LncRNA Meg3 promotes oxygen and glucose deprivation injury by decreasing angiogenesis in hBMECs by targeting the miR­122­5p/NDRG3 axis.

Oxygen-glucose deprivation (OGD) is widely used as an in vitro model for stroke. The present study aimed to explore the mechanisms of action of long non-coding RNA (lncRNA) maternally expressed gene 3 (Meg3) in angiogenesis following OGD. The human brain microvascular endothelial cell line, hCMEC/D3, was used to establish the OGD model. lncRNA Meg3 was highly expressed in hCMEC/D3 cells subjected to OGD. Furthermore, it was found that the overexpression of lncRNA Meg3 decreased the proliferation, migration and angiogenesis of hCMEC/D3 cells subjected to OGD, and increased cell apoptosis. Meg3 silencing exerted the opposite effects. Subsequently, lncRNA Meg3 increased the expression of NDRG family member 3 (NDRG3) by directly binding to miR-122-5p. The overexpression of miR-122-5p and the knockdown of NDRG3 reversed the inhibitory effects of Meg3 overexpression on the proliferation, migration and angiogenesis of hCMEC/D3 cells subjected to OGD, as well as the promoting effects of Meg3 overexpression on cell apoptosis. The present study demonstrated that lncRNA Meg3 functions as a competing endogenous RNA by targeting the miR-122-5p/NDRG3 axis in regulating OGD injury.

Effect and Mechanism of Yisui Fuyongtang (YSFYT) Decoction on Cognitive Function and Synaptic Plasticity in Rats with Vascular Cognitive Impairment.

Vascular cognitive impairment (VCI) has emerged as the second major disease responsible for dementia, and there is still a lack of effective treatment methods for this disorder to date. Clinical medications have found that Yisui Fuyongtang (YSFYT) Decoction is effective in improving neurological signs and learning-memory functions in patients who develop white matter lesions and whole brain atrophy. To clarify the effect and molecular regulation mechanism of YSFYT Decoction on model rats, this research analyzed the influence of YSFYT Decoction on the learning-memory ability and lipid metabolism of rats based on behavioral and biochemical analysis. Further pathology and protein detection methods were adopted to investigate the action of YSFYT Decoction on the neurons in the hippocampus of model rats and the regulation of the brain derived neurotrophic factor (BDNF)-tyrosine protein kinase receptor B (TrkB) signaling pathway. Compared with the VCI group, after YSFYT Decoction administration, the ratio of swimming time in the platform, number of crossing the platform, number of active avoidance, and proportion of active avoidance of the rats were markedly increased, whereas the response latency was substantially reduced (p < 0.05). Biochemical tests indicated that contents of lipoprotein lipase (LPL), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) of the model rats in YSFYT Decoction treatment group were greatly reduced, whereas those of total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-PX), catalase (CAT), malondialdehyde (MDA), and superoxide dismutase (SOD) were elevated (p < 0.05). Additionally, Bcl-2 expression in YSFYT Decoction treatment group was significantly increased, but neuron apoptosis of the hippocampus tissue was reduced. Meanwhile, neuron number was apparently higher than that in VCI model group. Following Yisui Decoction treatment, expressions of growth-associated protein 43 (GAP43), synaptophysin (SYP), postsynaptic density 95 (PSD95), NMDAR subunit 2B (NR2B), BDNF, TrkB, phospho-mitogen-activated protein kinase (p-MAPK), extracellular signal-regulated kinase (ERK), phosphatidylinositol 3-kinase (PI3K), and phospho-protein kinase B (p-AKT) were markedly elevated. Taken together, YSFYT Decoction could activate the BDNF-TrkB signaling pathway, elevate Bcl-2 expression, and minimize neuronal apoptosis in hippocampus, thereby improving the behavioral characteristics and biochemical indicators of the VCI rat model.

Ginsenoside Rg3 induces apoptosis and inhibits proliferation by down-regulating TIGAR in rats with gastric precancerous lesions.

BACKGROUND: Ginsenoside Rg3 (GRg3) is one of the main active ingredients in Chinese ginseng extract and has various biological effects, such as immune-enhancing, antitumour, antiangiogenic, immunomodulatory and anti-inflammatory effects. This study aimed to investigate the therapeutic effect of GRg3 on gastric precancerous lesion (GPL) induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and the potential mechanism of action. METHODS: The MNNG-ammonia composite modelling method was used to establish a rat model of GPL. Histopathological changes in the rat gastric mucosa were observed by pathological analysis using haematoxylin-eosin staining to assess the success rate of the composite modelling method. Alcian blue-periodic acid Schiff staining was used to observe intestinal metaplasia in the rat gastric mucosa. Apoptosis was detected in rat gastric mucosal cells by terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling staining. The production level of reactive oxygen species (ROS) was determined by the dihydroethidium fluorescent probe method, and that of TP53-induced glycolysis and apoptosis regulator (TIGAR) protein was determined by immunohistochemical staining and western blotting. The production levels of nicotinamide adenine dinucleotide phosphate (NADP) and glucose-6-phosphate dehydrogenase (G6PDH) were determined by an enzyme-linked immunosorbent assay, and that of glutathione (GSH) was determined by microanalysis. RESULTS: GRg3 significantly alleviated the structural disorganization and cellular heteromorphism in the form of epithelial glands in the gastric mucosa of rats with GPL and retarded the progression of the disease. Overexpression of TIGAR and overproduction of NADP, GSH and G6PDH occurred in the gastric mucosal epithelium of rats with GPL, which in turn led to an increase in the ROS concentration. After treatment with GRg3, the expression of TIGAR and production of NADP, GSH G6PDH decreased, causing a further increase in the concentration of ROS in the gastric mucosal epithelium, which in turn induced apoptosis and played a role in inhibiting the abnormal proliferation and differentiation of gastric mucosal epithelial cells. CONCLUSION: Grg3 can induce apoptosis and inhibit cell proliferation in MNNG-induced GPL rats. The mechanism may be related to down-regulating the expression levels of TIGAR and production levels of GSH, NADP and G6PD, and up-regulating the concentration of ROS.

[Protective effect and immune mechanism of berberine on cerebral ischemia/reperfusion injury in rats].

Objective: To investigate the protective effect and immune mechanism of berberine on cerebral ischemia/reperfusion injury in rats. Methods: Fifty SD rats were randomly divided into sham operation group (Sham), model group (Model), berberine low dose groups (BBR-L, 25 mg/kg), berberine medium dose groups (BBR-M, 50 mg/kg) and berberine high dose groups (BBR-H, 100 mg/kg), with 10 rats in each group. Longa suture method was used to establish a rat model of cerebral ischemia/reperfusion, after 2 hours of ischemia, reperfusion for 24 hours. Rats in BBR-L, BBR-M and BBR-H were treated with berbrerine by gavage 2 hours after successful model building, while the sham operation group and the modle group were given the same volume of saline as described above. After 24 hours of administration, the activity of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), cytokine tumor necrosis factor α (TNF-α) , interferon ß (IFN-ß) , interleukin 6 (IL-6) and nitric oxide (NO) content were detected by ELISA assay. Serum CD4+, CD8+ and CD4+/CD8+ contents were measured by flow cytometry to investigate the immune function of each group. RT-qPCR and Western blot were used to detect NF-kappaB-NOD-like receptors 3 (NF-κB-NLRP3) signal axis key genes and protein expression in rat brain tissue. Results: Compared with the sham operation group, the degree of neurological deficit and the rate of cerebral infarction were increased in the model group (P＜0.05), and the levels of serum NO, TNF-α, IFN-ß, IL-6, NF-κB p65, NLRP3, ASC and caspase-1 in brain tissue were increased (P＜0.05), while the activities of SOD, GSH-Px and the levels of CD4+, CD8+ and CD4+/CD8+ in serum were decreased (P＜0.05). Compared with the model group, the degree of neurological deficit and the rate of cerebral infarction were increased in the BBR-H, BBR-M and BBR-L groups (P＜0.05), and the levels of serum NO, TNF-α, IFN-ß, IL-6, NF-κB p65, NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC) and caspase-1 in brain tissue were increased (P＜0.05), while the activities of SOD, GSH-Px and the levels of CD4+, CD8+ and CD4+/CD8+ in serum were decreased (P＜0.05). Conclusion: Berberine may reduce oxidative stress, inhibit inflammation, enhance immune function, and reduce cerebral ischemia/reperfusion injury in rats, which may be related to the inhibition of NF-κB-NLRP3 signaling.

Determination of trace vitamin C by ion-pair HPLC with UV detection in calcium gluconate and vitamin C compound oral solution.

A sensitive and specific reversed-phase high-performance liquid chromatographic method with ultraviolet detection was developed for the determination of vitamin C, using tetrabutylammonium hydroxide as an ion-pair reagent in a compound oral solution containing 100 mg/mL calcium gluconate and 1.25 mg/mL vitamin C. The aqueous phase contained 0.005 mol/L tetrabutylammonium hydroxide and the mobile phase consisted of a mixture of the aqueous phase-methanol (80:20, v/v, pH 6.0 adjusted by phosphoric acid). The linearity, sensitivity and specificity, accuracy, and stability of the procedure were evaluated. The calibration curves for vitamin C were linear in the range of 10.0-100.0 µg/mL. The percentage coefficient of variation of the quantitative analysis of the vitamin C in the products analysis was within 5%. The method was successfully applied to determine the stability of vitamin C in the compound oral solution. It was found that the vitamin C peak was symmetrical and the column efficiency was high. The method is simple and suitable for stability testing of a low concentration of vitamin C preparation.

Preparation of rosiglitazone maleate sustained-release floating microspheres for improved bioavailability.

The object of this study was to prepare rosiglitazone maleate (RM) sustained-release floating microspheres and investigate their pharmacokinetics. RM microspheres were prepared with ethyl cellulose (EC) and octadecyl alcohol as the carrier materials by an emulsion-solvent diffusion method, and the properties of morphology in vitro floating capability, drug loading (DL), entrapment efficiency (EE), in vitro release and in vivo pharmacokinetics were investigated. The prepared microspheres had a completely spherical shape. The percentage of microspheres floating after 12 h was (91.45 +/- 1.62)%, and the DL and EE were (9.31 +/- 0.31)% and (89.55 +/- 1.65)% respectively. Pharmacokinetic studies demonstrated that the RM floating microspheres were superior to commercial tablets in terms of the decrease in peak plasma concentration and maintenance of RM concentration in plasma. The area under the curve of plasma concentration-time (AUC) of the floating microspheres was equivalent to that of reference tablets. The results showed that floating microspheres are a feasible approach for the sustained-release preparation of drugs which have limited absorption sites in the upper small intestine.

Improvement of digoxin oral absorption in rabbits by incorporation into solid lipid nanoparticles.

In this study, digoxin (DG)-loaded solid lipid nanoparticles (DG-SLNs) were successfully prepared by an ultrasonic and high pressure homogenization method. The particle size and distribution, drug loading capacity, drug entrapment efficiency (EE %), zeta potential, and long-term physical stability of the SLNs were characterized in detail. A pharmacokinetic study was conducted in rabbits after oral administration of 0.25 mg DG in different SLNs and it was found that the relative bioavailability of DG in the SLNs was significantly increased compared with that of a DG solution. The addition of CMC-Na in SLNs also markedly increased the oral absorption of DG. These results indicate that DG absorption is enhanced significantly by employing SLN formulations and SLNs are a potential as an oral delivery carrier for poorly water soluble drugs.