K. Winter

Acrylamide is a reactive neurotoxin with a high intestinal bioavailability. Recently we have shown that under the pH regime of the gut acrylamide can react with proteins and that this reaction reduces the uptake of acrylamide in a gut model. On the other hand, using radioactive labeled acrylamide, Bjellaas et al. [Toxicol. Sci. 100, 374-380 (2007)] showed that in vivo the vast majority of orally administered acrylamide is absorbed and excreted as N-acetyl-S-(3-amino-3-oxopropyl)-cysteine with the urine. Therefore, we tested whether intestinal proteases can degrade a protein with acrylamide bound to cysteine residues. Furthermore we tested whether the product of this reaction, S-(3-amino-3-oxopropyl)-cysteine, can pass the intestinal barrier. Here we showed that S-(3-amino-3-oxopropyl)-cysteine is indeed a product of proteolytic degradation of acrylamide-treated proteins. Using Caco-2 cells as a gut model, we further showed that the non-protein amino acid S-(3-amino-3-oxopropyl)-cysteine is a substrate for the neutral and cationic amino acid transporter system. Hence we concluded that protein-bound acrylamide can be released in the intestine and that the resulting product S-(3-amino-3-oxopropyl)-cysteine is transported through the intestinal barrier and later excreted via the urine.

The aim was to determine the chemical composition of the essential oil of Kadsura longipedunculata and the biological activity of the oil and its major components. The essential oil from stem bark of Kadsura longipedunculata was analysed by capillary gas chromatography (GLC/FID) and gas chromatography-mass spectrometry (GLC/MS). The ability of the oil to reduce diphenylpicrylhydrazine (DPPH(*)) was used to evaluate the antioxidant activity. Inhibition of both lipoxygenase and prostaglandin E(2) was used to assess the anti-inflammatory activity. Antimicrobial activity was studied in vitro against a range of bacteria and fungi using diffusion and microdilution methods. Inhibition of trypanosome proliferation was assessed using resazurin as vital stain. The in-vitro cytotoxicity of the essential oil on six human cancer cell lines (HepG2, MIA PaCa-2, HeLa, HL-60, MDA-MB-231 and SW-480) was examined using the MTT assay. Fifty compounds, representing 97.63% of total oil, were identified. delta-Cadinene (21.79%), camphene (7.27%), borneol (6.05%), cubenol (5.12%) and delta-cadinol (5.11%) were found to be the major components of the oil. The oil exerted a good antimicrobial activity against all Gram-positive bacteria tested, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecalis. Streptococcus pyogenes and S. agalactiae were the most sensitive bacteria with a minimal inhibitory concentration (MIC) of 60 microg/ml oil. The essential oil showed a moderate fungicidal activity against yeasts, but it did not show any activity against Gram-negative bacteria. The essential oil showed a good trypanocidal activity in Trypanosoma b. brucei with an IC50 value of 50.52 +/- 0.029 microg/ml. Radical scavenging activity had an IC50 value of 3.06 +/- 0.79 mg/ml. 5-Lipoxygenase inhibition (IC50 = 38.58 microg/ml) and prostaglandin E(2) production inhibition (28.82% at 25 microg/ml) accounted for anti-inflammatory activity of the oil. The oil exhibited some degree of cytotoxic activity against MIA PaCa-2, HepG-2 and SW-480 cell lines with IC50 values of 133.53, 136.96 and 136.62 microg/ml, respectively. The oil increased caspase 3/7 activity (an indicator of apoptosis) 2.5-4 fold in MIA Paca-2 cells. Camphene and borneol did not show antioxidant activity. However, both compounds exhibited some degree of antimicrobial, trypanocidal, anti-inflammatory and cytotoxic activity. This investigation provided evidence for, and confirmed the efficacy of, K. longipedunculata, a traditionally used Chinese medicinal plant for the treatment of inflammation and infection.

The objective of the present study was to evaluate in vitro antitrypanosomal and cytotoxic activities of crude extracts of 20 traditionally used medicinal plants of Tanzania. A total of 40 extracts (dichloromethane and methanol) were screened for antiproliferative activity of bloodstream form of T. b. brucei and human leukaemia HL-60 cell. Inhibition of cell proliferation was assessed using resazurin as vital stain. Of the 40 extracts tested, the dichloromethane extract from bark of Warburgia salutaris (Canellaceae) exhibited the most potent antitrypanosomal activity with an IC50 value of 10.68 μg/ml. A dichloromethane extract from Lannea stuhlmannii (Anacardiaceae) was found to be the most cytotoxic extract against HL-60 (IC50 = 27.15 μg/ml). Out of the 20 plants tested, 5 plants exhibited trypanocidal activity with IC50 values below 20 μg/ml. These 5 plants: Entandrophragma bussei (Meliaceae), Securidaca longepedunculata (Polygalaceae), Warburgia salutaris (Canellaceae), Zanha africana (Sapindaceae) and Zanthoxylum chalybeum (Rutaceae) could therefore serve as sources of lead compounds for treatment of trypanosomiasis. Copyright © 2009 John Wiley & Sons, Ltd.

Terpenoids represent the largest class of secondary metabolites and usually do not contain nitrogen or sulfur in their structures. Many terpenoids serve as defence compounds against microbes and herbivores and/or are signal molecules to attract pollinating insects, fruit-dispersing animals or predators which can destroy insect herbivores. As a consequence, many terpenoids have pronounced pharmacological activities and are therefore interesting for medicine and biotechnology. The first part of the biosynthesis is the generation of a C5 unit, such as isopentenyl diphosphate (IPP) or dimethylallyl diphosphate (DMAPP). Two independent pathways have been discovered that can produce the C5 unit: the mevalonate and the methylerythritol phosphate (MEP) pathway. Depending on the number of C5 units, we distinguish hemiterpenes C5, monoterpenes including iridoids (C10), sesquiterpenes (C15), diterpenes (C20), sesterterpenes (C25), triterpenes (including steroids) (C30), tetraterpenes (C40) and polyterpenes (>C40). The biosynthesis (including enzymes, genes and their regulation) of mevalonate and the methylerythritol phosphate pathway and the consecutive pathways leading to mono-, sesqui- and diterpenes are discussed in this chapter in detail.

Cancer cells often develop multidrug resistance (MDR) which is a multidimensional problem involving several mechanisms and targets. This study demonstrates that chelidonine and an alkaloid extract from Chelidonium majus, which contains protoberberine and benzo[c]phenanthridine alkaloids, has the ability to overcome MDR of different cancer cell lines through interaction with ABC-transporters, CYP3A4 and GST, by induction of apoptosis, and cytotoxic effects. Chelidonine and the alkaloid extract inhibited P-gp/MDR1 activity in a concentration-dependent manner in Caco-2 and CEM/ADR5000 and reversed their doxorubicin resistance. In addition, chelidonine and the alkaloid extract inhibited the activity of the drug modifying enzymes CYP3A4 and GST in a dose-dependent manner. The alkaloids induced apoptosis in MDR cells which was accompanied by an activation of caspase-3, -8,-6/9, and phosphatidyl serine (PS) exposure. cDNA arrays were applied to identify differentially expressed genes after treatment with chelidonine and the alkaloid extract. The expression analysis identified a common set of regulated genes related to apoptosis, cell cycle, and drug metabolism. Treatment of Caco-2 cells with 50 μg/ml alkaloid extract and 50 μM chelidonine for up to 48 h resulted in a significant decrease in mRNA levels of P-gp/MDR1, MRP1, BCRP, CYP3A4, GST, and hPXR and in a significant increase in caspase-3 and caspase-8 mRNA. Thus, chelidonine is a promising model compound for overcoming MDR and for enhancing cytotoxicity of chemotherapeutics, especially against leukaemia cells. Its efficacy needs to be confirmed in animal models.

Psidium guajava L. (Myrtaceae) has been used traditionally against gastrointestinal disturbances and respiratory ailments. The chemical composition of the essential oil of both leaves and fruits were elucidated by gas–liquid chromatography/mass spectrometry (GLC/MS). Forty-five and forty-two compounds, accounting for 93.7% and 89.7% of the fruit and leaf oil, were identified, respectively. The dominant compounds were β-caryophyllene (17.6%) and limonene (11.0%) for the fruit oil and β-caryophyllene (16.9%) and selin-7(11)-en-4α-ol (8.3%) for the leaf oil. The radical scavenging activities of both essential oils were assessed by the diphenyl picrylhydrazyl (DPPH•) and deoxyribose degradation assays. Guava leaf oil reduced DPPH• radicals and prevented the degradation of the deoxyribose with ic50 values of 3.59 and 12.64 μg/mL. The in vitro cytotoxicity of the oils in HepG2 and MCF-7 carcinoma cells was examined using the SRB assay (ic50 32.53 and 49.76 μg/mL for the leaves and fruit oils against HepG2 cells). Inhibition of 5-lipoxygenase (5-LOX) was used to evaluate the anti-inflammatory activity of both oils (ic50 130.69 and 196.45 μg/mL for the leaves and fruit oils). The anti-inflammatory activity was explained via virtual docking of the major identified compounds to the main sites in the 5-LOX crystal structure.

Objectives:
Eremophila (Scrophulariaceae) is an endemic Australian genus with 214 species, which is commonly known as Fuchsia bush, Emu bush or Poverty bush. Plants of this genus played an important role for the Australian Aborigines who used them widely for medicinal and ceremonial purposes. Many studies have been carried out on many species of this genus and have generated immense data about the chemical composition and corresponding biological activity of extracts and isolated secondary metabolites.
Key findings:
Thorough phytochemical investigations of different Eremophila species have resulted in the isolation of more than 200 secondary metabolites of different classes with diterpenes as major constituents. Biological studies and traditional clinical practice demonstrated that Eremophila and its bioactive compounds possess various pharmacological properties. Plants were employed especially as a cardiotonic drug and also as potent anti-inflammatory, antimicrobial and antiviral agents.
Summary:
Further investigations are required to explore other Eremophila species, to evaluate the different biological activities of either their extracts or the isolated compounds and the possible underlying modes of action."

"The volatile secondary metabolites of essential oils from fruit peel and leaves of variegated pink-fleshed lemon (Citrus x limon) were investigated using GLC and GLC-MS (gas-liquid chromatography-mass spectroscopy). Altogether 141 compounds were identified and quantified, accounting for 99.59% and 96.33% of the total hydrodistilled peel and leaf oil, respectively. Limonene occurred in higher amounts in fruit peel (52.73%) than in leaf oil (29.13%). Neral (12.72%), neryl acetate (8.53%), p-menth-1-en-7-al (4.63%), beta-pinene (6.35%), and nerol (4.42%) were the most abundant constituents in leaf oil, whereas gamma-terpinene (9.88%), beta-pinene (7.67%), geranial (4.44%), and neral (3.64%) dominated in the fruit peel oil. The antioxidant, anti-inflammatory, antitrypanosomal, and antimicrobial activities of the fruit peel essential oil were evaluated. The oil had a low antioxidant activity with an IC50 value of (26.66 ± 2.07) mg/ml as compared to the efficient antioxidant ascorbic acid [IC50 (16.32 ± 0.16) µg/ml]. The oil moderately inhibited soybean 5-lipoxygenase (5-LOX) with an IC50 value of (32.05 ± 3.91) µg/ml and had moderate antitrypanosomal activity [IC50 (60.90 ± 0.91) µg/ml]. In addition, moderate antimicrobial activities were detected against Gram-positive bacteria (Bacillus subtilis, Staphylococcus capitis, Micrococcus luteus), one Gram-negative bacterium (Pseudomonas fluorescens), and yeasts (Saccharomyces cerevisiae, Candida parapsilosis)."

Alzheimer's & Dementia: The Journal of the Alzheimer's Association, Volume 7, Issue 4, Pages S655-S656, July 2011, Authors:Dorothea Kaufmann; Mohamed Ashour; Ahmad Tahrani; Frank Sporer; Florian Herrmann; Michael Wink.

A detailed phytochemical study of the aerial parts of Bupleurum marginatum Wall. ex DC revealed a novel aryltetraline lactone lignan identified as 9-(benzo[d][1,3]dioxol-5-yl)-6,7,8-trimethoxy-3a,4,9,9a-tetrahydronaphtho[2,3-c]furan-1(3H)-one (marginatoxin) along with nine known compounds and characterization of five other compounds either by GLC/MS or LC/MS techniques. Chemical structures of the isolated compounds were unambiguously elucidated by both 1D, 2D NMR and mass spectrometry techniques.The in vitro cytotoxic activity of both methanol and dichloromethane extracts as well as the isolated compounds was assessed in two human cancer cell lines HepG2 and HeLa using the MTT assay. The new aryltetraline lactone lignan exhibited a potent cytotoxic activity with IC50 values of 12.14 and 16.90 μM after 24 h treatment for HepG2 and HeLa cells, respectively.The phytochemical study of the aerial parts of Bupleurum marginatum revealed a novel aryltetraline lactone lignan (9) along with 14 known compounds. Their structures have been determined by 1D- and 2D-NMR and MS analyses. The isolated lignans possessed cytotoxic activity against HepG2 and HeLa cells.► A detailed phytochemical study of the aerial parts extract led to isolation and characterization of 15 compounds. ► A new aryltetraline lactone lignan was identified as marginatoxin. ► The cytotoxic activity of the isolated compounds in both HepG2 and HeLa cancer cell lines are reported.

A selective analytical method based on high-performance liquid chromatography, combined with atmospheric pressure ionisation mass spectrometry, was developed for the detection of atractyloside. The analysis was performed on an Xterra Phenyl column utilising a gradient elution profile and a mobile phase consisting of 10 mM aqueous ammonium acetate buffer-methanol-acetonitrile. The calibration curve of the method (1 ng/ml-160 microg/ml) was best described by a second order polynomial function (r2 = 0.998) but displayed good linearity in the range of 100 ng/ml-1 microg/ml (r2 = 0.999). The limit of detection for the atractyloside standard was determined and found to be 100 pg/ml and the limit of quantification of atractyloside in tuber matrix was found to be 250 pg/ml. The relative standard deviation of the method was on average below 5% (n = 8). The method was successfully applied to the analysis of Callilepis laureola tubers and unknown powdered samples for the presence of atractyloside.

Summary.   A widely distributed host race of Tyria jacobaeae lives on Senecio jacobaea and related species and accumulates pyrrolizidine alkaloids (“PA race”), another race, which is restricted to the Alps and found on Petasites paradoxus, sequesters sesquiterpenes, such as petasol and isopetasol. Nucleotide sequences of the mitochondrial 16S rDNA gene show 1% sequence divergence, indicating that genetical differences exist between

Stonechats (genus Saxicola) are passerine birds with an extraordinarily large breeding distribution. Recent studies provide strong evidence that the taxon shows far greater geographic differentiation than originally suspected, with African, Siberian and European stonechats forming distinct, monophyletic groups that have been suggested to be species in their own right. Here, we present additional data on the geographic differentiation among African

A tremendous interest exists in the Western world in Traditional Chinese Medicine (TCM) with rapidly increasing
export rates of TCM products from China to Europe and USA. This led to a national decision of the Chinese government to
implement a “Plan for the Modernization of Chinese Medicine”. Concerning the use of Chinese medicinal herbs, two major
directions can be distinguished. One field is phytochemistry and pharmacognosy. Secondary metabolites isolated from Chinese
plants can be easily subjected to pharmacological, molecular biological, and pharmacogenomic analyses using methods of
modern cell and molecular biology as exemplified for camptothecin from Camptotheca acuminata in the present review. The
second field of interest is phytomedicine. Standardized international quality guidelines help to improve quality, safety and
efficacy of Chinese medicinal herbs. Sustainability of natural products from TCM can be reached by breeding high-yield
varieties or by biotechnological approaches. In the long term, natural products from TCM can contribute to the development of
molecular target-guided therapies and individualized treatment strategies.