Repair-driven DNA tetrahedral nanomachine combined with DNAzyme for 8-oxo guanine DNA glycosylase activity assay, drug screening and intracellular imaging.

8-oxo guanine DNA glycosylase (8-oxoG DNA glycosylase), a crucial DNA repair enzyme, is essential for maintaining genome integrity and preventing diseases caused by DNA oxidative damage. Imaging 8-oxoG DNA glycosylase in living cells requires a dependable technique. In this study, we designed a DNAzyme-modified DNA tetrahedral nanomachine (DTDN) powered by 8-oxoG restoration. Incorporating a molecular beacon probe (MB), the constructed platform was used for amplified in situ monitoring of 8-oxoG DNA glycosylase. Under normal conditions, duplexing with a complementary strand modified with two 8-oxoG sites inhibited the activity of DNAzyme. The restoration of DNAzyme activity by the repair of intracellular 8-oxoG DNA glycosylase on 8-oxoG bases can initiate a signal amplification reaction. This detection system can detect 8-oxoG DNA glycosylase activity linearly between 0 and 20 U mL-1, with a detection limit as low as 0.52 U mL-1. Using this method, we were able to screen 14 natural compounds and identify 6 of them as 8-oxoG DNA glycosylase inhibitors. In addition, a novel approach was utilized to assess the activity of 8-oxoG DNA glycosylase in living cells. In conclusion, this method provides a universal tool for monitoring the activity of 8-oxoG DNA glycosylase in vitro and in living cells, which holds great promise for elucidating the enzyme's functionality and facilitating drug screening endeavors.

Prevalence of skin diseases among elderly prisoners in Taiwan: an examination of skin health in prison.

BACKGROUND: Although prisoner health is a topic of significant importance, it has received limited attention in epidemiological studies, likely due to challenges in obtaining data. Therefore, this study aimed to investigate the prevalence of skin diseases among elderly prisoners in Taiwan. METHODS: We examined the presence of skin diseases in 2215 elderly prisoners based on the International Classification of Diseases, 9th revision Clinical Modification (ICD-9-CM). Additionally, the most common types of skin diseases among elderly prisoners in Taiwan were identified. RESULTS: The prevalence of skin diseases among prisoners was estimated to be 55.03%. Elderly men prisoners exhibited a higher prevalence of skin diseases than the women prisoners. The most common skin diseases observed were as follows: contact dermatitis and other forms of eczema; pruritus and related conditions; cellulitis and abscesses; and urticaria. CONCLUSION: Skin diseases were identified in more than half of the elderly prisoners. The overall quality of life of elderly prisoners can be improved by addressing their skin health, which would contribute to the fulfilment of their basic human rights. CLINICAL TRIALS NUMBER: NA.

The association between air pollution and obesity: an umbrella review of meta-analyses and systematic reviews.

The objective of this umbrella review was to investigate comprehensive and synthesized evidence of the association between ambient air pollution and obesity based on the current systematic reviews and meta-analyses. Related studies from databases including PubMed, EMBASE, Web of Science, and the Cochrane Library, published before July 16, 2023, were considered in the analysis. All selected systematic reviews and meta-analyses were included in accordance with PRISMA guidelines. The risk of bias and the methodological quality were evaluated using the AMSTAR 2 tool. The protocol for this umbrella review was documented in PROSPERO with the registration number: CRD42023450191. This umbrella review identified 7 studies, including 5 meta-analyses and 2 systematic reviews, to assess the impacts of air pollutants on obesity. Commonly examined air pollutants included PM1, PM2.5, PM10, NO2, SO2, O3. Most of the included studies presented that air pollution exposure was positively associated with the increased risk of obesity. The impact of air pollution on obesity varied by different ambient air pollutants. This study provided compelling evidence that exposure to air pollution had a positive association with the risk of obesity. These findings further indicate the importance of strengthening air pollution prevention and control. Future studies should elucidate the possible mechanisms and pathways linking air pollution to obesity.

Self-perceived knowledge, attitude, and practice of evidence-based medicine before and after training among healthcare workers in Taizhou, China.

BACKGROUND: Evidence-based medicine (EBM) is the combination of the best research evidence with our clinical expertise, specific situations, and the unique values of our patients. It is essential to evaluate the effectiveness of EBM training for healthcare workers (HCWs). OBJECTIVES: This study aims to assess the impact of EBM training on HCWs' knowledge, attitude, and practice (KAP) related to EBM. METHODS: A self-reported online survey was carried out to investigate KAP related to EBM among HCWs at a tertiary hospital in Taizhou, China. HCWs participated in EBM training on 9 and 10 September 2023. The questionnaire survey was conducted to understand KAP related to EBM before and after the training, and to compare and analyze the results before and after the training. The R software (version 4.1.0) was used to analyze data. RESULTS: Sixty-four HCWs completed the survey with a response rate of 52.5% (64/122). The overall average scores of KAP related to EBM before training were 55.3, 63.0, and 34.5, respectively, and 56.9, 66.5, and 34.7 were the scores of KAP after training. HCWs' scores of knowledge (P = 0.033) and attitude (P < 0.001) related to EBM improved significantly after the training. CONCLUSION: This study implied that EBM training may improve the knowledge and attitude of HCWs, and its teaching effect is considerable.

Association between abusive supervision and nurses' withholding voice about patient safety: the roles of impression management motivation and speak up-related climate.

BACKGROUND: Abusive supervision by the nurse manager significantly influences nurses' withholding voice about patient safety. The role of impression management motivation and speak up-related climate is crucial in understanding their connection. This study aimed to explore the relationship between abusive supervision, impression management motivation, speak up-related climate, and withholding voice about patient safety. METHODS: This cross-sectional study employed a convenience sampling method to recruit 419 clinical nurses from Taizhou Hospital, Zhejiang Province, China, between 1 November 2022 and 31 January 2023. The study adhered to the STROBE checklist. Abusive supervision and impression management motivation were assessed using the Chinese versions of the Abusive Supervision Scale and the Impression Management Motivation Scale, respectively. Withholding voice about patient safety and speak up-related climate were identified using the Chinese version of the Speaking Up about Patient Safety Questionnaire. RESULTS: Nurse leaders' abusive supervision (ß=0.40, p<0.01) and nurses' impression management motivation (ß=0.10, p<0.01) significantly and positively influenced nurses' withholding voice about patient safety. We introduced impression management motivation as a mediating variable, and the effect of abusive supervision on nurses' withholding voice decreased (ß from 0.40 to 0.38, p< 0.01). Nurses' speak up-related climate played a moderating role between abusive supervision and impression management motivation (ß= 0.24, p<0.05). CONCLUSIONS: Abusive supervision by nursing leaders can result in nurses withholding voice about patient safety out of self-protective impression management motives. This phenomenon inhibits nurses' subjective initiative and undermines their proactive involvement in improving patient safety, and hinders the cultivation of a culture encouraging full participation in patient safety, which should warrant significant attention.

Dibenzocyclooctadiene lignans from the family Schisandraceae: A review of phytochemistry, structure-activity relationship, and hepatoprotective effects.

Liver injury is a common pathological process characterized by massive degeneration and abnormal death of liver cells. With increase in dead cells and necrosis, liver injury eventually leads to nonalcoholic fatty liver disease (NAFLD), hepatic fibrosis, and even hepatocellular carcinoma (HCC). Consequently, it is necessary to treat liver injury and to prevent its progression. The drug Bicylol is widely employed in China to treat chronic hepatitis B virus (HBV) and has therapeutic potential for liver injury. It is the derivative of dibenzocyclooctadiene lignans extracted from Schisandra chinensis (SC). The Schisandraceae family is a rich source of dibenzocyclooctadiene lignans, which possesses potential liver protective activity. This study aimed to comprehensively summarize the phytochemistry, structure-activity relationship and molecular mechanisms underlying the liver protective activities of dibenzocyclooctadiene lignans from the Schisandraceae family. Here, we had discussed the analysis of absorption or permeation properties of 358 compounds based on Lipinski's rule of five. So far, 358 dibenzocyclooctadiene lignans have been reported, with 37 of them exhibited hepatoprotective effects. The molecular mechanism of the active compounds mainly involves antioxidative stress, anti-inflammation and autophagy through Kelch-like ECH-associating protein 1/nuclear factor erythroid 2 related factor 2/antioxidant response element (Keap1/Nrf2/ARE), nuclear factor kappa B (NF-кB), and transforming growth factor ß (TGF-ß)/Smad 2/3 signaling pathways. This review is expected to provide scientific ideas for future research related to developing and utilizing the dibenzocyclooctadiene lignans from Schisandraceae family.

Gender differences in oral health among prisoners: a cross-sectional study from Taiwan.

BACKGROUND: The prevalence of oral diseases among Taiwanese prisoners has rarely been investigated. This study aimed to estimate the gender-specific prevalence of oral disease in a sample of Taiwanese prisoners. METHODS: We included 83,048 participants from the National Health Insurance (NHI) Program. Outcomes were measured using the clinical version of the International Classification of Diseases, Ninth Revision (ICD-9-CM). For prevalence, we provide absolute values and percentages. We also performed a χ2 test to assess sex and age group differences in the percentage of disease in the oral cavity, salivary glands, and jaw. RESULTS: The prevalence rate of oral diseases was 25.90%, which was higher than that of the general population. The prevalence of oral diseases in female prisoners was higher than that in male prisoners (p < 0.001), and the prevalence of oral diseases in prisoners aged ≤ 40 was higher than that of prisoners aged > 40. Among all cases of diagnosed oral diseases, the top three diseases were dental hard tissue diseases (13.28%), other cellulitis and abscesses (9.79%), and pruritus and related conditions (2.88%), respectively. The prevalence of various oral diseases in female prisoners was significantly higher than that in male prisoners. CONCLUSION: Oral disease is common among Taiwanese prisoners. Female prisoners had a higher prevalence of oral, salivary gland, and jaw diseases than male prisoners. Therefore, early prevention and appropriate treatment are required and also a need for gender-specific oral disease products given the differences in the prevalence of oral disease among male and female prisoners.

Relationship between nosocomial infections and coronavirus disease 2019 in the neurosurgery unit: clinical characteristics and outcomes from a Chinese Tertiary-Care Hospital.

BACKGROUND: The COVID-19 pandemic has raised awareness of infection prevention and control. We found that the incidence of nosocomial infection in neurosurgery has changed. This study aimed to evaluate the impact of "coronavirus disease 2019 (COVID-19) prevention and control measures" on nosocomial infections in neurosurgery. METHODS: To explore changes in nosocomial infections in neurosurgery during the COVID-19 pandemic, the clinical data of inpatients undergoing neurosurgery at Taizhou Hospital of Zhejiang Province between January 1 and April 30, 2020 (COVID-19 era) were first analyzed and then compared with those from same period in 2019 (first pre-COVID-19 era). We also analyzed data between May 1 and December 31, 2020 (post-COVID-19 era) at the same time in 2019 (second pre-COVID-19 era). RESULTS: The nosocomial infection rate was 7.85% (54/688) in the first pre-COVID-19 era and 4.30% (26/605) in the COVID-19 era (P = 0.01). The respiratory system infection rate between the first pre-COVID-19 and COVID-19 eras was 6.1% vs. 2.0% (P < 0.01), while the urinary system infection rate was 1.7% vs. 2.0% (P = 0.84). Between the first pre-COVID-19 and COVID-19 eras, respiratory system and urinary infections accounted for 77.78% (42/54) vs. 46.15% (12/26) and 22.22% (12/54) vs. 46.15% (12/26) of the total nosocomial infections, respectively (P < 0.01). Between the second pre-COVID-19 and post-COVID-19 eras, respiratory system and urinary accounted for 53.66% (44/82) vs. 40.63% (39/96) and 24.39% (20/82) vs. 40.63% (39/96) of the total nosocomial infections, respectively (P = 0.02). CONCLUSIONS: The incidence of nosocomial infections in neurosurgery reduced during the COVID-19 pandemic. The reduction was primarily observed in respiratory infections, while the proportion of urinary infections increased significantly.

Heilaohuacid G, a new triterpenoid from Kadsura coccinea inhibits proliferation, induces apoptosis, and ameliorates inflammation in RA-FLS and RAW 264.7 cells via suppressing NF-𝜠B pathway.

Heilaohu, the roots of Kadsura coccinea, has been used in Tujia ethnomedicine to treat rheumatic arthritis (RA). Heilaohuacid G (1), a new 3,4-seco-lanostane type triterpenoid isolated from the ethanol extract of Heilaohu, whose structure was determined using HR-ESI-MS data, NMR spectroscopic analyses, and ECD calculations. In this study, our purpose is to elucidate the mechanisms of Heilaohuacid G in the treatment of RA by inhibited proliferation of rheumatoid arthritis-fibroblastoid synovial (RA-FLS) cells and inhibited the inflammatory reactions in LPS-induced RA-FLS and RAW 264.7 cell lines via inhibiting NF-κB pathway. The biological activity screening experiments indicated that Heilaohuacid G significantly inhibited proliferation of RA-FLS cells with IC50 value of 8.16 ± 0.47 µM. CCK-8 assay, ELISA, flow cytometry assay, and Western blot were used to measure the changes of cell viability, apoptosis, and the release of inflammatory cytokines. Heilaohuacid G was found not only induced RA-FLS cell apoptosis, but also inhibited the inflammatory reactions in LPS-induced RA-FLS and RAW 264.7 cell lines via inhibiting NF-κB pathway. Furthermore, Heilaohuacid G (p.o.) at doses of 3.0, 6.0, and 12.0 mg/kg and the ethanol extracts of Heilaohu (p.o.) at doses of 200, 400, and 800 mg/kg both were confirmed antiinflammatory effects on xylene-induced ear mice edema model.

A Review of the Phytochemistry and Pharmacology of the Fruit of Siraitia grosvenorii (Swingle): A Traditional Chinese Medicinal Food.

Siraitia grosvenorii (Swingle) C. Jeffrey ex Lu et Z. Y. Zhang is a unique economic and medicinal plant of Cucurbitaceae in Southern China. For hundreds of years, Chinese people have used the fruit of S. grosvenorii as an excellent natural sweetener and traditional medicine for lung congestion, sore throat, and constipation. It is one of the first species in China to be classified as a medicinal food homology, which has received considerable attention as a natural product with high development potential. Various natural products, such as triterpenoids, flavonoids, amino acids, and lignans, have been released from this plant by previous phytochemical studies. Phar- macological research of the fruits of S. grosvenorii has attracted extensive attention, and an increasing number of extracts and compounds have been demonstrated to have antitussive, expectorant, antiasthmatic, antioxidant, hypoglycemic, immunologic, hepatoprotective, antibacte- rial, and other activities. In this review, based on a large number of previous studies, we summarized the related research progress of the chemical components and pharmacological effects of S. grosvenorii, which provides theoretical support for further investigation of its biological functions and potential clinical applications.

New Terpenoids from Potentilla freyniana Bornm. and Their Cytotoxic Activities.

Two new A-ring contracted triterpenoids, madengaisu A and madengaisu B, and one undescribed ent-kaurane diterpenoid, madengaisu C, along with 20 known compounds were isolated from the roots of Potentilla freyniana Bornm. The structures were elucidated using extensive spectroscopic techniques, including 1D and 2D-NMR, HR-ESI-MS, ECD spectra, IR, and UV analysis. Moreover, all isolated constituents were evaluated for their anti-proliferative activity against RA-FLS cells and cytotoxic activities against the human cancer cell lines Hep-G2, HCT-116, BGC-823, and MCF-7. Ursolic acid and pomolic acid displayed moderate inhibitory activity in RA-FLS cells with IC50 values of 24.63 ± 1.96 and 25.12 ± 1.97 µM, respectively. Hyptadienic acid and 2α,3ß-dihydroxyolean-12-en-28-oic acid 28-O-ß-d-glucopyranoside exhibited good cytotoxicity against Hep-G2 cells with IC50 values of 25.16 ± 2.55 and 17.66 ± 1.82 µM, respectively. In addition, 2α,3ß-dihydroxyolean-13(18)-en-28-oic acid and alphitolic acid were observed to inhibit HCT-116 cells (13.25 ± 1.65 and 21.62 ± 0.33 µM, respectively), while madengaisu B and 2α,3ß-dihydroxyolean-13(18)-en-28-oic acid showed cytotoxic activities against BGC-823 cells with IC50 values of 24.76 ± 0.94 and 26.83 ± 2.52 µM, respectively, which demonstrated that triterpenes from P. freyniana may serve as therapeutic agents for RA and cancer treatment.

Oxidized high-density lipoprotein enhances endocrine disorders and ovarian damage in rats.

Previous findings have highlighted the association between oxidized high-density lipoprotein (ox-HDL) and polycystic ovary syndrome (PCOS) development; however, the underlying mechanism remains unclear. Under such context, the present study aimed to investigate the mechanism underlying the involvement of ox-HDL in PCOS in relation to the p65/micro-RNA-34a (miR-34a)/FOS axis. PCOS rat models were established with the injection of dehydroepiandrosterone (6 mg/100 g body weight). Both PCOS-modelled rats and granulosa cells (GCs) were received treatment with ox-HDL in order to identify its role in PCOS. Next, apoptosis and viability of GCs were detected with the application of TdT-mediated dUTP Nick-End Labeling and flow cytometry and Cell counting kit-8, respectively. A series of assays were performed to determine the interaction among ox-HDL, p65, miR-34a, FOS and nuclear factor-κB (NF-κB). The results revealed high expression of ox-HDL in PCOS, and enhanced endocrine disorders and ovarian damage in rats. ox-HDL promoted apoptosis of GCs and decreased its viability. ox-HDL activated NF-κB pathway and induced p65 phosphorylation to promote miR-34a expression. miR-34a targeted and inhibited FOS expression. In conclusion, our findings suggested that ox-HDL promoted the activation of p65 and transcription of miR-34a, which stimulated apoptosis of GCs and inhibited expression of FOS, resulting in the overall acceleration of PCOS development.

Dibenzocyclooctadiene lignans from Kadsura coccinea alleviate APAP-induced hepatotoxicity via oxidative stress inhibition and activating the Nrf2 pathway in vitro.

Phytochemical investigation on the roots of Kadsura coccinea led to the isolation five previously unknown dibenzocyclooctadiene lignans, named heilaohusuins A-E (1-5). Their structures determined by NMR spectroscopy, HR-ESI-MS, and ECD spectra. Hepatoprotection effects of a series of dibenzocyclooctadiene derivatives (1-68) were investigated against acetaminophen (APAP) induced HepG2 cells. Compounds 2, 10, 13, 21, 32, 41, 46, and 49 showed remarkable protective effects, increasing the viabilities to > 52.2% (bicyclol, 52.1 ± 1.3%) at 10 µM. The structure-activity relationships (SAR) for hepatoprotective activity were summarized, according to the activity results of dibenzocyclooctadiene derivatives. Furthermore, we found that one new dibenzocyclooctadiene lignan heilaohusuin B attenuates hepatotoxicity, the mechanism might be closely correlated with oxidative stress inhibition via activating the Nrf2 pathway.

Anti-gastric cancer activity and mechanism of natural compound "Heilaohulignan C" isolated from Kadsura coccinea.

In this research, we analyzed the antitumor activity of one new compound Heilaohulignan C (B-6) on the human gastric carcinoma cells. MTT, cell migration, Calcein AM/Propidium Iodide (PI), and flow cytometry in BGC-823 cell line (gastric tumor). Western blot was utilized to distinguish the protein level. Xenografts nude mice were used for in vivo anticancer analysis. H&E staining and laboratory investigation was accomplished for toxicity study. MTT test demonstrated the cytotoxicity of BGC-823 cells, Calcein AM/Propidium Iodide (PI) examine indicated increment dead cells proportion with a high dose of B-6, Flow cytometry (FACS) measure showed that B-6 influenced gastric cancer cells by initiating apoptosis. Western blot analysis confirmed that (B-6) decrease the level of Bcl-2 and increase the level of p53, Bax, and cleaved Caspase-3, this confirms that the B-6 doing the apoptosis through caspase and cytochrome C apoptotic pathways. Also, B-6 particularly decline the tumor volume and tumor size in the xenograft mice. H&E staining additionally supports that B-6 does not have any toxic impact on the normal tissues. This research supports that B-6 have pharmacological activity against gastric cancer, by p53 and mitochondrial dependent apoptotic pathway, and have no toxicity on normal tissues.

Chemistry and Pharmacological Activity of Sesquiterpenoids from the Chrysanthemum Genus.

Plants from the Chrysanthemum genus are rich sources of chemical diversity and, in recent years, have been the focus of research on natural products chemistry. Sesquiterpenoids are one of the major classes of chemical constituents reported from this genus. To date, more than 135 sesquiterpenoids have been isolated and identified from the whole genus. These include 26 germacrane-type, 26 eudesmane-type, 64 guaianolide-type, 4 bisabolane-type, and 15 other-type sesquiterpenoids. Pharmacological studies have proven the biological potential of sesquiterpenoids isolated from Chrysanthemum species, reporting anti-inflammatory, antibacterial, antitumor, insecticidal, and antiviral activities for these interesting molecules. In this paper, we provide information on the chemistry and bioactivity of sesquiterpenoids obtained from the Chrysanthemum genus which could be used as the scientific basis for their future development and utilization.

Endogenous Cys-Assisted GSH@AgNCs-rGO Nanoprobe for Real-Time Monitoring of Dynamic Change in GSH Levels Regulated by Natural Drug.

Glutathione (GSH) levels are closely related to the homeostasis of redox state which directly affects human disease occurrence by regulating cell apoptosis. Hence, real-time monitoring of dynamic changes in intracellular GSH levels is urgently needed for disease early diagnosis and evaluation of therapy efficiency. In this study, an endogenous cysteine (Cys)-assisted detection system based on GSH@AgNCs and reduced graphene oxide (rGO) with high sensitivity and specificity was developed for GSH detection. Compared with GSH, GSH@AgNCs with weaker affinity and bonding force was quite easier to extrude from the rGO surface when competing against GSH, leading to the obvious change in fluorescence signal. This phenomenon was termed as "a crowding out effect". Furthermore, the presence of Cys can improve GSH assay sensitivity by enhancing the quenching efficiency of rGO on the GSH@AgNCs. In vitro assay indicated that the efficiency of fluorescence recovery was positively related with GSH concentration in the range from 0 to 10 mM. In addition, the method was employed for real-time monitoring of the dynamic changes in GSH levels regulated by natural drugs. The imaging results showed that the natural compound 3 (C3) can downregulate GSH levels in HepG2 cells, which was accompanied by reactive oxygen species (ROS) release and apoptosis induction. Finally, the method was used to monitor the change of GSH levels in serum samples with chronic hepatitis B (CHB) infection. The results demonstrated that the occurrence and development of CHB may be positively correlated with GSH levels to some extent. Overall, the above results demonstrate the potential application of this new nanosystem in anticancer natural drug screening and clinical assay regarding GSH levels.

Isovaleroylbinankadsurin A ameliorates cardiac ischemia/reperfusion injury through activating GR dependent RISK signaling.

Ischemia/reperfusion (I/R) injury is a pathological process caused by reperfusion. The prevention of I/R injury is of great importance as it would enhance the efficacy of myocardial infarction treatment in patients. Isovaleroylbinankadsurin A (ISBA) has been demonstrated to possess multiple bioactivities for treating diseases. However, its protective effect on myocardial I/R injury remains unknown. In this study, the cardiomyocytes hypoxia/reoxygenation (H/R) in vitro model and coronary artery ligation in vivo model were used to examine the protective effect of ISBA. Apoptosis was determined by flow cytometry and Caspase 3 activity. Protein level was determined by Western blot. The mitochondrial viability was examined with mitochondrial viability stain assay. Mitochondrial membrane potential was detected by JC-1 staining and reactive oxygen species (ROS) was stained with 2',7'-dichlorodihydrofluorescein diacetate (DCF-DA). The binding interactions between ISBA and receptors was simulated by molecular docking. Results showed that ISBA effectively protected cardiomyocytes from I/R injury in in vitro and in vivo models. It remarkably blocked the apoptosis induced by H/R injury through the mitochondrial dependent pathway. Activation of the reperfusion injury salvage kinase (RISK) pathway was demonstrated to be essential for ISBA to exert its protective effect on cardiomyocytes. Moreover, molecular docking indicated that ISBA could directly bind to glucocorticoid receptor (GR) and thus induce its activation. Furthermore, the treatment of GR inhibitor RU486 partially counteracted the protective effect of ISBA on cardiomyocytes, consistent with the results of docking.Most attractively, by activating GR dependent RISK pathway, ISBA significantly elevated the cellular anti-oxidative capacity and hence alleviated oxidative damage induced by I/R injury. In conclusion, our study proved that ISBA protected the heart from myocardial I/R injury through activating GR dependent RISK pathway and consequently inhibiting the ROS generation. It provides a valuable reference for ISBA to be developed as a candidate drug for cardiovascular diseases.

A cascade amplification platform assisted with DNAzyme for activity analysis, kinetic study and effector screening of Fpg in vitro.

As a highly conserved damage repair protein, Fpg can specifically recognize and digest 8-oxoG from a damaged DNA backbone. Meanwhile, DNAzyme, a single-stranded DNA with enzymatic activity, can cleave RNA in the presence of cofactors. In this study, we established a highly sensitive method for Fpg assay using a DNAzyme-mediated signal cascade amplification strategy. Based on the Fpg-dependent fluorescence response of the "turn-on" manner, we could reliably determine Fpg activity down to 0.14 U mL-1 with a linear response from 0.10 to 40 U mL-1 under optimal conditions. In addition, this strategy was successfully applied to analyze the kinetic parameter of Fpg with Km of 0.061 µM. Furthermore, the developed sensing system was used to screen the regulators of Fpg from natural compounds and antibiotics. These results indicated that all of the 14 natural compounds and 6 kinds of antibiotics deferentially showed an active effect on Fpg in vitro. In summary, these results show that the method not only provides an alternative for monitoring Fpg activity but also shows great potential for drug screening in the future.

A novel fluorescence method for activity assay and drug screening of T4 PNK by coupling rGO with ligase reaction.

T4 polynucleotide kinase (PNK) is the primary member of the 5'-kinase family that can transfer the γ-phosphate residue of ATP to the 5'-hydroxyl group of oligonucleotides. In this article, using the differential quenching ability of reduced graphene oxide (rGO) towards the fluorophore-labeled DNA probe, we propose a novel method for detecting T4 PNK activity assisted by ligase reaction. Under the optimized conditions, the detection limit of T4 PNK was estimated to be 0.0002 U µL-1 in the linear region of 0.001 U µL-1-0.1 U µL-1. Additionally, the developed method was used to screen regulators of T4 PNK from natural compounds. The compound f isolated from the root of Kadsura coccinea (Lem.) A.C. Smith was found to stimulate T4 PNK activity in a concentration-dependent manner in vitro. Finally, the method was used to monitor the relation of T4 PNK activity with pelvic inflammatory disease (PID). The results demonstrated that the development of this disease could inhibit T4 PNK activity to some extent. In summary, the above data indicate that the method not only provides a universal platform for monitoring T4 PNK activity, but also shows great potential to be used in drug screening and clinic diagnosis.

Lignans from Tujia Ethnomedicine Heilaohu: Chemical Characterization and Evaluation of Their Cytotoxicity and Antioxidant Activities.

Heilaohu, the roots of Kadsura coccinea, has a long history of use in Tujia ethnomedicine for the treatment of rheumatoid arthritis and gastroenteric disorders, and a lot of work has been done in order to know the material basis of its pharmacological activities. The chemical investigation led to the isolation and characterization of three new (1⁻3) and twenty known (4⁻23) lignans. Three new heilaohulignans A-C (1⁻3) and seventeen known (4⁻20) lignans possessed dibenzocyclooctadiene skeletons. Similarly, one was a diarylbutane (21) and two were spirobenzofuranoid dibenzocyclooctadiene (22⁻23) lignans. Among the known compounds, 4⁻5, 7, 13⁻15 and 17⁻22 were isolated from this species for the first time. The structures were established, using IR, UV, MS and NMR data. The absolute configurations of the new compounds were determined by circular dichroism (CD) spectra. The isolated lignans were further evaluated for their cytotoxicity and antioxidant activities. Compound 3 demonstrated strong cytotoxic activity with an IC50 value of 9.92 µM, compounds 9 and 13 revealed weak cytotoxicity with IC50 values of 21.72 µM and 18.72 µM, respectively in the HepG-2 human liver cancer cell line. Compound 3 also showed weak cytotoxicity against the BGC-823 human gastric cancer cell line and the HCT-116 human colon cancer cell line with IC50 values of 16.75 µM and 16.59 µM, respectively. A chemiluminescence assay for antioxidant status of isolated compounds implied compounds 11 and 20, which showed weak activity with IC50 values of 25.56 µM and 21.20 µM, respectively.