The role of phytochemicals as potential prodrugs or therapeutic substances against tumors has come in the spotlight in the very recent years, thanks to the huge mass of encouraging and promising results of the in vitro activity of many phenolic compounds from plant raw extracts against many cancer cell lines. Little but important evidence can be retrieved from the clinical and nutritional scientific literature, where flavonoids are investigated as major pro-apoptotic and anti-metastatic compounds. However, the actual role of these compounds in cancer is still far to be fully elucidated. Many of these phytochemicals act in a pleiotropic and poorly specific manner, but, more importantly, they are able to tune the reactive oxygen species (ROS) signaling to activate a survival or a pro-autophagic and pro-apoptosis mechanism, depending on the oxidative stress-responsive endowment of the targeted cell. This review will try to focus on this issue.

Elevated plasma levels of homocysteine (Hcy) are a recognized risk factor for stroke. This relationship represents one aspect of the debated `Hcy hypothesis’. Elevated Hcy may be an independent and treatable cause of atherosclerosis and thrombotic vascular diseases. Further observations indicate that proper dietary supplementation with B-vitamins decreases total plasma Hcy concentrations and may be an effective intervention for stroke prevention. Metabolic vitamin B₁₂ deficiency is a nutritional determinant of total Hcy and stroke risk. Genetic factors may link B vitamins with stroke severity due to the impact on Hcy metabolism of polymorphism in the genes coding for methylenetetrahydrofolate reductase, methionine-synthase, methionine synthase reductase, and cystathionine β-synthase. Several meta-analyses of large randomized controlled trials exist. However, they are not completely in agreement about B vitamins' role, particularly folic acid levels, vitamin B₁₂, and B₆, in lowering the homocysteine concentrations in people at high stroke risk. A very complex relationship exists between Hcy and B vitamins, and several factors appear to modify the preventive effects of B vitamins in stroke. This review highlights the regulating factors of the active role of B vitamins active in stroke prevention. Also, inputs for further large, well-designed studies, for specific, particularly sensitive subgroups are given.

Qualitative composition and content of biologically active compounds in the peach leaves and 50% ethanol extract obtained from peach leaves have been studied. The total content of phenolic compounds, determined by spectrophotometry in peach leaves was as 3,17±0,15%; tannins – 1,02±0,05%; amounts of flavonoids – 2,54±0,12% and the amounts of hydroxycinnamic acids – 1,59±0,07%. The qualitative composition and content of phenolic compounds in the 50% ethanol extract was studied with HPLC using an Agilent Technologies chromatograph (model 1100) equipped with a continuous-flow vacuum degasser G1379A, a 4-channel lowpressure gradient pump G13111A, an automatic injector G1313A, a column thermostat G13116A, a diode array detector G1316A. Nine phenolic substances were found, including five hydroxycinnamic acids and four flavonoids. The dominant substances of all determined compounds were kaempferol-3-O-glucoside (46,70%) and rutin (21,59%). Among flavonoids, kaempferol glycosides dominated over quercetin glycosides in a 3: 1 ratio. Among hydroxycinnamic acids, the predominant component was chlorogenic acid, its part was 57.65% of the sum of hydroxycinnamic acids. Free and linked monosaccharides, such as glucose, galactose, rhamnose, arabinose and ribose, were identified in the extract, and their amount was determined by HPLC. Arabinose was identified just in linked form. Obtained results will be used for standardization of the peach leaves and extract and for further pharmacological research.

Determination of phenolic compounds in prunus domestica leaves extract