Organosulfur compound protects against memory decline induced by scopolamine through modulation of oxidative stress and Na+/K+ ATPase activity in mice.

The present study investigated the possible effect of BMMS in protecting against memory impairment in an Alzheimer's disease model induced by scopolamine in mice. Another objective was to evaluate the involvement of oxidative stress and Na+/K+ ATPase activity in cerebral cortex and hippocampus of mice. Male Swiss mice were divided into four groups: groups I and III received canola oil (10 ml/kg, intragastrically (i.g.)), while groups II and IV received BMMS (10 mg/kg, i.g.). Thirty minutes after treatments, groups III and IV received scopolamine (1 mg/kg, intraperitoneal (i.p.)), while groups I and II received saline (5 ml/kg, i.p.). Behavioral tests were performed thirty minutes after scopolamine or saline injection. Cerebral cortex and hippocampus were removed to determine the thiobarbituric acid reactive species (TBARS) levels, non-protein thiols (NPSH) content, catalase (CAT) and Na+/K+ ATPase activities. The results showed that BMMS pretreatment protected against the reduction in alternation and latency time induced by scopolamine in the Y-maze test and step-down inhibitory avoidance, respectively. In the Barnes maze, the latency to find the escape box and the number of holes visited were attenuated by BMMS. Locomotor and exploratory activities were similar in all groups. BMMS pretreatment protected against the increase in the TBARS levels, NPSH content and CAT activity, as well as the inhibition on the Na+/K+ ATPase activity caused by scopolamine in the cerebral cortex. In the hippocampus, no significant difference was observed. In conclusion, the present study revealed that BMMS protected against the impairment of retrieval of short-term and long-term memories caused by scopolamine in mice. Moreover, antioxidant effect and protection on the Na+/K+ ATPase activity are involved in the effect of compound against memory impairment in AD model induced by scopolamine.

Protective effect of ((4-tert-butylcyclohexylidene) methyl) (4-methoxystyryl) sulfide, a novel unsymmetrical divinyl sulfide, on an oxidative stress model induced by sodium nitroprusside in mouse brain: involvement of glutathione peroxidase activity.

OBJECTIVES: In this study, the antioxidant action of ((4-tert-butylcyclohexylidene) methyl) (4-methoxystyryl) sulfide, a novel unsymmetrical divinyl sulfide, against oxidative damage induced by sodium nitroprusside (SNP) in brains of mice was investigated. METHODS: Mice received SNP (0.335 µmol/site, intracerebroventricular) 30 min after administration of sulfide (10 mg/kg, intragastrically). After 1 h, animals were sacrificed and the brains were removed to biochemistry analysis. Thiobarbituric acid reactive species (TBARS), protein carbonyl (PC) and non-protein thiol (NPSH) levels, as well as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST) activities were determined. KEY FINDINGS: SNP increased TBARS and PC levels, CAT, GPx, GR and GST activities and reduced NPSH levels. Administration of the sulfide attenuated the changes produced by SNP and increased per se GPx activity in brains of mice. Toxicological parameters revealed that this compound did not cause acute renal or hepatic damage. CONCLUSIONS: In conclusion, ((4-tert-butylcyclohexylidene) methyl) (4-methoxystyryl) sulfide protected against oxidative damage caused by SNP in mouse brain. GPx activity is involved, at least in part, in the cerebral antioxidant action of this compound.

Use of papaya seeds as a biosorbent of methylene blue from aqueous solution.

In this study papaya seeds were used to remove methylene blue dye from aqueous solution. Papaya seeds were characterized as possessing a macro/mesoporous texture and large pore size. Studies were carried out in batches to evaluate the effect of contact time and pH (2-12) on the removal of dye. It was observed that the adsorption of dye was better in the basic region (pH 12). The equilibrium data were analyzed using Langmuir, Freundlich, Dubinin-Raduschkevich, Tempkin, Jovanovich, Redlich-Peterson, Sips, Toth and Radke-Prausnitz isotherms. The equilibrium data were best described by the Langmuir isotherm with a maximum adsorption capacity of 637.29 mg g(-1). Adsorption kinetic data were fitted using the pseudo-first-order and pseudo-second-order model. The adsorption kinetic is very fast and was best described by the pseudo-second-order model.

Evaluation of activity of a commercial amylase under ultrasound-assisted irradiation.

The main objective of this work was to evaluate the effects of ultrasound irradiation on the activity of a commercial amylase. A central composite design was carried out to assess the effects of temperature and pH on the enzyme activity in the presence and absence of ultrasound irradiation. The activation energy, the influence of treatment time as well as the substrate concentration on enzyme activity were also determined in the presence and absence of ultrasound irradiation. The results demonstrated that the effect of temperature was less pronounced in the presence of ultrasound, resulting in a decreasing of about 80% in the activation energy in comparison with the value obtained in the absence. The enzyme showed activities about 3 times higher for temperatures up to 40 °C in the presence of ultrasound. The pH negatively affected the activity in the presence of ultrasound, whereas in the absence a positive effect was verified. The ultrasound irradiation is a promising technology to be used in enzymatic reaction due to its positive effects on enzyme activity.

Optimization of enzymatic hydrolysis of cassava to obtain fermentable sugars.

This work evaluates the enzymatic hydrolysis of starch from cassava using pectinase, α-amylase, and amyloglucosidase. A central composite rotational design (CCRD) was carried out to evaluate the effects of amyloglucosidase, pectinase, reaction time, and solid to liquid ratio. All the experiments were carried out in a bioreactor with working volume of 2 L. Approximately 98% efficiency hydrolysis was obtained, resulting in a concentration of total reducing sugar released of 160 g/L. It was concluded that pectinase improved the hydrolysis of starch from cassava. Reaction time was found to be significant until 7 h of reaction. A solid to liquid ratio of 1.0 was considered suitable for hydrolysis of starch from cassava. Amyloglucosidase was a significant variable in the process: after its addition to the reaction media, a 30%-50% increase in the amount of total reducing sugar released was observed. At optimal conditions the maximum productivity obtained was 22.9 g/(L·h).