The uremic toxin indoxyl sulfate acts as a pro- or antioxidant on LDL oxidation.

Uremic toxins have been shown to play a role in chronic kidney disease (CKD) associated oxidative stress. Oxidative stress and inflammation have been associated with increased risk of cardiovascular disease in uraemia. The oxidative modification of LDL may play a role in early atherogenesis. Enhanced LDL oxidation has been found in uremic patients which may account for accelerated atherosclerosis observed in CKD. The uremic toxin indoxyl sulfate (IS) has been reported to exert oxidative and antioxidative activity. Thus, in the present study we have investigated the influence of IS on the atherogenic modifications of LDL exposed in vitro to different oxidising systems. The transition metal ion (Cu(2+)) and hemin/H2O2 induced lipid oxidation reactions monitored by conjugated diene formation, were inhibited by the presence of IS, which points to possible antioxidant effects by this uremic toxin. A protective effect of IS on LDL apoprotein modification by the exposure to the product of the myeloperoxidase/H2O2/Cl(-) system HOCl, was also observed as estimated by protein carbonyl formation. In contrast, a marked increase in conjugated dienes and lipid hydroperoxides was observed when lipid oxidation was initiated by the free radical generator AAPH in presence of IS. The GC-MS analysis revealed the formation of indole-2,3-dione and 6,12-dihydro-6,12-dioxo-indolo[2,1-b]quinazoline (tryptanthrin) in IS/AAPH reaction. A scheme for the generation of tryptanthrin from IS via indoxyl radicals is proposed, which may facilitate LDL lipid oxidation. Our observations add further insight in the Janus-faced properties of this important uremic toxin.

A new alkylated benzoquinone from rhizomes of Iris kumaonensis.

A novel alkylated unsaturated p-benzoquinone designated as 3-[(z)-12'-heptadecenyl]-2-hydroxy-5-methoxy-1,4-benzoquinone was isolated from hexane extract of the rhizomes of Iris kumaonensis and it's structure was confirmed by extensive spectroscopic analysis, IR, MS, HREIMS, 1D, 2D NMR and comparison with the literature data of known compounds.

Antimicrobial study of essential oils of Ocimum gratissimum leaves and Zanthoxylum xanthoxyloides fruits from Cameroon.

An investigation of antimicrobial activities of essential oils of fresh leaves of Ocimum gratissimum and the essential oil of the dried fruits of Zanthoxylum xanthoxyloides was carried out. The essential oils showed extensive inhibition zones and are, therefore, effective antimicrobial systems.

Protection of stored maize against Sitophilus zeamais (Motsch.) by use of essential oils of spices from Cameroon.

In storage, maize as other cereals is currently attacked by insects. The main specie present in Cameroon is Sitophilus zeamais (Coleop. Curculionidae). The popular way to prevent its damages is the use of synthetic insecticides. These chemicals extend their activities to non target animals. They are potentially dangerous for consumers and are implicated in the pollution of the environment. The development of products killing pests which are consumer-friendly is to be improved. In this respect, the use of essential oils from spices and aromatic plants could help. Six essential oils were tested, 3 are causes of high insect mortality. Xylopia aethiopica Dunal (Anonaceae) killed 97% of adults weevils and Ocimum gratissimum, (L.) (Lamiaceae) 74% after 4 days after ingestion. Piper nigrum (L.) (Piperaceae) killing more than 96% of weevil 48 hours after the contact. The potential of these non toxic products to protect stored maize against attacks of S. zeamais is hereby appraised.

Analysis of leaf volatiles of Zanthoxylum gillettii used in folk medicine of Cameroon.

The essential oil and the corresponding headspace sample of the leaves of ZONTHIOXYLUM GILLETTII (Rutaceae) were analyzed by gas chromatographic-spectroscopic and olfactoric methods. Mainly monoterpenes such as myrcene, TRANS-beta-ocimene, limonene, camphene, alpha- and beta-pinene which are impact compounds were found in the essential oil and headspace sample. Sesquiterpenes such as beta-caryophyllene, alpha- and beta-farnesene, beta-bisabolol, gamma-cadinene and nerolidol and alphatic components such as 2-undecanone and dodecanal were also identified and contribute to the typical odor impression as well as to the reported therapeutic properties of this ZONTHOXYLUM species.

Fragrance compounds and essential oils with sedative effects upon inhalation.

Fragrance compounds and essential oils with sedative effects influence the motility of mice in inhalation studies under standardized conditions. A significant drop in the motility of mice was registered following exposure to these fragrances. The same results were achieved when the mice were artificially induced into overagitation by intraperitoneal application of caffeine and subsequently subjected to inhalation of fragrance compounds and essential oils. These results proved the sedative effects of these fragrants via inhalative exposure in low concentrations. Blood samples were taken from the mice after a 1-h inhalation period. Chromatographic and spectroscopic methods were used to detect and characterize the actual effective compounds after solid-phase extraction. Serum concentrations of 42 different substances, including fragrance compounds, were found in low ranges (ng/mL serum). The results contribute to the correct interpretation of the term aromatherapy (i.e., a stimulating or sedative effect on the behaviour of individuals only upon inhalation of fragrance compounds).

[Effects of valerian root oil, borneol, isoborneol, bornyl acetate and isobornyl acetate on the motility of laboratory animals (mice) after inhalation]. / Wirkungen von Baldrianöl, Borneol, Isoborneol, Bornylacetat und Isobornylacetat auf die Motilität von Versuchstieren (Mäusen) nach Inhalation.

The aromatherapeutical use of commercial valerian root oil (Chinese origin) and of pure fragrance compounds--borneol, isoborneol, bornyl acetate (main constituent of the proved valerian root oil) and isobornyl acetate--as potentially drugs with sedative effects after inhalation was investigated in an animal experiment (mice). In additional analyses the mice were treated i.p. by caffeine and distinct sedative effects were observed only by inhalation of the cited substances.

Analysis of fragrance compounds in blood samples of mice by gas chromatography, mass spectrometry, GC/FTIR and GC/AES after inhalation of sandalwood oil.

After inhalation experiments with sandalwood oil and the pure fragrance compounds coumarin and alpha-terpineol, substances were detected and measured in the blood samples of test animals (mice) using gas chromatography/mass spectrometry (GC/MS) (MID) in connection with GC/FTIR (SWC), GC/AES (carbon and oxygen trace) and flame ionization detection/gas chromatography. Using tiglinic acid benzyl ester as the internal standard the following concentrations in serum could be found: alpha-santalol 6.1 ng/mL, beta-santalol 5.3 ng/mL and alpha-santalene 0.5 ng/mL. In separate inhalation experiments with coumarin and with alpha-terpineol the corresponding concentrations were 7.7 ng/mL and 6.9 ng/mL, respectively.

Investigations of animal blood samples after fragrance drug inhalation by gas chromatography/mass spectrometry with chemical ionization and selected ion monitoring.

The fragrance compounds linalool (1) and linalyl acetate (2) could be detected, identified and quantified (1: 7-9 ng ml-1; and 2: 1-2 ng ml-1 and 4-5 ng ml-1 as free linalool) in blood samples after inhalation in animal experiments (mice) by gas chromatography/mass spectrometry (GC/MS) with chemical ionization (CI) (ammonia); selected ion monitoring (SIM) mode (1: m/z 81, 137 and 154; 2: 47, 57 and 137) and GC/flame ionization detection (FID). The inhalation of these monoterpenes in concentrations of 5 mg l-1 air leads to a significant reduction of the motility of the test animals down to 30-40% with respect to the control group.

Aromatherapy: evidence for sedative effects of the essential oil of lavender after inhalation.

The sedative properties of the essential oil of Lavender (Lavandula angustifolia Miller) and of its main constituents--linalool and linalyl acetate--were investigated in mice followed up in a series of experimental procedures. The significant decrease in the motility of female and male laboratory animals under standardized experimental conditions is found to be closely dependent on the exposure time to the drugs. Nevertheless after an injection of caffeine into mice a hyperactivity was observed which was reduced to nearly a normal motility only by inhalation of these fragrance drugs. In particular the correlation of the motility of the animals to linalool in serum is experimentally proven, thus furnishing evidence of the aromatherapeutical use of herbal pillows employed in folk medicine since ancient times in order to facilitate falling asleep or to minimize stressful situations of man.