Cistanche tubulosa alleviates ischemic stroke-induced blood-brain barrier damage by modulating microglia-mediated neuroinflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: Ischemic stroke (IS) has both high morbidity and mortality. Previous research conducted by our group demonstrated that the bioactive ingredients of the traditional medicinal and edible plant Cistanche tubulosa (Schenk) Wight (CT) have various pharmacological effects in treating nervous system diseases. However, the effect of CT on the blood-brain barrier (BBB) after IS are still unknown. AIM OF THE STUDY: This study aimed to identify CT's curative effect on IS and explore its underlying mechanism. MATERIALS AND METHODS: IS injury was established in a rat model of middle cerebral artery occlusion (MCAO). Gavage administration of CT at dosages of 50, 100, and 200 mg/kg/day was carried out for seven consecutive days. Network pharmacology was used for predicting the pathways and potential targets of CT against IS, and subsequent studies confirmed the relevant targets. RESULTS: According to the results, both neurological dysfunction and BBB disruption were exacerbated in the MCAO group. Moreover, CT improved BBB integrity and neurological function and protected against cerebral ischemia injury. Network pharmacology revealed that IS might involve neuroinflammation mediated by microglia. Extensive follow-up studies verified that MCAO caused IS by stimulating the production of inflammatory factors and microglial infiltration. CT was found to influence neuroinflammation via microglial M1-M2 polarization. CONCLUSION: These findings suggested that CT may regulate microglia-mediated neuroinflammation by reducing MCAO-induced IS. The results provide theoretical and experimental evidence for the efficacy of CT therapy and novel concepts for the prevention and treatment of cerebral ischemic injuries.

Effect and Mechanisms of Quercetin for Experimental Focal Cerebral Ischemia: A Systematic Review and Meta-Analysis.

Quercetin, a naturally occurring flavonoid, is mainly extracted from tea, onions, and apples. It has the underlying neuroprotective effect on experimental ischemic stroke. A systematic review and meta-analysis were used to assess quercetin's efficacy and possible mechanisms in treating focal cerebral ischemia. Compared with the control group, twelve studies reported a remarkable function of quercetin in improving the neurological function score (NFS) (P < 0.05), and twelve studies reported a significant effect on reducing infarct volume (P < 0.05). Moreover, two and three studies showed that quercetin could alleviate blood-brain barrier (BBB) permeability and brain water content, respectively. The mechanisms of quercetin against focal cerebral ischemia are diverse, involving antioxidation, antiapoptotic, anti-inflammation, and calcium overload reduction. On the whole, the present study suggested that quercetin can exert a protective effect on experimental ischemic stroke. Although the effect size may be overestimated because of the quality of studies and possible publication bias, these results indicated that quercetin might be a promising neuroprotective agent for human ischemic stroke. This study is registered with PROSPERO, number CRD 42021275656.

Component-target network and mechanism of Qufeng Zhitong capsule in the treatment of neuropathic pain.

ETHNOPHARMACOLOGICAL RELEVANCE: Qufeng Zhitong capsule (QFZTC) is a traditional Chinese medicine (TCM) clinically used for treating pain. However, the active ingredients of QFZTC and its pharmacological mechanism in the treatment of neuropathic pain (NP) remain unclear. AIM OF THE STUDY: We aimed to identify the active ingredients of QFZTC and reveal its target genes and underlying mechanism of action in NP. MATERIALS AND METHODS: High-performance liquid chromatography (HPLC) was used to identify the active ingredients of QFZTC. Network pharmacology analysis was conducted to determine the core targets and pathway enrichment of QFZTC. An NP mice model was established through chronic compression injury (CCI) surgery of the sciatic nerve, while von Frey instrumentation and a thermal stimulator were employed to measure the sensitivity of mice to mechanical and thermal stimuli. Immunofluorescence was used to observe the expression of TLR4 and p-P65 in microglia. Western blotting was used to detect the levels of protein expression of Iba-1, TLR4, MyD88, P65, p-P65, and c-Fos, while ELISA kits were used to detect the release of TNF-α, IL-6, and IL-1ß. RESULTS: Seven active ingredients were identified in QFZTC: gallic acid, loganylic acid, syringin, corilagin, loganin, ellagic acid, and osthole. Network analysis identified TLR4, TNF, IL6, IL1ß, and c-Fos as core targets, and Toll-like receptors and NF-κB as core signaling pathways. Treatment with QFZTC significantly relieved mechanical allodynia and thermal hyperalgesia in CCI mice models. CCI induced an increase in the expression of TLR4 and p-P65 in microglia, whereas QFZTC dose-dependently reduced the expression of Iba-1, TLR4, MyD88, and p-P65 in the spinal cord. QFZTC inhibited the expression of the c-Fos pain marker and reduced the expression of the TNF-α, IL-6, and IL-1ß inflammatory factors. CONCLUSION: We combined the active ingredients of QFZTC with network pharmacology research to clarify its biological mechanism in the treatment of NP. We demonstrated that QFZTC reduced NP in mice probably through regulating the spinal microglia via the TLR4/MyD88/NF-κB signaling pathway. Hence, QFZTC could be regarded as a potential drug for relieving NP.

LIFGO: A modular laser-induced fluorescence detection system based on plug-in blocks.

In this work, a laser-induced fluorescence (LIF) detection system built in a modular assembling mode was developed based on commercial LEGO blocks and 3D printed blocks. We designed and fabricated a variety of 3D printed building blocks fixed with optical components, including laser light source, filters, lens, dichroic mirror, photodiode detector, and control circuits. Utilizing the relatively high positioning precision of the plug-in blocks, a modular construction strategy was adopted using the flexible plug-in combination of the blocks to build a highly sensitive laser-induced fluorescence detection system, LIFGO. The LIFGO system has a simple structure which could be constructed by inexperienced users within 3 h. We optimized the structure and tested the performance of the LIFGO system, and its detection limits for sodium fluorescein solution in 100 µm i.d. and 250 µm i.d. capillaries were 7 nM and 0.9 nM, respectively. Based on the LIFGO system, we also built a simple capillary electrophoresis (CE) system and applied it to the analysis of DNA fragments to demonstrate its application possibility in biochemical analysis. The separation of 7 fragments in DL500 DNA markers were completed in 600 s. Because of the features of low cost (less than $100) and easy-to-build construction, we introduced the LIFGO system to the experimental teaching of instrumental analysis for undergraduate students. The modular construction form of the LIF detection system greatly reduces the threshold of instrument construction, which is conducive to the popularization of the LIF detection technique in routine laboratories as well as the reform of experimental teaching mode.

Integrin α2ß1 is involved in T-2 toxin-induced decrease of type II collagen in C28/I2 chondrocytes.

The T-2 toxin exerts a variety of toxic effects on both experimental animals and humans. The integrin family plays a major role in mediating cell-ECM interactions. Therefore, the present study aimed to investigate the involvement of integrin α2ß1 in T-2 toxin-induced C28/I2 chondrocyte damage. The pathological damage of articular cartilage injury induced by T-2 toxin was observed by H&E staining. The expression levels of collagen 2 and MMP-13 (Matrix metalloproteinases 13) were detected using immunohistochemistry in articular cartilage tissues and western blotting in the cells. The blocking effect of integrin α2ß1 inhibitor on T-2 toxin-induced chondrocyte matrix degradation was examined by western blotting. Further, the effect of integrin α2ß1 inhibitor on T-2 toxin-induced chondrocyte apoptosis was analyzed. About 100 ng/g body weight (BW)/day T-2 toxin was fed to Sprague-Dawley (SD) rats, T-2 toxin treatment (0, 6, 12, and 24 ng/mL) induced C28/I2 chondrocytes. Both in vivo and in vitro, chondrocyte survival was inhibited, and the production of type II collagen was significantly reduced (p < 0.05). However, the level of MMP-13 was up-regulated (p < 0.05). Matrix degradation was effectively blocked after the pre-treatment by integrin α2ß1 inhibitor (p < 0.05). Conclusively, Integrin α2ß1 is a critical signaling pathway for communication between cells and the extracellular matrix, the present study provides a new clue to elucidate the mechanism of T-2 toxin-induced chondrocyte damage.

JNK/AP-1 activation contributes to tetrandrine resistance in T-cell acute lymphoblastic leukaemia.

T-cell acute lymphoblastic leukaemia (T-ALL) is a challenging malignancy with a high relapse rate attributed to drug resistance. Tetrandrine (TET), a bisbenzylisoquinoline alkaloid extracted from a Chinese herb, is a potential anti-cancer and anti-leukaemic drug. In this study we investigated the mechanisms of TET resistance in T-ALL cells in vitro. Among the four T-ALL cell lines tested, Jurkat and CEM cells exhibited the lowest and highest resistance to TET with IC50 values at 24 h of 4.31±0.12 and 16.53±3.32 µmol/L, respectively. When treated with TET, the activity of transcription factor activator protein 1 (AP-1) was significantly decreased in Jurkat cells but nearly constant in CEM cells. To avoid cell-specific variation in drug resistance and transcription factor activities, we established a TET-R Jurkat subclone with the estimated IC50 value of 10.90±.92 µmol/L by exposing the cells to increasing concentrations of TET. Interestingly, when treated with TET, TET-R Jurkat cells exhibited enhanced AP-1 and NF-κB activity, along with upregulation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) signaling pathways, whereas the expression of P-gp was not altered. Selective inhibition of JNK but not ERK suppressed AP-1 activity and TET resistance in TET-R Jurkat cells and in CEM cells. These results demonstrate that Jurkat cells acquire TET resistance through activation of the JNK/AP-1 pathway but not through P-gp expression. The JNK/AP-1 pathway may be a potential therapeutic target in relapsed T-ALL.

Fluorescent coumarin-based probe for cysteine and homocysteine with live cell application.

Cysteine (Cys) and homocysteine (Hcy) are two of important biological thiols and function as important roles in several biological processes. The development of Cys and Hcy probes will help to explore the functions of biothiols in biological systems. In this work, a new coumarin-based probe AC, containing an acryloyl moiety, was developed for Cys and Hcy detection in cells. Cys and Hcy undergo a nucleophilic addition and subsequent cyclization reaction to remove to the acryloyl group and yield a fluorescent product, 7-hydroxylcomuarin. The probe AC showed good selectivity for cysteine and homocysteine over glutathione and other amino acids and had low detection limits of 65nM for Cys and 79nM for Hcy, respectively. Additionally, confocal imaging experiments demonstrated that the probe AC can be applied to visualize Cys and Hcy in living cells.

Small-angle measurement with highly sensitive total-internal-reflection heterodyne interferometer.

In this paper, a high-sensitivity total-internal-reflection (TIR) heterodyne interferometer is proposed for measuring small angles. In the proposed interferometer, a half-wave plate and two quarter-wave plates that exhibit specific optic-axis azimuths are combined to form a phase shifter. When a rhomboid prism is placed between the phase shifter and an analyzer that exhibits suitable transmission-axis azimuth, it shifts and enhances the phase difference of the s- and p-polarization states at double TIR. The enhanced phase difference is dependent on the incident angle; thus small angles can be easily and accurately measured by estimating the phase difference. The experimental results demonstrate the feasibility of this method. Angular resolution and sensitivity levels superior to 1.2×10⁻4 deg (2.1×10⁻6 rad) and 100 (deg/deg), respectively, were attainable in a dynamic range of 0.5 deg.