Lipid peroxidation as a predictive biomarker of the early stage of cancer.

Prostate cancer continues to be a major cause of morbidity and mortality in men around the world. The data concerning the antioxidant status and the degree of lipid peroxidation at the moment of the initiation of cancer is limited. The aim of this research is to assess the effect of selected minerals (zinc, selenium, iron, copper and calcium) on the growth of the neoplastic process and the concentrations of selected biomarkers of the oxidative damage in rats with implanted prostate cancer cells. It was found that the diet supplementation with selected minerals (zinc, selenium, iron, copper and calcium) affect the occurrence of prostate tumor growth in the examined rats. The intraperitoneal implantation of prostate cancer cells resulted in the occurrence of prostatic adenoma in 71% of the examined rats. In the rats that were additionally supplemented with selenium and with copper, the cancer cell aggregates constituted, respectively, 25% and 38% of the cases. As a result of implantation of cancer cells, the level of biomarkers of lipid peroxidation increased both in the urine and in tissues of the examined animals (rat group without supplementation). No relationship was found between the process of lipid peroxidation due to the supplementation with selenium and copper, and the lower incidence of cancer and the induction of apoptosis. The reduced activity of antioxidative enzymes (catalase, superoxide dismutase and glutathione peroxidase) creates favorable conditions for the formation of cancer cell aggregates, which was shown in the rats whose diet was supplemented with iron. In summary, we conclude that lipid peroxidation represents a fruitful approach to early stage cancer prevention. Supplementation of rats with trace elements correlated with the risk of developing cancer, but the mechanisms of this action is complicated and dose-dependent.

Hydroxycinnamoyl derivatives and secoiridoid glycoside derivatives from Syringa vulgaris flowers and their effects on the pro-inflammatory responses of human neutrophils.

Thirteen new compounds including caffeoyl-glucaric and p-coumaroyl-altraric acid derivatives, one monoterpenoid glucoside, four secoiridoid glycosides, and three hydroxycinnamoyl phenylpropanoid glycosides esterified with an oleoside 11-methyl ester along with fifteen known compounds were isolated from flowers of Syringa vulgaris L. (Oleaceae). Their structures were elucidated by high-resolution spectroscopic methods. The tested compounds were able to decrease the production of reactive oxygen species. Moreover, oleoechinacoside (13), demethylhydroxyoleonuezhenide (14), demethyloleonuezhenide (15), syringaoleoacteoside (25) and oleoacteoside (26) at the concentration of 50µM, moderately suppressed the LPS-stimulated release of pro-inflammatory chemokine IL-8 and TNF-α from human neutrophils. Moreover, oleonuezhenide (12), oleoside 11-methyl ester (16) and oleoacteoside (26) at the concentration of 50µM were able to induce the surface expression of interleukin 10 receptor, which is suppressed by the incubation of monocyte/macrophage cells with LPS.

Oenothera paradoxa defatted seeds extract containing pentagalloylglucose and procyanidins potentiates the cytotoxicity of vincristine.

The purpose of the study was a comparison of Oenothera paradoxa Hudziok defatted seeds extract (EPE) effect with the activity of individual constituents of the extract: pentagalloylglucose (PGG), gallic acid, (+)-catechin and the procyanidin fraction, as well as an assessment of the combined effect of EPE and vincristine (VCR) in the absence or presence of MRP1 (indomethacin) and P-glycoprotein (verapamil) inhibitors, on two human cancer cell lines, metastatic melanoma (HTB-140) and hepatoma (HepG2). The presence of EPE, PGG and procyanidins caused a marked reduction in viability (MTT assay) and rise in mortality (LDH release assay) of HTB-140 cells. The combined use of EPE (25 µg/mL) and VCR (1 µM) in HTB-140 and HepG2 cells produced an increased cytotoxicity as compared to vincristine alone - by more than 4 and 1.5 times, respectively. In HTB-140 cells, the level of intracellular ATP (measured by bioluminescence) was lowered over 7-fold as a result of exposure to the combination of EPE and VCR, while the addition of MRP-1 inhibitor did not cause an increased cytotoxicity or further lowering of the ATP level. Our results demonstrate that EPE, containing PGG and procyanidins, significantly increased the sensitivity of cancer cells, particularly the melanoma cells, to the action of vincristine.

Dual inhibition of metallopeptidases ACE and NEP by extracts, and iridoids from Ligustrum vulgare L.

AIM OF THE STUDY: In order to confirm the traditional use of Ligustrum vulgare L. (common privet, Oleaceae) we investigated the inhibitory activity of different extracts from leaves (LlE), flowers (LflE) and fruits (LfrE) on metallopeptidases ACE and NEP. MATERIALS AND METHODS: Powdered plant materials were first extracted with water and then with ethyl acetate and n-butanol saturated with water. The metallopeptidases activity was determined using in vitro fluorimetric assays. RESULTS: At a concentration of 100microg/ml the ethyl acetate extracts showed the highest activity. The bio-guided fractionation of the leaves extract led to the isolation of two iridoids which were identified by (1)H, (13)C and HETCOR NMR spectroscopy as oleuropein and ligstroside aglycones. Both compounds are dual ACE/NEP inhibitors with IC(50) of 20 and 25microM for ACE and IC(50) of 35 and 75microM for NEP, respectively. Secoirydoids glycosides, tyrozol and hydroxytyrozol, as well as, flavonoids present in the ethyl acetate extracts showed little or no inhibitory activity. CONCLUSIONS: Our results partially support the diuretic and hypotensive activities of common privet.