Antibiotic Prescription in Patients With Coronavirus Disease 2019: Analysis of National Health Insurance System Data in the Republic of Korea.

BACKGROUND: Although coronavirus disease 2019 (COVID-19) is a viral infection, antibiotics are often prescribed due to concerns about accompanying bacterial infection. Therefore, we aimed to analyze the number of patients with COVID-19 who received antibiotic prescriptions, as well as factors that influenced antibiotics prescription, using the National Health Insurance System database. METHODS: We retrospectively reviewed claims data for adults aged ≥ 19 years hospitalized for COVID-19 from December 1, 2019 to December 31, 2020. According to the National Institutes of Health guidelines for severity classification, we calculated the proportion of patients who received antibiotics and the number of days of therapy per 1,000 patient-days. Factors contributing to antibiotic use were determined using linear regression analysis. In addition, antibiotic prescription data for patients with influenza hospitalized from 2018 to 2021 were compared with those for patients with COVID-19, using an integrated database from Korea Disease Control and Prevention Agency-COVID19-National Health Insurance Service cohort (K-COV-N cohort), which was partially adjusted and obtained from October 2020 to December 2021. RESULTS: Of the 55,228 patients, 46.6% were males, 55.9% were aged ≥ 50 years, and most patients (88.7%) had no underlying diseases. The majority (84.3%; n = 46,576) were classified as having mild-to-moderate illness, with 11.2% (n = 6,168) and 4.5% (n = 2,484) having severe and critical illness, respectively. Antibiotics were prescribed to 27.3% (n = 15,081) of the total study population, and to 73.8%, 87.6%, and 17.9% of patients with severe, critical, and mild-to-moderate illness, respectively. Fluoroquinolones were the most commonly prescribed antibiotics (15.1%; n = 8,348), followed by third-generation cephalosporins (10.4%; n = 5,729) and beta-lactam/beta-lactamase inhibitors (6.9%; n = 3,822). Older age, COVID-19 severity, and underlying medical conditions contributed significantly to antibiotic prescription requirement. The antibiotic use rate was higher in the influenza group (57.1%) than in the total COVID-19 patient group (21.2%), and higher in severe-to-critical COVID-19 cases (66.6%) than in influenza cases. CONCLUSION: Although most patients with COVID-19 had mild to moderate illness, more than a quarter were prescribed antibiotics. Judicious use of antibiotics is necessary for patients with COVID-19, considering the severity of disease and risk of bacterial co-infection.

Stability and safety of transbronchial dye mixture for preoperative localization in a porcine model.

OBJECTIVE: For thoracoscopy, the usefulness of a dye mixture of indigo carmine and Lipiodol for localizing lung lesions has been reported. However, little is known about the stability and safety of this dye mixture injected on the visceral pleura through a bronchoscope. METHODS: Porcine models were divided into three groups according to the detection time of the dye mixture: group A with a detection time of 4 h; group B, 8 h; and group C, 24 h. A dye mixture of indigo carmine and Lipiodol (0.5 mL each) was sprayed onto the visceral pleura both in the ventral and dorsal regions via a spray catheter. RESULTS: Twelve markings were created on the visceral pleura of the porcine lung (six ventral and six dorsal) in the six porcine models. At predetermined detection times, all 12 dye markings (100%) were visible on the visceral pleura. The mean longest diameter of the dye marking in the ventral and dorsal regions was 18.8 mm and 24.3 mm, respectively. In groups B and C, pathological changes in the lymphatic system, such as lymphatic dilatations, were found; minimal changes were found in group B, however, these changes with oval-shaped lymphatic cysts and Lipiodol accumulation, were more evident in group C. CONCLUSIONS: The dye mixture of indigo carmine and Lipiodol had reliable stability and visibility. In terms of safety, it may be necessary to check the dye mixture on the lung surface within 8 h.

Vasodilatory Effect of Phellinus linteus Extract in Rat Mesenteric Arteries.

Phellinus linteus is a well-known medicinal mushroom that is widely used in Asian countries. In several experimental models, Phellinus linteus extracts were reported to have various biological effects, including anti-inflammatory, anti-cancer, hepatoprotective, anti-diabetic, neuroprotective, and anti-angiogenic activity. In the present study, several bioactive compounds, including palmitic acid ethyl ester and linoleic acid, were identified in Phellinus linteus. The intermediate-conductance calcium-activated potassium channel (IKCa) plays an important role in the regulation of the vascular smooth muscle cells' (VSMCs) contraction and relaxation. The activation of the IKCa channel causes the hyperpolarization and relaxation of VSMCs. To examine whether Phellinus linteus extract causes vasodilation in the mesenteric arteries of rats, we measured the isometric tension using a wire myograph. After the arteries were pre-contracted with U46619 (a thromboxane analogue, 1 µM), Phellinus linteus extract was administered. The Phellinus linteus extract induced vasodilation in a dose-dependent manner, which was independent of the endothelium. To further investigate the mechanism, we used the non-selective K+ channel blocker tetraethylammonium (TEA). TEA significantly abolished Phellinus linteus extract-induced vasodilation. Thus, we tested three different types of K+ channel blockers: iberiotoxin (BKca channel blocker), apamin (SKca channel blocker), and charybdotoxin (IKca channel blocker). Charybdotoxin significantly inhibited Phellinus linteus extract-induced relaxation, while there was no effect from apamin and iberiotoxin. Membrane potential was measured using the voltage-sensitive dye bis-(1,3-dibutylbarbituric acid)-trimethine oxonol (DiBAC4(3)) in the primary isolated vascular smooth muscle cells (VSMCs). We found that the Phellinus linteus extract induced hyperpolarization of VSMCs, which is associated with a reduced phosphorylation level of 20 KDa myosin light chain (MLC20).

Protective Effects of Radish Extract Against Neurotoxicity in Mice and PC12 Cells.

A variety of natural compounds have been used to reduce the oxidative stress associated with Alzheimer's disease, and many of these defend cells from oxidative stress-induced neuronal toxicity. In this study, the protective effect of radish (Raphanus raphanistrum) extract was investigated in mice and PC12 cells. In vivo behavioral tests were completed to examine the protective effects of the extract on amyloid beta (Aß)-peptide1-42-induced learning and memory impairment in a mouse model. The extract increased spontaneous alternation behaviors and step-through latency in mice. We discovered that administration of the extract reduced lipid peroxidation and Aß aggregation in a biochemical study of mice brain tissues. Treatment with the extract also increased acetylcholine and catalase activity in the brain. Furthermore, the radish extract attenuated H2O2-induced oxidative stress in cells. Through sequential fractionation of the radish extract, the active compound was identified as oleamide. These results suggest that the radish extract could have a protective role against oxidative stress-induced neuronal toxicity, possibly owing to the antioxidative activity of oleamide.

Differential Change in the Prevalence of the Ascaris, Trichuris and Clonorchis infection Among Past East Asian Populations.

As we learn more about parasites in ancient civilizations, data becomes available that can be used to see how infection may change over time. The aim of this study is to assess how common certain intestinal parasites were in China and Korea in the past 2000 years, and make comparisons with prevalence data from the 20th century. This allows us to go on to investigate how and why changes in parasite prevalence may have occurred at different times. Here we show that Chinese liver fluke (Clonorchis sinensis) dropped markedly in prevalence in both Korea and China earlier than did roundworm (Ascaris lumbricoides) and whipworm (Trichuris trichiura). We use historical evidence to determine why this was the case, exploring the role of developing sanitation infrastructure, changing use of human feces as crop fertilizer, development of chemical fertilizers, snail control programs, changing dietary preferences, and governmental public health campaigns during the 20th century.

Synergistic effect of Korean red ginseng and Pueraria montana var. lobata against trimethyltin-induced cognitive impairment.

Many edible plant extracts exhibit biological activities. For example, the ethanol extract of Pueraria montana var. lobata (P. montana) inhibits acetylcholinesterase (AChE), and red ginseng is well known for promoting health. In this study the authors investigated the synergistic effect of P. montana and red ginseng extracts on AChE activity in vitro and in mouse brain tissues and trimethyltin (TMT)-induced cognitive impairment in a mouse model of TMT-induced neurodegeneration. A diet containing a mixture of P. montana and red ginseng extracts reversed learning and memory impairments in Y-maze and passive avoidance behavioral tests. In addition, the mixture inhibited AChE activity and lipid peroxidation synergistically.

Erucamide from Radish Leaves Has an Inhibitory Effect Against Acetylcholinesterase and Prevents Memory Deficit Induced by Trimethyltin.

In this study, we investigated a potent acetylcholinesterase inhibitor that was isolated from radish leaf (Raphanus sativus L.) extracts. Through sequential fractionation of radish leaf extract, the active constituent was identified as cis-13-docosenamide (erucamide). To validate the potency, erucamide derived from radish leaves was supplemented in diets and then fed to trimethyltin (TMT)-exposed mice. Specifically, mice had free access to a control diet or diets containing different concentrations of erucamide for 3 weeks, followed by an injection of TMT (2.5 mg/kg body weight). Our results showed that pretreatment of mice with erucamide (20 and 40 mg/kg body weight per day) significantly attenuated the TMT-induced learning and memory deficits that were assessed by Y-maze and passive avoidance tests. These findings suggest that radish leaves, and possibly its isolated erucamide, may have preventive effects against memory deficits related to Alzheimer's disease by modulation of cholinergic functions.

Horse-riding accidents and injuries in historical records of Joseon Dynasty, Korea.

Only a few osteological reports describe bone injuries thought to have been caused by falls from horses. Nevertheless, anthropological study alone is insufficient for establishing the correlates of such equestrian accidents. We therefore reviewed the records in Seungjeongwon ilgi (Diaries of the Royal Secretariat) and Joseon wangjo silrok (Annals of the Joseon Dynasty) of the Korea's Joseon period (1392-1910 CE). Although the mechanisms of trauma were diverse, the Joseon documents recorded many injuries caused by horse-riding accidents. During 1625-1872 CE, equestrian-related accidents occurred almost every year, overwhelming other causes of trauma. In all horse-riding accidents (n=142), 37.77% of the records offer detailed data about the traumatic mechanism. Injuries occurred most frequently to the extremities (79.58%), which were followed by the trunk (34.5%) and head (4.92%). Although we do not think that this attempt can explain every paleopathological case, our historical review shows that equestrian-related injuries could be considered as one of the major causes for the bone trauma observed among ancient equestrian people.

Cinnamomum loureirii Extract Inhibits Acetylcholinesterase Activity and Ameliorates Trimethyltin-Induced Cognitive Dysfunction in Mice.

The pathogenesis of Alzheimer's disease (AD) has been linked to the deficiency of neurotransmitter acetylcholine (ACh) in the brain, and the main treatment strategy for improving AD symptoms is the inhibition of acetylcholinesterase (AChE) activity. In the present study, we aimed to identify potent AChE inhibitors from Cinnamomum loureirii extract via bioassay-guided fractionation. We demonstrated that the most potent AChE inhibitor present in the C. loureirii extract was 2,4-bis(1,1-dimethylethyl)phenol. To confirm the antiamnesic effects of the ethanol extract of C. loureirii, mice were intraperitoneally injected with the neurotoxin trimethyltin (2.5 mg/kg) to induce cognitive dysfunction, and performance in the Y-maze and passive avoidance tests was assessed. Treatment with C. loureirii extract significantly improved performance in both behavioral tests, suggesting that this extract may be neuroprotective and therefore beneficial in preventing or ameliorating the degenerative processes of AD, potentially by restoring cholinergic function.

Bio-Anthropological Studies on Human Skeletons from the 6th Century Tomb of Ancient Silla Kingdom in South Korea.

In November and December 2013, unidentified human skeletal remains buried in a mokgwakmyo (a traditional wooden coffin) were unearthed while conducting an archaeological investigation near Gyeongju, which was the capital of the Silla Kingdom (57 BCE- 660 CE) of ancient Korea. The human skeletal remains were preserved in relatively intact condition. In an attempt to obtain biological information on the skeleton, physical anthropological, mitochondrial DNA, stable isotope and craniofacial analyses were carried out. The results indicated that the individual was a female from the Silla period, of 155 ± 5 cm height, who died in her late thirties. The maternal lineage belonged to the haplogroup F1b1a, typical for East Asia, and the diet had been more C3- (wheat, rice and potatoes) than C4-based (maize, millet and other tropical grains). Finally, the face of the individual was reconstructed utilizing the skull (restored from osseous fragments) and three-dimensional computerized modeling system. This study, applying multi-dimensional approaches within an overall bio-anthropological analysis, was the first attempt to collect holistic biological information on human skeletal remains dating to the Silla Kingdom period of ancient Korea.

Perilla frutescens Extract Ameliorates Acetylcholinesterase and Trimethyltin Chloride-Induced Neurotoxicity.

One of the critical features of Alzheimer's disease is cognitive dysfunction, which is, in part, due to decreases in acetylcholine (ACh). The ethanol extract of Perilla frutescens was selected for isolating the acetylcholinesterase (AChE) inhibitor based on preliminary screening. In vivo behavioral tests were performed to examine the effects of the P. frutescens extract on trimethyltin chloride-induced impairment of learning and memory in mice. A diet containing P. frutescens extract effectively reversed learning and memory impairment on the Y-maze and passive avoidance tests. To isolate the active compound from the P. frutescens extract, solvent partitioning, silica gel open column chromatography, thin-layer chromatography, and high-performance liquid chromatography were used. The AChE inhibitor was identified as rosmarinic acid.

Habitual dietary intake of ß-carotene, vitamin C, folate, or vitamin E may interact with single nucleotide polymorphisms on brachial-ankle pulse wave velocity in healthy adults.

PURPOSE: The interaction between genetics and diet may explain the present disagreement in the protective role of vitamin intake on cardiovascular disease. We cross-sectionally assessed the interaction of habitual dietary intake of ß-carotene, vitamin C, folate, and vitamin E with single nucleotide polymorphisms (SNPs) on brachial-ankle pulse wave velocity (baPWV), a measure of arterial stiffness. METHODS: Dietary intakes of ß-carotene, vitamin C, folate, and vitamin E were quantified by a food frequency questionnaire in 3198 healthy men and women (≥ 40 years) from the Korea Multi-Rural communities Cohort study. baPWV was measured, and 19 SNPs were genotyped. The associations and interactions between dietary vitamin intake, SNP genotype, and baPWV were assessed using general linear models. RESULTS: In both men and women, dietary intake of ß-carotene, vitamin C, folate, or vitamin E and baPWV were not directly associated. Vitamin C, folate, and vitamin E intake had an interaction with rs4961 (ADD1) genotype on baPWV in men. rs4961 also interacted with folate intake on baPWV in women. In women, rs10817542 (ZNF618) and rs719856 (CD2AP) had an interaction with ß-carotene and folate intake and rs5443 (GNB3) had an interaction with vitamin E intake on baPWV. In general, minor allele homozygotes with low vitamin intake had higher baPWV than other subgroups. Results were similar when supplement users were excluded. CONCLUSIONS: Higher intake of dietary vitamin C, folate, and vitamin E may be related to high baPWV in healthy Korean men who are minor allele homozygotes of rs4961. In healthy Korean women, dietary folate, ß-carotene, and vitamin E intake may affect baPWV differently according to rs4961, rs10817542, rs719856, or rs5443 genotype. Greater dietary intake of these nutrients may protect those that are genetically vulnerable to stiffening of the arteries.

Effect of Chaenomeles sinensis Extract on Choline Acetyltransferase Activity and Trimethyltin-Induced Learning and Memory Impairment in Mice.

The aim of this study was to search for a novel choline acetyltransferase (ChAT) activator from plants traditionally grown in Korea. An ethanol extract from Chaenomeles sinensis Koehne showed the highest ChAT-activating effect in vitro in an assay that used human neuroblastoma cells and [(14)C]acetyl-CoA. The active compound was speculated to be stearic acid methyl ester (SAME). In an in vivo experiment, C. sinensis extract and SAME improved trimethyltin (TMT)-induced deficits in learning and memory in mice as assessed by a Y-maze behavioral test and a passive avoidance test. The C. sinensis extract might attenuate the TMT-induced brain disorder. This study suggests that SAME from C. sinensis might be useful in the treatment of Alzheimer's disease.

Effects of probiotics (cultured Lactobacillus subtilis/Streptococcus faecium) in the treatment of alcoholic hepatitis: randomized-controlled multicenter study.

BACKGROUND: Probiotics might reduce gut-derived microbial lipopolysaccharide (LPS) by restoring bowel flora in patients with alcoholic hepatitis (AH). We evaluated the therapeutic effects of probiotics in patients with AH. PATIENTS AND METHODS: Between September 2010 and April 2012, 117 patients (probiotics 60 and placebo 57) were prospectively randomized to receive the 7 days of cultured Lactobacillus subtilis/Streptococcus faecium (1500 mg/day) or placebo. All patients were hospitalized and were not permitted to consume alcohol for the 7 days of the study. Liver function test, proinflammatory cytokines, LPS, and colony-forming units by stool culture were examined and compared after therapy. RESULTS: In both groups, the mean levels of aspartate aminotransferase/alanine aminotransferase, alkaline phosphatase, γ-glutamyl transpeptidase, bilirubin, and prothrombin time were significantly improved after 7 days of abstinence. In the probiotics group (baseline and after), albumin (3.5 ± 0.7 and 3.7 ± 0.6 g/dl, P=0.038) and tumor necrosis factor-α (121 ± 244 and 71 ± 123 pg/ml, P=0.047) showed differences. In addition, the number of colony-forming units of Escherichia coli was significantly reduced (435 ± 287 and 168 ± 210, P=0.002). In the placebo group, the level of LPS (1.7 ± 2.8 and 2.0 ± 2.7 EU/ml) was significantly increased. In the intergroup comparison, significant differences in the levels of tumor necrosis factor-α (P=0.042) and LPS (P=0.028) were observed between the groups. CONCLUSION: Immediate abstinence is the most important treatment for patients with AH. In addition, 7 days of oral supplementation with cultured L. subtilis/S. faecium was associated with restoration of bowel flora and improvement of LPS in patients with AH.

The cross-sectional relationship between dietary calcium intake and metabolic syndrome among men and women aged 40 or older in rural areas of Korea.

BACKGROUND/OBJECTIVES: Studies conducted in Western populations have suggested that dietary calcium may protect against metabolic abnormalities, but there is little evidence of this effect in Asians, who have relatively low calcium intake. We evaluated the cross-sectional relationship between dietary calcium and metabolic syndrome among Korean men and women aged 40 years and over. SUBJECTS/METHODS: A total of 6,375 subjects aged 40 years and over and were recruited between January 2005 and February 2010 from the baseline study of the Multi-Rural Communities Cohort Study in Rural Communities (MRCohort). A food frequency questionnaire was used to collect dietary information. Metabolic syndrome was defined using the modified criteria published in the Third Report of the National Cholesterol Education Program Adult Treatment Panel. RESULTS: Calcium intake was related inversely to metabolic syndrome in women (P-value = 0.0091), but not in men (P = 0.1842). Among metabolic components, high waist circumference (WC) (P = 0.0426) and high blood glucose (P = 0.0027) in women and hypertriglyceridemia (P = 0.0017) in men were inversely correlated with calcium intake. Excluding those who used calcium or multinutrient supplements did not attenuate the relationship between dietary calcium and metabolic abnormalities. CONCLUSION: Dietary calcium intake from foods may be inversely related to metabolic syndrome, WC, and blood glucose among women in rural areas of Korea.

Forensic palynological analysis of intestinal contents of a Korean mummy.

Experimental studies show that pollen resides in the intestinal tract for a minimum of seven days to at least 21 days. Because of this long residence time, pollen analysis is an important avenue of forensic research. Pollen provides evidence of the environment of the decedent as well as foods and medicine. We analyzed a coprolite recovered from a Korean mummy. The decedent was a high-ranking general who lived during the 16th or 17th centuries. Twenty pollen types were recovered. These ranged from 100 s to 10,000 s of pollen grains per gram of coprolite. Importantly, comparison of the coprolite pollen spectrum to modern aeropalynology studies of Korea suggests that the general died in winter between middle November to late February. Economic pollen types were most abundant. Economic refers to dietary, medicinal, spice, and beverage types. Dietary pollen types include pollen from Oryza (rice), Eriogonum (buckwheat), Brassicaceae (mustard family), and Solanaceae (tomato-chile pepper family). Pollen consistent with dandelion is present and may represent its use as food. Tens of thousands of grains from water plants, bur-reed or cattail, dominate the pollen spectrum. We believe that this was introduced with water. The large numbers of water-related pollen suggest that the general consumed broth, tea, or soup for a considerable time before death.

Predicting stroke outcome using clinical- versus imaging-based scoring system.

BACKGROUND: Several models to predict outcome in ischemic stroke patients receiving intravenous (i.v.) alteplase can be divided into clinical-based and imaging-based systems. Alberta Stroke Program Early Computed Tomography (CT) Score (ASPECTS) and Dense cerebral artery sign/early infarct signs on admission CT scan, prestroke modified Rankin Scale (mRS) score, Age, Glucose level at baseline, Onset-to-treatment time, and baseline National Institutes of Health Stroke Scale score (DRAGON) are typical imaging- and clinical-based scoring systems, respectively. Therefore, we compared predictability of stroke outcome of clinical (DRAGON)- and imaging (ASPECTS)-based scoring systems. METHODS: We analyzed patients who were diagnosed with middle cerebral artery territory stroke and treated with i.v. alteplase at Gachon University Gil Hospital over 5 years and compared performance of 2 scoring systems for prediction of good functional outcome (mRS, 0-2) with Pearson correlation and area under the curve-receiver operating characteristic (AUC-ROC). In addition, we analyzed predicting power of several clinical factors and 2 scoring systems by multiple regression analysis. RESULTS: Study population (N = 120) had mean age of 66.2 ± 13.2 years. ASPECTS (r = -.841, P < .0001) and DRAGON (r = .657, P < .0001) were significantly correlated with good functional outcome. In addition, statistical comparisons suggested that ASPECTS (AUC-ROC, .972; 95% confidence interval [CI], .947-.996) is significantly superior to DRAGON (AUC-ROC, .854; 95% CI, .786-.922) in predicting functional outcome (difference between areas, .118 ± .0332; 95% CI, .0559-.180, P = .0002). Multiple regression analysis revealed that ASPECTS was the independent predictor of good prognosis (OR, 6.59 per 1-point increase; 95% CI, 2.35-18.49; P < .0001 and OR, 77.67 for ASPECTS ≥ 8; 95% CI, 14.30-421.79; P < .0001). CONCLUSIONS: ASPECTS is superior method for predicting functional outcome in acute ischemic stroke patients receiving i.v. alteplase compared with DRAGON and integration of ASPECTS score into clinical care pathway as decision-making tool can be reasonable.

The effect of coffee, tea, and caffeine consumption on serum uric acid and the risk of hyperuricemia in Korean Multi-Rural Communities Cohort.

Caffeine, a commonly consumed food constituent, is known to exert beneficial physiological effects in humans. There is a lack of comprehensive population data for the effects of caffeine intake on urate metabolism. Therefore, the aim of this study was to determine whether coffee, tea, and caffeine intake influences serum uric acid and the risk of hyperuricemia in the Korean Multi-Rural Communities Cohort. We enrolled 9,400 participants in this study. An assessment of various dietary intake amounts of substances such as coffee and tea was performed using a food frequency questionnaire. The content of caffeine was calculated from coffee (74 mg/cup) and tea (15 mg/cup) intake information from the past year. Multivariate logistic regression models, multiple linear regression models, and analysis of covariance were applied to identify any association of dietary intake with serum uric acid levels or the risk of hyperuricemia. No trends for coffee, tea, or caffeine intake were found according to each quintile with serum uric acid in males, although there were weak, marginally significant trends between the content of coffee and caffeine intake and serum uric acid level in females (p = 0.07 for both). Tea intake in males and caffeine intake in females were significantly different between non-hyperuricemia and hyperuricemia (p = 0.04 and p = 0.04, respectively). In addition, a significant association of serum uric acid level with tea intake in males (ß = 0.0006, p = 0.02) and with tea intake and caffeine intake in females (ß = 0.0003, p = 0.04 and ß = 0.0006, p = 0.02, respectively) was observed. There was no effect of coffee, tea, or caffeine intake on the risk of hyperuricemia in either males or females. This study suggests that caffeine consumption might have an effect on serum uric acid in females. However, coffee, tea, and caffeine intake amounts were not associated with the risk of hyperuricemia.

An optimized extraction technique for acetylcholinesterase inhibitors from the Camellia japonica seed cake by using response surface methodology.

The response surface methodology (RSM) was used to optimize the extraction conditions for the acetylcholinesterase (AchE) inhibitory activity and extraction yield from Camellia japonica seed cake. Predicted values for AchE inhibition and extraction yield were 19.41 and 13.35%, respectively, which are in good agreement with the experimental values from validation, suggesting that RSM may provide a useful tool to optimization processes.

Ligularia fischeri extract protects against oxidative-stress-induced neurotoxicity in mice and PC12 cells.

Alzheimer's disease (AD) is pathologically characterized by the presence of amyloid plaques in brain and the overproduction of amyloid beta (Aß), leading to learning and memory impairment and intense oxidative stress. In this study, the protective effect of Ligularia fischeri extract was investigated using PC12 cells. L. fischeri extract attenuated hydrogen-peroxide-induced DNA fragmentation in cells. In vivo behavioral tests were performed to examine the effects of the extract on amyloid-ß peptide1-42-induced impairment of learning and memory in mice. A diet containing the extract increased alternation behaviors in the Y-maze test and step-through latency of passive avoidance task. Moreover, we found that consumption of the extract decreased lipid peroxidation in a biochemical study of brain tissue in mice. High-performance liquid chromatography was used to identify the active compounds in the extract. These results suggest that L. fischeri extract could be protective against Aß-induced neurotoxicity, possibly due to the antioxidative capacity of its constituent, 3-O-caffeoylquinic acid.