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Vascular dementia (VaD), one of the major consequences after stroke, is the second reason for the cognitive decline in aged people. Chronic cerebral hypoperfusion (CCH) is considered as the main cause for cognitive impairment in VaD patients. In our previous study, a synthetic compound, 4-trifluoromethyl-(

N-Phenylpropenoyl-l-amino acids (NPAs) are inducible nitric oxide synthase (iNOS) inhibitors possessing preventive effects for Parkinson's disease (PD). Here, structural modifications for improving the iNOS inhibitory activity and blood-brain barrier (BBB) permeability of NPAs were conducted, leading to 20 optimized NPA derivatives (1-20). Compound 18, with the most potent activity (IC50 = 74 nM), high BBB permeability (Pe = 19.1 × 10-6 cm/s), and high selectivity over other NOS isoforms, was selected as the lead compound. Further studies demonstrated that 18 directly binds to iNOS. In the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced acute PD model, the oral administration of 18 (1 and 2 mg/kg) exerted preventive effects by alleviating the loss of dopaminergic (DAergic) neurons. Notably, in the MPTP-/probenecid-induced chronic PD model, the same dose of 18 also displayed a therapeutic effect by repairing the damaged DAergic neurons. Finally, good pharmacokinetic properties and low toxicity made 18 a promising candidate for the treatment of PD.

Ischemic stroke is one of the leading causes of death and disability worldwide. The severe sequelae caused by ischemic thrombolysis and the narrow time window are now the main clinical challenges. Our previous study has reported 4-Trifluoromethyl-(E)-cinnamoyl]-L-4-F-phenylalanine Acid (AE-18) was a promising candidate for Parkinson's Disease. In this study, the preventive and therapeutic effects of AE-18 on focal cerebral ischemia-reperfusion injury and the mechanisms are explored. In oxygen glucose deprivation/reoxygenation (OGD/R)-induced well-differentiated PC12 cells model, AE-18 (10 or 20 μM) can significantly reduce nerve damage when administered before or after molding. In middle cerebral artery occlusion-reperfusion (MCAO/R) rat model, pre-modelling, or post-modelling administration of AE-18 (5 or 10 mg/kg) was effective in reducing neurological damage, decreasing infarct volume and improving motor disturbances. In addition, AE-18 (5 mg/kg) given by intravenous injection immediately after occlusion significantly reduce the infarct volume caused by reperfusion for different durations, indicating that AE-18 could extend the time window of thrombolytic therapy. Further studies demonstrate that AE-18 exerts the effects in the prevention, treatment, and prolongation of the time window of cerebral ischemic injury mainly through inhibiting excitotoxicity and improving BBB permeability, VEGF and BDNF. These results suggest that AE-18 is a good candidate for the treatment of ischemic stroke.

A series of clovamide analogues, namely, 1a–13a and 1b–13b, was synthesized and evaluated for their anti-neuroinflammatory activities using BV-2 microglia cells. Among these compounds, six (1b, 4b–8b) showed NO inhibition with no or weak cytotoxicity (CC50 > 100 μM), especially 4b, and showed an IC50 value of 2.67 μM. Enzyme activity and docking assay revealed that the six compounds, especially 4b, target inducible NO synthase (iNOS) and exhibit potent inhibitory effects on iNOS with IC50 values ranging from 1.01 μM to 29.23 μM 4b significantly suppressed the expression of pro-inflammatory cytokines in lipopolysaccharide-stimulated cells. Notably, the oral administration of 4b remarkably improved dyskinesia, reduced the expression of glial fibrillary acidic protein (GFAP)-a marker of neuroinflammation, and increased tyrosine hydroxylase-positive cells in 1-methyl-4-phenyl-1,2,3,6-tetrahydro-pyridine-induced Parkinson's disease (PD) mouse models. These observations demonstrated that 4b is an effective and promising candidate for PD therapy.

Background Blue light can directly penetrate the lens and reach the retina to induce retinal damage, causing dry age-related macular degeneration (dAMD). Cynaroside (Cyn), a flavonoid glycoside, was proved to alleviate the oxidative damage of retinal cells in vitro. However, whether or not Cyn also exerts protective effect on blue light-induced retinal degeneration and its mechanisms of action are unclear. Purpose This study aims to evaluate the protective effects of Cyn against blue-light induced retinal degeneration and its underlying mechanisms in vitro and in vivo. Study design/methods Blue light-induced N-retinylidene-N-retinylethanolamine (A2E)-laden adult retinal pigment epithelial-19 (ARPE-19) cell damage and retinal damage in SD rats were respectively used to evaluate the protective effects of Cyn on retinal degeneration in vitro and in vivo. MTT assay and AnnexinV-PI double staining assay were used to evaluate the in vitro efficacy. Histological analysis, TUNEL assay, and fundus imaging were conducted to evaluate the in vivo efficacy. ELISA assay, western blot, and immunostaining were performed to investigate the mechanisms of action of Cyn. Results Cyn decreased the blue light-induced A2E-laden ARPE-19 cell damage and oxidative stress. Intravitreal injection of Cyn (2, 4 μg/eye) reversed the retinal degeneration induced by blue light in SD rats. Furthermore, Cyn inhibited the nuclear translocation of NF-κB and induced autophagy, which led to the clearance of overactivated pyrin domain containing 3 (NLRP3) inflammasome in vitro and in vivo. Conclusion Cyn protects against blue light-induced retinal degeneration by modulating autophagy and decreasing the NLRP3 inflammasome.

• In this study, seven clovamide analogues (1–7) were designed and synthesized, and the neuroprotection of 1–7 as well as 8–15 (prepared in our previous work) against H2O2-induced oxidative stress was evaluated in SH-SY5Y cells. Results showed that 1–7 with catechol groups exhibited better neuroprotective effects than 8–15, and their EC50 values ranged from 4.26 to 23.83 μM, especially 1, indicating that the moiety of catechol governed the activities of these compounds. Furthermore, oral administration of 1 (10 or 20 mg/kg) was demonstrated to possess anti-PD effect through alleviating apoptosis and oxidative stress in vitro and in vivo, and to up-regulate the expression of heme oxygenase-1 (HO-1) via PI3K/AKT/mTOR pathway. Finally, the pharmacokinetic (PK) assessment of 1 was determined in rats. These findings suggested that 1 might be an effective candidate for PD therapy.

Application of mono (6A-N-ethylenediamine-6A-deoxy) perphenylcarbamoylated β-cyclodextrin (β-CD) bonded stationary phase (CSP) in micro-high performance liquid chromatography (micro-HPLC) and pressurized capillary electrochromatography (p-CEC) was firstly presented. A series of racemic α-amidophosphonates were resolved in reversed- and normal-phase modes on this CSP. The investigated chromatographic parameters include retention factor (k′), separation factor (α) and resolution (Rs) of solutes. In addition, the structural variation of the solutes and the experimental factors affecting chiral separations have been examined, including the percentage of alcohol modifier, the linear velocity (u) of the mobile phase, electrical field strength, etc. Baseline separation was achieved for most of the entities. Hydrophobic interaction, steric effect and π–π interaction contribute to the possible mechanism. Comparative results indicate that higher Rs value up to 3.1 was found in micro-HPLC, higher efficiency up to 29,970 in p-CEC.

Half-fronds of Spirodela polyrrhiza accumulated high level of endogenous serine when they had been cultivated under long-day conditions and on a cytokinin-free medium for 4 days, after which the irreversible senescence process was triggered. When 1 μM 6-benzyl adenine (6-BA) was included in the medium, the accumulation of endogenous serine was significantly inhibited, and at the same time the biological activity of half-fronds was increased. Application of exogenous l -serine into medium at 1 mM initiated senescence of half-fronds, as well as intact plants, under the conditions of long-day and darkness. Application of 6-BA into the medium with l -serine postponed the appearance of serine level peak and senescence syndrome, although the senescence process was not prevented. It was also observed that half-fronds cultivated in the darkness on a medium with only inorganic nutrients had a very low level of endogenous serine and maintained their biological activity for up to 2 months. These data shows that high level of endogenous l -serine can initiate senescence in Spirodela polyrriza and cytokinin can inhibit the accumulation of endogenous l -serine. The possible reason for the accumulation of endogenous serine under long-day conditions was investigated. The activity of serine glyoxylate aminotransferase (SGAT), which catalyzes the conversion of l -serine to hydroxypyruvate, was found to decrease gradually in half-fronds during cultivation under long-day conditions, but to be maintained by 6-BA application. Northern blot analysis was used to detect the changes in the level of transcript encoding SAGT, and results showed that the expression of this gene was up-regulated by cytokinin but down-regulated during senescence.

The preparation, characterization and potential liquid chromatographic applications of two totally and partly functionalized β-cyclodextrin-bonded stationary phases were presented. Separation of a series of organophosphorus racemic compounds was achieved under normal and reverse-phase conditions. Separation factor was up to 1.812 and resolution up to 4.072. The influence of chromatographic conditions was investigated and the possible chiral recognition mechanism was proposed.