The Neuroprotective Effect of L-Stepholidine on Methamphetamine-Induced Memory Deficits in Mice.

Repeated methamphetamine (METH) exposure can cause severe neurotoxicity to the central nervous system, and lead to memory deficits. L-Stepholidine (L-SPD) is a structurally identified alkaloid extract of the Chinese herb Stephania intermedia, which elicits dopamine (DA) D1-type receptors partial agonistic activity and D2-type receptors antagonistic activity. In this study, we investigated the effect of L-SPD on METH-induced memory deficits in mice and its underlying mechanisms. We found that repeated exposure to METH (10 mg/kg, i.p., once per day for 7 consecutive days) impaired memory functions in the novel object recognition experiment. Pretreatment of L-SPD (10 mg/kg, i.p.) significantly improved METH-induced memory deficits in mice. Meanwhile, the protein expression of dopaminergic D2 receptors in hippocampus area was significantly increased by repeated METH exposure, while the protein expression of dopamine transporter (DAT) was significantly reduced. Additionally, the protein expression of phospho-protein kinase A (p-PKA) was significantly increased by repeated METH exposure. The hyperpolarization-activated cyclic-nucleotide-gated non-selective cation 1 (HCN1) channel, which was a key regulator of memory functions and could be regulated by p-PKA, was also significantly increased by repeated METH exposure. These changes caused by METH could be prevented by L-SPD pretreatment. Therefore, our data firstly showed that pretreatment of L-SPD exhibited the protective effect against METH-induced memory deficits, possibly through reducing METH-induced upregulation of dopaminergic pathway and HCN1 channels.

2 Hz EA Reduces Heroin Withdrawal-Induced Hyperalgesia and Heroin Relapse by Downregulating P2X3 Receptors in DRG Neurons.

Electroacupuncture (EA) has effective analgesic effects. Our previous study demonstrated that the upregulation of P2X3 receptors in the dorsal root ganglia (DRG) might participate in heroin withdrawal-induced hyperalgesia. The aim of this study is to further explore whether 2 Hz EA reduces heroin relapse associated with its analgesic effect and whether P2X3 receptors in the DRG are involved in this process. 2 Hz EA was adopted to treat the heroin SA rats in the present study. Heroin-seeking and pain sensitivity were evaluated. The expression of P2X3 receptors in the DRG was detected. Our results showed that compared with the control group, the reinstatement, thermal hyperalgesia, and mechanical allodynia of the heroin-addicted group were increased significantly. The expression of P2X3 receptors in the DRG was increased markedly. After being treated using 2 Hz EA, reinstatement was reduced, hyperalgesia was decreased, and the upregulated expression of P2X3 receptors in the DRG had decreased significantly compared to that in the heroin-addicted group. Consequently, our results indicated that 2 Hz EA was an effective method for treating heroin-induced hyperalgesia and helping prevent relapse, and the potential mechanism might be related to the downregulation of P2X3 receptor expression in the DRG.

Krill oil protects PC12 cells against methamphetamine-induced neurotoxicity by inhibiting apoptotic response and oxidative stress.

Methamphetamine (METH) exposure can cause severe effects to the nervous system; however, the underlying molecular mechanism of neurotoxicity caused by METH is still unclear. Oxidative stress and apoptosis are linked in the pathophysiology of many neurodegenerative diseases. Krill oil (KO) benefits human health via its strong antioxidant ability. Therefore, we hypothesized that KO supplementation might effectively prevent METH-induced neurotoxicity via the inhibition of apoptotic responses and oxidative damages. In this study, PC12 cells were exposed to both METH (3 mmol/L) and KO (0.1, 0.2, 0.4, 0.8 µg/mL) in vitro for 24 h, and the following parameters were measured to detect apoptosis and oxidative stress responses that were triggered by METH: cell viability, the oxidative enzyme system, NO production, ROS production, apoptosis, mitochondrial membrane potential and protein expression of cleaved caspase-3. The results indicate that KO mitigates the apoptotic response post-METH exposure in PC 12 cells by increasing cell viability, decreasing protein expression of cleaved caspase-3, reducing apoptotic rates, and decreasing dissipation of mitochondrial membrane potential. In addition, the study revealed increases in SOD and GSH activity, and decreases in MDA content, NO and ROS production, suggesting that KO is beneficial in reducing oxidative stress, which may also play a role in the regulation of METH-triggered apoptotic response. Consequently, these data indicate that KO could potentially alleviate METH-induced neurotoxicity via the reduction of apoptotic responses and oxidative damages.

[Effect of Ginsenoside Rg2 and Its Stereoisomers on Oxygen-Glucose Deprivation and Reperfusion Induced Cortical Neuronal Injury Model].

OBJECTIVE: To observe the effect of natural type ginsenoside Rg2 (Rg2) and its stereoisomers [20 (R)-Rg2 and 20 (S)-Rg2] at different concentrations on oxygen-glucose deprivation/ reperfusion (OGD/R) induced cortical neuronal injury model in vitro, and to explore the mechanism, and compare their differences of action. METHODS: Cortical neurons after 7-day culture were randomly divided into 5 groups, i.e., the control group, the model group, the Rg2 group, 20 (R) -Rg2 group, and 20 (S) - Rg2 group. Cortical neurons in the Rg2 group, 20 (R)-Rg2 group, and 20(S)-Rg2 group were pretreated with 20, 40, and 80 µmol/L Rg2, 20 (R) -Rg2, and 20 (S) -Rg2 for 24 h to prepare OGD/R model. The cell survival rate, the activity of Caspase-3, the intracellular Ca2+ concentration, contents of superoxide dismutase (SOD) and malondialdehyde (MDA) were detected 24 h later. RESULTS: Compared with the control group, cell survival rates and activities of SOD obviously decreased, the activity of Caspase-3, Ca2+ fluorescent optical gray value, and contents of MDA significantly increased with statistical difference (P < 0.05). Compared with the model group, cell survival rates and activities of SOD obviously increased, the activity of Caspase-3, Ca2+ fluorescent optical gray value, and contents of MDA significantly decreased in 20 µmol/L Rg2 group, 40 µmol/L 20 (R) -Rg2 group, and 80 µmol/L 20 (S) -Rg2 group (P < 0.05). Compared with 20(S)-Rg2 group, cell survival rates increased and contents of MDA significantly decreased in 20, 40, and 80 µmol/L Rg2 and 20 (R)-Rg2 groups (P < 0.05). The activity of Caspase-3 decreased and contents of SOD increased in 80 µmol/L 20 (R)-Rg2 group, and 40, 80 µmol/L Rg2 groups (P < 0.05). Ca2+ fluorescent optical gray value decreased in 40, 80 µmol/L Rg2 and 20 (R)-Rg2 groups (P < 0.05). Compared with 20 (R)-Rg2 group, Ca2+ fluorescent optical gray value decreased in 80 µmol/L Rg2 group (P < 0.05); contents of SOD increased in 40 and 80 µmol/L Rg2 groups (P < 0.05); contents of MDA decreased in 20, 40, and 80 µmol/L Rg2 groups (P < 0.05). CONCLUSIONS: Rg2 and its stereoisomers could improve cell vitality of cortical neurons against OGD/R induced injury. This might be related to improving anti-apoptotic capacities and antioxidant abilities, and reducing Ca2+ inflow. Besides, the neuroprotective effect of 20 (R) -Rg2 was better than that of 20 (S) -Rg2, but inferior to that of Rg2.

Levo-tetrahydropalmatine, a natural, mixed dopamine receptor antagonist, inhibits methamphetamine self-administration and methamphetamine-induced reinstatement.

Despite the high prevalence of methamphetamine (METH) use, no FDA-approved pharmacological treatment is currently available for individuals with a METH addiction. Levo-tetrahydropalmatine (l-THP) is an alkaloid substance derived from corydalis and stephania that has been used in traditional Asian medicine for its analgesic, sedative and hypnotic properties. Previous pharmacological studies of l-THP indicated that it not only binds to D1 and D2 receptors but also has a low affinity for D3 receptors and may function as an antagonist. The unique pharmacological profile of l-THP suggests that it may have potential therapeutic effects on drug addiction; however, the effects of l-THP in individuals with METH addictions are largely unknown. In this study, we investigated the effects of l-THP on METH self-administration and METH-induced reinstatement. In our experiments, l-THP (1.25, 2.50 and 5.00 mg/kg, i.p.) decreased METH self-administration under the fixed-ratio 1 schedule. l-THP (2.50 and 5.00 mg/kg, i.p) also prevented the METH-induced reinstatement of METH-seeking behaviors. Interestingly, l-THP (1.25 and 2.50mg/kg, i.p) did not affect locomotor activity following METH injection (1mg/kg) suggesting that the observed effects of l-THP (2.50mg/kg) on METH-induced reinstatement were not due to motor impairments. Thus, l-THP (a natural, mixed dopamine (DA) receptor antagonist) attenuates METH self-administration and METH-induced reinstatement.

The dopamine receptor antagonist levo-tetrahydropalmatine attenuates heroin self-administration and heroin-induced reinstatement in rats.

Opiate addiction is a chronic recrudescent disorder characterized by a high rate of relapse. Levo-tetrahydropalmatine (l-THP) is an alkaloid substance extracted from Corydalis and Stephania and is contained in a number of traditional Chinese herbal preparations. Compared to other dopamine receptor antagonists, l-THP has lower affinity for D2 receptors than for D1 receptors, and a recent study showed that l-THP also binds to D3 receptors, possibly functioning as an antagonist. The unique pharmacological profile of l-THP suggests that l-THP may be effective for the treatment of opiate addiction. In this study, we investigated the effects of l-THP on heroin self-administration and reinstatement triggered by a priming injection of heroin in abstinent rats trained to stably self-administer heroin under an extinction/reinstatement protocol, and found that l-THP (2.5 and 5 mg/kg, i.p.) decreased heroin self-administration on the fixed-ratio 1 schedule and dose-dependently (1.25, 2.5 and 5 mg/kg, i.p.) inhibited heroin-induced reinstatement of heroin-seeking behavior. Importantly, l-THP (1.25 and 2.5 mg/kg, i.p.) did not affect locomotion, indicating that the observed effects of l-THP on reinstatement do not appear to be due to motor impairments. The present results demonstrated that dopamine receptor antagonist l-THP attenuates heroin self-administration and heroin-induced reinstatement.

[Pharmacokinetics study of compound xueshuantong soft capsules].

OBJECTIVE: To establish a RP-HPLC method for determination of the content of ginsenoside Rg1 in the rabbits aqueous humor, blood and ocular tissues, which were given intragastric administration with the co-xueshuantong soft capsules. The drug concentration in rabbits at different times after oral administration has been determined and the pharmacokinetics characteristics has been researched. METHOD: The compound xueshuantong soft capsules were administrated to the healthy New Zealand rabbits by gavage (10 mg x kg(-1) per rabbit). The concentration of Ginseng Rg1 in aqueous humor, blood and ocular tissues at different time was determined by RP-HPLC. RESULT: RP-HPLC can be established for the determination of ginsenoside Rg1 in the rabbits aqueous humor, blood, ocular tissue. The calibration of curves was linear within the range of 7.60-152.0 mg x L(-1) (r = 0.999 6) for ginsenoside Rg1 in aqueous humor and the calibration of curves were linear within the range of 10.35-103, 50 mg x L(-1) (r = 0.999 8) for ginsenoside Rg1 in blood. Determination of the recovery rate to meet the requirements. CONCLUSION: The ginsenosides Rg1 could transmit the blood-ocular barrier into the eyes and reach a certain concentration. The research provides a theoretical and experimental basis for the systemic administration of compound Xueshuantong to treat eye diseases.

[The study of removing salt in salt Aconiti Lateralis Radix Praeparata].

OBJECTIVE: To study the method and technique to remove the salt of salt Aconiti Lateralis Radix Praeparata. METHODS: Took the Aconiti Lateralis Radix Praeparata alkaloids, polysaccharides and the content of removing salt as the indexes, and then compared with the original process. RESULTS: There was no obvious difference between these two way on the content of the Aconiti Lateralis Radix Praeparata alkaloids and polysaccharides,and the time of removing salt has reduced from 7 days (168 h) to 1.5 h. CONCLUSION: The new way reduces the time to remove salt obviously, and saves water; The research fills in the gaps of removing the salt of salt Aconiti Lateralis Radix Praeparata and provides thought and method for processing technology of Aconiti Lateralis Radix Praeparata

[Effect of multi-micronutrients supplementation on memory ability of schoolchildren].

OBJECTIVE: To study the effect of multi-micronutrients on memory ability of school children. METHODS: In this double-blind and placebo-controlled test, the children aged 9 to 11 years, in the forth grade from two primary school in Sichuan Province, were recruited after health examination. A total of 275 children were randomly designed by the whole class as the test group taken multi-micronutrient supplement and the control group given with placebo for 4 months. Memory quotient, intelligence, average reaction time of children in two clusters were assessed before and after supplementation. RESULTS: The mean scores of the memory quotients and the Wechsler Memory Scale scores (Digit summation\ Visual Reproduction\ touch memory) of multi-micronutrients group were significantly higher (P < 0.05) than those of control group. The mean incremental scores of the memory quotients of the rural test group were significantly higher (P < 0.05) than those of the rural control group. There was no significant difference between the test group and control group in intelligence. CONCLUSION: It was seemed that multi-micronutrients supplement could improve memory ability of schoolchildren.

Effect of composite salvia injection on platelet parameters in children with anaphylactoid purpura.

OBJECTIVE: To explore the effect of composite salvia injection (CSI) on platelet parameters in children with anaphylactoid purpura (AP) and its clinical significance. METHODS: One hundred and fifty children with AP were assigned to two groups, 80 in Group A and 70 in Group B. They were treated, respectively, with conventional therapy only or conventional therapy combined with CSI. Their platelet parameters, including blood platelet count (BPC), mean platelet volume (MPV), platelet distribution width (PDW) and plateletcrit (PCT) were determined at the acute stage and convalescent stage, respectively. RESULTS: At the acute stage, the BPC in AP children of both groups was in the normal range, but significant abnormality was shown in the levels of MPV, PDW and PCT. As for comparisons of these parameters at the convalescent stage, significant difference between the two groups was also shown in terms of MPV, PDW and PCT (P<0.05 or P<0.01). CONCLUSION: Although platelet shows no quantitative change in the pathogenic process of AP, important functional changes are surely existent. CSI could promote the normalization of platelet function.

The mechanism involved in the repression of the mu opioid receptor gene expression in CEM x174 cells infected by simian immunodeficiency virus.

Morphine can promote the pathogenesis of human acquired immunodeficiency syndrome through binding to the mu opioid receptor (MOR) in immune cells. Previous investigation has suggested that expression of the MOR gene in lymphocytes is triggered by cooperative interaction between transcription factors, specificity protein 1 (Sp1) and Ying Yang 1 (YY1), in the promoter region. However, the specific molecular mechanism by which immunodeficiency virus infection impacts regulation of the MOR gene expression in lymphocytes is still unclear. In this study, it was demonstrated that SIV (SIVmac239) infection may result in gradual reduction of the MOR gene expression and Sp1 during a period of 48 h postinfection by analysis of quantitative real-time RT-PCR and Western blotting. The results of methylation-specific PCR showed that two of 14 CpG islands adjacent to the Sp1 and YY1 elements in the promoter region were methylated, which together with reduced Sp1, contributed to the failure of interaction of Sp1 with YY1 and their binding to the elements, as determined by coimmunoprecipitation, chromatin immunoprecipitation-real-time PCR, and EMSAs. The repression of the MOR gene secondary to SIVmac239 infection could be abolished by the demethylating agent 5-aza-2'-deoxycytidine. Transfection with Sp1-expressing vector (PN3-Sp1) was also able to enhance the activity of the promoter in SIVmac239-infected cells. We therefore concluded that aberrant methylation of the promoter and reduction of Sp1 resulting from SIVmac239 infection led to the silencing of the MOR gene. This finding will be helpful in understanding the synergistic mechanism of HIV infection and morphine addiction in the pathogenesis of AIDS.