Effect of parsley (Petroselinum crispum, Apiaceae) juice against cadmium neurotoxicity in albino mice (Mus musculus).

BACKGROUND: Parsley was employed as an experimental probe to prevent the behavioral, biochemical and morphological changes in the brain tissue of the albino mice following chronic cadmium (Cd) administration. METHODS: Non-anesthetized adult male mice were given parsley juice (Petroselinum crispum, Apiaceae) daily by gastric intubation at doses of 10 and 20 g/kg/day. The animals were divided into six groups: Group A, mice were exposed to saline; Groups B and C, were given low and high doses of parsley juice, respectively; Group D, mice were exposed to Cd; Groups E and F, were exposed to Cd and concomitantly given low and high doses of parsley, respectively. RESULTS: Cd intoxication can cause behavioral abnormalities, biochemical and histopathological disturbances in treated mice. Parsley juice has significantly improved the Cd-associated behavioral changes, reduced the elevation of lipid peroxidation and normalized the Cd effect on reduced glutathione and peroxidase activities in the brain of treated mice. Histological data have supported these foundations whereas Cd treatment has induced neuronal degeneration, chromatolysis and pyknosis in the cerebrum, cerebellum and medulla oblongata. CONCLUSION: The low dose (5 g/kg/day) of parsley exhibited beneficial effects in reducing the deleterious changes associated with Cd treatment on the behavior, neurotransmitters level, oxidative stress and brain neurons of the Cd-treated mice.

Partial physicochemical properties and relative stability of polyhydroxylated dibenzofurans: theoretical and experimental study.

Polyhydroxylated dibenzofuran (PHODF) is an important degradation product of polychlorinated dibenzofuran (PCDF). Four types of hydrogen bonds (the one between a hydroxyl and the oxygen atom in the matrix, between hydroxyls at ortho positions, between the oxygen atom of hydroxyl at position 1 and the hydrogen atom of the matrix at position 9, and between hydroxyls at positions 1 and 9) exist in PHODFs. The energies of the hydrogen bonds were ascertained by comparing the two configurational isomers as approximately 8-11 kJ mol⁻¹, 16-21 kJ mol⁻¹, 5-8 kJ mol⁻¹ and 23-25 kJ mol⁻¹, respectively. An experiment was designed to verify the bond energies, and the entrance geometry on main paths was studied by AIM 2000 program. The most stable in each group of configurational isomers was ascertained on the basis of evaluating the effect of hydrogen bonds. Their thermodynamic properties (standard state entropy S°, standard enthalpy Δ(f)H° and standard Gibbs energy of formation Δ(f)G°) were calculated from the combination of density functional theory (DFT) at B3LYP/6-311G** level and isodesmic reactions. Octanol/water partition coefficients (log K(ow)) were calculated on line with molinspiration methodology based on group contributions. The number and position of hydroxyl substitution (N(PHOS)) can be a good indicator of these properties for all stable PHODF congeners. The configurations most likely to form are those with a hydrogen bond (Type IV). How intramolecular hydrogen bond influences ionization was also investigated and the first-order ionization constant for each stable conformation was obtained with the self-consistent reaction field (SCRF) method.

Toxicity assessment on three direct dyes (D-BLL, D-GLN, D-3RNL) using oxidative stress bioassay and quantum parameter calculation.

Textile dyes and dye industrial effluents are widely known for esthetic and toxicity problems. The toxicity of three direct dyes, Direct Blending Rebine (D-BLL), Direct Blending Scarlet (D-GLN), and Direct Blending Yellow (D-3RNL), were examined by the antioxidase and lipid peroxide index. Fish (Carassius auratus) were exposed to 100mg/L test compounds or injected with 200µg/kg corresponding dyes, and then samples of liver were collected at different times (0.5, 1, 3, 5, 7, 10, 13, 17 and 22d ) for analysis of superoxide dismutase (SOD), catalase (CAT), and contents of malondialdehyde (MDA). There is an obvious difference between two poisoning conditions and results indicated injection pattern have a more sensitive response. Besides, SOD, CAT and MDA levels displayed different variation trend following the prolonged duration, implying that dye metabolism generated less toxic or more active substance. The comparison among their intensity of enzyme inhibition showed that the toxicity order is D-BLL>D-GLN>D-3RNL. Additionally, three direct dye molecules were optimized based on the quantum mechanical charge density of a solute molecule interacting with a continuum description of the solvent (SMD) of Self-consistent Reaction Field Theory (SCRF) on B3LYP/LAN2BM level and the stable configurations were obtained. Wiberg bond orders were analyzed and atom in molecule (AIM) 2000 program was employed to estimate the interaction between atoms. The possible degradation pathways and toxicities were speculated based on the computations. The calculation is consistent with the experimental results and analysis.

Environment-related properties of polyhydroxylated dibenzo-p-dioxins.

Polyhydroxylated dibenzo-p-dioxins (PHODDs) are important metabolic and synthetic products of polychlorinated dibenzo-p-dioxins (PCDDs). Two types of hydrogen bonds exist in PHODD molecules: one between a hydroxyl group (HO) and an oxygen atom of the ether bond, and the other between two ortho hydroxyls of a benzene ring. By fully optimized calculation with density functional theory (DFT), their bond energies were ascertained to be approximately 9-14 kJ/mol and 15-19 kJ/mol respectively by the comparison of standard Gibbs energy of formation (Δ(f)G(θ)) between different molecules, which was experimentally verified. The two types of hydrogen bonds affect the hydrophilicity and stability of the molecules. The torsional potential of hydroxyls and the orientation making the congener most stable were obtained. The octanol-water partition coefficients (logK(ow)s) were calculated based on the group contribution method, and the standard state entropy (S(θ)), standard enthalpy (Δ(f)H(θ)) of formation and Δ(f)G(θ) were obtained from the combination of DFT calculation and isodesmic reaction for the stable PHODD congeners. The number and position of hydroxyl substitution (N(PHOS)) were employed as descriptors to establish quantitative structure-property relationship (QSPR) models. Although the hydrophilicity of PHODDs increases with the number of hydroxyl groups, it is impaired by the intramolecular hydrogen bonds. The logK(ow)s of PHODDs are much smaller than those of PCDDs, and the variation trend with the number of substituents is different. In addition, the relative stability order of PHODD congeners was theoretically proposed, which is quite different from that of PCDDs. Considering the ionization in water, first-order ionization constants of PHODDs were calculated according to the results of SMD method of Self-Consistent Reaction Field Theory (SCRF), and they were influenced by the hydrogen bonds.

Prediction of supercooled liquid vapor pressures and n-octanol/air partition coefficients for polybrominated diphenyl ethers by means of molecular descriptors from DFT method.

The molecular geometries of 209 polybrominated diphenyl ethers (PBDEs) were optimized at the B3LYP/6-31G level with Gaussian 98 program. The calculated structural parameters were taken as theoretical descriptors to establish two novel QSPR models for predicting supercooled liquid vapor pressures (P(L)) and octanol/air partition coefficients (K(OA)) of PBDEs based on the theoretical linear solvation energy relationship (TLSER) model, respectively. The two models achieved in this work both contain three variables: most negative atomic partial charge in molecule (q(-)), dipole moment of the molecules (mu) and mean molecular polarizability (alpha), of which R(2) values are both as high as 0.997, their root-mean-square errors in modeling (RSMEE) are 0.069 and 0.062 respectively. In addition, the F-value of two models are both evidently larger than critical values F(0.05) and the variation inflation factors (VIF) of variables herein are all less than 5.0, suggesting obvious statistic significance of the P(L) and K(OA) predicting models. The results of Leave-One-Out (LOO) cross-validation for training set and validation with external test set both show that the two models obtained exhibited optimum stability and good predictive power. We suggest that the QSPRs derived here can be used to predict accurately P(L) and K(OA) for non-tested PBDE congeners from Mono-BDEs to Hepta-BDEs and from Mono-BDEs to Hexa-BDEs, respectively.

QSPR modeling of n-octanol/water partition coefficients and water solubility of PCDEs by the method of Cl substitution position.

The number of Cl substitution positions (N(PCS)) of all 209 possible molecular structure patterns of polychlorinated diphenyl ethers (PCDEs) were correlated with their partition properties n-octanol/water partition coefficient (lgK(ow)) and sub-cooled liquid water solubilities (-lgS(w,l)). The correlation coefficients (R) and the leave-one-out (LOO) cross-validation correlation coefficients (R(cv)) of all the 6-descriptor models for lgK(ow) and -lgS(w,l) are more than 0.98. By using stepwise multiple regression (SMR), the best two models of lgK(ow) with three descriptors (R=0.9,913) and lgS(w,l) with four descriptors(R=0.9,818) were obtained respectively. Based on these equations, the two properties of all 209 PCDEs were predicted. Model validation showed that the two models exhibit optimum stability and high predictive power. Moreover, results of prediction were further compared with data from similar studies by molecular connectivity indices (MCIs) and PM3 methods.

Reaction space map representation of the chlorination/dechlorination reactions of polychlorobenzenes.

The reaction space map (RESMAP) representation is proposed for the comprehensive description of the chlorination and dechlorination reactions of polychlorobenzenes. By using the B3LYP/6-311G energies and by assuming the chemical reactions which govern the chlorination and dechlorination processes of polychlorobenzenes, the relative energies of polychlorobenzenes and polychlorophenyl radicals were defined artificially. They were collected as the RESMAP which has the relative energies of polychlorobenzenes at the diagonal parts and the polychlorophenyl radicals connecting two polychlorobenzenes at the off-diagonal parts. The RESMAPs created for three models for the chlorination/dechlorination processes provided a general view of the thermodynamically controlled isomer distributions and chlorination/dechlorination reaction patterns for benzene and (poly)chlorinated benzenes.