Polyprenols mitigate cognitive dysfunction and neuropathology in the APP/PS1 mouse.

Alzheimer's disease (AD) is a very common neurodegenerative disorder in the elderly and brings considerable financial and social problems worldwide. In this study, polyprenols were firstly evaluated the effects on the cognitive deficits and neuropathology in APP/PS1 mice model of AD. At 3 months old, the APP/PS1 mice were divided into model group; polyprenols low, middle, and high dosage group; and positive drug group. Age-matched wild-type mice were chosen in control group. The administration by oral gavage lasted 6 months. Polyprenols treatment significantly improved cognitive impairment of double transgenic mice compared with vehicle control treatment in behavioral tests. In addition, immunohistochemistry and enzyme-linked immunosorbent assay showed that there were significantly reductions in neuritic plaques and the level of hyperphosphorylated tau in brain of polyprenols-treated mice. Furthermore, we found that polyprenols treatment reduced the apoptotic cells in brain sections of 9-month-old APP/PS1 mice. These results reveal that polyprenols exert neuroprotective effects in APP/PS1 mice and could represent an effective treatment for AD.

A cell-based, high-throughput homogeneous time-resolved fluorescence assay for the screening of potential κ-opioid receptor agonists.

AIM: The aim of this study was to identify κ-opioid receptor (KOR) agonists from a library of 80 000 small-molecule compounds and provide the experimental basis for the development of new analgesic candidates. METHODS: The cell-based, high-throughput screen for human KOR agonists was based on the LANCE cAMP assay. Preliminary structure-activity relationship (SAR) analysis was applied according to the compounds' structures. An acetic acid twisting experiment was used to verify the pharmacodynamics. RESULTS: In total, 31 compounds were identified as KOR agonists after preliminary and secondary screening. Of these compounds, five demonstrated significant KOR-stimulating activity that was comparable to U-50,488, a selective KOR agonist. The EC50 values for I-7, I-8, I-10, II-5, and II-8 were 13.34 ± 1.65, 14.01 ± 1.84, 9.57 ± 0.19, 14.94 ± 0.64, and 8.74 ± 0.72 nmol/L, respectively. Based on SAR studies, the stimulating activity of compounds with 5-phenyl-7-(trifluoromethyl)-4,5,6,7-tetrahydropyrazolo [1, 5-a] pyrimidine (group I) and 3,4-dimethoxy-N-(2-oxoethyl)-N-p-tolylbenzenesulfonamide (group II) parent structures were higher than the compound with a 5-hydroxy-2-methylbenzofuran-3-carboxylic acid (group III) parent structure. Pharmacodynamic experiments indicated that 20-40 µg/kg ip of compounds I-10 and II-8 significantly decreased the number of writhes induced by acetic acid; this finding is consistent with the SAR studies. Furthermore, the analgesic effects of compounds I-10 and II-8 were significantly antagonized in the presence of the selective KOR antagonist nor-BNI. CONCLUSION: These findings collectively indicate that compounds I-10 and II-8 exhibit significant analgesic activities, providing evidence, at least in part, for their clinical application as new analgesic drugs.

[Protective effect of Pinus massoniana bark extracts against cisplatin-induced nephrotoxicity in human embryonic kidney cells].

OBJECTIVE: To investigate the in vitro protective effect of Pinus massoniana bark extracts (PMBE) against cisplatin-induced nephrotoxicity in human embryonic kidney cells (HEK293), and preliminarily study its mechanism. METHOD: Human embryonic kidney cells (HEK293) were cultured in vitro. The MTT assay was adopted to test the effect of PMBE and cisplatin on growth of HEK293 cells, and the protective effect of PMBE on cisplatin-induced nephrotoxicity of HEK293, and then detect the intracellular reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH) content, catalase (CAT), superoxide dismutase (SOD) and activity of thioredoxin reductase (TrxR). RESULT: PMBE could promote growth of HEK293 cells at low concentrations, but generate slight nephrotoxicity at high concentration. Cisplatin could inhibit growth of HEK293 cells, increase ROS and MDA content, while reducing SOD, CAT and TrxR. The pre-protective PMBE was added to reduce cisplatin's injury to HEK293 cells, ROS, MDA and GSH content, SOD, CAT and TrxR within certain range. CONCLUSION: PMBE at specific concentration has the protective effect in cisplatin-induced nephrotoxicity in HEK293 cells. Its mechanism may be related to PMBE's antioxidant activity.

Effects of polyprenols from pine needles of Pinus massoniana on ameliorating cognitive impairment in a D-galactose-induced mouse model.

Cognitive deficiency and oxidative stress have been well documented in aging and in neurodegenerative disorders such as Alzheimer's disease. In this study, we assessed the therapeutic effect of polyprenols on D-galactose-induced cognitive impairment in mice by testing on of behavioral and cognitive performance. In order to explore the possible role of polyprenols against D-galactose-induced oxidative damages, we assessed various biochemical indicators. Chronic administration of D-galactose (150 mg/kg·d, s.c.) for 7 weeks significantly impaired cognitive performance (both in step-through passive and active avoidance tests) and locomotor activity (in open-field test) and the ability of spatial learning and memory (in Morris water maze test) compared with the control group. The results revealed that polyprenols treatment for 2 weeks significantly ameliorated model mice's cognitive performance and oxidative defense. All groups of polyprenols enhanced the learning and memory ability in step-through passive and active avoidance tests, locomotor activity in open-field test, and the ability of spatial learning and memory in Morris water maze test. Furthermore, high and middle level of polyprenols significantly increased total antioxidative capacity (T-AOC), glutathione peroxidase (GSH-Px), super oxide dismutase (SOD) activity, neprilysin (NEP), and ß-site AßPP cleaving enzyme 1 (BACE1) expression, while nitric oxide (NO), nitric oxide synthase (NOS) activity, malondialdehyde (MDA) concentration, and the level of Aß1-42 and presenilin 1 (PS1) were decreased. Polyprenols have a significant relieving effect on learning, memory, and spontaneous activities in a D-galactose-induced mouse model and ameliorates cognitive impairment and biochemical dysfunction in mice. In summary, we have demonstrated that polyprenols may ameliorate memory and cognitive impairment via enhancing oxidative defense and affecting generation and dissimilation of Aß-related enzymes, suggesting that polyprenols represent a novel drug for treating Alzheimer's disease.