Stepwise Coordination-Driven Metal-Phenolic Nanoparticle as a Neuroprotection Enhancer for Alzheimer's Disease Therapy.

Current therapeutic strategies for Alzheimer's disease (AD) mainly focus on inhibition of aberrant amyloid-ß peptide (Aß) aggregation. However, these strategies cannot repair the side symptoms (e.g., high neuronal oxidative stress) triggered by Aß accumulation and thus show limited effects on suppressing Aß-induced neuronal apoptosis. Herein, we develop a stepwise metal-phenolic coordination approach for the rational design of a neuroprotection enhancer, K8@Fe-Rh/Pda NPs, in which rhein and polydopamine are effectively coupled to enhance the treatment of AD in APPswe/PSEN1dE9 transgenic (APP/PS1) mice. We discover that the polydopamine inhibits the aggregation of Aß oligomers, and rhein helps repair damage to neurons triggered by Aß aggregation. Based on molecular docking, we demonstrate that the polydopamine has a strong interaction with Aß monomers/fibrils through its multiple recognition sites (e.g., catechol groups, imine groups, and indolic/catecholic π-systems), thereby reducing Aß burden. Further investigation of the antioxidant mechanisms suggests that K8@Fe-Rh/Pda NPs promote the mitochondrial biogenesis via activating the sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptor gamma coactivator 1-alpha pathway. This finally inhibits neuronal apoptosis. Moreover, an intravenous injection of these nanoparticles potently improves the cognitive function in APP/PS1 mice without adverse effects. Overall, our work provides a promising approach to develop advanced nanomaterials for multi-target treatment of AD.

Effects of Trichoderma harzianum biofertilizer on growth, yield, and quality of Bupleurum chinense.

The use of chemical fertilizers and pesticides led to a decline in the quality and yield of Bupleurum chinense. The aim of this study was to determine the effects of Trichoderma harzianum biofertilizer on the growth, yield, and quality of radix bupleuri and microbial responses. The results showed that T. harzianum biofertilizer promoted the growth of B. chinense and increased the yield and quality of radix bupleuri. In addition, it increased the contents of NH4 +-N, NO3 --N, available K, and available P and increased the activities of sucrase and catalase in the rhizosphere soil. High-throughput analysis showed that the dominant bacteria in the rhizosphere were Proteobacteria (28%), Acidobacteria (23%), and Actinobacteria (17%), whereas the dominant fungi were Ascomycota (49%), Zygomycota (30%), and Basidiomycota (6%). After the application of T. harzianum biofertilizer, the abundance of Proteobacteria and Actinobacteria (relative to total bacteria) and Ascomycota and Basidiomycota (relative to total fungi) increased, but the relative abundance of Acidobacteria decreased. Canonical correlation analysis (CCA) showed that the relative abundance of Pseudarthrobacter, Streptomyces, Rhizobium, Nocardioides, Minimedusa, and Chaetomium were positively correlated with NO3 --N, NH4 +-N, available K, available P, sucrase, and catalase in microbial communities, whereas Aeromicrobium and Mortierella were positively correlated with soil organic matter and urease. These results suggest that T. harzianum biofertilizer could significantly improve the yield and quality of radix bupleuri by changing the structure of soil microbial flora and soil enzyme activity. Therefore, it could be recommended for commercial scale production of Bupleurum.

Response of soil microecology to different cropping practice under Bupleurum chinense cultivation.

The effects of cropping practices on the rhizosphere soil physical properties and microbial communities of Bupleurum chinense have not been studied in detail. The chemical properties and the microbiome of rhizosphere soil of B. chinense were assessed in the field trial with three cropping practices (continuous monocropping, Bupleurum-corn intercropping and Bupleurum-corn rotation). The results showed cropping practices changed the chemical properties of the rhizosphere soil and composition, structure and diversity of the rhizosphere microbial communities. Continuous monocropping of B. chinense not only decreased soil pH and the contents of NO3--N and available K, but also decreased the alpha diversity of bacteria and beneficial microorganisms. However, Bupleurum-corn rotation improved soil chemical properties and reduced the abundance of harmful microorganisms. Soil chemical properties, especially the contents of NH4+-N, soil organic matter (SOM) and available K, were the key factors affecting the structure and composition of microbial communities in the rhizosphere soil. These findings could provide a new basis for overcoming problems associated with continuous cropping and promote development of B. chinense planting industry by improving soil microbial communities.

Rhein Ameliorates Cognitive Impairment in an APP/PS1 Transgenic Mouse Model of Alzheimer's Disease by Relieving Oxidative Stress through Activating the SIRT1/PGC-1α Pathway.

Mitochondrial oxidative stress plays an important role in the pathogenesis of Alzheimer's disease (AD). Recently, antioxidant therapy has been considered an effective strategy for the treatment of AD. Our previous work discovered that rhein relieved mitochondrial oxidative stress in ß-amyloid (Aß) oligomer-induced primary neurons by improving the sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptor gamma coactivator 1-alpha- (PGC-1α-) regulated mitochondrial biogenesis. While encouraging results have been provided, mechanisms underlying the beneficial effect of rhein on AD are yet to be elucidated in vivo. In this study, we evaluated the therapeutic effect of rhein on an APP/PS1 transgenic (APP/PS1) mouse model of AD and explored its antioxidant mechanisms. As a result, rhein significantly reduced Aß burden and neuroinflammation and eventually ameliorated cognitive impairment in APP/PS1 mice. Moreover, rhein reversed oxidative stress in the brain of APP/PS1 mice and protected neurons from oxidative stress-associated apoptosis. Further study revealed that rhein promoted mitochondrial biogenesis against oxidative stress by upregulating SIRT1 and its downstream PGC-1α as well as nuclear respiratory factor 1. Improved mitochondrial biogenesis not only increased the activity of superoxide dismutase to scavenge excess reactive oxygen species (ROS) but also repaired mitochondria by mitochondrial fusion to inhibit the production of ROS from the electron transport chain. Notably, the exposure of rhein in the brain analyzed by tissue distribution study indicated that rhein could permeate into the brain to exert its therapeutic effects. In conclusion, these findings drive rhein to serve as a promising therapeutic antioxidant for the treatment of AD. Our research highlights the therapeutic efficacy for AD through regulating mitochondrial biogenesis via the SIRT1/PGC-1α pathway.

Rheum tanguticum Alleviates Cognitive Impairment in APP/PS1 Mice by Regulating Drug-Responsive Bacteria and Their Corresponding Microbial Metabolites.

Drugs targeting intestinal bacteria have shown great efficacy for alleviating symptoms of Alzheimer's disease (AD), and microbial metabolites are important messengers. Our previous work indicated that Rheum tanguticum effectively improved cognitive function and reshaped the gut microbial homeostasis in AD rats. However, its therapeutic mechanisms remain unclear. Herein, this study aimed to elaborate the mechanisms of rhubarb for the treatment of AD by identifying effective metabolites associated with rhubarb-responsive bacteria. The results found that rhubarb reduced hippocampal inflammation and neuronal damage in APP/PS1 transgenic (Tg) mice. 16S rRNA sequencing and metabolomic analysis revealed that gut microbiota and their metabolism in Tg mice were disturbed in an age-dependent manner. Rhubarb-responsive bacteria were further identified by real-time polymerase chain reaction (RT-PCR) sequencing. Four different metabolites reversed by rhubarb were found in the position of the important nodes on rhubarb-responsive bacteria and their corresponding metabolites combined with pathological indicators co-network. Furthermore, in vitro experiments demonstrated o-tyrosine not only inhibited the viabilities of primary neurons as well as BV-2 cells, but also increased the levels of intracellular reactive oxygen species and nitric oxide. In the end, the results suggest that rhubarb ameliorates cognitive impairment in Tg mice through decreasing the abundance of o-tyrosine in the gut owing to the regulation of rhubarb-responsive bacteria. Our study provides a promising strategy for elaborating therapeutic mechanisms of bacteria-targeted drugs for AD.

Diversity Analysis and Associated Antimicrobial Activity of Essential Oil in Pyrrosia petiolosa.

The continued development of folk medicine to potentially treat infectious diseases has resulted in an increase in natural sources of antimicrobial agents, particularly the use of plant essential oils containing volatile products from secondary metabolism. The objectives of this investigation were to (i) analyze the chemical components of essential oils using GC/MS and (ii) to examine their in vitro antimicrobial activities against four strains of bacteria (Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Shigella flexneri) and one fungus (Candida albicans) by determining minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) in liquid and solid media, respectively, from different Pyrrosia petiolosa locations. Eighty-eight evaporable compounds were confirmed in their essential oils; the major components in the oils were 2,4-pentadienal (12.5 %), phytol (10.5 %) and nonanal (8.6 %). Based on hierarchical cluster analysis, Pyrrosia samples were categorized into four groups, indicating significant essential oil diversity from different Pyrrosia locations. Results also indicated that essential oils had a broad spectrum of antibacterial activities, particularly against Shigella flexneri and Staphylococcus aureus with MICs of 5 µL/mL. Results from this investigation are the first to record the chemical component and antimicrobial potential of essential oils from different P. Petiolosa locations.

Chemical Components and Antibacterial Activity of the Essential Oil of Six Pyrrosia Species.

The present study was aimed at analyzing the chemical components of the essential oil from six Pyrrosia species by GC/MS and evaluating their in vitro antibacterial activities. Seventy volatile compounds were identified in the essential oil of six Pyrrosia samples. The identified volatile components were divided into following nine categories: aldehydes, terpenoids, fatty acids, ketones, furans, hydrocarbons, alcohols, esters, and phenols. The major components of the essential oil were 2,4-pentadienal, phytol and nonanal. The antimicrobial assays showed that the essential oils from Pyrrosia samples exhibited a broad-spectrum antimicrobial activity. However, P. lingua had the highest antibacterial activity against Staphylococcus aureus (ATCC 25923) with a minimum inhibitory concentration (MIC) of 2.5 µL/mL. This article is the first report of the chemical components and antimicrobial activity of the essential oil from six Pyrrosia species, which will lay the foundation for developing medicinal resources from Pyrrosia fronds.

A Framework for Agricultural Pest and Disease Monitoring Based on Internet-of-Things and Unmanned Aerial Vehicles.

With the development of information technology, Internet-of-Things (IoT) and low-altitude remote-sensing technology represented by Unmanned Aerial Vehicles (UAVs) are widely used in environmental monitoring fields. In agricultural modernization, IoT and UAV can monitor the incidence of crop diseases and pests from the ground micro and air macro perspectives, respectively. IoT technology can collect real-time weather parameters of the crop growth by means of numerous inexpensive sensor nodes. While depending on spectral camera technology, UAVs can capture the images of farmland, and these images can be utilize for analyzing the occurrence of pests and diseases of crops. In this work, we attempt to design an agriculture framework for providing profound insights into the specific relationship between the occurrence of pests/diseases and weather parameters. Firstly, considering that most farms are usually located in remote areas and far away from infrastructure, making it hard to deploy agricultural IoT devices due to limited energy supplement, a sun tracker device is designed to adjust the angle automatically between the solar panel and the sunlight for improving the energy-harvesting rate. Secondly, for resolving the problem of short flight time of UAV, a flight mode is introduced to ensure the maximum utilization of wind force and prolong the fight time. Thirdly, the images captured by UAV are transmitted to the cloud data center for analyzing the degree of damage of pests and diseases based on spectrum analysis technology. Finally, the agriculture framework is deployed in the Yangtze River Zone of China and the results demonstrate that wheat is susceptible to disease when the temperature is between 14 °C and 16 °C, and high rainfall decreases the spread of wheat powdery mildew.

Wildfire Detection Using Sound Spectrum Analysis Based on the Internet of Things.

Wildfire is a sudden and hazardous natural disaster. Currently, many schemes based on optical spectrum analysis have been proposed to detect wildfire, but obstacles in forest areas can decrease the efficiency of spectral monitoring, resulting in a wildfire detection system not being able to monitor the occurrence of wildfire promptly. In this paper, we propose a novel wildfire detection system using sound spectrum analysis based on the Internet of Things (IoT), which utilizes a wireless acoustic detection system to probe wildfire and distinguish the difference in the sound between the crown and the surface fire. We also designed a new power supply unit: tree-energy device, which utilizes the biological energy of the living trees to generate electricity. We implemented sound spectrum analysis on the data collected by sound sensors and then combined our classification algorithms. The results describe that the sound frequency of the crown fire is about 0-400 Hz, while the sound frequency of the surface fire ranges from 0 to 15,000 Hz. However, the accuracy of the classification method is affected by some factors, such as the distribution of sensors, the loss of energy in sound transmission, and the delay of data transmission. In the simulation experiments, the recognition rate of the method can reach about 70%.

Maximum Data Collection Rate Routing Protocol Based on Topology Control for Rechargeable Wireless Sensor Networks.

In Rechargeable Wireless Sensor Networks (R-WSNs), in order to achieve the maximum data collection rate it is critical that sensors operate in very low duty cycles because of the sporadic availability of energy. A sensor has to stay in a dormant state in most of the time in order to recharge the battery and use the energy prudently. In addition, a sensor cannot always conserve energy if a network is able to harvest excessive energy from the environment due to its limited storage capacity. Therefore, energy exploitation and energy saving have to be traded off depending on distinct application scenarios. Since higher data collection rate or maximum data collection rate is the ultimate objective for sensor deployment, surplus energy of a node can be utilized for strengthening packet delivery efficiency and improving the data generating rate in R-WSNs. In this work, we propose an algorithm based on data aggregation to compute an upper data generation rate by maximizing it as an optimization problem for a network, which is formulated as a linear programming problem. Subsequently, a dual problem by introducing Lagrange multipliers is constructed, and subgradient algorithms are used to solve it in a distributed manner. At the same time, a topology controlling scheme is adopted for improving the network's performance. Through extensive simulation and experiments, we demonstrate that our algorithm is efficient at maximizing the data collection rate in rechargeable wireless sensor networks.

Chemical composition and antibacterial activity of the essential oil from Pyrrosia tonkinensis (Giesenhagen) Ching.

The present study aimed to analyse the chemical components of the essential oil from Pyrrosia tonkinensis by GC-MS and evaluate the in vitro antibacterial activity. Twenty-eight compounds, representing 88.1% of the total essential oil, were identified and the major volatile components were trans-2-hexenal (22.1%), followed by nonanal (12.8%), limonene (9.6%), phytol (8.4%), 1-hexanol (3.8%), 2-furancarboxaldehyde (3.5%) and heptanal (3.1%). The antibacterial assays showed that the essential oil of P. tonkinensis had good antibacterial activities against all the tested microorganisms. This paper first reported the chemical composition and antimicrobial activity of the essential oil from P. tonkinensis.

Antibacterial and anti-inflammatory activities of extract and fractions from Pyrrosia petiolosa (Christ et Bar.) Ching.

ETHNOPHARMACOLOGICAL RELEVANCE: Pyrrosia petiolosa is commonly used as a traditional Chinese medicine for treatment of acute pyelonephritis, chronic bronchitis and bronchial asthma. This study aims to evaluate the antibacterial activity of the ethanol extract and its derived fractions of Pyrrosia petiolosa obtained with solvents of different polarities and to perform the anti-inflammatory screening. MATERIALS AND METHODS: The powdered aerial parts of Pyrrosia petiolosa were used to extract various fractions with ethanol, petroleum ether, ethyl acetate, N-butanol and aqueous. Qualitative phytochemical screening was performed on the ethanol extract, petroleum ether fraction, ethyl acetate fraction, N-butanol fraction and aqueous fraction. The agar diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were employed to evaluate antibacterial activity of the ethanol extract and fractions. The in vitro cytotoxicity of ethanol extract and fractions was determined using MTT assay. The anti-inflammatory activity was analyzed using the mouse ear swelling induced by xylene. RESULTS: The phytochemical screening revealed the presence of anthraquinones, flavonoids, terpenoids, steroids, saponins, phenols and reducing sugars in the extract and fractions. Antibacterial results showed that petroleum ether fraction and N-butanol fraction inhibited all the tested microorganisms with the maximum inhibition zone of 15.25±0.35 mm. Ethyl acetate fraction also exhibited good antibacterial activity except Pseudomonas aeruginosa ATCC 27853, while extract and aqueous fraction inhibited 8 out of 13 (61.5%) of the tested microorganisms. The MIC values of ethanol extract and fractions ranged from 1.25 to 10.00 mg/mL and most of the MBC values were equal or twice as high as the corresponding MIC values. The in vitro cytotoxicity showed the ethanol extract and fractions exhibited non-toxic or low toxic activity against lung cancer cell lines A549 and mouse spleen cells. In anti-inflammatory experiment, ethanol extract at 5.0 and 10.0 mg/kg exhibited significant anti-inflammatory activity against the mouse ear swelling induced by xylene and the maximum inhibition rate reached as high as 67%. CONCLUSIONS: Pyrrosia petiolosa could be a potential candidate for future development of a novel antibacterial and anti-inflammatory agent.

Comparative pharmacognosy of Pyrrosia petiolosa and Pyrrosia davidii

Pyrrosia petiolosa (Christ) Ching, Polypodiaceae, is an important medicinal pteridophyte used for the treatment of nephritis and bronchitis, while P. davidii (Giesenhagen. ex Diels) Ching, Polypodiaceae, often substitutes medicinal Pyrrosia in clinic. The present study was aimed to compare the pharmacognosy of P. petiolosa and P. davidii, including plant morphology, microscopic characteristics, physico-chemical parameters, UV and IR spectrum, and HPLC fingerprint. It was revealed that the two herbs had basically similar pharmacognostical characteristics but with certain differences. The present study contributes to the standardization and verification of these medicinal materials.

Comparative analgesic effect of Ligusticum chuanxiong pieces and its products in mice.

The present study was undertaken with the objective of finding out the comparative analgesic effect of Ligusticum chuanxiong (LC) pieces decoction, LC formula granule decoction, liquored LC pieces decoction and liquored LC formula granule decoction. The analgesic effects were analyzed using the hot plate and acetic-induced writhing test in mice, and antidysmenorrheic effect was observed with primary dysmenorrhea model. The results showed that four kinds of LC decoction had definite effect in delaying incubation period and decreasing the writhing frequency within 30 min. They also effectively relieved dysmenorrhea. Moreover, liquored LC had better analgesic effect than crude LC in four decoctions.

Expression of thymosin alpha1-thymopentin fusion peptide in Pichia pastoris and its characterization.

Thymopentin plays an important role in improving imbalanced immune systems of patients, however, it has a limited half-life in plasma. To get more stable and active thymopentin analogs, a fusion thymosin alpha1-thymopentin (Talpha1-TP5) gene was synthesized and cloned into vector pGAPZalphaA. Talpha1-TP5 fusion peptide was expressed in pichia pastoris and purified by metal chelating chromatography and gel filtration chromatography. The circular dichroism spectra (CD) indicated that the secondary structure of Talpha1-TP5 fusion peptide is dominated by a-helix and random coil. In vitro analysis showed that the plasma half-life of Talpha1-TP5 fusion peptide is 140 +/- 14 min, which is longer than that of TP5 (5.6+/-0.7 min) and Talpha1 (127+/-11 min). The in vitro activity assay presented that Talpha1-TP5 fusion peptide has greater activity in promoting proliferation of Kunming mouse splenocytes, and in vivo experiment it showed better activity in promoting the phagocytosis of macrophages and secretion of IL-2 than both Talpha1 and TP5. Our findings suggest that Talpha1-TP5 fusion peptide might be a potential therapeutic agent.