Revealing active constituents within traditional Chinese Medicine used for treating bacterial pneumonia, with emphasis on the mechanism of baicalein against multi-drug resistant Klebsiella pneumoniae.

ETHNOPHARMACOLOGICAL RELEVANCE: The emergence of antibiotic-resistant bacteria has rendered it more challenging to treat bacterial pneumonia. Traditional Chinese medicine (TCM) has superior efficacy in the treatment of pneumonia, and it has the unique advantage of antibacterial resistance against multi-drug resistant (MDR) bacteria, but the medication rule and pharmacological mechanism of its antibacterial activity are not clear. AIM OF THE STUDY: This study aims to reveal Chinese medication patterns in treating bacterial pneumonia to select bioactive constituents in core herbs, predict their pharmacological mechanisms and further explore their antibacterial ability against clinically isolated MDR Klebsiella pneumoniae (KP) and their antibacterial mechanisms. MATERIALS AND METHODS: The high-frequency medicinal herbs to treat lung diseases were first screened from Pharmacopoeia of the People's Republic of China (ChP.), and then bioactive compounds in core herbs and targets for compounds and disease were collected. Potential targets, signaling pathways, and drugs' core components were determined by constructing protein-protein interaction network, enrichment analysis and "component-target-pathway-disease" network were mapped by Cytoscape 3.8.2, and the potential therapeutic value of selected core components was verified by comparing the disease targets in the GEO database with the herbal component targets in the ITCM database. The clinically isolated KP were screened by drug sensitivity tests with meropenem (MEM), polymyxin E (PE), and tigecycline and biofilm-forming assay; broth microdilution, chessboard methods and biofilm morphology and permeability experiments were employed to determine the antibacterial, bactericidal and biofilm inhibition ability of selected bioactive constituents alone and in combination with antibiotics; The mechanism of bioactive components on quorum sensing (QS) genes LuxS and LuxR was predicted by molecular docking and tested by RT-PCR. RESULTS: The 13 core Chinese medicines were obtained by mining ChP., and 615 potential targets of core herbal medicine were screened, and the PI3K-Akt signaling pathway might play crucial roles in the therapeutic process. In-vitro experiments revealed that the selected core compounds, including forsythoside B, baicalin, baicalein, and forsythin, all have antibacterial activity, in which baicalein had the strongest ability and a synergistic effect in combination with MEM or PE. Their synergy exhibited a stronger effect on biofilms of MDR KP, inhibiting biofilm formation, disrupting formed biofilms, and removing the residual structures of dead bacteria. Baicalein was predicted to have stable binding capacity to LuxS and LuxR genes by molecular docking, and RT-PCR results verified that the combination of baicalein with MEM or PE was effective in inhibiting the expression of QS genes (LuxS and LuxR) and consequently suppressing biofilm formation. CONCLUSION: The core Chinese herbal medicine in the ChP. to treat lung diseases has a multi-component, multi-target, and multi-pathway synergy to improve bacterial pneumonia. Experimental studies have confirmed that the bioactive compound baicalein was able to combat MDR KP alone and synergistic with MEM or PE, inhibited and disrupted biofilms via regulating LuxS and LuxR genes, and further disturbed quorum sensing system to promote the therapeutic efficacy, which provides a new pathway and rationale for treating MDR KP-induced bacterial pneumonia.

Ligustrazine Attenuates Hyperhomocysteinemia-induced Alzheimer-like Pathologies in Rats.

Ligustrazine, an alkaloid extracted from the traditional Chinese herbal medicine Ligusticum Chuanxiong Hort, has been clinically applied to treat the cerebrovascular diseases. Hyperhomocysteinemia (Hhcy) is an independent risk factor for Alzheimer's disease (AD). Memory deficits can be caused by Hhcy via pathologies of AD-like tau and amyloid-ß (Aß) in the hippocampus. Here, we investigated whether homocysteine (Hcy) can induce AD-like pathologies and the effects of ligustrazine on these pathologies. The Hcy rat model was constructed by 14-day Hcy injection via vena caudalis, and rats were treated with daily intragastric administration of ligustrazine at the same time. We found that the pathologies of tau and Aß were induced by Hcy in the hippocampus, while the Hcy-induced tau hyperphosphorylation and Aß accumulation could be markedly attenuated by simultaneous ligustrazine treatment. Our data demonstrate that ligustrazine may be used as a promising neuroprotective agent to treat the Hcy-induced AD-like pathologies.

The Effects of Transcranial Direct Current Stimulation Versus Electroacupuncture on Working Memory in Healthy Subjects.

Objective: Working memory (WM) can influence human thought processes through interactions with perception, long-term memory, and behavior. In recent years, transcranial direct current stimulation (tDCS) and electric acupuncture have been used to improve the performance of WM. Therefore, due to the n-back task as a continuous performance task that is commonly used to measure WM, the aim of this study is to investigate the differences in short-term efficacy between tDCS and electroacupuncture on WM under n-back task paradigm in healthy subjects. Methods: Forty-four college students (age: 23.70 ± 1.52 years; education: 16.93 ± 2.24 years) were recruited as experimental subjects and randomly divided into two groups by a random double-blind two-stage crossover experiment design. Group A received a tDCS intervention followed by at least 1 week of washout period and then the electroacupuncture intervention. Group B had the opposite sequence of interventions. The WM test under the n-back task paradigm was conducted before and after each intervention, and the changes in the accuracy (number of correct responses) and correct response time (RT) before and after the interventions were detected. The data were statistically analyzed using SPSS 24.0 to compare the short-term efficacy of tDCS and electroacupuncture on WM under different tasks. Results: In the 0-back task and 1-back tasks, there was no significant difference in the accuracy or RT before and after the interventions between tDCS and electroacupuncture stimulation. In the 2-back task, there was no significant difference in the accuracy before and after interventions between tDCS and electroacupuncture stimulation. However, there was a significant difference in RT (p < 0.05), which was lower after tDCS than after electroacupuncture in the 2-back task. Conclusion: The results show that tDCS with anodal stimulation on the left dorsolateral prefrontal cortex could increase the RT of the 2-back task performance in comparison with electroacupuncture stimulation of the Baihui (GV20) and Shenting (DU24) acupoints. The present results indicate that tDCS may have greater impact on WM in healthy subjects than electroacupuncture stimulation.

[Influence of sample loading and test conditions on NIR veracity and study of analysis error source].

The influence of sample test conditions on the NIR veracity was studied with homemade grating diffuse NIR instrument using Yunnan flue-cured tobacco. Deducing analysis error was achieved by model self-emendation when a global NIR model was set up. Without regarding the influence of loading samples and test conditions, the test repetition error, re-loading error and samples tightness error, which were brought by instrument S/N, accounted for 50%, 30% and 20% of the total error, respectively. Depressing sample could reduce errors brought by sample tightness. Changes in test conditions could bring more analysis error, which was larger than the total of repetition error. These results theoretically explain the influence of sample test conditions on the NIR analysis veracity, which can provide basic theory data for farther improvement of homemade instrument and offer a new idea for resolving this problem.

[Influence of sample annum and distribution of chemical values on NIR veracity].

The influence of sample annum and the distribution of sample component on NIR veracity was studied with homemade grating diffuse NIR instrument using Yunnan flue-cured tobacco. Results showed that sample annum had an obvious influence on the total sugar and nicotine models, but had an unconspicuous influence on the total-nitrogen model. Models set up by samples, whose component content distribution was normal school, was better than those set up by even distribution. The conclusion in this study has a significant referenced value for the method and principle to select representative samples to modeling from a large amount of specimens.

[New technology for sample preprocessing in NIR analysis].

Sample's moisture content and granularity would have an important influence on NIR veracity. Preprocesssing methods have been used for NIR analysis to achieve better NIR veracity. With Yunnan flue-cured tobacco as study materials, the authors innovatively applied microwave fast drying technology and home pulverizer to tobacco preprocessing, which could finish the preprocessing in 5 min, faster than the traditional methods such as oven drying and sifting. Results showed that: microwave fast drying technology could improve NIR analysis veracity when samples' moisture content had a wide range; influence of samples' granularity on NIR veracity could be eliminated after 25 s home pulverizer shatter. This study can offer a new method for NIR analysis workers to simplify NIR preprocessing.