• Natural Product Sciences
• /
• v.11 no.3
• /
• pp.179-182
• /
• 2005

We investigated that water extract of Acanthopanax sessiliflorus roots rescued the N-methyl-D-aspartate (NMDA), agonist of glutamate receptor, -induced toxicity in rat organotypic hippocampal slice culture. When the cell death in NMDA only-treated hippocampal slices was set 100%, A. sessiliflorus decreased the cell death to 75.4, 51.6, 48.9, and 40.6% at 1, 10, 50, and $100\;{\mu}g/ml$ treatment, respectively. On the basis of these results, the water extract of A. sessiliflorus roots may be a preventive agent against NMDA-induced cytotoxicity.

• Anatomy and Cell Biology
• /
• v.57 no.2
• /
• pp.155-162
• /
• 2024

Cerebral ischemia is the important cause of worldwide disability and mortality, that is one of the obstruction of blood vessels supplying to the brain. In early stage, glutamate excitotoxicity and high level of intracellular calcium (Ca²⁺) are the major processes which can promote many downstream signaling involving in neuronal death and brain tissue damaging. Moreover, autophagy, the reusing of damaged cell organelles, is affected in early ischemia. Under ischemic conditions, autophagy plays an important role to maintain energy of the brain and its function. In the other hand, over intracellular Ca²⁺ accumulation triggers excessive autophagic process and lysosomal degradation leading to autophagic process impairment which finally induce neuronal death. This article reviews the association between intracellular Ca²⁺ and autophagic process in acute stage of ischemic stroke.

• Biomolecules & Therapeutics
• /
• v.32 no.1
• /
• pp.154-161
• /
• 2024

Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disorder that causes progressive paralysis. L-Citrulline is a nonessential neutral amino acid produced by L-arginine via nitric oxide synthase (NOS). According to previous studies, the pathogenesis of ALS entails glutamate toxicity, oxidative stress, protein misfolding, and neurofilament disruption. In addition, L-citrulline prevents neuronal cell death in brain ischemia; therefore, we investigated the change in the transport of L-citrulline under various pathological conditions in a cell line model of ALS. We examined the uptake of [¹⁴C]L-citrulline in wild-type (hSOD1wt/WT) and mutant NSC-34/ SOD1^G93A (MT) cell lines. The cell viability was determined via MTT assay. A transport study was performed to determine the uptake of [¹⁴C]L-citrulline. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis was performed to determine the expression levels of rat large neutral amino acid transported 1 (rLAT1) in ALS cell lines. Nitric oxide (NO) assay was performed using Griess reagent. L-Citrulline had a restorative effect on glutamate induced cell death, and increased [¹⁴C]L-citrulline uptake and mRNA levels of the large neutral amino acid transporter (LAT1) in the glutamate-treated ALS disease model (MT). NO levels increased significantly when MT cells were pretreated with glutamate for 24 h and restored by co-treatment with L-citrulline. Co-treatment of MT cells with L-arginine, an NO donor, increased NO levels. NSC-34 cells exposed to high glucose conditions showed a significant increase in [¹⁴C]L-citrulline uptake and LAT1 mRNA expression levels, which were restored to normal levels upon co-treatment with unlabeled L-citrulline. In contrast, exposure of the MT cell line to tumor necrosis factor alpha, lipopolysaccharides, and hypertonic condition decreased the uptake significantly which was restored to the normal level by co-treating with unlabeled L-citrulline. L-Citrulline can restore NO levels and cellular uptake in ALS-affected cells with glutamate cytotoxicity, pro-inflammatory cytokines, or other pathological states, suggesting that L-citrulline supplementation in ALS may play a key role in providing neuroprotection.

• Journal of Radiation Protection and Research
• /
• v.17 no.1
• /
• pp.11-19
• /
• 1992

To find out an effective way of treating the toxicity of cadmium, concentrations of $K^+,\;Ca^{2+}$ and c-AMP, and activities of GOT and GPT in blood of rats were determined at definite time intervals after administration of cadmium to rats. Cadmium caused more decrease of $Ca^{2+}$ concentration than $K^+$ concentration but increases of GOT and GPT activities and of c-AMP concentrations. The decreased concentration of $Ca^{2+}$ was not recovered by selenium or metallothionein. However, the increased activities of GOT and GPT, and the c-AMP concentration were down regulated remarkably by selenium but not by metallothionein. These results suggested that selenium might have the compensate effects concerning toxic index against cadmium such as increases of GOT and GPT activities, and of c-AMP concentration.

• CELLMED
• /
• v.4 no.3
• /
• pp.18.1-18.5
• /
• 2014

Leea asiatica (L.) Ridsdale, a folk medicinal plant is used by the ethnic people of North East India for the treatment of hepatic disorder. In this study, we have investigated the hepatoprotective and antioxidant activity of L. asiatica leaves against acetaminophen induced hepatotoxicity. Methanol extract of L. asiatica (150 and 300 mg/kg/day, p.o.) were administered to rats for three consecutive days followed by single acetaminophen (3000 mg/kg, p.o.) administration on $3^{rd}$ day. After 48 h of acetaminophen administration animals were sacrificed and biochemical estimation of serum, in vivo antioxidant activity using liver tissue were carried out. High levels of serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, serum alkaline phosphatase, total bilirubin, direct bilirubin, total cholesterol and triglycerides were observed in disease control group, which found near to normal in extract treated groups. Higher dose exhibited significant hepatoprotective activity against acetaminophen induced toxicity. Level of superoxide dismutase, catalase, glutathione peroxidase in liver tissue, and reduced glutathione in liver and blood were also significantly increased in extract (300 mg/kg) treated animals compare to disease control group. In this study we found that leaves of L. asiatica exhibited potent hepatoprotective activity against acetaminophen induced hepatic damage in experimental animals which justify the folklore claim, and the possible mechanism of this activity may be due to strong antioxidant activities of extract.

• Journal of The Korean Society of Clinical Toxicology
• /
• v.4 no.1
• /
• pp.61-64
• /
• 2006

Glufosinate ammonium (GLA), a phosphinic acid derivate of glutamate, is a broad-spectrum contact herbicide. It structurally resembles glutamate, a typical excitatory amino acid in the central nervous system. In korea, the ingestion of GLA for suicidal attempt or accidental event has increased. The neurological complication of GLA intoxication are characterized by loss of consciousness, convulsion, or memory impairment. But, the exact mechanism of GLA toxicity is yet unknown. This report is about a patient with GLA intoxication who showed anterograde amnesia with selective bilateral hip-pocampal lesions supported GLA intoxication with literature reviews supported.

• Advances in Traditional Medicine
• /
• v.9 no.3
• /
• pp.225-231
• /
• 2009

The present study deals with the amelioration by Lagerstroemia speciosa Linn. leaf extract against hepatotoxicity induced by carbon tetrachloride ($CCl_4$), which was evaluated in terms of serum marker enzymes like serum glutamate pyruvate transaminase, serum glutamate oxaloacetate transaminase, alkaline phosphatase, serum total bilirubin, total protein levels along with concomitant hepatic and antioxidants like superoxide dismutase, catalase, glutathione, glutathione peroxidase and lipid peroxidation enzymes were monitored. These biochemical parameters altered by the single dose level of $CCl_4$ (0.75 ml/kg body weight, i.p). Pre treatment with L. speciosa prior to the administration of $CCl_4$, at the doses of 50 and 250 mg/kg. body weight/day, p.o. for 7 days, significantly restored all the serum and liver tissue parameters near to the normal levels, respectively. Silymarin was used as a reference standard, prior to the administration of $CCl_4$ to rats. These findings indicate the protective potential of L. speciosa against hepato toxicity which possibly involve mechanism related to its ability of selective inhibitors of (reactive oxygen species like antioxidants brought about significant inhibition of TBARS suggesting possible involvement of $O_2{\cdot}-$, $HO_2{\cdot}$, and ${\cdot}OH$. In conclusion, the amelioration may be attributed to the synergistic effects of its constituents rather than to any single factor as the leaves are rich in tannins, sterols, flavonoids, saponins etc.

• Natural Product Sciences
• /
• v.9 no.2
• /
• pp.83-86
• /
• 2003

In the present study, Thespesia populnea (Malvaceae) bark was extracted with methanol and water. The extracts were vacuum dried to yield the respective methanol (MET) and aqueous extract (AET). The extracts were evaluated for hepatoprotective activity against carbon tetrachloride $(CCl_{4})$ induced liver damage at 2 dose levels (250 and 500 mg/kg). The biochemical parameters observed in serum were total bilirubin, alkaline phosphatase (ALP), serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT) levels and total protein. Aspartate transaminase (AST), alanine transaminase (ALT) and total protein levels in liver were also evaluated. Histopathological study on the liver tissue was also performed. The extracts exhibited dose dependent reduction in total bilirubin, ALP SGOT, SGPT, AST, ALT and increase in total protein (serum and liver) levels. The extracts also exhibited only mild hepatocytic damage compared to the $CCl_{4}$ Treated group. MET was found to exhibit higher hepatoprotection than AET.

• Archives of Pharmacal Research
• /
• v.29 no.8
• /
• pp.699-706
• /
• 2006

The present study evaluated antioxidant and neuroprotective activities of hesperidin, a flavanone mainly isolated from citrus fruits, and its aglycone hesperetin using cell-free bioassay system and primary cultured rat cortical cells. Both hesperidin and hesperetin exhibited similar patterns of 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities. While hesperidin was inactive, hesperetin was found to be a potent antioxidant, inhibiting lipid peroxidation initiated in rat brain homogenates by $Fe^{2+}$ and L-ascorbic acid. In consistence with these findings, hesperetin protected primary cultured cortical cells against the oxidative neuronal damage induced by $H_2O_2$ or xanthine and xanthine oxidase. In addition, it was shown to attenuate the excitotoxic neuronal damage induced by excess glutamate in the cortical cultures. When the excitotoxicity was induced by the glutamate receptor subtype-selective ligands, only the N-methyl-D-aspartic acid-induced toxicity was selectively and markedly inhibited by hesperetin. Furthermore, hesperetin protected cultured cells against the $A_{{\beta}(25-35)}-induced$ neuronal damage. Hesperidin, however, exerted minimal or no protective effects on the neuronal damage tested in this study. Taken together, these results demonstrate potent antioxidant and neuroprotective effects of hesperetin, implying its potential role in protecting neurons against various types of insults associated with many neurodegenerative diseases.

• Korean Journal of Pharmacognosy
• /
• v.45 no.3
• /
• pp.214-219
• /
• 2014

Artemisia apiacea is a traditional herbal medicine using treatment of eczema and jaundice in Eastern Asia including China, Korea, and Japan. In this study, the three phytosterol constituents were isolated and identified from the hexane fraction of 80% aqueous methanol extract of A. apiacea. Compounds were isolated using open column chromatography (silica gel). Their chemical structures were also established using $^1H$-NMR and $^{13}C$-NMR. Moreover, neuroprotective activity of each compound against glutamate-induced neurotoxicity in hippocampal HT-22 cell line was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Furthermore, Inhibition of reactive oxygen species (ROS) and calcium ion ($Ca^{2+}$) accumulation were measured for elucidation of neuroprotective mechanism of isolated compounds. They showed that stigmasterol had neuroprotective activity against the glutamate-induced toxicity by inhibition of ROS and $Ca^{2+}$ production. In conclusion, isolated compound of A. apiacea might be useful for therapeutic agent against neurodegenerative diseases.