Effects of embelin on lipid peroxidation and free radical scavenging activity against liver damage in rats.

The study aimed to evaluate the hepatic antioxidant capacity of embelin (from Embelia ribes) using different antioxidant tests, free radical scavenging activity and lipid peroxidation in albino rats. Carbon tetrachloride (CCl4) treatment to rats has been more susceptible to peroxidative damage through production of reactive metabolites, namely trichloromethyl-free radicals (CCl3• and/or CCl3• OO•) as measured by thiobarbituric acid reactive species. After the induction of liver damage by CCl4 intoxication to rats, the concentration of lipid peroxidation was significantly (P ≤ 0.001) higher in liver and serum, along with concomitant decrease in the levels of antioxidants and cytochrome P450 enzyme in liver as compared to vehicle controls. The activities of marker enzymes--transaminases (AST, ALT), alkaline phosphatase (ALP), γ-glutamyl transpeptidase (GGT), lactate dehydrogenase (LDH)--along with the total bilirubin and total protein levels were altered significantly (P ≤ 0.001) in the serum of CCl4-treated rats. When these rats received embelin orally (25 mg/kg) from day 1 to day 15, peroxidative damage was minimal in both liver and serum along with effectively inducing the antioxidant potential in CCl4-treated rats. The biochemical results were compared with the standard drug silymarin--a combination of flavonolignans of Silybum marianum and histology of liver sections. In conclusion, this study suggests that embelin acts as a natural antioxidant against hepatotoxicity induced in rats.

Quantification of ziram and zineb residues in fog-water samples.

The present paper describes the extractive quantification of zinc-dithiocarbamate fungicides, i.e. ziram (zinc bis-dimethyldithiocarbamate) and zineb (zinc ethylene-1,2-bis-dithiocarbamate) in fog-water samples. The method is based on the releasing of equivalent amount of zinc from the fungicides and its subsequent determination by visible spectrophotometry or by flame-atomic absorption spectrometry (flame-AAS). For spectrophotometry, the sample contained up to 48mug of ziram and 42mug of zineb was first equilibrated with chloroform. The recovery results show that only ziram content was extracted into chloroform. Then, the sample was treated with NH(4)SCN and surfactants (i.e. CPC and TX-100) solutions, and extracted with toluene to remove interference of inorganic zinc and other metal ions, if present in the sample. The residue was further used for zineb determination. The chloroform extract and residue were then digested separately with nitric acid to release Zn(II), which were then analyzed spectrophotometerically with 4-(2-pyridylazo)-resorcinol in the micellar medium (TX-100) for the determination of ziram and zineb, respectively. The complex shows lambda(max) at 495nm. The molar absorptivity in terms of ziram/zineb was determined to be (8.05) x 10(4)Lmole(-1)cm(-1). The detection limits for ziram and zineb were calculated to be 20 and 21mugL(-1) (with R.S.D. < 1.5%), respectively. Whereas, the optimum concentration ranges were 0.08-1.6 and 0.07-1.4mgL(-1), respectively. Alternatively, the Zn contents present in chloroform extract and in residue were directly analyzed using flame-AAS without undergoing the digestion procedure, and ziram and zineb were determined, respectively. The optimum concentration ranges were 0.9-4.8 and 0.8-4.3mgL(-1), while the detection limits were calculated to be 145 and 144mugL(-1), respectively with R.S.D. < 2.5%. The methods are free from interference of almost all ions [including Zn(II)] and other dithiocarbamate pesticides, which can commonly associate with ziram/zineb in fog-water.

A naphthoquinone derivative from Tectona grandis (Linn.).

A new naphthoquinone derivative has been isolated, along with a number of prenylnaphthoquinone congeners, from the heartwood of Tectona grandis (Linn.). It was characterized as dehydro-alpha-isodunnione (1) by careful analysis of its spectral data.

Specific determination of ferbam residues in fog-water.

A specific method for the determination of a fungicide, i.e. iron(III) dimethyldithiocarbamate (ferbam) in fog-water samples is described. The method is based on the releasing of equivalent amount of iron from the fungicide and subsequently determination by spectrophotometrically or by flame-atomic absorption spectrometrically (flame-AAS). The fungicide was extracted with chloroform/toluene from the samples and digested with nitric acid. For spectrophotometric determination, the solution was then treated with ammonium thiocyanate solution in presence of the surfactants and absorbance was measured at 475 nm. Whereas, the digested solution was directly applied for flame-AAS determination of ferbam. The molar absorptivity in terms of ferbam was determined to be (3.49)x10(4) l mol(-1) cm(-1). The detection limits for spectrophotometric and flame-AAS methods were calculated to be 62 and 111 ppb ferbam (R.S.D. <1 and <3%), respectively. Whereas, the optimum concentration ranges for the analysis of ferbam are 4-120 and 1.5-55 mug in final volume, respectively. The methods are freed from interference of almost all ions [including Fe(II) and Fe(III)], which can commonly associate with ferbam in fog-water. The methods have been successfully applied to fog samples collected from agriculture sites of Raipur (central India).