quercetin against DE.

Sodium tanshinone IIA sulfonate protects against Aß-induced cell toxicity through regulating Aß process.

Sodium tanshinone IIA sulfonate (STS) has been reported to prevent Alzheimer's disease (AD). However, the mechanism is still unknown. In this study, two in vitro models, Aß-treated SH-SY5Y cells and SH-SY5Y human neuroblastoma cells transfected with APPsw (SH-SY5Y-APPsw cells), were employed to investigate the neuroprotective of STS. The results revealed that pretreatment with STS (1, 10 and 100 µmol/L) for 24 hours could protect against Aß (10 µmol/L)-induced cell toxicity in a dose-dependent manner in the SH-SY5Y cells. Sodium tanshinone IIA sulfonate decreased the concentrations of reactive oxygen species, malondialdehyde, NO and iNOS, while increased the activities of superoxide dismutase and glutathione peroxidase in the SH-SY5Y cells. Sodium tanshinone IIA sulfonate decreased the levels of inflammatory factors (IL-1ß, IL-6 and TNF-α) in the SH-SY5Y cells. In addition, Western blot results revealed that the expressions of neprilysin and insulin-degrading enzyme were up-regulated in the SH-SY5Y cells after STS treatment. Furthermore, ELISA and Western blot results showed that STS could decrease the levels of Aß. ELISA and qPCR results indicated that STS could increase α-secretase (ADAM10) activity and decrease ß-secretase (BACE1) activity. In conclusion, STS could protect against Aß-induced cell damage by modulating Aß degration and generation. Sodium tanshinone IIA sulfonate could be a promising candidate for AD treatment.

Long noncoding RNA MEG3 regulates rheumatoid arthritis by targeting NLRC5.

Rheumatoid arthritis (RA) is one of the chronic systemic autoimmune diseases that cardinally affect the joints. Many people all over the world suffer from the disease. Fibroblast-like synoviocytes (FLSs) play a significant role in the occurrence and development of RA. The long noncoding RNA maternally expressed gene 3 (MEG3) is an imprinted gene, which participates in various cancers as a tumor suppressor. Previous studies have shown that nucleotide oligomerization domain (NOD)-like receptors 5 (NLRC5) plays a key role in inflammatory and autoimmune diseases. Nonetheless, we know very little about the biofunctionality of MEG3 during the development of RA. In this paper, we used complete Freund's adjuvant (CFA)-induced rats as RA animal models. The level of MEG3 significantly reduced in CFA-induced synovial tissues and FLSs, whereas the NLRC5 levels were increased. Enforced expression of MEG3 may be responsible for the decreased level of NLRC5 and inflammatory cytokine level. The results of methylation-specific PCR suggested that the MEG3 gene promoter was significantly methylated in CFA-induced synovial tissues and FLSs. More important, hypermethylation of MEG3 promoter could be inhibited by 5-aza-2-deoxycytidine (5-azadC; methylation inhibitor). Besides, the expression of NLRC5 significantly decreased followed by 5-azadc. Furthermore, DNA methyltransferases 1 (DNMT1) increased in CFA-induced synovial tissues and cells. These results indicated that MEG3 regulates RA by targeting NLRC5 potentially.

[Prognostic Value of Prothrombin Time and Activated Partial Thromboplastin Time in Newly Diagnosed Patients with Multiple Myeloma].

OBJECTIVE: To evaluate the clinical and prognostic value of prothrombin time (PT) and activated partial thromboplastin time (APTT) in newly diagnosed patients with multiple myeloma (MM). METHODS: The clinical data of 116 newly diagnosed MM patients in the Second Hospital and Third Hospital of Shanxi Medical University from October 2014 to March 2022 were analyzed retrospectively, and the patients were divided into two groups: normal PT and APTT group and prolonged PT or APTT group. The differences in sex, age, classification, staging, bleeding events, laboratory indicators [including hemoglobin (Hb), platelet count (PLT), serum calcium, serum albumin (ALB), lactate dehydrogenase (LDH), serum creatinine and ß2-microglobulin], and cytogenetic characteristics between the two groups of patients were compared. The effect of prolonged PT or APTT on survival of patients with MM was analyzed. RESULTS: Compared with patients in normal PT and APTT group, patients in prolonged PT or APTT group were more likely to experience bleeding events (χ2=5.087, P =0.024), with lower ALB levels (χ2=4.962, P =0.026) and PLT levels (χ2=4.309, P =0.038), and higher serum calcium levels (χ2=5.056, P =0.025). The positive rates of del17p, del13q and 1q21+ in prolonged PT or APTT group were higher than those in normal PT and APTT group, but the difference was not statistically significant (P >0.05). K-M survival analysis showed that the prolonged PT or APTT group had a shorter median progression-free survival (PFS) (P =0.032) and overall survival (OS) (P =0.032). Multivariate Cox analysis showed that prolonged PT or APTT (HR=2.116, 95%CI :1.025-4.372, P =0.043) and age ≥65 years (HR=2.403, 95%CI : 1.195-4.836, P =0.014) were independent risk factor for OS in newly diagnosed MM patients. However, prolonged PT or APTT had no significant effect on PFS of newly diagnosed MM patients (HR=1.162, 95%CI : 0.666-2.026, P =0.597). CONCLUSION: Newly diagnosed MM patients with prolonged PT or APTT have worse clinical indicators, shorter PFS and OS. Prolonged PT or APTT is an independent risk factor for OS in MM patients.

Multifaceted roles of lymphatic and blood endothelial cells in the tumor microenvironment of hepatocellular carcinoma: A comprehensive review.

The tumor microenvironment is a complex network of cells, extracellular matrix, and signaling molecules that plays a critical role in tumor progression and metastasis. Lymphatic and blood vessels are major routes for solid tumor metastasis and essential parts of tumor drainage conduits. However, recent studies have shown that lymphatic endothelial cells (LECs) and blood endothelial cells (BECs) also play multifaceted roles in the tumor microenvironment beyond their structural functions, particularly in hepatocellular carcinoma (HCC). This comprehensive review summarizes the diverse roles played by LECs and BECs in HCC, including their involvement in angiogenesis, immune modulation, lymphangiogenesis, and metastasis. By providing a detailed account of the complex interplay between LECs, BECs, and tumor cells, this review aims to shed light on future research directions regarding the immune regulatory function of LECs and potential therapeutic targets for HCC.

Dichotomous roles of ADAR1 in liver hepatocellular carcinoma and kidney renal cell carcinoma: Unraveling the complex tumor microenvironment and prognostic significance.

BACKGROUND: Adenosine deaminase acting on RNA 1 (ADAR1) is an RNA-editing enzyme that significantly impacts cancer progression and various biological processes. The expression of ADAR1 mRNA has been examined in multiple cancer types using The Cancer Genome Atlas (TCGA) dataset, revealing distinct patterns in kidney chromophobe (KICH), kidney renal clear cell carcinoma (KIRC), kidney renal papillary cell carcinoma (KIRP), and liver hepatocellular carcinoma (LIHC) compared to normal controls. However, the reasons for these differential expressions remain unclear. METHODS: In this study, we performed RT-PCR and western blotting (WB) to validate ADAR1 expression patterns in clinical tissue samples. Survival analysis and immune microenvironment analysis (including immune score and stromal score) were conducted using TCGA data to determine the specific cell types associated with ADAR1, as well as the key genes in those cell types. The relationship between ADAR1 and specific cell types' key genes was verified by immunohistochemistry (IHC), using clinical liver and kidney cancer samples. RESULTS: Our validation analysis revealed that ADAR1 expression was downregulated in KICH, KIRC, and KIRP, while upregulated in LIHC compared to normal tissues. Notably, a significant correlation was found between ADAR1 mRNA expression and patient prognosis, particularly in KIRC, KIRP, and LIHC. Interestingly, we observed a positive correlation between ADAR1 expression and stromal scores in KIRC, whereas a negative correlation was observed in LIHC. Cell type analysis highlighted distinct relationships between ADAR1 expression and the two stromal cell types, blood endothelial cells (BECs) and lymphatic endothelial cells (LECs), and further determined the signature gene claudin-5 (CLDN5), in KIRC and LIHC. Moreover, ADAR1 was inversely related with CLDN5 in KIRC (n = 26) and LIHC (n = 30) samples, verified via IHC. CONCLUSIONS: ADAR1 plays contrasting roles in LIHC and KIRC, associated with the enrichment of BECs and LECs within tumors. This study sheds light on the significant roles of stromal cells within the complex tumor microenvironment (TME) and provides new insights for future research in tumor immunotherapy and precision medicine.

Internalizing and externalizing problems mediate the relationship between maltreatment and self-harm among UK adolescents.

BACKGROUND: Maltreatment is a significant predictive factor for self-harm in adolescents. Internalizing and externalizing problems are both common psychopathological issues in adolescents. This study aimed to look into the link between maltreatment and self-harm in a large sample of adolescents in the UK, as well as the mediating effects that internalizing and externalizing problems play in this link. METHODS: Data were pulled from the UK Millennium Cohort Study, and a total of 8894 adolescents were included in this analysis. All variables were assessed by Questionnaires. Path analysis was performed to assess the mediating effects of internalizing and externalizing problems in the link between maltreatment and self-harm. RESULTS: 23.4 % of samples reported self-harm incidents during the preceding 12 months. Emotional abuse and physical abuse were significantly related to self-harm, and adolescents who had experienced multiple forms of maltreatment were more prone to self-harm. Mediation analysis revealed that internalizing problems were the primary mediator in the link between emotional abuse and self-harm, with the mediation effect size being 0.29. Internalizing and externalizing problems performed similarly in the link between physical abuse and self-harm, with mediation effect sizes of 0.23 and 0.19, respectively. LIMITATIONS: The majority of the data was gathered through self-reporting. CONCLUSIONS: Emotional abuse and physical abuse were significant predictors of self-harm, and their links with self-harm were partially mediated via internalizing and externalizing problems. Better supervision of maltreatment, and timely intervention for both internalizing and externalizing problems, are critical in preventing self-harm among adolescents.

[Clinical Characteristics and Nomogram Model of Nosocomial Infection in Patients with Newly Diagnosed Multiple Myeloma].

OBJECTIVE: To explore the clinical characteristics of nosocomial infection in newly diagnosed multiple myeloma(NDMM) patients, and establish a predictive nomogram model. METHODS: The clinical data of 164 patients with MM who were treated in Shanxi Bethune Hospital from January 2017 to December 2021 were retrospectively analyzed. The clinical characteristics of infection were analyzed. Infections were grouped as microbiologically defined infections and clinically defined infections. Univariate and multivariate regression models were used to analyze the risk factors of infection. A nomogram was established. RESULTS: 164 patients with NDMM were included in this study, and 122 patients (74.4%) were infected. The incidence of clinically defined infection was the highest (89 cases, 73.0%), followed by microbial infection (33 cases, 27.0%). Among 122 cases of infection, 89 cases (73.0%) had CTCAE grade 3 or above. The most common site of infection was lower respiratory in 52 cases (39.4%), upper respiratory tract in 45 cases (34.1%), and urinary system in 13 cases (9.8%). Bacteria(73.1%) were the main pathogens of infection. Univariate analysis showed that ECOG ≥2, ISS stage Ⅲ, C-reactive protein ≥10 mg/L, serum Creatinine ≥177 µmol/L had higher correlation with nosocomial infection in patients with NDMM. Multivariate regression analysis showed that C-reactive protein ≥10 mg/L (P＜0.001), ECOG ≥2 (P=0.011) and ISS stage Ⅲ （P=0.024） were independent risk factors for infection in patients with NDMM. The nomogram model established based on this has good accuracy and discrimination. The C-index of the nomogram was 0.779（95%CI: 0.682-0.875）. Median follow-up time was 17.5 months, the median OS of the two groups was not reached (P=0.285). CONCLUSION: Patients with NDMM are prone to bacterial infection during hospitalization. C-reactive protein ≥10 mg/L, ECOG ≥2 and ISS stage Ⅲ are the risk factors of nosocomial infection in NDMM patients. The nomogram prediction model established based on this has great prediction value.

[Clinical Characteristics and Risk Factors for 30-Day Mortality in Patients with Hematologic Diseases Infected by Carbapenem-Resistant Organisms].

OBJECTIVE: To explore the clinical characteristics of hospitalized patients with hematologic diseases complicated with carbapenem-resistant organisms (CRO) infection and analyze the risk factors of 30-day all-cause mortality. METHODS: The clinical data and laboratory test data of 77 hospitalized patients with hematologic diseases complicated with CRO infection in department of hematology of the Third Hospital of Shanxi Medical University from January 2015 to December 2020 were retrospectively analysed, the risk factors of 30-day all-cause mortality after CRO infection were analyzed by multivariate logistic regression. RESULTS: Among the total of 77 patients with hematologic diseases complicated with CRO infection, 29 died and 48 survived within 30 days of infection, with a case fatality rate of 37.66%. A total of 93 strains of CRO were isolated from these patients, of which Acinetobacter baumannii had the highest detection rate (25.81%, 24/93), followed by Pseudomonas aeruginosa (18.28%, 17/93). The lung was the most common site of CRO infection. The detected pathogens were highly resistant to carbapenems, and 64.52% (60/93) of the pathogens were resistant to imipenem with minimum inhibitory concentration (MIC)≥16 µg/ml. The results of the univariate analysis showed that albumin concentration <25 g/L (P =0.048), serum creatinine concentration≥120 µmol/L (P =0.023), age-adjusted Charlson comorbidity index (ACCI) (P =0.037) and primary treatments (supportive treatment, immunosuppressive therapy, chemotherapy, HSCT) (P =0.048) were significantly associated with 30-day all-cause mortality after infection. The results of multivariate logistic regression analysis showed that when CRO infection confirmed, albumin concentration <25 g/L (P =0.014, OR=6.171), serum creatinine concentration≥120 µmol/L (P =0.009, OR=10.867) were independent risk factors for 30-day mortality of patients with hematologic diseases complicated with CRO infection. CONCLUSION: The mortality rate of CRO-infected patients with hematologic diseases is high. The detected pathogenic bacteria are highly resistant to imipenem. The albumin concentration <25 g/L and the serum creatinine concentration≥ 120 µmol/L at diagnosis of CRO infection were independent risk factors for 30-day mortality of the patients with hematologic diseases.

Physiological and transcriptomic analysis dissects the molecular mechanism governing meat quality during postmortem aging in Hu sheep (Ovis aries).

Introduction: Hu sheep, known for its high quality and productivity, lack fundamental scientific research in China. Methods: This study focused on the effects of 24 h postmortem aging on the meat physiological and transcriptomic alteration in Hu sheep. Results: The results showed that the 24 h aging process exerts a substantial influence on the mutton color, texture, and water content as compared to untreated group. Transcriptomic analysis identified 1,668 differentially expressed genes. Functional enrichment analysis highlighted the importance of glycolysis metabolism, protein processing in endoplasmic reticulum, and the FcγR-mediated phagocytosis pathway in mediating meat quality modification following postmortem aging. Furthermore, protein-protein interaction analysis uncovered complex regulatory networks involving glycolysis, the MAPK signaling pathway, protein metabolism, and the immune response. Discussion: Collectively, these findings offer valuable insights into the molecular mechanisms underlying meat quality changes during postmortem aging in Hu sheep, emphasizing the potential for improving quality control strategies in mutton production.

Application of liposome encapsulation technique to improve anti-carcinoma effect of resveratrol.

AIM: The promising anti-tumor effect of resveratrol (RES) has aroused much interest in recent years, but its clinical application was seriously hindered due to its poor solubility in water. The aim of this study was to improve the water solubility of RES by liposome encapsulation technique for effective tumor treatment. METHODS: This study develops two liposomal formulations to solubilize RES by reverse-phase evaporation method with or without poly(ethylene glycol-2000)-grafted distearolyl phosphatidylethanolamine (DSPE-PEG(2000)). The effect of different formulation factors on the encapsulation efficiency (EE) and the particle sizes were investigated. These factors included the mass ratio of drug to soybean phosphatidylcholine (drug/SPC), the mass ratio of cholesterol to soybean phosphatidylcholine (chol/SPC), the volume ratio of water phase/organic phase and the microfluidization process. The drug release studies were performed in various media, simulating the desired application conditions. The cytotoxicity study was carried out by MTT assay on HeLa and Hep G2 cell lines. RESULTS: The RES EE of 95% was obtained when using drug/SPC (1:40 mass ratio), Chol/SPC (1:10 mass ratio), water phase/oil phase (1:2 volume ratio), microfluidization process (entrance pressure 6 kpa, two times of cycle time). The addition of DSPE-PEG(2000) into the formulation showed little effect on the formation and properties of RES liposome. The release of RES was pH-independent. RES liposomes and PEG-modified liposomes performed significant inhibition effects on both cells growth due to the solubilized RES. CONCLUSION: RES can be effectively loaded into liposomes and its anti-cancer effect was evidently improved by the application of liposome encapsulation technique.

O-alkyl and o-benzyl hesperetin derivative-1L attenuates inflammation and protects against alcoholic liver injury via inhibition of BRD2-NF-κB signaling pathway.

Alcoholic liver injury (ALI) is a major risk factor for alcoholic liver disease, characterized by excessive inflammatory response and abnormal liver dysfunction. Previous studies have indicated that O-alkyl and o-benzyl hesperetin derivative-1 L (HD-1 L) has anti-inflammatory and hepato-protective effects in CCl4-induced liver injury. However, its effect on ALI and underlying mechanism has not been elucidated. This study was designed to evaluate the protective effects of HD-1 L on alcoholic liver injury and reveal the underlying mechanisms. ALI model was established in male C57BL/6 J mice (aged 6-8 weeks) by Gao-Binge protocol. The mice were received different doses of HD-1 L (25 mg/kg, 50 mg/kg, 100 mg/kg) by daily intragastric administration, respectively. Liver function and inflammation were measured. Mechanism underlying the anti-inflammatory and hepato-protective effect of HD-1 L were studied in RAW264.7 cells. In alcoholic liver injury mice, HD-1 L effectively improved the liver pathology, and remarkably reduced the levels of alanine transaminase (ALT), aspartate transaminase (AST), triglyceride (TG) and total cholesterol (T-CHO) in serum. Moreover, HD-1 L markedly suppressed inflammation in vivo and inhibited the secretion of inflammatory factors in vitro. Our results showed that HD-1 L decreased the activity of Bromodomain-containing Protein 2 (BRD2) and inhibited expression of BRD2 in vivo and in vitro. Furthermore, HD-1 L further alleviated alcohol-induced inflammation after blocking BRD2 with inhibitor (JQ1) or BRD2 small interfering (si)-RNA in RAW264.7 cells. Besides, HD-1 L failed to effectively exert its anti-inflammatory effects after over expression of BRD2. In addition, HD-1 L significantly inhibited the phosphorylation and activation of NF-κB-P65 mediated by BRD2. In conclusion, HD-1 L alleviated liver injury and inflammation mainly by inhibiting BRD2-NF-κB signaling pathway, and HD-1 L may be a potential anti-inflammatory compound in treatment of alcoholic liver disease.

Salvianolic acid B ameliorates non-alcoholic fatty liver disease by inhibiting hepatic lipid accumulation and NLRP3 inflammasome in ob/ob mice.

Non-alcoholic fatty liver disease (NAFLD) has high occurrence in the global world, which poses serious threats to human health. Salvianolic acid B (SalB), an extract of the root of Salvia miltiorrhiza, has the protective effect on metabolic homeostasis. However, the mechanism is still unknown. In this study, we used ob/ob mice, a model of NAFLD, to explore the hepatoprotective effects of SalB. The results showed that SalB significantly reduced the body weights and liver weights, and ameliorated plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), hepatic free fatty acid (FFA), total cholesterol (TC) levels, and hepatic TG and TC levels in ob/ob mice. SalB reduced the number of lipid droplets and inhibited hepatic lipogenesis by regulating peroxisome proliferator-activated receptor gamma (PPARγ), fatty acid synthase (FASN), stearoyl-Co A desaturase 1 (SCD1), and cluster of differentiation 36 (CD36). Compared to ob/ob mice, the lower expressions of the pro-inflammatory cytokines, such as interleukin-1ß (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and F4/80, were observed after SalB treatment. Importantly, SalB treatment inhibited the activation of NLRP3 inflammasome and reduced the severity of liver inflammation. Our findings suggested that SalB improved NAFLD pathology in ob/ob mice by reducing hepatic lipid accumulation and NLRP3 inflammasome activation, which might be the potential hepatoprotective mechanism of SalB.

[Neuropsychological study of false memory in patients with amnesia mild cognitive impairment].

OBJECTIVE: To explore the profile of false memory in aMCI (amnesia mild cognitive impairment) and to elucidate the neuropsychological mechanism of false memory. METHODS: False memory provoked by pictures and feeling-of-knowing (FOK) test in episodic memory (EM) were conducted in 25 aMCI patients at our hospital from October 2009 to May 2010. And 25 age and education level-matched healthy patients were recruited into the healthy control (HC) group. RESULTS: As compared with HC group, the rate of false memory was higher in the aMCI group. The rate of false memory in recall stage was 26% ± 7% and that of questionnaire stage 28% ± 12%. And the difference between two group was significant (t = 14.437, 7.597, P < 0.05). The FOK-EM of correct judgment and false recognition in the aMCI group (41% ± 10%) was higher than the HC group. And the difference was significant (t = 4.207, P < 0.05). The rates of false memory in recall and questionnaire stages were positively correlated with FOK-EM in aMCI group (r = 0.563, 0.705, P < 0.01). CONCLUSION: The aMCI patients tend to have more false memory provoked by pictures. The deficit of memory monitoring in aMCI may be the foundation of false memory.

(+/-)-Dievodialetins A-G: Seven pairs of enantiomeric coumarin dimers with anti-acetylcholinesterase activity from the roots of Evodia lepta Merr.

Seven pairs of undescribed enantiomeric bis-coumarins, (±)-dievodialetins A-G, were separated from the roots of Evodia lepta Merr. Two coumarin nuclei were linked via a 1,4-dimethyl4-vinylcyclohexene moiety in (±)-dievodialetins C-G. The structures of the undescribed compounds, including their absolute configurations were elucidated by spectroscopic analyses, X-ray diffraction, and computational calculations. In the biosynthetic pathways, these bis-coumarins were presumably derived from the precursors demethylsuberosin and 3-(3-methylbut-2-enyl)umbelliferone via a [4 + 2] Diels-Alder reaction. Besides, all compounds exhibited neuroprotective effects by inhibiting acetylcholinesterase (AChE) activity with IC50 values ranging from 7.3 to 12.1 nM and they also suppressed oxidative stress (MDA and SOD) and neuroinflammation (IL-1ß and IL-6).

Polyphenols from the flower of Hibiscus syriacus Linn ameliorate neuroinflammation in LPS-treated SH-SY5Y cell.

The flower of Hibiscus syriacus Linn is a well-known traditional Chinese medicine (TCM) and health food in China, which has been used to treat dysentery, vaginal discharge, and hemorrhoids. In this study, five polyphenols (compounds 1-5) and five fatty acids (compounds 6-10) were isolated from the ethanol extract of the flower of H. syriacus. The isolated compounds were characterized by spectroscopic techniques. Polyphenols, an important type of natural product, have variety of biological activities. Here, we employed LPS or H2O2-treated SH-SY5Y cell models to test the neuroprotective effect of compounds 1-10. Results found compounds 1-5 (concentration range was around 20 µM on LPS model, concentration range was around 13 µM on H2O2 model), not compounds 6-10, exhibited neuroprotective effect in LPS or H2O2-treated SH-SY5Y cell. PCR analysis showed that compounds 1-5 can effectively improve the mRNA expression of synapse-related gene and neurotrophic factors (Syp, NGF and BDNF) in LPS-treated SH-SY5Y cell. In addition, compounds 1-5 decreased the levels of ROS and MDA and increased the activities of SOD, GSH-Px and CAT in LPS-treated SH-SY5Y cell. Furthermore, compounds 1-5 inhibited neuroinflammation (TNF-α, IL-1ß and IL-6) in LPS-treated SH-SY5Y cell. In conclusion, the polyphenols in the flower of H. syriacus could be a promising candidate for preventive effect of neuroinflammation.

Carnosine ameliorates age-related dementia via improving mitochondrial dysfunction in SAMP8 mice.

Dementia is a kind of age-related neurodegenerative disease. Carnosine, an endogenous dipeptide consisting of ß-alanine and l-histidine, has been shown to have neuroprotective effects. However, the exact mechanism is still obscure. In this study, senescence-accelerated mouse prone 8 (SAMP8) mice, an age-related animal model, were used. Carnosine (100 and 200 mg kg-1 day-1) was orally administered to the mice once daily for six weeks. Behavioral tests, western blotting, and detection kits were used to evaluate the potential effects of carnosine on SAMP8 mice. Open-field and new object recognition experiments have shown that carnosine improved cognitive deficits in SAMP8 mice. Carnosine decreased the levels of malondialdehyde (MDA) and reactive oxygen species (ROS), increased the activity of superoxide dismutase (SOD) and the level of adenosine triphosphate (ATP) in SAMP8 mice. Concomitantly, western blotting results proved that carnosine increased the protein expressions of Mitofusin-1, Mitofusin-2, and Bcl-2 and reduced the protein expressions of P-Drp1, Bax, cleaved Caspase-3 and NLRP3 inflammasomes in the hippocampus of SAMP8 mice. The present data provided evidence that carnosine might improve cognitive impairment in SAMP8 mice through modulating mitochondrial dysfunction.

Metformin Ameliorates Aß Pathology by Insulin-Degrading Enzyme in a Transgenic Mouse Model of Alzheimer's Disease.

Alzheimer's disease (AD) is the most common neurodegenerative disease. The accumulation of amyloid beta (Aß) is the main pathology of AD. Metformin, a well-known antidiabetic drug, has been reported to have AD-protective effect. However, the mechanism is still unclear. In this study, we tried to figure out whether metformin could activate insulin-degrading enzyme (IDE) to ameliorate Aß-induced pathology. Morris water maze and Y-maze results indicated that metformin could improve the learning and memory ability in APPswe/PS1dE9 (APP/PS1) transgenic mice. 18F-FDG PET-CT result showed that metformin could ameliorate the neural dysfunction in APP/PS1 transgenic mice. PCR analysis showed that metformin could effectively improve the mRNA expression level of nerve and synapse-related genes (Syp, Ngf, and Bdnf) in the brain. Metformin decreased oxidative stress (malondialdehyde and superoxide dismutase) and neuroinflammation (IL-1ß and IL-6) in APP/PS1 mice. In addition, metformin obviously reduced the Aß level in the brain of APP/PS1 mice. Metformin did not affect the enzyme activities and mRNA expression levels of Aß-related secretases (ADAM10, BACE1, and PS1). Meanwhile, metformin also did not affect the mRNA expression levels of Aß-related transporters (LRP1 and RAGE). Metformin increased the protein levels of p-AMPK and IDE in the brain of APP/PS1 mice, which might be the key mechanism of metformin on AD. In conclusion, the well-known antidiabetic drug, metformin, could be a promising drug for AD treatment.

CGY-1, a biflavonoid isolated from cardiocrinum giganteum seeds, improves memory deficits by modulating the cholinergic system in scopolamine-treated mice.

Certain biflavonoids have been proven to protect against cognitive dysfunction. A new biflavonoid, CGY-1, isolated from Cardiocrinum giganteum seeds, has not yet been reported to have any neuroprotective effect. In this study, a scopolamine-induced memory deficit model was used to explore the neuroprotective effect of CGY-1. Behavioral experiments, such as tests using the Morris water maze, the Y-maze and the fear conditioning test, were conducted. The results revealed that oral administration of CGY-1 (20 and 40 mg/kg) and donepezil shortened the escape latency, improved the percentage of spontaneous alternation, and increased the freezing times, respectively. CGY-1 decreased the levels of reactive oxygen species and malondialdehyde and increased the activities of superoxide dismutase and glutathione peroxidase in the hippocampus. In addition, CGY-1 decreased the activity of acetylcholinesterase and increased the activities of choline acetyltransferase and acetylcholine in the hippocampus. Furthermore, qPCR and western blot results revealed that the expressions of neurotrophic factors, brain-derived neurotrophic factor and nerve growth factor were upregulated in the hippocampus after CGY-1 treatment. In conclusion, CGY-1 could be a promising candidate for the treatment of cognitive dysfunction.