Effects of potassium humate solution and soaking periods on germination characteristics of undelinted cotton seeds (Gossypium hirsutum L.).

The present study was conducted to determine the effects of soaking in potassium humate (PH) solution (55% humic acid, 30% fulvic acid and 8% potassium hydroxide) and distilled water (DW) for different periods (0, 4, 8 and 16 hours) on germination characteristics of undelinted seeds of cotton cv Ersan-92. Radicle, hypocotyl and seedling length, radicle and hypocotyl elongation rate and vigor index increased by PH solution treatment and increasing soaking periods. The medium x soaking period interactions were significant except for germination percentage. Sixteen hour soaking period gave the highest values of investigated characteristics. It is suggested that pre-sowing PH solution treatment may be useful to provide a good stand establishment.

Lipid peroxidation, antioxidant enzymes and glutathione levels in human erythrocytes exposed to colloidal iron hydroxide in vitro

The free form of the iron ion is one of the strongest oxidizing agents in the cellular environment. The effect of iron at different concentrations (0, 1, 5, 10, 50, and 100 µM Fe3+) on the normal human red blood cell (RBC) antioxidant system was evaluated in vitro by measuring total (GSH) and oxidized (GSSG) glutathione levels, and superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px) and reductase (GSH-Rd) activities. Membrane lipid peroxidation was assessed by measuring thiobarbituric acid reactive substance (TBARS). The RBC were incubated with colloidal iron hydroxide and phosphate-buffered saline, pH 7.45, at 37oC, for 60 min. For each assay, the results for the control group were: a) GSH = 3.52 + ou - 0.27 µM/g Hb; b) GSSG = 0.17 + ou - 0.03 µM/g Hb; c) GSH-Px = 19.60 + ou - 1.96 IU/g Hb; d) GSH-Rd = 3.13 + ou - 0.17 IU/g Hb; e) catalase = 394.9 + ou - 22.8 IU/g Hb; f) SOD = 5981 + ou - 375 IU/g Hb. The addition of 1 to 100 µM Fe3+ had no effect on the parameters analyzed. No change in TBARS levels was detected at any of the iron concentrations studied. Oxidative stress, measured by GSH kinetics over time, occurs when the RBC are incubated with colloidal iron hydroxide at concentrations higher than 10 µM of Fe3+. Overall, these results show that the intact human RBC is prone to oxidative stress when exposed to Fe3+ and that the RBC has a potent antioxidant system that can minimize the potential damage caused by acute exposure to a colloidal iron hydroxide in vitro.

Effect of chronic non-lethal doses of non-metals and metals on hepatic metallothionein in Channa punctatus (Bloch).

Compared to non-metal toxicants (ammonia, 1.56 ppm; and phenol, 10 ppm), the metals (CdCl2, 30 ppm; HgCl2, 16.7 ppb; and ZnCl2, 6 ppm) significantly induced hepatic metallothionein (MT) concentrations in C. punctatus, exposed independently to non-lethal doses of these toxicants for 28 days. It is suggested that hepatic MT serves as a metal-sequestering protein and is involved in the detoxication of metals only and ensures protection from toxic chemicals in ambience.

Extracción y cuantificación de los polifenoles de la pulpa de café / Extraction and quantification of polyphenols from coffee pulp

Se cuantificaron los polifenoles totales en extractos de pulpa de café, utilizando el método de Folin-Ciocalteau, e incorporándose en esta técnica el uso del polímetro polivinilpirrolidona (PVP), a fin de eliminar las interferencias. Los polifenoles condensados se determinaron aplicando el procedimiento de la vainillina acidificada, y empleando como patrones, ácido clorogénico para la prueba de Folin-Ciocalteau, y catequina para las de vainilina. Luego se trazó una curva de calibración en el solvente respectivo, para cada uno de los extractos. Los solventes empleados para extraer la pulpa fueron metanol puro; metanol-agua, 50:50; hidróxido de amonio al 3%, e hidróxido de calcio al 1%, ensayándose dos tiempos de extracción para cada uno de ellos (10 minutos y una hora). No se encontraron diferencias en los que respecta a la cantidad de polifenoles extraídos entre los dos tiempos sometidos a ensayo. Los solventes alcalinos NH4OH (3%) y Ca (OH)2 (1%) extrajeron la mayor cantidad de polifenoles totales en el término de 10 minutos. Sin embargo, en ese mismo tiempo, el NH4OH (3%) fue más eficaz en cuanto a extraer polifenoles condensados. Los resultados que aquí se notifican sugieren que el tratamiento de la pulpa de café con solventes alcalinos puede beneficiar el valor nutritivo de la pulpa de café