Quantitative Determination of p-Cymene, Thymol, Neryl Acetate, and ß-Caryophyllene in Different Growth Periods and Parts of Eupatorium fortunei Turcz. by GC-MS/MS.

Eupatorium fortunei Turcz. is a widely used Chinese herbal medicine in China. In this study, a gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) method was developed and validated to simultaneously determine the contents of p-cymene, thymol, neryl acetate, and ß-caryophyllene in roots, stems, and leaves of Eupatorium fortunei Turcz. harvested at different growth periods. All four constituents could be detected in leaves, three could be detected in stems except ß-caryophyllene, and only thymol could be detected in roots. The order of the total contents of four constituents in different parts was leaves > stems > roots. It indicated that the leaves could be the proper medicinal parts of Eupatorium fortunei Turcz. The content of four constituents in leaves varied a lot among different growth periods and showed an M-shaped change trend with the growth of Eupatorium fortunei Turcz. The four constituents accumulated to the highest values in early July followed by mid-September. Accordingly, the best harvest time of Eupatorium fortunei Turcz. is early July and mid-September.

Uptake and Distribution Characteristic and Health Risk Assessment of Heavy Metal(loid)s in Platycodon Grandiflorum (Jacq.) A.DC. with Growth from a Medicinal Herb Garden of Xi'an, China.

The different parts of Platycodon grandiflorum were collected from a medicinal herb garden to determine five heavy metal(loid)s (Pb, Cd, As, Hg, and Cu) contents at different growth stages. The data showed that the plant accumulated varying amounts of metal(loid)s in the order Cu > Hg > Pb > As > Cd. Five heavy metal(loid) concentrations decreased in the early growth stage and then increased in the flowering season. The contents of heavy metal(loid)s except Hg in the stem were relatively lower than other tissues. The flower of Platycodon grandiflorum can highly accumulate heavy metal(loid)s, especially for Cu in the flowering period. Pb, Cd, and Cu contents in stem generally increased with growth time, while Cd and Cu in root decreased during growth time. The average daily intake doses of five heavy metal(loid)s in the root of Platycodon grandiflorum were all below the safety guideline and the target hazard quotient was less than 1.

Fractionation analysis and health risk assessment of heavy metals in six traditional Chinese medicines.

Traditional Chinese medicines (TCMs) are widely used to treat various diseases in China and some countries, and TCM products are becoming increasingly available and popular worldwide. But TCMs are facing the challenge of heavy metal pollution. In this work, we examined the total contents and fractionations of Pb, Cd, Hg, and Cu in six TCMs (Angelicae Sinensis Radix (ASR), Chuanxiong Rhizoma (CR), Polygonati Rhizoma (PR), Astragali Radix (AR), Carthami Flos (CF), and Paeoniae Radix Rubra (PRR)) and evaluated the health risk of four heavy metals in these TCMs. The results showed that Cd, Pb, and Cu contents were considerably high and the amount of Cd in six TCMs, Pb in CR, ASR, AR, and CF, and Hg in ASR, PR, and PRR exceeded the limit values. The predominant fractions of Pb, Cd, and Cu were exchangeable and carbonate fractions in six TCMs; Hg mainly existed in organic and residual fractions. The average daily intake dose (ADD) and target hazard quotient (THQ) of Pb based on total content and total THQ of four heavy metals based on bioaccessible fractions in AR and PRR exceeded the safety guideline. These results indicated that the potential health risk could occur by taking these TCMs.

Comparative pharmacokinetics of verapamil and norverapamil in normal and ulcerative colitis rats after oral administration of low and high dose verapamil by UPLC-MS/MS.

In this study, UC rat model was established by administration of 5% (w/v) dextran sulfate sodium, and the pharmacokinetics of verapamil and norverapamil were evaluated in normal and UC rats using UPLC-MS/MS after oral administration of 5 mg/kg and 50 mg/kg verapamil.The peak concentration (Cmax) and the area under plasma concentration-time curves (AUC) of verapamil in UC rats after oral administration of 5 mg/kg were significantly greater (2.5 times and 2 times, respectively) than those in normal rats, but the clearance rate (Cl) was significantly lower (by 50%). For norverapamil, Cmax and AUC were significantly greater (2.8 times and 2.5 times, respectively), and Cl was significantly lower (by 45%). But, pharmacokinetic parameters of verapamil and norverapamil after oral administration of 50 mg/kg were no significant differences between UC and normal rats.The better absorption and poor excretion for low-dose verapamil may be attributed to down-regulation of P-gp expression in the intestine and kidney. No significant differences of pharmacokinetic parameters for high-dose verapamil may be explained as the saturation of an efflux mechanism.The findings of this study suggested that in UC patients, doses of verapamil should be decreased when low-dose verapamil was orally administrated.

Metabolic profiles of Xiao Chai Hu Tang in mouse plasma, bile and urine by the UHPLC-ESI-Q-TOF/MS technique.

Xiao Chai Hu Tang (XCHT) is sold as traditional medicine or dietary supplement in worldwide. To understand metabolism profile of traditional medicine is key point in their logical pharmacological research and clinical application. Based on our previous research of the chemical and absorption signature of XCHT in vitro, we proposed a novel strategy to identify the bioactive components of XCHT in vivo. This strategy have two steps: firstly, based on the parents' database in vitro, built-in and editable biotransformations for phase I and phase II metabolism reactions with MassHunter Metabolite ID software (building metabolites database). Secondly, mouse plasma, bile and urine samples were analyzed by UHPLC-ESI-Q-TOF/MS technique, and the absorbed parents and metabolites were compared and identified with the XCHT's digital library using MassHunter Metabolite ID software. In total, 27 parent compounds and 26 metabolites of XCHT were identified in vivo, 2'-O-xylosyl saikosaponin b2 or b1 was reported for the first time. Saponins and their related metabolites were predominantly excreted into the bile, but flavonoids were excreted by both hepatic as well as renal excretion. Flavonoids, saponins, gingerol and their related metabolites were the absorbed components in cardiovascular system and bioactive components of XCHT. Phase I reactions (hydrolysis, hydroxylation and oxidation) and phase II reactions (glucuronidation) were identified and involved in the mouse metabolism of XCHT.

Evaluation of the acute and chronic toxicity of the jiangu capsules.

Saussureae involucratae Flos is the primary component of the jiangu capsule, which also consists of 12 types of natural medicine. It is a traditional Chinese medicine used to treat a number of conditions including arthralgia, cold and sore muscles, stiff limbs, inconvenient flexion and activity limitation caused by different types of osteoarthritis. The present study was performed to assess the safety of the jiangu capsule following acute and chronic administration in mice and rats. In the acute study, mice were treated with the jiangu capsule orally at 16 g/kg/day, the highest dose, for 14 days. In the chronic oral toxicity study, rats were treated with 2, 4 and 8 g/kg/day of the jiangu capsule for 6 months. The general condition, body weight changes, food and water consumption, hematological and biochemical parameters, urinalysis, systematic anatomy and organ weights of the rats were monitored and histopathological examination was performed at the end of 3 and 6 months' daily administration, and following 14 days of withdrawal. There were no signs of toxicity in the general condition and body weight of the mice was not significantly affected by the treatment. Furthermore, necropsy findings for the animals in the acute and chronic toxicity studies demonstrated that no mortalities had occurred. The results of the current study indicate that treatment with the jiangu capsule did not induce mortality or any detectable abnormalities in mice and rats.

Nicotinic acid inhibits vascular inflammation via the SIRT1-dependent signaling pathway.

Nicotinic acid (NA) has recently been shown to inhibit inflammatory response in cardiovascular disease. Sirtuin1 (SIRT1), a NAD(+)-dependent class III histone deacetylase, participates in the regulation of cellular inflammation. We hypothesized that dietary supplementation of NA could attenuate vascular inflammation via modulation of SIRT1 pathway. New Zealand White rabbits received chow or chow supplemented with 0.6% (wt/wt) NA for 2 weeks. Acute vascular inflammation was induced in the animals by placing a non-occlusive silastic collar around the left common carotid artery. At 24 h after collar implantation, the collar-induced production of C-reactive protein and monocyte chemotactic protein-1 was significantly suppressed in the NA-supplemented animals. Meanwhile, NA also decreased the expression of cluster of differentiation 40 (CD40) and CD40 ligand, but up-regulated SIRT1 expression, both in rabbits and in lipopolysaccharide-stimulated endothelial cells. Moreover, knockdown of SIRT1 reversed the inhibitory effect of NA on CD40 expression. Further study revealed that NA also decreased the expression of CD40 partly through mammalian target of rapamycin. These results indicate that NA protects against vascular inflammation via the SIRT1/CD40-dependent signaling pathway.

Discovery of novel antagonists of glycoprotein IIb/IIIa-mediated platelet aggregation through virtual screening.

The glycoprotein IIb/IIIa receptor is the final common pathway of platelet aggregation, regardless of the agonist, and thus represents an ideal therapeutic target for blocking thrombus formation. RUC-2 is a novel glycoprotein IIb/IIIa inhibitor of adenosine-5'-diphosphate (ADP)-induced platelet aggregation, importantly which exhibits a unique mode of binding with respect to classical Arg-Gly-Asp (RGD)-based glycoprotein IIb/IIIa antagonists. To identify new chemotypes that inhibit glycoprotein IIb/IIIa-mediated platelet aggregation like RUC-2, we performed a combination of structure-based pharmacophore screening and structure-based virtual screening approach to screen over 7.3 million small molecules based on the RUC-2-glycoprotein IIb/IIIa crystal structure. Three of the eleven hit compounds identified by virtual screening showed promising activity with IC50 values between 16.9 and 90.6µmolL(-1) in a human platelet aggregation assay induced by ADP and thrombin. The binding conformations of these three were analyzed to provide a rationalization of their activity profile. These compounds may serve as potential novel scaffolds for further development of glycoprotein IIb/IIIa antagonists.

Analysis and retention behavior of isoflavone glycosides and aglycones in Radix Astragali by HPLC with hydroxypropyl-ß-cyclodextrin as a mobile phase additive.

In order to determine isoflavone glycosides (calycosin-7-O-ß-D-glucoside and formononetin-7-O-ß-D-glucoside) and aglycones (calycosin and formononetin), a simple HPLC method with isocratic elution employing hydroxypropyl-ß-cyclodextrin (HP-ß-CD) as a mobile phase additive was developed. Various factors affecting the retention of isoflavone glycosides and aglycones in the C(18) reversed-phase column, such as the nature of cyclodextrins, HP-ß-CD concentration, and methanol concentration, were systematically studied. The results show that HP-ß-CD, as a very effective mobile phase additive, can markedly reduce the retention of isoflavone glycosides and aglycones, and the decrease magnitudes of isoflavone aglycones are more than those of their glycosides. The role of HP-ß-CD in the developed HPLC method is attributed to the formation of the inclusion complexes between isoflavone glycosides (or aglycones) and HP-ß-CD. So, the apparent formation constants of the isoflavone glycosides (or aglycones)/HP-ß-CD inclusion complexes also were investigated. Isoflavone glycosides (and aglycones) form the 1:1 inclusion complexes with HP-ß-CD, and the isoflavone aglycones/HP-ß-CD complexes are more stable than the isoflavone glycosides/HP-ß-CD complexes. Finally, the optimized method was successfully applied for the determination of isoflavone glycosides and aglycones in Radix Astragali samples.

Simultaneous analysis and retention behavior of major isoflavonoids in Radix Puerariae lobatae and Radix Puerariae thomsonii by high performance liquid chromatography with cyclodextrins as a mobile phase modifier.

In order to differentiate two species of Radix Puerariae (Radix Puerariae lobatae and Radix Puerariae thomsonii) and to determine major isoflavonoids (puerarin, daidzin, daidzein and genistein) in the samples, a simple high performance liquid chromatography (HPLC) method with isocratic elution employing cyclodextrins (CDs) as mobile phase additives was developed. Various factors affecting the retention of isoflavonoids in the C(18) reversed-phase column, such as the nature of CDs, the concentration of hydroxypropyl-ß-cyclodextrin (HP-ß-CD) and the methanol percentage in the mobile phase, were studied. Experimental results confirmed that HP-ß-CD, as a very effective mobile phase additive, could markedly reduce the retention of isoflavonoids, especially daidzein and genistein. The elution of four isoflavonoids could be achieved on a Kromasil(®) C(18) column within 56 min by using the methanol-water contained 5 mM HP-ß-CD (25/75, v/v) mixture as the mobile phase. The formation of the inclusion complexes between isoflavonoids and HP-ß-CD explained the modification of the retention of analytes. The apparent formation constants determined by HPLC confirmed that the stoichiometry of HP-ß-CD-isoflavonoid complexes was 1:1, and the stability of the complexes depended on the size and property of isoflavonoids. The optimized method was successfully applied for the simultaneous determination of major isoflavonoids in P. lobatae and P. thomsonii samples. This work provides a useful method for the analysis of traditional Chinese herbs.

Determination of paeoniflorin, calycosin-7-O-ß-D-glucoside, ononin, calycosin and formononetin in rat plasma after oral administration of Buyang Huanwu decoction for their pharmacokinetic study by liquid chromatography-mass spectrometry.

The purpose of this study was to simultaneously investigate the pharmacokinetics of five bioactive compounds in rat plasma after oral administration of Buyang Huanwu decoction (BYHWD) using high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS). The separations were performed on a Thermo Hypersil Gold C(18) analytical column (50 × 2.1 mm, 3 µm) with the column temperature kept at 30°C. The quantitative analysis was performed using a quadrupole mass spectrometer detector operated under selected ion monitoring mode. A linear gradient elution of A (0.1% formic acid solution) and B (100% acetonitrile) was used at a flow rate of 0.2 mL/min. The method was validated within the concentration ranges 1.8-450, 6.0-1500, 2.0-500, 1.2-300 and 1.2-150 ng/mL for paeoniflorin, calycosin-7-O-ß-d-glucoside, ononin, calycosin and formononetin, respectively. The calibration curves were linear with correlation coefficients > 0.99. The lower limits of quantitations were < 6.0 ng/mL. The method was further applied to assess the pharmacokinetics of the five bioactive constituents of BYHWD in rat plasma.

Protective effects of chinese traditional medicine buyang huanwu decoction on myocardial injury.

Many clinical studies have reported that Buyang Huanwu Decoction (BYHWD) has a protective effect on ischemic heart disease (IHD). In the present study, the protective effect of BYHWD on myocardial ischemia was investigated. Different doses of BYHWD and Compound Danshen Dropping Pills (CDDP) were lavaged to rats, respectively, isoproterenol (ISO) was intraperitoneally injected in to all animals to induce myocardial ischemia except the control group. Electrocardiogram (ECG) of each animal was recorded; activities of lactate dehydrogenase (LDH), creatine kinase (CK) and aspartate aminotransferase (AST) in serum were detected. As the results of ECG showed, pre-treatment with BYHWD inhibited ischemic myocardial injury, and the activities of LDH, CK and AST were lower than those in the myocardial ischemia model group, which suggests that BYHWD rescues the myocardium from ischemia status. To research the potential mechanism, the level of nitric oxide (NO), nitric oxide syntheses (NOS) and inducible nitric oxide syntheses (iNOS), the expression of iNOS and ligand of cluster of differentiation 40 (CD40L) were detected. The results revealed that BYHWD significantly decreased the level of NO, NOS and iNOS in serum. Moreover, BYHWD decreased the expression of iNOS and CD40L in myocardial tissues. These results indicate that the protective effect of BYHWD on myocardial ischemia and mechanism are associated with inhibition of iNOS and CD40L expression.

Down-regulation of CD40 gene expression and inhibition of apoptosis with Danshensu in endothelial cells.

Danshen is commonly used in China for the treatment of atherosclerosis-related disorders such as cardiovascular and cerebrovascular diseases. Research shows that it also has immunostimulation properties. The present study evaluates the protective effect of danshensu, an active water-extractable component isolated from danshen, on an endothelial cell line (CRL-1730) treated with hydrogen peroxide (H(2)O(2)). Danshensu significantly inhibited endothelial cell viability induced by H(2)O(2). The treatment of endothelial cells with danshensu resulted in most cells being arrested in the S and G(2)/M phases of the cell cycle. The fraction of cells in G(0)/G(1) phase was markedly decreased by danshensu treatment compared to the control groups. The apoptosis was also markedly decreased after danshensu treatment. Additionally, danshensu restrains decreased nitric oxide level, increased the release of lactate dehydrogenase and expression of cluster of differentiation 40 (CD40) significantly. These results suggest that danshensu protects endothelial cells from the damage induced by H(2)O(2) through its CD40 anti-inflammatory approach and cell apoptosis inhibition.

Tanshinone IIA downregulates the CD40 expression and decreases MMP-2 activity on atherosclerosis induced by high fatty diet in rabbit.

Tanshinone IIA (Tan IIA) is a member of the major lipophilic components abstracted from the root of Salvia miltiorrhiza Bunge and has the capacity of anti-atherosclerosis. To investigate the potential mechanism, we established an animal model by giving high fatty diet to rabbits and Tan IIA was given in different dose. Then, superoxide dismutase (SOD) activity and the malondialdehyde (MDA) level in serum were detected using spectrophotometry; cluster of differentiation 40 (CD40) expression of cellular membrane fraction of aortas and matrix metalloproteinase-2 (MMP-2) activity of total protein extract of aortas were detected by Western Blotting and Zymography, respectively. Compared with the control group, the level of MDA, the expression of CD40 and the MMP-2 activity were increased while the SOD activity was decreased significantly in model group. After Tan IIA administration, the SOD activity was significantly increased while the level of MDA was decreased; both the expression of CD40 and the activity of MMP-2 were decreased. It is suggested that Tan IIA not only inhibits the oxidation but also suppresses the inflammation in atherosclerotic lesion. Our data suggest that not only anti-oxidation but also anti-inflammation by decrease the expression of CD40 and MMP-2 activity maybe the potential mechanisms by which Tan IIA anti-atherosclerosis.

[Study on the extraction of the total alkaloids from Caulopyhllum robustum].

OBJECTIVE: To study the technological parameters of the extraction process of the total alkaloids from Caulopyhllum robstum. METHODS: Taspine, whiVh is main component of the total alkaloids from Caulopyhllum robustum, was selected as an evaluating marker and determined by HPLC. The orthogonal test was used to optimize extracting conditions in the process of acid water extraction. Then the optimized conditions for purification using cation exchange resin were investigated. RESULTS: The optimized conditions in the process of acid water extraction were 1% hydrochloric acid as much as seven times of the medicine amount for 24hs and three times. Then the extraction of acid water was purified with a column of macroporous cation exchange resin LSD001 at 2 ml/min of flow rate, then eluted with 10BV of 4% aqueous ammonia ethanol. The extraction ratio of the total alkaloids was 1. 35% and the content of taspine of the total alkaloids was 6. 80%. CONCLUSION: This technology is simply, cheap effective and feasible for manufacture in great scale.

Adjunctive herbal medicine with carbamazepine for bipolar disorders: A double-blind, randomized, placebo-controlled study.

Chinese herbal medicines possess the therapeutic potential for mood disorders. This double-blind, randomized, placebo-controlled study was designed to evaluate the efficacy and side effects of the herbal medicine called Free and Easy Wanderer Plus (FEWP) as an adjunct to carbamazepine (CBZ) in patients with bipolar disorders. One hundred and twenty-four bipolar depressed and 111 manic patients were randomized to treatment with CBZ alone, CBZ plus FEWP, or equivalent placebo for 12 weeks. CBZ was initiated at 300mg/day and FEWP was given at a fixed dose of 36g/day. Efficacy measures included the Hamilton Rating Scale for Depression, Montgomery-Asberg Depression Rating Scale , Young Mania Rating Scale, Bech-Rafaelsen Mania Scale, and Clinical Global Impression-Severity (CGI-S). CBZ monotherapy produced significantly greater improvement on manic measures at week 2 through endpoint and CGI-S of depression at endpoint compared to placebo. CBZ monotherapy also yielded significantly higher clinical response rates than placebo on bipolar depression (63.8% vs. 34.8%, p=0.044) and mania (87.8% vs. 57.1%, p=0.012). Compared to CBZ monotherapy, adjunctive FEWP with CBZ resulted in significantly better outcomes on the three measures of depression at week 4 and week 8 and significantly greater clinical response rate in depressed subjects (84.8% vs. 63.8%, p=0.032), but failed to produce significantly greater improvement on manic measures and the response rate in manic subjects. There was a lesser incidence of dizziness and fatigue in the combination therapy compared to CBZ monotherapy. These results suggest that adjunctive FEWP has additive beneficial effects in bipolar patients, particularly for those in depressive phase.

Protective effect of tanshinone IIA on human umbilical vein endothelial cell injured by hydrogen peroxide and its mechanism.

Tanshinone IIA (Tan IIA) is isolated from Salvia miltiorrhiza, the root of which is widely used as a traditional Chinese medicine to treat atherosclerosis. The aim of the present study was to evaluate the putative protective effect of Tan IIA in a human umbilical vein endothelial cell line (ECV-304) injured by hydrogen peroxide in vitro and the mechanism of its protection. The percentage of cell viability was evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. The endothelial cell apoptosis and expression of cluster of differentiation 40 (CD40) were detected by flow cytometric analysis. Preincubation with Tan IIA significantly increased the viability of ECV-304 cell injured by hydrogen peroxide, which was accompanied with the increased nitric oxide level and superoxide dismutase activity in a dose-dependent manner. Moreover, cell apoptosis and CD40 expression were decreased in a dose-dependent manner. In conclusion, our data suggests that Tan IIA protects ECV-304 cell damage induced by hydrogen peroxide through its anti-oxidant effect and CD40 anti-inflammatory approach.

Screening, analysis and in vitro vasodilatation of effective components from Ligusticum Chuanxiong.

Effective components, ligustilide and butylidenephthalide, from Ligusticum Chuanxiong (Ligusticum wallichii Franchat, Umbelliferae) were screened and identified by using a cell membrane chromatography (CMC) and a gas chromatography/mass spectrometry (GC/MS). The components showed the effects of inhibiting vasoconstriction in vitro on rat abdominal aorta segments. The screening procedure was performed in a rat artery CMC column (50 mm x 2.0 mm I.D.) with a sodium phosphate buffer (pH 7.4) as mobile phase at 37 degrees C. The identification was accomplished by a DB-5MS 30 m capillary column (0.25 mm I.D., 0.25 microm film thickness) with helium as carrier gas operating under program control temperature and electron impact ionization mass spectrometer in a scan mode. Results demonstrated that ligustilide and butylidenephthalide can act on rat artery cell membrane similar to verapamil in CMC system. They significantly inhibited the vasoconstrictions induced by norepinephrine bitartrate (NE) and calcium chloride (CaCl2). The relaxing effect of ligustilide on the NE- and CaCl2-induced constrictions is more potent than that of butylidenephthalide. Ligustilide and butylidenephthalide seem to be the two main effective components of Ligusticum Chuanxiong as a traditional Chinese medicine for treating blood vessel diseases.

Chromatography studies on bio-affinity of nine ligands of alpha1-adrenoceptor to alpha1D subtypes overexpressed in cell membrane.

To improve selectivity and specificity of cell membrane chromatography (CMC), the chromatography affinities of nine ligands of alpha1-adrenergic receptor(AR)to alpha1D-AR subtype were investigated. The human embryonic kidney (HEK) 293 cells expressed by cDNA of alpha1D-AR subtypes were cultured and cell membrane stationary phase (CMSP) was prepared. Then the interactions between ligands and alpha1D-AR in CMSP were investigated using CMC. The affinity rank order to alpha1D-AR subtype obtained from CMC for the nine alpha1-adrenoceceptor ligands is: prazosin, BMY7378, phentolamine, oxymetazoline, 5-methylurapidil, norepinephrine, phenylephrine, methoxamine, RS-17053. The affinity rank order is similar and correlates well with that obtained from others' radioligand binding assays (RBA). CMSP prepared by transfected HEK293 cells with alpha1-D-adrenoceptor cDNA and CMC method could be used to evaluate affinities of -drug-receptor and drug-receptor subtypes and to screen drugs selective to alpha1D-AR.

The herbal medicine Dipsacus asper wall extract reduces the cognitive deficits and overexpression of beta-amyloid protein induced by aluminum exposure.

Excess aluminum (Al) exposure impairs neurocognitive function in humans and animals. Epidemiologic studies have shown a potential link between chronic Al exposure and Alzheimer's disease. In the present study, we sought to evaluate the protective effects of the herbal medicine Dipsacus asper extract against the cognitive impairment and overexpression of hippocampal beta-amyloid protein (Abeta) induced by chronic Al exposure in rats. Vitamin E (VE) was used as a positive control. Following exposure to 0.3% aluminum chloride (AlCl(3)) solution for 90 days in their drinking water, animals displayed a striking decrease (>80%) in step-through latency in the passive avoidance task and a significant increase (123%) in the number of Abeta immunoreactive cells in the hippocampus compared to controls. Al-exposed animals were then randomly assigned to receive vehicle, Dipsacus asper extract (4 g/kg), or VE (40 mg/kg) treatment up to 5 months. Both Dipsacus asper extract and VE significantly ameliorated animal's performance impairment in the passive avoidance task and suppressed the overexpression of hippocampal Abeta immunoreactivity. The effects of Dipsacus asper extract, but not VE, increased with time of treatment. The present results suggest that Dipsacus asper extract may possess therapeutic effects against Alzheimer's disease.