Further in vitro evaluation of antiradical and antimicrobial activities of phytol.

The antiradical activity of phytol was evaluated by electron paramagnetic resonance towards hydroxyl radical (·OH), superoxide anion radical (·O2(-)), methoxy radical (·CH2OH), carbon-dioxide anion radical (·CO2(-)), as well as towards nitric-oxide radical (·NO) and 2,2-diphenyl-1-picrylhydrazyl (·DPPH) radical. It reduced the production of all tested radicals showing more promising activity against ·CO2(-), ·CH2OH and ·DPPH radicals (56%, 50% and 48%, respectively) in comparison with ·NO, ·O2(-) and ·OH radicals (38%, 23% and 15%, respectively). The antimicrobial activity of phytol was evaluated by the microdilution method against eight bacterial and eight fungal strains. To varying degrees, it was proven to be active against all tested bacteria and fungi (MIC 0.003-0.038 mg/mL and MBC 0.013-0.052 mg/mL, MIC 0.008-0.016 mg/mL and MFC 0.090-0.520 mg/mL, respectively). According to the obtained results, medical foods containing phytol may support development of new therapies for heart disease.

Role of fructose in the adaptation of plants to cold-induced oxidative stress.

This work presents findings, which indicate important role of fructose, fructose 6-phosphate (F6P), and fructose 1,6-bisphosphate (FBP) in preservation of homeostasis in plants under low temperature. Cold combined with light is known to incite increased generation of superoxide in chloroplasts leading to photoinhibition, but also an increased level of soluble sugars. In the present study, oxidative stress in pea leaves provoked by cold/light regime was asserted by the observed decrease of the level of oxidized form of PSI pigment P700 (P700+). Alongside, the increased antioxidative status and the accumulation of fructose were observed. The antioxidative properties of fructose and its phosphorylated forms were evaluated to appraise their potential protective role in plants exposed to chilling stress. Fructose, and particularly F6P and FBP exhibited high capacities for scavenging superoxide and showed to be involved in antioxidative protection in pea leaves. These results combined with previously established links implicate that the increase in level of fructose sugars through various pathways intercalated into physiological mechanisms of homeostasis represents important non-enzymatic antioxidative defense in plants under cold-related stress.

Characteristics of thiamin transport in the isolated perfused guinea pig heart.

The cellular uptake of (14C)-thiamin hydrochloride was studied in the isolated perfused guinea pig heart, using the rapid single circulation, paired-tracer technique, in which D-(3H)-mannitol serves as an extracellular marker. Cellular uptake of this vitamin was estimated by directly comparing venous dilution profiles of (14C) and (3H) radioactivities in the absence and presence of unlabelled thiamin hydrochloride and pyrithiamin hydrobromide. The maximal cellular uptake (Umax) of thiamin was very low (5.31 +/- 1.79%), while in the presence of 10 mM unlabelled thiamin and 1 mM pyrithiamin, Umax was significantly greater (9.71 +/- 1.57% and 12.30 +/- 0.82%, respectively). Our data suggest that there is a saturable mechanism of sarcolemmal thiamin transport out of myocardial cell, while this transport into the cell is unsaturable.