Isolation of volatiles from Nigella sativa seeds using microwave-assisted extraction: effect of whole extracts on canine and murine CYP1A.

The volatile components of Nigella sativa seeds were isolated using microwave-assisted extraction (MAE) and identified using gas chromatography. Further investigations were carried out to demonstrate the effects of whole extracts on canine (dog) and murine (rat) cytochrome P450 1A (CYP1A). The optimal extraction conditions of MAE were as follows: 25 mL of water, medium level of microwave oven power and 10 min of extraction time. A total of 32 compounds were identified under the conditions using GC-FID and GC-MS. Thymoquinone (38.23%), p-cymene (28.61%), 4-isopropyl-9-methoxy-1-methyl-1-cyclohexene (5.74%), longifolene (5.33%), α-thujene (3.88) and carvacol (2.31%) were the main compounds emitted from N. sativa seeds. Various extracts including pure compounds, essential oil, nonpolar partition, relatively high-polar/nonpolar partition, and polar partition extracts effectively inhibited the reaction of ethoxyresorufin O-de-ethylation, which is specified for CYP1A activity both in dog and rat. This in vitro data should be heeded as a signal of possible in vivo interactions. The use of human liver preparations would considerably strengthen the practical impact of the data generated from this study.

Simple multiresidue extraction method for the determination of fungicides and plant growth regulator in bean sprouts using low temperature partitioning and tandem mass spectrometry.

A simple multiresidue analytical method is developed for the simultaneous determination of carbendazim (CB), thiabendazole (TB), and 6-benzyl aminopurine (6-BA) in bean sprouts. The samples were extracted with acetonitrile followed by partitioning at -80°C for 5-10 min. A YMC C(8) column was used to separate the analytes before being qualitatively and quantitatively determined by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) in positive ion mode using multiple reaction monitoring (MRM). The matrix-matched calibration curves showed good linearity in the range 0.01-1.0 mg/kg with correlation coefficients in excess of 0.998. The mean recoveries were in the range of 80.4-96.3% at 0.1 and 0.5 spiked levels, and the relative standard deviations (RSDs) were in the range of 0.5-7.6%. The limits of quantifications (LOQ) were in the range of 0.005-0.01 mg/kg. The method was successfully applied to 90 samples (among which 45 were organic) collected from a commercial bean sprout production house throughout the city. Except for 6-BA, the rest of the analytes had values lower than their LOQs. In sum, carbendazim, thiabendazole, and 6-BA were extracted in a single step, and no steps for clean-up or concentration of the extracts were needed. The current method can be used for sensitive and accurate determination and confirmation of residues in bean sprout samples.

Protective effects of garlic extract and vitamin C against in vivo cypermethrin-induced cytogenetic damage in rat bone-marrow.

The cytogenetic damage inflicted by the synthetic pyrethroid insecticide cypermethrin (CYP) on the bone-marrow of male white rats, as well as possible protective role of two natural elements: garlic extract (GRE, 500mg/kg) and vitamin C (VTC, 20mg/kg) against the mutagenic potential of the insecticide were assessed. CYP was orally intubated in a single treatment (1/2 LD(50)) or in repeated treatments (1/5 LD(50) daily, for 5 successive days), either alone, or concomitantly with repeated oral intubations (5 successive days) of each individual putative protector, or with their combination (GRE or/and VTC). One hundred and twenty male rats were divided over into five groups of each 24 animals. The groups received nothing, a single dose or repeated treatments with insecticide alone, or associated with putative natural elements, separately or in combinations. Animals were sacrificed at their scheduled times and their femoral bone-marrows were flushed out to be utilized in the micronucleus test and metaphase chromosomal aberration assay. The results show that CYP administration significantly induced clastogenic effects, as revealed by the significant increase in the mean frequencies of micronucleated polychromatic erythrocytes and various structural chromosomal aberrations in bone-marrow metaphase cells of all groups of treated rats. On the other hand, this investigation clearly revealed the protective role of GRE and VTC, either each alone or in combination, against the mutagenic potential of cypermethrin: the garlic extract was often more efficient in its protective action against the insecticide toxicity than vitamin C. while the combination of both natural elements produced, in most cases, a more pronounced protective effect than when each was administered alone.

Protective effects of garlic extract and vitamin C against in vivo cypermethrin-induced teratogenic effects in rat offspring.

Exposure of male (55.1 mg/kg b.wt. orally for 60 days) and/or pregnant female Wistar rats (55.1 mg/kg b.wt. orally at days 6-15 of gestation), to the insecticide cypermethrin (CYP); resulted in the development of a lot of external morphological deformities and visceral malformations in their offspring pubs, which signify the potential of such insecticide to induce reproductive toxicity and teratogenesis. Data cleared that CYP treatment induced significant increase in the percentages of post-implantation deaths, dwarf foeti and subcutaneous oedema beside significant decrease in percentages of live borne foeti and uterine implants. CYP also caused many visceral malformations among different treated groups including nasal, ophthalmic, cerebral, pulmonary, cardiac and renal malformations. Concomitant oral administration of garlic extract or vitamin C (5 days/week) to treated fathers and/or pregnant mothers with CYP provided significant reduction in the percentage of the foetal malformations induced by the insecticide, when compared with the control. The current study proves that garlic and ascorbic acid dampen the reproductive toxicity and/or teratogenicity of cypermethrin toxicity in rats; therefore might prove to be effective dietary supplements in developing countries where pesticide pollution is high.

Development of a multiresidue method for the determination of multiclass pesticides in soil using GC.

The principal objective of the present study was to develop a multiresidue analytical method for 62 pesticides in a soil matrix. Soil samples were fortified with known quantities of pesticides at two different concentration levels (0.1 and 0.01 microg/g) and the analytes were extracted via a liquid-solid extraction method. The pesticides were separated on an HP5 capillary column and were detected by gas chromatography coupled to an electron capture detector (GC-ECD). The method was validated, considering its good linearities (r(2) = 0.978-0.999), specificity and recovery characteristics. Recoveries were found between 70.3 and 113.4% for all pesticides except edifenphos (67.5%) and dichlobenil (69.5%) spiked at a 0.1 microg/mL concentration level and 74.5-117% except ethalfluralin (63.3%) and dichlobenil (51.9%) spiked at a concentration of 0.01 microg/mL. The developed method could be utilized as a simple and cost-effective method for the routine analysis of 62 pesticides in soil samples.