In vivo hepatoprotective activity of active fraction from ethanolic extract of Eclipta alba leaves

The alcoholic extract of fresh leaves of the plant Eclipta alba (Ea), previously reported for is hepatoprotective activity was fractionated into three parts to chemically identify the most potent bioactive fraction. The hepatoprotective potential of the fraction prepared from extract was studied in vivo in rats and mice against carbon tetrachloride induced hepatotoxicity. The hepatoprotective activity was determined on the basis of their effects on parameters like hexobarbitone sleep time, zoxazolamine paralysis time, bromosulphaline clearance, serum transaminases and serum bilirubin. Fraction EaII (10-80 mg/kg, p.o.) containing coumestan wedelolactone and desmethylwedelolactone as major components with apigenin, luteolin, 4-hydroxybenzoic acid and protocateuic acid as minor constituents exhibited maximum hepatoprotective activity and is the active fraction for hepatoprotective activity of Eclipta alba leave. The acute toxicity studies have shown that like Ea, Fraction EaII also high safety margin.     

Mulberroside F isolated from the leaves of Morus alba inhibits melanin biosynthesis

The current study was carried out to investigate the in vitro effects of an 85% methanol extract of dried Morus alba leaves on melanin biosynthesis, which is closely related to hyperpigmentation. These extracts inhibited the tyrosinase activity that converts dopa to dopachrome in the biosynthetic process of melanin. Mulberroside F (moracin M-6, 3'-di-O-beta-D-glucopyranoside), which was obtained after the bioactivity-guided fractionation of the extracts, showed inhibitory effects on tyrosinase activity and on the melanin formation of melan-a cells. This compound also exhibited superoxide scavenging activity that is involved in the protection against auto-oxidation. But its activity was low and was weaker than of kojic acid. These results suggest that mulberroside F isolated from mulberry leaves might be used as a skin whitening agent.     

石菖蒲α-细辛醚抗癫痫作用的实验研究

目的探讨石菖蒲成分α-细辛醚的抗癫痫作用。方法采用MES、MST及Lithium-pilocarpine模型;预先给予不同剂量的α-细辛醚,2次/d,连续28d,记录发作潜伏期、发作级别及惊厥动物数,对比观察α-细辛醚在控制3种模型癫痫发作中的疗效。结果石菖蒲α-细辛醚能对抗MES、MST模型小鼠及Lithium-pilocarpine模型大鼠的惊厥发作,抗惊厥率分别为40%～100%、50%～90%、40%～80%;能明显延长MST模型小鼠及Lithium-pilocarpine模型大鼠惊厥发作潜伏期,分别为70～180s和4～15min;并能降低Lithi-um-pilocarpine模型大鼠惊厥发作级别达1.96。结论石菖蒲α-细辛醚具有确切的抗癫痫作用,是一种广谱抗癫痫药。     

Chrysoeriol isolated from Eurya cilliata leaves protects MC3T3-E1 cells against hydrogen peroxide-induced inhibition of osteoblastic differentiation

Chrysoeriol is a flavonoid compound found in several tropical medicinal plants. To elucidate the protective effects of chrysoeriol isolated from Eurya cilliata on the response of osteoblasts to oxidative stress, osteoblastic MC3T3‐E1 cells were incubated with chrysoeriol and/or H₂O₂, and markers of osteoblast function and oxidative damage were examined. Chrysoeriol treatment significantly (P < 0.05) reversed the cytotoxic effect of H₂O₂ and increased collagen content, alkaline phosphatase activity and calcium deposition of osteoblasts in the presence of H₂O₂. These effects were blocked by ICI182780, suggesting that chrysoeriol's effect might be partly involved in estrogen action. Moreover, H₂O₂‐induced reduction of osteocalcin was recovered in the presence of chrysoeriol. Chrysoeriol significantly (P < 0.05) decreased the production of receptor activator of nuclear factor‐κB ligand, interleukin‐6, protein carbonyl and malondialdehyde of MC3T3‐E1 cells in the presence of H₂O₂. These results demonstrate that chrysoeriol isolated from E. cilliata can protect osteoblasts from oxidative stress‐induced toxicity. Copyright © 2010 John Wiley & Sons, Ltd.     

mGlu1 and mGlu5 receptor antagonists lack anticonvulsant efficacy in rodent models of difficult-to-treat partial epilepsy

Modulation of metabotropic glutamate (mGlu) receptors represents an interesting new approach for the treatment of a range of neurological and psychiatric disorders. Several lines of evidence suggest that functional blockade of group I (mGlu1 and mGlu5) receptors may be beneficial for treatment of epileptic seizures. This study was conducted to investigate whether mGlu1 or mGlu5 receptor antagonists have the potential to block partial or secondarily generalized seizures as occurring in partial epilepsy, the most common and difficult-to-treat type of epilepsy in patients. For this purpose, we systemically administered novel highly selective and brain penetrable group I mGlu receptor antagonists, i.e., the mGlu1 receptor antagonist EMQMCM [3-ethyl-2-methyl-quinolin-6-yl-(4-methoxy-cyclohexyl)-methanone methanesulfonate] and the mGlu5 receptor antagonist MTEP ([(2-methyl-1,3-thiazol-4-yl) ethynyl] pyridine), at doses appropriate for mGlu1 or mGlu5 receptor-mediated effects in rodent models of partial seizures. Two models were used: the 6-Hz electroshock model of partial seizures in mice and the amygdala-kindling model in rats. Clinically established antiepileptic drugs were included in the experiments for comparison. Antiepileptic drugs exerted significant anticonvulsant effects in both models, while EMQMCM and MTEP were ineffective in this regard, although both compounds were administered up to doses associated with essentially full receptor occupancy and with typical mGlu receptor-mediated effects in rodent models of anxiety or pain. Brain microdialysis for determining extracellular levels of MTEP following i.p. administration in rats substantiated that effective brain concentrations were reached at times of our experiments in seizure models. The present results do not support a significant anticonvulsant potential of group I mGlu receptor antagonists in rodent models of difficult-to-treat partial epilepsy.     

旱莲草化学成分旱莲甙A和旱莲甙B的分离和鉴定

自旱莲草全草（Eclipta alba (L.)Hassk）中分得4个三萜化合物，经理化常数测定和光谱（IR，MS，UV，^1HNMR,^13CNMR和^13C-^1H COSY）解析，2个已知的三萜化合物分别为囊酸（echinocystic acid,1）和齐墩果酸（oleanolic acid,2），另2个为新化合物，分别命名为旱莲甙A（ecliptasaponin A,3）和旱莲甙B（ecliptasaponin B,4），Ⅰ和Ⅱ为首次从鳢肠属植物中获得。     

Adaptive changes in the pharmacodynamics of midazolam in different experimental models of epilepsy: kindling,cortical stimulation and genetic absence epilepsy

1. The objective of this investigation was to determine quantitatively whether experimental epilepsy is associated with a change in the pharmacodynamics of benzodiazepines in vivo. For that purpose the pharmacodynamics of midazolam were quantified by an integrated pharmacokinetic-pharmacodynamic approach in three different models of experimental epilepsy: amygdala kindling, cortical stimulation and genetic absence epilepsy.
2. The time course of the EEG effect was determined in conjunction with the decline of drug concentrations after intravenous administration of 10 mg kg⁻¹ midazolam. The pharmacokinetics of midazolam were most adequately described by a bi-exponential equation. No influence of epilepsy on the pharmacokinetics of midazolam was observed.
3. The increase in β activity (11.5–30 Hz) of the EEG as derived by Fast Fourier Transformation analysis was used as pharmacodynamic endpoint. For each individual rat the increase in β activity was directly related to the concentration in blood on the basis of the sigmoidal E_max pharmacodynamic model. In all three models a significant reduction in the maximal effect was observed, in amygdala kindling 28%, in the cortical stimulation model 49% and in genetic absence epilepsy 37%. No differences in the other pharmacodynamic parameters, E₀, EC_50,u and Hill factor, were observed.
4. It is inferred that in three different models of epilepsy there is a similar change in GABAergic functioning which is associated with a significant reduction in the intrinsic activity of midazolam in vivo. These models provide therefore a useful basis for further studies on the mechanism of epilepsy-induced changes in pharmacodynamics of anti-epileptic drugs.

     

桑叶中的黄酮类化合物

为了研究桑叶的化学成分与生物活性之间的相关性, 采用硅胶、Sephadex LH-20、RP-C₁₈等色谱方法分离纯化, 通过核磁共振谱、质谱等波谱分析手段鉴定化合物结构。从长穗桑的95%乙醇提取物中分离到4个Diels-Alder类加合物, 分别鉴定为mulberrofuran F₁ (1)、mulberrofuran F (2)、chalcomoracin (3) 和kuwanon J (4); 2个查耳酮类化合物, 鉴定为morachalcone A (5) 和isobavachalcone (6); 3个黄酮类化合物, 鉴定为 norartocarpetin (7)、kuwanon C (8) 和6-geranylapigenin (9)。化合物1和6为首次从该种植物中分离, 化合物4～5、7～9为首次从桑叶中分离得到, 其中化合物1为新化合物。采用MTT法对化合物1～5进行了抗肿瘤活性筛选, 结果显示化合物1～3对人肿瘤细胞A549、Bel7402、BGC823、HCT-8以及A2780具有抑制作用。     

Assessment of cognitive functions in animal models of schizophrenia

Impaired cognitive functioning is recognized as an integral feature of schizophrenia. These deficits have emerged not only as an important predictor of clinical and social outcomes but also as a target for schizophrenia therapeutics. Several cognitive functions have been identified as being commonly deficient in schizophrenia patients, including attention, working memory, reasoning and problem solving, visual learning and memory or social cognition. The selected neuropsychological tests measuring these specific domains were included in the MATRICS Consensus Cognitive Battery (MCCB) and in the Cambridge Neuropsychological Test Automated Battery (CANTAB). While the MCCB and the CANTAB are used in clinical trials of cognition-enhancing drugs for schizophrenia, there is a growing need for a translational test battery that can be used in animal models. To reduce the translational gap between preclinical and clinical studies, the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CINTRICS) programme has recommended animal tasks with construct validity for the evaluation of cognitive domains that are affected in schizophrenia. This review will overview rodent tests that are widely used to identify schizophrenia-like cognitive impairments, including CINTRICS’s recommendations and novel touchscreen-based procedures.     

Curcumin decreases oxidative stress in mitochondria isolated from liver and kidneys of high-fat diet-induced obese mice

Oxidative stress plays a key role in obesity and diabetes-related mitochondrial dysfunction. Mitochondrial dysfunction is characterized by increased oxidative damage, nitric oxide (NO) synthesis, and a reduced ratio of adenosine-5'-triphosphate (ATP) production/oxygen consumption. Curcumin represents a potential antioxidant and anti-inflammatory agent. In this study, our objective was to determine the effect of curcumin treatment on oxidative stress and mitochondrial dysfunction in high-fat diet (HFD)-induced obese mice (OM). These results suggest that curcumin treatment increased oxygen consumption and significantly decreased lipid and protein oxidation levels in liver mitochondria isolated from HFD-induced OM compared with those in the untreated OM (UOM). In kidney mitochondria, curcumin treatment significantly increased oxygen consumption and decreased lipid and protein peroxidation levels in HFD-induced OM when compared with those in UOM. Curcumin treatment neither has any effect on body weight gain nor have any effects on mitochondrial NO synthesis. These findings suggest that obesity induces oxidative stress and mitochondrial dysfunction, whereas curcumin may have a protective role against obesity-induced oxidative stress and mitochondrial dysfunction.     

Nephro-protective potential of Morus alba,a prospective experimental study on animal models

Context: Morus alba L. (Moraceae) is traditionally used for the treatment of urinary incontinency due its strong diuretic properties.

Objective: The present study explores the renal protective effects of M. alba, due to its free radical scavenging properties, in order to provide experimental evidence for its established use.

Materials and methods: Ethanolic extract (200?mg/kg/d) derived from M. alba fruit was employed in rabbits as a co-therapy (GM-al) with gentamicin (80?mg/kg/d) for a period of 3?weeks. Biochemical kidney functioning parameters, urinary isozymes, and histopathological examination were performed.

Results: The results showed that ethanol extract of Morus alba L. prevented alterations in serum creatinine (4.02?±?0.14, p?<?0.0001), blood urea nitrogen (54.18?±?2.60, p?<?0.0001), and serum uric acid levels (2.34?±?0.12, p?<?0.001). However, a decrease in creatinine clearance and urinary volume was observed in experimental groups. Histopathological examination and urinary enzymes excretion also suggested the protective role of the extract.

Discussion and conclusions: The co-administration of M. alba with gentamicin prevented renal functioning alterations expected with the use of gentamicin alone. Therefore, it can be concluded that M. alba to protect from kidney damage, which may be because of its free radical scavenging and diuretic properties.     

Antioxidant activity against H2O2-induced cytotoxicity of the ethanol extract and compounds from Pyrola decorate leaves

Context: The leaves of Pyrola decorate H. Andr (Pyrolaceae), known as Luxiancao, have long been used for treating kidney deficiency, gastric haemorrhage and rheumatic arthritic diseases in traditional Chinese medicine.

Objective: The phytochemicals and antioxidant capacities in vitro of P. decorate leaves were investigated.

Materials and methods: Ethanol, petroleum ether, acetidin, n-butyl alcohol and aqueous extracts of Pyrola decorate leaves were prepared by solvent sequential process, and then isolated and purified to obtain phytochemicals. Cell viability was measured by MTT assay. PC12 cells were pretreated for 24?h with different extractions of P. decorate leaves at concentrations of 0.1, 0.5, 1, 5 and 10?mg/mL, then H₂O₂ of 0.4?mM was added in all samples for an additional 2?h. The antioxidant capacities of betulin, ursolic acid and monotropein were determined in PC12 cells against H₂O₂ induced cytotoxicity in vitro as well.

Results: Nine compounds (1–9) were isolated and structurally determined by spectroscopic methods, especially 2D NMR analyses. Ethanol extract treated groups showed inhibitory activity with IC₅₀ value of 10.83?mg/mL. Betulin, ursolic acid and monotropein were isolated from P. decorate, and demonstrated with IC₅₀ values of 6.88, 6.15 and 6.13?μg/mL, respectively.

Discussion and conclusions: In conclusion, Pyrola decorate is a potential antioxidative natural plant and worth testing for further pharmacological investigation in the treatment of oxidative stress related neurological disease.     

Assessment of topical non-steroidal anti-inflammatory drugs in animal models

Four commercial gel preparations of topical anti-inflammatory agents have been assessed in six animal models commonly used to determine the biological activity of non-steroidal anti-inflammatory agents for systemic administration. Only UV-induced erythema of the skin, adjuvant induced arthritis and the measurement of vascular permeability proved suitable for differentiation of the potency of the four topical agents. Carrageenin-induced paw oedema, the cotton pellet test and the assessment of the pain threshold according to Randall and Selitto were of little value. The effects of the gel preparation of diclofenac (CAS 15307-86-5) diethylammonium (Voltaren Emulgel) were comparable to two preparations containing 1% and 5% active ingredient, respectively. Gel 4 showed low overall activity. The experiments demonstrated that some of the models used for the assessment of anti-inflammatory agent for systemic administration proved suitable for the testing of topical preparations and that percutaneous absorption was insufficient to elicit anti-inflammatory effect in the animals at sites remote from the site of application.     

Neurogenesis in the epileptic brain: a brief overview from temporal lobe epilepsy

Dentate granule cell neurogenesis persists throughout life in the hippocampus of mammals. Alterations in this process occur in many neurological diseases, including epilepsy. Among the different types of epilepsy, the most frequent is temporal lobe epilepsy (TLE). Therefore, a number of laboratory studies use animal models of TLE to observe the fate of neuronal cells after seizures. Hippocampal neurogenesis is very sensitive to physiological and pathological stimuli. Seizures, as pathological stimuli, alter both the extent and the pattern of neurogenesis, which is associated with cognitive function. Various alterations in neurogenesis are observed depending on the amount of time that has elapsed after the seizures. In acute seizures, neurogenesis generally increases, whereas in chronic epilepsy, neurogenesis decreases. Moreover, several methods currently used for the treatment of brain disorders such as TLE can also have significant impacts on cognitive functions. This review is focused on the recent findings regarding neurogenesis in animal models of TLE.     

Two novel flavanes from the leaves of Morus alba L.

Two new flavanes, (2R,4S)-2′,4′-dihydroxy-2H-furan-(3″,4″:8,7)-flavan-4-ol (1) and (2S)-2′,4′-dihydroxy-7-methoxyl-8-butyricflavane (2), together with four known flavonoids, were isolated from the leaves of Morus alba L. Their structures were determined on the basis of spectroscopic analysis.     

Nifedipine affects the anticonvulsant activity of topiramate in various animal models of epilepsy

Topiramate (TPM), a new generation antiepileptic drug was investigated for its anticonvulsant effects in various models of genetically determined and chemically induced epilepsy in rodents. In addition, based on recent electrophysiological data suggesting that TPM may interact with L-type Ca(2+) channels, we evaluated the effects of a concomitant administration of L-type Ca(2+) channel modulators on TPM's antiepileptic properties. TPM, dose-dependently, protected against audiogenic seizures in DBA/2 mice. Concomitant treatment with TPM and a low dose of L-type Ca(2+) channel antagonists nifedipine or verapamil or with the L-type Ca(2+) channel agonist, S(-)-1,4-dihydro-2,6-dimethyl-5-nitro-4-[2-(trifluoromethyl)phenyl]-3-pyridinecarboxylic acid methyl ester (Bay k 8644) was able to increase the ED(50) for this drug. TPM also protected against seizures induced by alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA), 4-aminopyridine (4-AP) and pentylenetetrazole (PTZ), but this activity was not significantly modified by nifedipine. TPM, dose-dependently, reduced the number and duration of epileptic spike-wave discharges (SWDs) both in WAG/Rij rats and lethargic (lh/lh) mice, two genetic models of absence epilepsy. Nifedipine decreased TPM's activity in WAG/Rij rats but paradoxically enhanced it in lh/lh mice, whereas Bay k 8644 displayed opposite effects in both absence models. These results confirm TPM's broad spectrum of anticonvulsant activity and support the proposal that a modulation of neuronal L-type Ca(2+) channel activity plays an important role in its antiepileptic activity.