Tolerance and accumulation of lead by species of <Emphasis Type="Italic">Iris</Emphasis> L.

Seedling development, accumulation and distribution of lead (Pb) in Iris lactea var. chinensis (Fisch.) Koidz. and I. tectorum Maxim. were studied using plants grown in sand culture and exposed to 0–10 mmol l⁻¹ concentrations of Pb supplied as Pb(NO₃)₂ for 28 days. A significant reduction in dry weight (dw) of shoots and roots of I. lactea var. chinensis was observed at 6 and 10 mmol l⁻¹, respectively, and a significant reduction in dw of shoots and roots of I. tectorum was observed at 6 mmol l⁻¹. Concentration of Pb in the shoots and roots of I. lacteal var. chinensis exposed to 4 mmol l⁻¹ Pb reached 1,109 μg g⁻¹ and 2,408 μg g⁻¹ dw, respectively. The index of tolerance (IT) of I. lactea var. chinensis among 0–8 mmol l⁻¹ Pb treatments were not significantly different, while those of I. tectorum at 6 mmol l⁻¹ Pb were significantly decreased. The results indicated that I. lactea var. chinensis was more tolerant to Pb than I. tectorum. Sub-cellular localization of Pb in root cells was evaluated using transmission electron microscopy (TEM) and Pb deposits were found along the plasma membrane of some root tip cells of I. lactea var. chinensis treated at 10 mmol l⁻¹ Pb. Deposits of Pd were also observed along the surface, in the root tip cell wall and in the cytoplasm of a few malformed cells of I. tectorum exposed at 10 mmol l⁻¹ Pb treatment. One possible mechanism to explain these observations may be that most cells can maintain normal activities in the plant by sacrificing a small number of cells that accumulate a large amount Pb and show toxicity. Future studies should be designed to test this hypothesis.     

Evaluation of genotoxicity and effects on reproduction of nonylphenol in <Emphasis Type="Italic">Oreochromis niloticus</Emphasis> (Pisces: cichlidae)

Nonylphenol ethoxylate (NPE) is widely used as a component of detergents, paints, pesticides, and many other products. In the aquatic environment NPE breakdown to 4-nonylphenol (NP), which is more stable and persistent. NP is estrogenic in fish, avian, and mammals and is described as an environmental pollutant with endocrine disruptor characteristics. The genotoxicity of NP was evaluated through micronuclei assay and single cell gel electrophoresis (Comet assay) in peripheral erythrocytes of Oreochromis niloticus exposed in vivo. The study on reproductive development was also carried out in male and female gonads of O. niloticus. Lethal concentration (LC 50%) of 0.032 ml l⁻¹ was previously determined. We ran assays with O. niloticus exposed to concentrations of 1.0, 10.0, and 16.0 μl l⁻¹ of NP diluted in water. Our results showed that NP was not genotoxic. However, 3-day exposure to NP in concentrations of 1.0, 10.0, and 16.0 μl l⁻¹ of water increased the frequency of reproductive stages in males and females. The histology of the reproductive tract of the treated fish was significantly altered in females treated with 16.0 μl l⁻¹ of water when compared to controls. Analogous estrogenic effects were observed, such as accelerated maturation of oocytes and spermatogenesis. These results showed that the O. niloticus reproductive system is sensitive to NP estrogenicity.     

Cadmium tolerance and accumulation by two species of <Emphasis Type="Italic">Iris</Emphasis>

Seedlings of Iris lactea var. chinensis (Fisch.) Koidz. and I. tectorum Maxim. were subjected to 0–160 mg l⁻¹ Cd in hydroponic system and harvested after 42 days to determine effects on root and shoot dry mass. A subset of 16-day-old seedlings was exposed to 1000 mg l⁻¹ Cd to characterize sub-cellular localization of Cd in root cells. The Cd contents in the shoots of I. lactea var. chinensis reached 529 μg g⁻¹ dry weight (dw) at 80 mg l⁻¹ Cd treatment and in the shoots of I. tectorum reached 232 μg g⁻¹ dw at 40 mg l⁻¹ Cd treatment, without showing signs of visible toxicity. The Cd contents in the shoots of both two test species exceeded 100 μg g⁻¹, the critical value of Cd hyperaccumulator. The indices of tolerance (ITs) of I. lactea var. chinensis were higher than those of I. tectorum under 10–160 mg l⁻¹Cd stress. Sub-cellular localization of Cd in root cells was evaluated using transmission electron microscopy (TEM) and Cd deposits were found in the cell walls, in the cytoplasm and on the inner surface of xylem vessels in the root tip of I. lactea var. chinensis and I. tectorum. A few cells in the root tip of I. tectorum were necrotic. The results showed that the tolerance and accumulation of Cd by I. lactea var. chinensis were higher than those of I. tectorum, suggesting that I. lactea var. chinensis has potential application in phytoremediation.     

Dissolved organic carbon reduces uranium toxicity to the unicellular eukaryote <Emphasis Type="Italic">Euglena gracilis</Emphasis>

The influence of dissolved organic carbon (DOC), in the form of Suwannee River fulvic acid (SRFA), on uranium (U) toxicity to the unicellular eukaryote, Euglena gracilis (Z strain), was investigated at pH 6. In a background medium without SRFA, exposure of E. gracilis to 57 μg L⁻¹ U resulted in a 50% reduction in growth (IC₅₀). The addition of 20 mg L⁻¹ DOC (as SRFA), reduced U toxicity 4 to 5-fold (IC₅₀ increased to 254 μg L⁻¹ U). This reduction in toxicity was also evident at more sensitive effect levels with a 10% reduction in growth (IC₁₀) occurring at 5 μg L⁻¹ U in the background medium and at 17 μg L⁻¹ U in the SRFA medium, respectively. This amelioration of toxicity with the addition of SRFA was linked to a decrease in the bioavailability of U, with geochemical speciation modelling predicting 84% of U would be complexed by SRFA. The decrease in bioavailability of U in the presence of SRFA was also evident from the 11–14 fold reduction in the cellular concentration of U compared to that of E. gracilis in the background medium. Stepwise multiple linear regression analyses indicated that UO₂ ²⁺ alone explained 51% of the variation in measured U toxicity to E. gracilis. Preliminary U exposures to E. gracilis in the presence of a reactive oxygen species probe, suggest exposure to ≥60 μg L⁻¹ U may induce oxidative stress, but this endpoint was not considered to be a sensitive biological indicator.     

Suitability of <Emphasis Type="Italic">Daphnia similis</Emphasis> as an alternative organism in ecotoxicological tests: implications for metal toxicity

The acute toxicity of metals to Daphnia similis was determined and compared to other daphnid species to evaluate the suitability of this organism in ecotoxicology bioassays. To verify the performance D. similis in toxicity tests, we also investigated the effect of Pseudokirchneriella subcapitata at 1 × 10⁵ and 1 × 10⁶ cells ml⁻¹ on Cd and Cr acute toxicity to the cladoceran. Daphnid neonates were exposed to a range of chromium and cadmium concentrations in the absence and presence of the algal cells. Metal speciation calculations using MINEQL⁺ showed that total dissolved metal concentrations in zooplankton culture corresponded to 96.2% free Cd and 100% free Cr concentrations. Initial total dissolved metal concentrations were used for 48 h-LC₅₀ determination. LC₅₀ for D. similis was 5.15 × 10⁻⁷ mol l⁻¹ dissolved Cd without algal cells, whereas with 1 × 10⁵ cells ml⁻¹, it was significantly higher (7.15 × 10⁻⁷ mol l⁻¹ dissolved Cd). For Cr, the 48 h-LC₅₀ value of 9.17 × 10⁻⁷ mol l⁻¹ obtained for the cladoceran in tests with 1 × 10⁶ cells ml⁻¹ of P. subcapitata was also significantly higher than that obtained in tests without algal cells (5.28 × 10⁻⁷ mol l⁻¹ dissolved Cr). The presence of algal cells reduced the toxicity of metals to D. similis, as observed in other studies that investigated the effects of food on metal toxicity to standard cladocerans. Comparing our results to those of literature, we observed that D. similis is as sensitive to metals as other standardized Daphnia species and may serve as a potential test species in ecotoxicological evaluations.     

Effects of 4-nonylphenol,fish predation and food availability on survival and life history traits of <Emphasis Type="Italic">Daphnia magna</Emphasis> straus

This study aimed to investigate the compound effect of environmentally relevant 4-nonylphenol (NP) concentrations and natural stressors—namely fish predation and food availability—on Daphnia magna, which were exposed to four NP concentrations (0, 1, 5 and 10 μg l⁻¹) under optimum or low food concentrations (1.00 and 0.075 mg C l⁻¹, respectively) in water (un)conditioned by a fish predator (Alburnus alburnus). A(n) “environmentally relevant” and “no observable effect” concentration (NOEC) of NP (10 μg l⁻¹) resulted in a significant reduction (P < 0.01**) in daphnids’ survival when it was encountered concurrently with conditions of low food availability and presence of fish predation. The significance of the results lies in the observation that not only environmentally relevant concentrations of NP but also NP concentrations reported to have no observable effect on daphnids may in reality have unexpected critical effects on D. magna survival under conditions more parallel to natural ecosystems. The deterioration of the life-history traits—namely, NP-induced delay in the age at first reproduction (P < 0.001***) and fish kairomone-induced reduction in the size at first reproduction (P < 0.001***)—of the D. magna individuals is also crucial, as such alterations could significantly influence future generations and result in ultimate adverse effects at the community level because large-bodied daphnids are key-stone species in freshwater ecosystems. The results of this study demonstrate the importance of taking into account environmentally realistic conditions while investigating the effects of NOEC levels of toxicants on non-target aquatic species.     

Bioaccumulation and degradation of pesticide fluroxypyr are associated with toxic tolerance in green alga <Emphasis Type="Italic">Chlamydomonas reinhardtii</Emphasis>

The herbicide fluroxypyr is widely used for controlling weeds and insects but intensive use of fluroxypyr has resulted in its widespread contamination in soils and aquatic ecosystems. To evaluate the eco-toxicity of fluroxypyr to green algae, bioaccumulation and degradation of fluroxypyr in Chlamydomonas reinhardtii, a model unicellular alga, along with its biological adaptation to fluroxypyr toxicity were investigated. The microalgae were treated with fluroxypyr at 0.05–1.00 mg l⁻¹ for 2 days or 0.50 mg l⁻¹ for 1–5 days. The growth of C. reinhardtii was stimulated at low levels of fluroxypyr (0.05–0.5 mg l⁻¹) but inhibited at high concentrations (0.75–1.00 mg l⁻¹). Fluroxypyr was significantly accumulated by C. reinhardtii. Interestingly, the accumulated fluroxypyr could be rapidly degraded in the cells. On day 5 more than 57% of cellular fluroxypyr was degraded. Our results indicated that accumulation and degradation of fluroxypyr occurred simultaneously. Treatment with 0.05–1.00 mg l⁻¹ fluroxypyr for 30 min induced significant production of reactive oxygen species and as a consequence resulted in accumulation of peroxides and DNA degradation. Additionally, activities of several major antioxidant enzymes were activated in C. reinhardtii exposed to high levels of fluroxypyr. Overall, the present studies represent the initial comprehensive analyses of the green alga C. reinhardtii in adaptation to the fluroxypyr-contaminated aquatic ecosystems.     

Acute and chronic effects of sodium and potassium on the tropical freshwater cladoceran <Emphasis Type="Italic">Pseudosida ramosa</Emphasis>

In this study, the toxicities of sodium and potassium to the tropical freshwater cladoceran Pseudosida ramosa were assessed. Acute toxicity tests on this species showed that the 48-h LC₅₀ of Na⁺ was 556 mg l⁻¹, while that of K⁺ was 17.7 mg l⁻¹. Long-term exposure of female P. ramosa to sodium reduced the total number of survivors from 10 to 6 at a concentration of 249 mg l⁻¹, 21-day fecundity from 20.4 to 14.3 eggs female⁻¹ at concentrations ranging from 72 to 249 mg l⁻¹, 21-day fertility from 20.1 to 6.5 neonates female⁻¹ at concentrations ranging from 25 to 249 mg l⁻¹. Furthermore, fecundity of each brood from the second to the fifth was significantly lower at 249 mg l⁻¹ and fertility of each brood from the first to the fifth at concentrations ranging from 25 to 249 mg l⁻¹. A significant decrease in fertility was associated with an increase in the number of aborted eggs. Long-term exposure to potassium decreased the 21-day fecundity of P. ramosa from 14.2 to 10.8 eggs female⁻¹ at a concentration of 11 mg l⁻¹ and fertility (fourth brood only) at 6.2 and 11 mg l⁻¹. Tropical reservoirs located near areas where the soil is overloaded with fertilizers and ferti-irrigation with vinasse already show concentrations of Na⁺ and K⁺ very close to those producing sub-lethal long-term effects on P. ramosa. A possible consequence is that organisms of the aquatic biota cannot adapt and freshwater taxa may become locally extinct, transferring dominance to salt-tolerant taxa.     

The mysid <Emphasis Type="Italic">Siriella armata</Emphasis> as a model organism in marine ecotoxicology: comparative acute toxicity sensitivity with <Emphasis Type="Italic">Daphnia magna</Emphasis>

Siriella armata (Crustacea, Mysidacea) is a component of the coastal zooplankton that lives in swarms in the shallow waters of the European neritic zone, from the North Sea to the Mediterranean. Juveniles of this species were examined as standard test organisms for use in marine acute toxicity tests. The effects of reference toxicants, three trace metals (Copper, Cadmium and Zinc), and one surfactant, sodium dodecyl sulfate (SDS) were studied on S. armata neonates (<24 h) reared in the laboratory. Acute toxicity tests were carried out with filtered sea water on individual chambers (microplate wells for metals or glass vials for SDS) incubated in an isothermal room at 20°C, with 16 h light: 8 h dark photoperiod for 96 h. Each neonate was fed daily with 10–15 nauplii of Artemia salina. Acute (96 h) LC₅₀ values, in increasing order, were 46.9 μg/L for Cu, 99.3 μg/L for Cd, 466.7 μg/L for Zn and 8.5 mg/L for SDS. The LC₁₀, NOEC and LOEC values were also calculated. Results were compared with Daphnia magna, a freshwater cladoceran widely used as a standard ecotoxicological test organism. Acute (48 h) LC₅₀ values were 56.2 μg/L for Cu, 571.5 μg/L for Cd, 1.3 mg/L for Zn and 27.3 mg/L for SDS. For all the reference toxicants studied, the marine mysid Siriella armata showed higher sensitivity than the freshwater model organism Daphnia magna, validating the use of Siriella mysids as model organisms in marine acute toxicity tests.     

Physiological response of Cu and Cu mine tailing remediation of <Emphasis Type="Italic">Paulownia fortunei</Emphasis> (Seem) Hemsl

The physiological responses and Cu accumulation of Paulownia fortunei (Seem) Hemsl. were studied under 15.7–157 μmol L⁻¹ Cu treatments in liquid culture for 14 days; the impacts of Cu concentration in the seedlings were evaluated under Cu mine tailing culture with acetic acid and EDTA treatment for 60 days. Results showed that the concentrations of Chl-a, Chl-b and Carotenoids significantly increased (p < 0.05) at 15.7–78.7 μmol L⁻¹Cu treatment and significantly decreased at 157 μmol L⁻¹ treatment after 14 days of Cu exposure. The activities of superoxide dismutase (SOD) and catalase (CAT) significantly increased as Cu levels were enhanced and the activities of both SOD and CAT under 157 μmol L⁻¹ Cu stress were 2.9 and 1.9 times higher than that of control, respectively. The concentrations of proline and soluble sugars in the leaves of P. fortunei significantly increased as the Cu concentrations were elevated. Cu concentrations in roots, stems and leaves of P. fortunei increased significantly as Cu levels increased and reached 1911, 101 and 93 μg g⁻¹ dry weights (DW) at 157 μmol L⁻¹ Cu treatment, respectively. The seedlings of P. fortunei cultivated in Cu tailing experienced unsuccessful growth and loss of leaves in all treatments due to poor nutrition of the Cu tailing. The dry weight of P. fortunei increased under all the treatments of acetic acid after 60 days exposure. However, dry weight significantly decreased under both levels of EDTA. The Cu concentrations increased significantly in roots and decreased in leaves when each was treated with both concentrations of acetic acid. The Cu concentrations in the roots, stems and leaves increased significantly, and the concentrations of Cu in the stems and leaves under the treatment of 2 μmol L⁻¹ EDTA reached 189.5 and 763.1 μg g⁻¹ DW, respectively. The result indicated that SOD, CAT, proline and soluble sugars played an important role in coping with the oxidative stress of copper. Acetic acid could promote growth and EDTA at the experimental levels, which could also enhance Cu absorption and translocation into the stems and leaves of P. fortune. Furthermore, acetic acid and EDTA could be rationally utilized in Cu-contaminated soil.     

Growth and antioxidant response in <Emphasis Type="Italic">Hydrocharis dubis</Emphasis> (Bl.) Backer exposed to linear alkylbenzene sulfonate

A two-week exposure experiment was designed to investigate the toxicity of linear alkylbenzene sulfonate (LAS) on the aquatic plant Hydrocharis dubis (Bl.) Backer, focusing on growth, photosynthetic pigments and the activities of antioxidant enzymes. No significant differences were observed in the growth parameters of H. dubis when H. dubis was exposed to lower LAS doses (≤10 mg l⁻¹). However, lower LAS doses remarkably promote the dry weight accumulation of H. dubis. Higher doses of LAS (>10 mg l⁻¹) resulted in significant decreases in all growth parameters of H. dubis. No significant effect on pigment contents was observed at up to 50 mg l⁻¹ LAS, beyond which pigment contents declined gradually. Malondialdehyde (MDA) content did not show obvious differences when H. dubis plants were exposed to ≤50 mg l⁻¹ LAS. Peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) activities showed a concentration-dependent increase up to LAS concentrations of 0.1–10 mg l⁻¹, followed by a clear decrease. The results of this study suggest that LAS significantly inhibited the growth and physiology of H. dubis when the dose of LAS exceeded 10 mg l⁻¹ . Therefore, LAS at current environmental concentrations dose not appear to cause evident phytotoxic effects on H. dubis.     

Time-dependent oxidative stress and histopathological changes in <Emphasis Type="Italic">Cyprinus carpio</Emphasis> L. exposed to microcystin-LR

Microcystins (MCs) are produced by cyanobacteria in aquatic environments and are a potential risk to aquatic organisms. Increasing evidence suggests that oxidative stress may play an important role in the toxicity mechanism of MCs on fish, but most studies were based on relatively high concentrations. In this study, the effect of time-dependent oxidative stress in livers of Cyprinus carpio L. (C. carpio) exposed to 10 μg l⁻¹ of microcystin-LR (MC-LR) for 0–14 days was investigated. MC-LR induced histopathological changes in liver and gills were also assessed after 14 days exposure. Electron paramagnetic resonance (EPR) spectrum was used to directly investigate the reactive oxygen species (ROS) in fish liver and results showed that hydroxyl radical (^∙OH) was significantly induced at 0.5 day and then tended to decline with an increase of exposure period. As a response of antioxidant, catalase (CAT) activity increased slightly at first and then decreased with exposure period. A pronounced promotion of glutathione-S-transferase (GST) indicated that the conjugation reaction of MC-LR and GSH occurred. A time-dependent decrease of reduced glutathione (GSH) with an increase of oxidized glutathione (GSSG) level suggested GSH was involved in detoxification of MC-LR in the liver. Oxidative damage was evidenced by the significant increase of malondialdehyde (MDA) level at 2–6 days. After 14 days exposure, a series of pathological changes, like partially dissolved parenchymal architecture, vacuolar degeneration, necrosis, hemorrhage and slight inflammatory cells infiltration in fish liver tissues could be observed. Scanning electron microscopic (SEM) studies showed that dissolved MC-LR could also result in pathological changes like partial broken epithelial cells, deformed taste buds and loose gill filament and lamella in gill tissues. These results suggest that although a restoring response occurred, C. carpio could still be adversely affected by MC-LR at 10 μg l⁻¹.     

A new furostanol saponin from <Emphasis Type="Italic">Asparagus cochinchinensis</Emphasis>

A new furostanol saponin, (25S)-26-O-β-d-glucopyranosyl-5β-furost-20(22)-en-3β, 15β,26-triol-3-O-[α-l-rhamnopyranosyl-(1–4)]-β-d-glucopyranoside, namely, aspacochioside D (1) were isolated from Asparagus cochinchinensis (Lour.) Merr, along with three known saponins, aspacochioside C (2), (25S)-5β-spirostan-3β-yl-O-[O-α-l-rhamnopyranosyl-(1–4)]-β-d-glucopyranoside (3), and pseudoprotoneodioscin (4). The structure of 1 was elucidated on the basis of chemical reactions and spectral analysis (IR, GC, ESI-MS, ¹H-NMR, ¹³C-NMR, DEPT, HMBC, HMQC and NOESY). The antiproliferative effects of 1–4 were evaluated in a cytotoxicity assay against the human tumor cell line, A549. Compound 2 (Aspacochioside C) exhibited moderate cytotoxicity against A-549, with an IC₅₀ value of 3.87 μg/mL.     

Sub-lethal effects of acetone on <Emphasis Type="Italic">Daphnia magna</Emphasis>

There is increasing concern about the sub-lethal effect of hydrophobic chemicals in the water medium. Even though acetone is a commonly used solvent in toxicity testing, few studies have focussed on its chronic toxicity to Daphnia magna and the available results are often contradictory. In this study, acetone was tested on D. magna in a 21-day exposure experiment and the effects on mortality, fertility and morphology of exposed organisms (F₀) and offspring (F₁–F₂, reared without acetone) were evaluated. No significant reduction of survival was observed with increasing concentrations, and no significant reduction in fecundity in any treatment group in terms of average number of daphnids per mother was observed. Abnormal development of second antennae was observed on F₁ from F₀ exposed to 79 mg l⁻¹ solvent. The ET50 of acetone on the number of mothers that produced deformed offspring over time was 12.5 days. Our results suggest that the acetone concentration should not exceed 7.9 mg l⁻¹, which is 10 times less than the allowed concentration as determined by OECD chronic assays on D. magna. More attention should be paid to small, water-soluble molecules usually considered of low concern for chronic toxicity because they might affect other metabolic pathways.     

Interethnic differences of <Emphasis Type="Italic">PEPT2</Emphasis> (<Emphasis Type="Italic">SLC15A2</Emphasis>) polymorphism distribution and associations with cephalexin pharmacokinetics in healthy Asian subjects

Objectives  The aims of this study were to characterize the population frequency of PEPT2 (SLC15A2) polymorphic variants in three Asian ethnic populations, namely Chinese, Malay and Asian Indian, and to investigate the associations of ethnicity (Chinese vs. Asian Indian), PEPT2 haplotype and cephalexin pharmacokinetics in healthy Asian subjects. Methods   PEPT2 polymorphisms were screened from a cohort of 96 Chinese, 96 Malay and 96 Asian Indian subjects. Cephalexin (1000 mg, orally) pharmacokinetics was characterized in an additional 15 Chinese and 15 Asian Indian healthy subjects. These 30 subjects were subsequently genotyped for their PEPT2 polymorphisms. Results  In total, ten common single nucleotide polymorphisms (SNPs) were detected in the three populations, forming two PEPT2 haplotypes. There were significant ethnic differences in PEPT2 haplotype distribution: the frequencies of the *1 and *2 alleles were 0.307 and 0.693 in the Chinese population, 0.495 and 0.505 in the Malay population and 0.729 and 0.271 in Asian Indian population, respectively. The C _max of cephalexin was significantly lower in the Chinese (29.80 ± 4.09 μg ml⁻¹) population than in the Asian Indian one (33.29 ± 4.97 μg ml⁻¹; P = 0.045). This difference could be explained by the higher average body weight of the Chinese population. There was no other significant difference in cephalexin pharmacokinetics between either ethnic or PEPT2 genotype groups. Conclusion   PEPT2 polymorphism distributions differ significantly between Chinese, Malay and Asian Indian populations. However, cephalexin pharmacokinetics is not meaningfully different between Chinese and Asian Indians. The association between the PEPT2 haplotype and cephalexin pharmacokinetics could not be confirmed, and future studies under better controlled conditions are needed.     

<Emphasis Type="Italic">In vitro</Emphasis> Na<Superscript>+</Superscript>/K<Superscript>+</Superscript>-ATPase inhibitory activity and antimicrobial activity of sesquiterpenes isolated from <Emphasis Type="Italic">Thujopsis dolabrata</Emphasis>

A series of sesquiterpenes and hinokitiol-related compounds (1–15) was isolated from the essential oil of Thujopsis dolabrata Sieb. et Zucc. var. hondai Makino, and their structures were determined by combined spectroscopic analyses. The inhibitory effects of these compounds on microbial cell growth and Na⁺/K⁺-ATPase were evaluated in vitro. It was found that (−)-elema-1,3,11(13)-trien-12-ol (5), α,β,γ-costol (8), and chamigrenol (11) inhibit the activities of Na⁺/K⁺-ATPase, with IC₅₀ values of 11.2 ± 0.11, 12.2 ± 0.09, and 15.9 ± 0.54 μg/mL, respectively. Thujopsene (1), cedrol (9), γ-cuparenol (10), and chamigrenol (11) showed potent antibacterial activity, with MIC values in the range of 25–50 μg/mL, and β-thujaplicin (12) exhibited a broad spectrum of antibacterial and antifungal activity. These results indicate that these isolated compounds are promising candidates for the development of potent Na⁺/K⁺ ATPase inhibitors and antimicrobial agents.     

Inhibition of DNA topoisomerases I and II and cytotoxicity of compounds from <Emphasis Type="Italic">Ulmus davidiana</Emphasis> var. <Emphasis Type="Italic">japonica</Emphasis>

Twenty five compounds including ten triterpenes (1–3, 5–11), six flavonoids (12–15, 24, 25), five lignans (17, 18, 21–23), two butenyl clohexnone glycosides (19–20), one fructofuranoside (16) and one fatty acid (4) were isolated from the roots of Ulmus davidiana var. japonica. The structures of those compounds were identified by comparing their physicochemical and spectral data with those of published in literatures. All the compounds were evaluated for DNA topoisomerase inhibitory activities and cytotoxicities. Among the purified compounds, 4 and 19 showed more potent inhibitory acitivities (IC₅₀: 39 and 19 μM, respectively) than camptothecin, as the positive control (IC₅₀: 46 μM) against topoisomerase I. Compounds, 4, 10, 12, 19, 24 and 25 showed strong inhibitory activities toward DNA topoisomerase II (IC₅₀: 0.1, 0.52, 0.47, 0.42, 0.17 μM and 17 nM, respectively), which were more potent than that of etoposide as positive control (IC₅₀: 20 μM). In A549 cell line, 5 and 6 showed cytotoxicities (IC₅₀: 4 μM and 3 μM, respectively, with IC₅₀ of camptothecin as positive control: 10.3 μM). In the HepG2 cell line, 3, 5 and 7 showed cytotoxicity (IC₅₀: 4, 3 and 4 μM, respectively, with IC₅₀ of camptothecin: 0.3 μM). Compounds 6, 12 and 23 showed cytotoxicities in the HT-29 cell line (IC₅₀: 19, 19 and 15 μM, respectively, with IC₅₀ of camptothecin: 2 μM).     

Isolation and quantitative analysis of peroxynitrite scavengers from <Emphasis Type="Italic">Artemisia princeps</Emphasis> var. <Emphasis Type="Italic">orientalis</Emphasis>

Young and mature Artemisia princeps var. orientalis (APO, Compositae) are used as a health food and a medicinal plant, respectively, in Korea. Here, we identified the in vitro potent peroxynitrite (ONOO⁻)-scavenging effect (IC₅₀, 0.26 μg/mL) of the components from the EtOAc fraction. Octadecylsilane column chromatography on the EtOAc fraction yielded two caffeoylquinic acid compounds, 3,5-di-O-caffeoyl-muco-quinic acid (1) and methyl 4,5-di-O-caffeoylquinate (2) by NMR spectroscopic data, which have not been reported before from APO. The IC₅₀ values of compounds 1 and 2 were 0.18 ± 0.01 μg/mL and 0.12 ± 0.00 μg/mL, respectively, lower than that of the positive control (L-penicillamine). HPLC data indicated that young APO (1: 30.3 mg/g dried weight, 2: 27.7 mg/g) contained considerably higher quantities of the two caffeoylquinic acids than mature APO (1: 1.77 mg/g dried weight, 2: 4.10 mg/g).