Stereological examination of curcumin’s effects on hippocampal damage caused by the anti-epileptic drugs phenobarbital and valproic acid in the developing rat brain

The anti-epileptic drugs phenobarbital and valproic acid have an extremely strong negative effect on cognitive processes such as learning and memory in the developing brain. We examined whether or not curcumin has protective effects on neuronal injury caused by these drugs in the developing rat brain. Young male Wistar rats were studied in two groups, a 7 days old and a 14 days old group (35 rats in each). Both groups were then divided into 7 sub-groups as the control, curcumin, dimethylsulfoxide, phenobarbital, valproic acid, phenobarbital + curcumin, and valproic acid + curcumin groups (n = 5 in each group). At 24 h after the intraperitoneal injection of the compounds, the rats were sacrificed, and the hippocampal tissue was subjected to stereological analysis with the optical fractionation method. Total numbers of neurons in the hippocampus of the 7 days old and 14 days old rats were calculated. It was found that treatment with phenobarbital resulted in a loss of 43% of the neurons, and valproic acid induced a loss of 57% of the neurons in the 7 days old rats. Curcumin prevented this loss significantly with only 19% in the phenobarbital group and 41% in the valproic acid group. In the 14 days old rat groups, phenobarbital was found to reduce the number of neurons by 30%, and valproic acid reduced it by 38%. Curcumin treatment limited neuronal loss to 3% in the phenobarbital + curcumin group and 10% in the valproic acid + curcumin group. These data strongly indicate that curcumin is a protective agent and prevents hippocampal neuronal damage induced by phenobarbital and valproic acid treatment.     

RP-HPLC法同时测定人血清中4种抗癫痫药的浓度

目的：建立同时测定人血清中拉莫三嗪(LTG)、苯巴比妥(PB)、苯妥英(PHT)和卡马西平(CBZ)浓度的高效液相色谱法。方法血清样品经甲醇沉淀蛋白后直接进样测定。色谱柱采用Waters Symmetry C18柱(250 mm×4.6 mm,5μm),流动相为甲醇-水(55∶45),检测波长235 nm。结果 LTG、PB、PHT和CBZ的线性范围分别是1.56~50、3.13~100、2.19~70、1.09~35μg/ml,平均回收率均>98%。结论本方法操作简便,结果准确,适用于临床治疗药物监测。     

Successful use of the two-tube approach for the treatment of phenobarbital poisoning without hemodialysis

Half-life of the antipsychotic vegetamin is very long, partially due to the presence of phenobarbital, and mortality due to phenobarbital poisoning is high. Here, we present the case of a 22-year-old female admitted to the emergency department with disturbed consciousness due to vegetamin overdose. Her blood phenobarbital level was elevated to 123 μg/ml. Phenobarbital undergoes enterohepatic circulation, and its retention in the intestine causes its blood levels to remain sustained. The utility of hemodialysis for drug poisoning has been previously reported; however, its efficiency is not yet established and its efficacy is low for drugs with long half-lives such as phenobarbital. Therefore, we performed a two-tube approach to adsorb phenobarbital in the intestines with activated charcoal delivered via a gastric tube and to remove the phenobarbital-adsorbed activated charcoal using whole bowel irrigation via an ileus tube 2 h later. The patient successfully eliminated the charcoal via stool, the blood phenobarbital level decreased drastically without hemodialysis, and the clinical course improved. We propose that this two-tube approach is suitable for treatment of poisoning with drugs that undergo enterohepatic circulation and have long half-lives.     

Enhanced elimination in acute barbiturate poisoning – A systematic review

Context.?Despite a worldwide decline in barbiturate use, cases of acute poisoning with severe toxicity are still noted, particularly in developing countries. Severe poisonings often require prolonged admission to an intensive care unit, so enhanced elimination might be useful to hasten recovery. Information regarding the efficacy of these techniques for individual barbiturates is not available in standard textbooks. Objective.?To determine the evidence supporting the effect of enhanced elimination and its role in the management of acute barbiturate poisoning. Methods.?A systematic review was conducted using broad search criteria in three databases. All potentially relevant articles were obtained, and reference lists were manually reviewed. Ninety-four publications fulfilling inclusion criteria were located. Studies were classified as controlled or uncontrolled, and clinical and pharmacokinetic end points were manually extracted. If not directly stated, standard pharmacokinetic methods were used to calculate the clearance and efficiency of enhanced elimination techniques for each barbiturate and tabulated for direct comparison. Prospective controlled clinical trials.?Two of the 94 publications were prospective controlled studies (only one stated that allocation was via blinded randomisation), and both assessed the effect of multiple-dose activated charcoal for acute phenobarbital poisoning. These studies demonstrated enhanced elimination with a decrease in elimination of half-life from approximately 80 to 40?h, but only one study reported clinical benefits. Uncontrolled series and single case reports.?Sufficient data to determine the clearance due to enhanced elimination were available in only 52 of these papers. Barbiturate clearances by enhanced elimination varied markedly among studies. While extracorporeal modalities appeared to increase the direct clearance of many barbiturates, there was insufficient information to confirm a clinical benefit. Conclusions.?There is limited evidence to support the use of enhanced elimination in the treatment of poisoning with most barbiturates. There is no role for urine alkalinisation, while multiple-dose activated charcoal may be useful for most phenobarbital and possibly primidone poisonings. Extracorporeal techniques appear to enhance elimination, but the clinical benefits, relative to the potential complications and cost, are poorly defined. Extracorporeal techniques such as haemodialysis and haemoperfusion can be considered for patients with life-threatening barbiturate toxicity such as refractory hypotension.     

Phenobarbital use and neurological problems in FMR1 premutation carriers

Fragile X Syndrome (FXS) is a neurodevelopmental disorder caused by a CGG expansion in the FMR1 gene located at Xq27.3. Patients with the premutation in FMR1 present specific clinical problems associated with the number of CGG repeats (55–200 CGG repeats). Premutation carriers have elevated FMR1 mRNA expression levels, which have been associated with neurotoxicity potentially causing neurodevelopmental problems or neurological problems associated with aging. However, cognitive impairments or neurological problems may also be related to increased vulnerability of premutation carriers to neurotoxicants, including phenobarbital. Here we present a study of three sisters with the premutation who were exposed differentially to phenobarbital therapy throughout their lives, allowing us to compare the neurological effects of this drug in these patients.     

Long‐term outcome of phenobarbital treatment for epilepsy in rural China: A prospective cohort study

Purpose: To evaluate the long‐term outcome of phenobarbital treatment for convulsive epilepsy in rural China, and to explore factors associated with overall seizure outcomes. Methods: We carried out follow‐up assessments of people who took part in an epilepsy community management program conducted in rural counties of six provinces in China. People with convulsive epilepsy who were previously untreated (or on irregular treatment) were commenced on regular treatment with phenobarbital. Information was collected using a standardized questionnaire by face‐to‐face interviews of the individuals (and their families where necessary). Information collected included treatment status, medication change, seizure frequency, and mortality. Key Findings: Among the 2,455 people who participated in the original program, outcomes were successfully ascertained during the follow‐up assessment in 1986. Among them, 206 had died. Information on treatment response was obtained in 1,780 (56% male; mean age 33.9 years, range 3–84; mean duration of follow‐up 6.4 years). Among them, 939 (53%) were still taking phenobarbital. The most common reasons for stopping phenobarbital were seizure freedom or substantial seizure reduction, socioeconomic reasons, and personal preference. Four hundred fifty‐three individuals (25%) became seizure‐free for at least 1 year while taking phenobarbital, 88% of whom did so at daily doses of 120 mg or below. Four hundred six (23%) reported adverse events, which led to withdrawal of phenobarbital in <1%. The most common adverse effects were malaise/somnolence (7.4%), dizziness (3%), and lethargy (2.6%). At the follow‐up assessment, 688 (39%) individuals had been seizure free for at least the previous year. People with persistent seizures had significantly longer duration of epilepsy and higher number of seizures in the 12 months before treatment. People who were taking AED treatment irregularly at recruitment were less likely to become seizure‐free. Significance: We observed long‐term benefits of regular treatment with phenobarbital for convulsive epilepsy in rural China. One hundred years after the discovery of its antiepileptic effect, phenobarbital is still playing an important role in the management of epilepsy.     

琥珀酸对惊厥幼鼠小脑浦肯野细胞的保护作用

目的 探讨琥珀酸(SA)对惊厥幼鼠小脑浦肯野细胞(PC)的保护作用。方法 将健康新生7 d Sprague-Dawley(SD)幼鼠120 只随机分为新生期组和发育期组,两组再随机分为正常对照组、惊厥模型组、小剂量苯巴比妥(PB)组(30 mg/kg)、大剂量PB 组(120 mg/kg)、小剂量琥珀酸(SA)组(30 mg/kg)、大剂量SA 组(120 mg/kg)。利用腹腔注射戊四氮制备幼鼠惊厥模型,正常对照组应用生理盐水替代。新生期各组大鼠分别在注射PB 或SA 或生理盐水后30 min 处死取小脑,发育期各组大鼠分别在注射PB 或SA 或生理盐水后养至30 d 时处死取小脑。采用全细胞膜片钳技术,在各组幼鼠小脑脑片上记录PC 动作电位(AP);采用低频刺激平行纤维(PF)诱发兴奋性突触后电流(EPSC),观察SA 对各组大鼠PC 长时程抑制(LTD)的影响。结果 与对照组相比,新生期和发育期惊厥幼鼠PC AP 频率均明显增高(P<0.05),发育期惊厥幼鼠PC AP 阈刺激明显降低(P<0.01),且PC EPSC 的幅值抑制程度明显增强(P<0.05);与对照组相比,新生期和发育期大剂量PB 组惊厥幼鼠PC AP 阈刺激明显降低(P<0.01),PC AP 频率明显增高(P<0.05),PC EPSC 抑制程度明显增强(P<0.05);新生期和发育期大剂量SA 组惊厥幼鼠PC AP 频率与惊厥组相比均明显降低(P<0.05);发育期两种剂量SA 组AP 产生的阈值与惊厥组相比均明显增高(P<0.05)。结论 SD 幼鼠新生期惊厥导致的小脑PC 兴奋性增高和PF-PC 突触可塑性异常可持续至发育期,PB 可能加重这种异常,而SA 能降低惊厥幼鼠小脑PC 的兴奋性,并对惊厥造成的PC LTD 的近期和远期异常有明显的修复作用。     

Normal zinc and iron concentrations in mice after early exposure to phenobarbital

Zinc and iron levels were studied in mice with early (pre/neonatal) exposure to phenobarbital, as the levels of these trace metals are known to be correlated with specific behaviors shown in our previous and present experiment to be affected by early phenobarbital administration. Mice were exposed to phenobarbital prenatally or neonatally. At adulthood they showed marked reduction from control in all parameters of eight-arm maze performance (P < 0.001). Since zinc is known to be correlated with this behavior, it was subsequently studied in barbiturate exposed animals. The differences between barbiturate exposed and control offspring for zinc levels in plasma, brain and hippocampus did not reach statistical significance. Our previous studies have shown that the number of dopamine receptors and the resulting apomorphine-induced climbing behavior is altered after early exposure to phenobarbital. The effect of iron level on dopamine receptors is now well established. Subsequently, a group of mice were tested for iron levels in their brain and liver. No significant differences were found.

It is suggested that deficits in the hippocampal behaviors, mainly eight-arm maze, after early exposure to phenobarbital are not related to changes in zinc levels. Similarly, early phenobarbital-induced alternation in dopamine receptors and the resulting dopaminergic behaviors are not related to changes in iron levels.     

利福喷丁和苯巴比妥诱导小鼠肝细胞滑面内质网增生的作用

利福喷丁是新型长效抗结核抗生素,通过透射电镜观察,发现它和典型的肝微粒体酶诱导剂苯巴比妥均能显著诱导小鼠肝细胞滑面内质网的增生。由于这种作用常与肝微粒体酶诱导作用有关,故本文从形态学方面证实了利福喷丁和苯巴比妥对肝微粒体酶具有诱导作用。     

小鼠脑缺血后的能量代谢改变和药物的作用

应用部分结扎小鼠颈总动脉(包括迷走神经)及小鼠断头法引起脑缺血后,脑组织的ATP和磷酸肌酸明显降低,乳酸明显升高。部分结扎颈动脉出现四肢无力、转圈及昏睡等症状,其严重程度与脑能量代谢改变相平行。皮下注射尼莫地平、硝苯吡啶、尼卡地平和三七皂甙对脑缺血有一定保护作用。苯巴比妥钠能改善正常和脑缺血小鼠的脑能量代谢,人参皂甙Rb₁可降低正常小鼠脑乳酸含量。