Evaluation of the botanical authenticity and phytochemical profile of black cohosh products by high-performance liquid chromatography with selected ion monitoring liquid chromatography-mass spectrometry

Black cohosh (Actaea racemosa L., syn. Cimicifuga racemosa L.) has become increasingly popular as a dietary supplement in the United States for the treatment of symptoms related to menopause, but the botanical authenticity of most products containing black cohosh has not been evaluated, nor is manufacturing highly regulated in the United States. In this study, 11 black cohosh products were analyzed for triterpene glycosides, phenolic constituents, and formononetin by high-performance liquid chromatography-photodiode array detection and a new selected ion monitoring liquid chromatography-mass spectrometry method. Three of the 11 products were found to contain the marker compound cimifugin and not cimiracemoside C, thereby indicating that these plants contain Asian Actaea instead of black cohosh. One product contained both black cohosh and an Asian Actaea species. For the products containing only black cohosh, there was significant product-to-product variability in the amounts of the selected triterpene glycosides and phenolic constituents, and as expected, no formononetin was detected.     

Characterization of the triterpene saponins of the roots and rhizomes of blue cohosh (Caulophyllum thalictroides).

Seven triterpene saponins were isolated from n-butanol fractions of blue cohosh (Caulophyllum thalictroides) roots and rhizomes. Their structures were established by spectral ((1)H NMR, (13)C NMR, 2D-NMR, and APCI-MS) techniques and chemical reactions as hederagenin 3-O-alpha-L-arabinopyranoside (1); caulophyllogenin 3-O-alpha-L-arabinopyranoside (2); hederagenin 3-O-beta-D-glucopyranosyl-(1-->2)-alpha-L-arabinopyranoside (3); 3-O-alpha-L-arabinopyranosyl-hederagenin 28-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside (4); 3-O-alpha-L-arabinopyranosyl- caulophyllogenin 28-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside (5); 3-O-beta-D-glucopyranosyl-(1-->2)-alpha-L-arabinopyranosyl- echinocystic acid 28-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside (6); 3-O-beta-D-glucopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-hederagenin 28-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside (7). All seven compounds were identified in this species for the first time.     

Quantification of the polyphenols and triterpene acids in chinese hawthorn fruit by high-performance liquid chromatography

The levels of seven polyphenols (epicatechin, procyanidin B2, procyanidin B5, procyanidin C1, hyperoside, isoquercitrin, and chlorogenic acid) and two triterpene acids (oleanolic acid and ursolic acid) in the matured fruits of Chinese hawthorn (Crataegus pinnatifida Bge. var. major N.E.Br.) were determined by high-performance liquid chromatography methods. The average contents of those constituents in 37 representative cultivars were 1405, 1505, 339, 684, 56, 41, 234, 952, and 147 microg/g fresh weight (FW), respectively. A significant inverse correlation between the procyanidin contents and the latitude of the geographical origin of the cultivars was observed (r = 0.3851, P < 0.02). Correlation analysis of the levels of the nine compounds in the 37 cultivars yielded a strong correlation (P < 0.001) between the individual levels of the four procyanidins and the sum of the procyanidins level (r = 0.7413-0.9898) and between the flavonoids and the chlorogenic acid (r = 0.5383-0.9212). The changes in level of the nine compounds in the hawthorn fruit were evaluated during maturation using the Hebei Dajinxing cultivar. Sixty-one days after blossom, the polyphenol level reached the highest point and the sum of the contents was 1.36 g/100 g FW.     

Determination of triterpene glycosides in sea cucumber (Stichopus japonicus) and its related products by high-performance liquid chromatography

A creative and sensitive method has been developed for the determination of triterpene glycosides concentrations in sea cucumber ( Stichopus japonicus) and related products by using d-quinovose (6-deoxyglucose) as the measurement standard by reverse-phase high-performance liquid chromatography (HPLC) and variable-wavelength detection. d-quinovose, which is a unique monosaccharide in holostane triterpene glycosides, was liberated by acid hydrolysis and precolumn derivatized by 1-phenyl-3-methyl-5-pyrazolone (PMP). PMP-quinovose was analyzed by HPLC with 22% acetonitrile in 0.05 M KH2PO4 aquatic solution (pH 5.2) as mobile phase. The calibration curves of d-quinovose were linear within the range of 6.56-164 mg/L (r(2) > 0.995). The contents of triterpene glycosides in various S. japonicus products were determined after appropriate pretreatment methods. The concentration of triterpene glycosides was calculated by the formula C = C(qui) x alpha (alpha = 8.5). The result showed that this method was a simple, rapid, and stable method for the determination of triterpene glycosides in S. japonicus products.     

Nuclear magnetic resonance spectroscopic based studies of the metabolism of black tea polyphenols in humans

Epidemiological studies indicate that a high intake of flavonoids is associated with an improved health status. Tea is one of the most abundant sources of flavonoids in the human diet. The bioavailability and biotransformation of tea flavonoids are, however, not clearly understood. The aim of the present study was to investigate the metabolism of black tea via a nonspecific screening method. (1)H nuclear magnetic resonance (NMR) spectroscopy was used to obtain nonselective profiles of urine samples collected from three human volunteers before and after a single dose of black tea. The complex spectroscopic profiles were interpreted with the use of pattern recognition techniques. Hippuric acid was confirmed as the major urinary black tea metabolite. One previously unknown metabolite was detected and identified as 1,3-dihydroxyphenyl-2-O-sulfate (sulfate conjugate of pyrogallol) using HPLC directly coupled to mass spectrometry and (1)H NMR spectroscopy. This study shows that NMR-pattern recognition studies can be used for the discovery of unknown flavonoid metabolites in humans.     

Extraction of polyphenols from processed black currant (Ribes nigrum L.) residues

The total phenol and anthocyanin contents of black currant pomace and black currant press residue (BPR) extracts, extracted with formic acid in methanol or with methanol/water/acetic acid, were studied. Anthocyanins and other phenols were identified by means of reversed phase HPLC, and differences between the two plant materials were monitored. In all BPR extracts, phenol levels, determined by the Folin-Ciocalteu method, were 8-9 times higher than in the pomace extracts. Acid hydrolysis liberated a much higher concentration of phenols from the pomace than from the black currant press residue. HPLC analysis revealed that delphinidin-3-O-glucoside, delphinidin-3-O-rutinoside, cyanidin-3-O-glucoside, and cyanidin-3-O-rutinoside were the major anthocyanins and constituted the main phenol class ( approximately 90%) in both types of black currant tissues tested. However, anthocyanins were present in considerably lower amounts in the pomace than in the BPR. In accordance with the total phenol content, the antioxidant activity determined by scavenging of 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation, the ABTS(*)(+) assay, showed that BPR extracts prepared by solvent extraction exhibited significantly higher (7-10 times) radical scavenging activity than the pomace extracts, and BPR anthocyanins contributed significantly (74 and 77%) to the observed high radical scavenging capacity of the corresponding extracts.     

Effects of infusion time and addition of milk on content and absorption of polyphenols from black tea

Epidemiological studies assessing the health benefits of drinking black tea are equivocal. Such disparity may reflect an inability of semiquantitative assessment to consider how infusion time and addition of milk affect the bioavailability of potentially beneficial antioxidant polyphenols. Six brands of tea demonstrated similar increases in antioxidant capacity and total phenolic and catechin contents with increasing infusion time. These results were unaffected by the addition of milk. Consumption of black tea (400 mL) was associated with significant increases in plasma antioxidant capacity (10%) and concentrations of total phenols (20%), catechins (32%), and the flavonols quercetin (39%) and kaempferol (45%) (all p < 0.01) within 80 min. This was unaffected by adding milk. Infusion time may therefore be a more important determinant in the absorption of polyphenols from black tea. Observational studies assessing the health benefits of tea consumption require recording of brewing methods as well as frequency of consumption.     

Chain-breaking antioxidant activity and cyclic voltammetry characterization of polyphenols in a range of green,oolong, and black teas

A series of eight green, eight oolong, and 17 black teas have been analyzed for polyphenol content by absorbance at 272 nm and cyclic voltammetry response at an inert carbon electrode, a new method developed to provide a rapid measure of easily oxidizable polyphenols in beverages. The chain-breaking antioxidant activity of the teas has also been determined during the chain oxidation of methyl linoleate in a pH 7.4 micellar solution, for which realistic kinetic parameters have been derived. While higher mean values were obtained for green teas than for oolong and black teas, the differences were not large, and the spread of values within each type was considerable. The absorbance at 272 nm correlated well with the cyclic voltammetry response only for green teas and black teas taken on their own. The cyclic voltammetry measure and the antioxidant activity correlated well only for the green teas, where the polyphenol content is dominated by epigallocatechin gallate.     

The geochemistry of black water in selected coastal streams of the Southeastern United States

Abstract

An investigation was conducted in a watershed formed by the tributaries of the Little River in South Georgia to study the nature of the humic and inorganic fractions of black water, and their influence on stream water quality. Large amounts of black colored water were sampled during 1983 to 1984 according to streamflow pattern in December, March, June and September. Measurements of air and water temperature and dissolved oxygen were made at the gaging sites, whereas water analysis for conductivity, Cl, NO₃‐N, NH₄‐N, P, total N, and other macro‐ and microelements were conducted in the laboratory. Fulvic (FA) and humic acid (HA) were isolated from the water samples, and analyzed by infrared and ¹³C NMR spectroscopy. Suspended clay from the water samples were collected and determined by x‐ray diffraction analysis. The results showed that black water was characterized by low conductivity and low ion concentrations indicating satisfactory chemical quality. The Na content was half the amount of other rivers in the Southeastern United States, whereas the ? content was similar to the world average. A seasonal fluctuation was noticed for Ca and Mg concentration. The increase of these ions during high streamflow in spring and summer was attributed to agricultural practices in the surrounding lands. Dissolved organic matter (DOM) concentration was highest in December during low streamflow. As DOM content decreased during high streamflow, water pH increased. A large part of the humified DOM was composed of fulvic acid, which was more aromatic in nature than soil‐fulvic acid as determined by ¹³C NMR. The suspended clay had a composition reflecting the clay mineralogy of Tifton soils in the surrounding uplands. It is believed that the Tifton soil, with its low activity clay and hence low CEC, may not be able to buffer the effect of acid leaching of black water.     

Stability and antioxidant activity of black currant anthocyanins in solution and encapsulated in glucan gel

The effects of ferric and ferrous ions, pH, and temperature on the stability and antioxidant activity of black currant anthocyanins (BCA) were studied, and the recovery of BCA from glucan gel [mixed linked (1-->3,1-->4)-beta-D-glucan] after using different encapsulating procedures was determined. The degradation of individual anthocyanins follows first-order kinetics and shows Arrhenius temperature dependence. The activation energies of individual anthocyanins, evaluated over the temperature range 60-100 degrees C, decrease with an increase in pH. While the antioxidant activity of BCA, measured by the ferric reducing antioxidant power assay, decreased with the degradation of anthocyanins, the completely degraded products still exhibited approximately 30% of the initial antioxidant activity. Ferric ions have a detrimental effect on the stability of BCA, especially for delphinidins. Freeze drying of encapsulated BCA gives approximately 20% higher recovery of individual anthocyanins than infrared drying.     

Antioxidant activity of black currant anthocyanin aglycons and their glycosides measured by chemiluminescence in a neutral pH region and in human plasma

The antioxidant activity of nine anthocyanin glycosides was measured in a neutral pH region using a chemiluminescence (CL) emission system in the presence of an H(2)O(2)-acetaldehyde system, and the intensities were found to be affected by three factors, pH value and both moieties of the aglycon and C-3 sugar. With an increase in pH from 4.0 to 9.0, the CL intensities increased from pH 5.0, reached their maxima at pH 6.0-7.0, and decreased at pH 9.0. Comparison of the intensities among the 3-glucosides with five different aglycons and the 3-glycosides with three different sugar moieties at C-3 showed that their strongest intensities were given by the delphinidin aglycon and 3-rutinosyl moiety, respectively. Monitoring of the CL intensity of human blood plasma for 8 h after oral administration of black currant anthocyanins (BCA) showed a rapid increase until 2 h, and a significant difference (P < 0.05) was recognized at 1-8 h.     

洪湖湿地生态系统稳定性评价研究

运用生态学和系统学理论,建立洪湖湿地生态系统稳定性评价指标体系,利用层次分析法评价得出洪湖湿地生态系统目前为中度稳定状态。政策法令是影响洪湖湿地生态系统稳定性的最重要因素;其他因素依次为湿地水质、旱涝灾害系数、湿地景观格局和洪湖湿地调蓄能力等,而气候调节能力、人口密度和区域经济发展规模等因素对系统稳定性的影响则较小。     

Antioxidant polyphenols in almond and its coproducts

Antioxidant efficacy of defatted almond whole seed, brown skin, and green shell cover extracts was evaluated by monitoring inhibition of human low-density lipoprotein (LDL) oxidation, inhibition of DNA scission, and metal ion chelation activities. The total phenolic contents of ethanolic extracts of brown skin and green shell cover of almond were 10 and 9 times higher than that of the whole seed, respectively. Brown skin extract at 50 ppm effectively inhibited copper-induced oxidation of human LDL cholesterol compared to whole seed and green shell cover extracts, which reached the same level of efficacy at 200 ppm. Green shell cover extract at 50 ppm level completely arrested peroxyl radical-induced DNA scission, whereas 100 ppm of brown skin and whole seed extracts was required for similar efficiencies. All three almond extracts exhibited excellent metal ion chelation efficacies. High-performance liquid chromatographic (HPLC) analysis revealed the presence of quercetin, isorhamnetin, quercitrin, kaempferol 3-O-rutinoside, isorhamnetin 3-O-glucoside, and morin as the major flavonoids in all extracts.     

Spatial variability and evaluation of status of micronutrients in selected soils around Taihu Lake, China

Background, aim, and scope  Soil micronutrients are essential for plant growth and human health. Spatial variability and evaluation of soil micronutrient status are the research hotspot. The plain of northern Zhejiang Province, around Taihu Lake, China, is a key agriculture production area. With the rapid development of agriculture in Zhejiang Province, the management of soil micronutrients is of increasing concern to sustain crop productivity and human health. Soil-available micronutrients in the study region have not previously been studied in detail. Primary objective of this research was to examine the spatial distribution and evaluation of soil-available micronutrients in the arable land in this agriculturally important region using geostatistics. The controlling factors for the spatial variability of available micronutrients were interpreted. The research findings attained in the present study are of fundamental significance in providing a guideline for precise agriculture management practice and sustaining food security. Materials and methods  Amounts of available Fe, Mn, Cu, Zn, B and Mo in 1893 soil samples taken from the arable land in nine counties in northern Zhejiang Province, around Taihu Lake, were measured and their spatial distribution patterns were investigated. Available Mn, Fe, Cu, and Zn were extracted with DTPA and analyzed by inductively coupled plasma–atomic emission spectroscopy. Available B was extracted with boiled water, then determined by inductively coupled plasma–optical emission spectroscopy. Available Mo was extracted with Tamm reagent and was then determined by inductively coupled plasma-mass spectrometry. Geostatistics was conducted for the data processing. Results  More than 50% of the arable land were deficient in available Mo, while more than 70% had extremely low amount of available B. Amounts of available Cu, Zn and Mn were relatively high, whereas the soils are extremely sufficient in available Fe. The geostatisticical data shows that Mn, Cu, Zn, and Mo were best fit with an exponential model, while Fe and B were best fit with a spherical and linear model, respectively. Copper and Mo had strong spatial dependency, which is attributable to the effects of natural factors including parent material, topography, and soil type; Fe, Mn, and Zn had medium spatial dependency; however, B had weak spatial dependency, indicating an involvement of anthropogenic factors. Nevertheless, the six micronutrients studied all show spatial distribution trend to a certain extent. Discussion  Based on the provincial classification standard of soil micronutrients and the results of the present study, regionalized management of soil micronutrients was recommended. We divided the soil micronutrients investigated in the present study into three types: Type I (Fe), Type II (Mn, Cu, and Zn) and Type III (B and Mo). Type I is sufficient, and its amount needs to be controlled; otherwise, it will be toxic to crops. Type II is enough and its amount does not need to be increased currently through micronutrient fertilization. However, Type III is deficient in substantial areas in the region studied and its cause of deficiency needs to be investigated; its availability needs to be improved to sustain the crop production and food quality. The availability of B and Mo in the north of Zhejiang Province should be regionally managed. Over the past two decades, the spatial variability of soil-available micronutrients in the study region was attributable to the soil formation factors as well as anthropogenic activities such as fertilization, cultivation, and other soil management practices. The lower available B and Mo concentrations in the arable land were apparently due to continuous cropping and intensive applications of fertilizers without adequate supply of micronutrients. The high available Fe and Mn concentrations in the soils were attributed to increasing soil acidification and relatively high soil organic matter contents. The high available Cu and Zn levels of the soils in this region were attributed to intensive utilization of animal manure as fertilizers. Conclusions  Based on the provincial classification standard and the results from the present study, regionalized management of soil micronutrients was recommended. Moreover, the present study would provide an insight into understanding the basis for the development of innovative strategies for land management practices such as precision farming and environmental risk assessment. Recommendations and perspectives  The research findings attained in the present study would help to improve our understanding of spatially variable availability of soil micronutrients and providing a quantitative basis for decision and policy making to develop innovative agricultural management strategies to sustain micronutrient nutrition. Further research should be conducted to elucidate the relationship between soil micronutrient and plant growth and human health.     

黑土区土壤侵蚀厚度对土地生产力的影响及其评价

为了研究黑土区土壤侵蚀厚度对土地生产力的影响,采用盆栽试验,人为剥离黑土表层0、5、10、15、20、25和30 cm土壤以模拟侵蚀厚度不同的耕层土壤,分析土壤侵蚀厚度对土壤理化性质、大豆生物性状和水分利用效率等指标的影响。并对TOPSIS(technique for order preference by similarity to ideal solution)模型进行改进,用于评价侵蚀厚度不同的土壤的土地生产力。结果表明:土壤全N、碱解N、全P、速效P、有机质含量和土壤田间持水率均随侵蚀厚度的增加而递减,土壤容重随侵蚀厚度的增加而递增。土壤侵蚀厚度对大豆生长有显著影响,随着侵蚀厚度的增加,大豆减产率呈"S型"曲线递增,产量、耗水量呈"Z型"曲线递减,水分利用效率呈指数曲线关系递减。改进的TOPSIS模型对不同侵蚀厚度下土地生产力的评价结果较为理想,计算的土地生产力指数随土壤侵蚀厚度的变化呈"Z型"曲线,与大豆产量的变化趋势相同,且二者呈指数函数关系,决定系数达0.996,均方根误差为0.65。研究结果可为黑土区土壤侵蚀防治提供理论依据。     

Landscape evaluation of female black bear habitat effectiveness and capability in the North Cascades, Washington

We used logistic regression to derive scaled resource selection functions (RSFs) for female black bears at two study areas in the North Cascades Mountains. We tested the hypothesis that the influence of roads would result in potential habitat effectiveness (RSFs without the influence of roads) being greater than realized habitat effectiveness (RSFs with roads). Roads consistently had a negative influence on black bear RSFs across seasons and study areas. Roads reduced habitat effectiveness during all seasons at both study areas and changes in the potential habitat values ranged from 1.7% to 16.9%. The greatest reduction in habitat values occurred during the early-season on the west-side study area due to high open road densities. These results support the hypothesis that roads reduce habitat effectiveness for black bears. The influence of roads could be reduced through road closures to reduce open road densities and limit traffic volumes. We then used the scaled RSFs in a habitat-based population model to assess the influences of timber harvest and roads on potential black bear population sizes. On the west-side study area the potential black bear population size was most influenced by moderate use roads and timber harvest during the early-season (41% reduction). On the east-side study area, low use roads had the greatest effect on potential black bear population during the early-season (10% reduction). During the late-season, in both study areas, roads had less influence on the potential population sizes as bears were able to access habitats away from roads. The habitat-population model provided reasonable estimates of bear densities compared to other study areas with similar habitats and could be extrapolated to estimate potential black bear populations in other areas with similar habitats. This approach may provide a useful link between the landscape ecology and population biology of black bears, and could eventually be useful in the development of habitat-based population viability analyses.     

葡萄器官酚类物质的含量研究

葡萄植株总酚含量的积累在其年生长期间呈双S型曲线.浆果膨大期开始积累,浆果着色期含量下降,浆果成熟期含量再次升高,随后急速下降.新梢中的总酚含量最高,卷须中的极低.不同品种叶片内总酚含量存在显著或极显著的差异.     

Quantitation of polyphenols in different apple varieties

Forty-one apple samples, representing eight of the most widely cultivated varieties in western Europe, were collected in Trentino, Italy. Samples were extracted from fresh fruit with a mixture of acetone/water to achieve a good extraction of polyphenols, including proanthocyanidin oligomers which were analyzed by normal-phase HPLC. Up to 20 compounds including catechin, epicatechin, B2 procyanidin, hydroxycinnamates, flavonols, anthocyanins, and dihydrochalcones were analyzed by reversed-phase HPLC and LC-MS. Total polyphenol content was independently measured with an optimized Folin-Ciocalteu assay. The mean content of total polyphenols lay between 66.2 and 211.9 mg/100 g of FW depending on the variety. With chromatographic analysis, it was possible to explain the whole amount of total polyphenols measured by the FC assay. Flavanols (catechin and proanthocyanidins) are the major class of apple polyphenols (71-90%), followed by hydroxycinnamates (4-18%), flavonols (1-11%), dihydrochalcones (2-6%), and in red apples anthocyanins (1-3%).     

Quantitative determination of hydroxy pentacyclic triterpene acids in vegetable oils

A simple and precise analytical method for the determination of hydroxy pentacyclic triterpene acids (HPTAs) in vegetable oils was developed. The acidic fraction was isolated by solid-phase extraction using bonded aminopropyl cartridges, and the extract was silylated and analyzed by gas chromatography. Repeatability and recovery of the method were determined. In virgin olive oils, similar amounts of oleanolic (3beta-hydroxyolean-12-en-28-oic) and maslinic (2alpha,3beta-dihydroxyolean-12-ene-28oic) acids and traces of ursolic (3beta-hydroxyurs-12-en-28-oic) acid were found. The main factor affecting HPTA concentration was the oil quality since that increases as the quality decreases, while olive variety, olive ripeness, and oil extraction system had less influence. In crude olive pomace oils, the concentrations were very much higher than in virgin olive oils. During refining processes, total or significant losses of HPTAs were observed. Esterified derivatives of HPTAs were not found.     

Black cohosh acts as a mixed competitive ligand and partial agonist of the serotonin receptor

Extracts of the rhizome of black cohosh [Actaea racemosa L., formerly called Cimicifuga racemosa (L.) Nutt.] were evaluated for potential mechanisms of action in the alleviation of menopausal hot flashes. Ovariectomized Sprague-Dawley rats were administered a 40% 2-propanol extract of black cohosh [4, 40, and 400 mg/(kg.day)] by gavage for 2 weeks with or without estradiol [50 microg/(kg.day)] to determine if black cohosh could act as an estrogen or antiestrogen on the basis of an increase in uterine weight or vaginal cellular cornification. No effects were observed on uterine weight or on vaginal cellular cornification in rats treated with black cohosh alone or in combination with 17beta-estradiol, indicating this black cohosh extract had no estrogenic or antiestrogenic properties in the ovariectomized rat model. To evaluate other potential pathways by which black cohosh might reduce menopausal hot flashes, serotonin activity was first assessed by the inhibition of radioligand binding to cell membrane preparations containing recombinant human serotonin receptor (5-HT) subtypes. A 40% 2-propanol extract of black cohosh was tested against 10 subtypes of the serotonin receptor, revealing the presence of compounds with strong binding to the 5-HT(1A), 5-HT(1D), and 5-HT(7) subtypes. Subsequent binding studies were carried out using 5-HT(1A) and 5-HT(7) receptors because of their association with the hypothalamus, which has been implicated in the generation of hot flashes. The black cohosh 40% 2-propanol extract inhibited [(3)H]lysergic acid diethylamide (LSD) binding to the human 5-HT(7) receptor (IC(50) = 2.4 +/- 0.4 microg/mL) with greater potency than binding of [(3)H]-8-hydroxy-2-(di-N-propylamino)tetralin to the rat 5-HT(1A) receptor (IC(50) = 13.9 +/- 0.6 microg/mL). Analysis of ligand binding data indicated that components of a black cohosh methanol extract functioned as a mixed competitive ligand of the 5-HT(7) receptor. In addition, a black cohosh methanol extract elevated cAMP levels in 293T-5-HT(7)-transfected HEK cells, suggesting the extract acted as a partial agonist at the receptor. The elevation in cAMP mediated by the black cohosh extract could be reversed in the presence of the antagonist methiothepin, indicating a receptor-mediated process. These data suggest that reductions in hot flashes in some women taking black cohosh may not be due to estrogenic properties. This study identifies other possible biological targets of black cohosh that could account for reported biological effects.