ABSTRACT
AIM: The aim of the present study was to investigate the dynamics of nitric oxide derivative (NOD) formation in mice with transplanted tumors and to analize whether synthetic NO-synthase inhibitors, NO-donors and natural compounds could modulate NOD synthesis. MATERIALS AND METHODS: In the study F(1)(C(57)BlxCBA), CBA/Lac, BDF and Balb/c mice were used. Endogenous NOD synthesis in mice with transplanted Ehrlich carcinoma (EC) and Lewis lung carcinoma (LLC) was estimated by measuring urine nitrates (NA) and nitrites (NI) excretion and their concentration in tumor tissue determined by cadmium-reduction method. RESULTS: It is shown that EC development is accompanied by increased endogenous NOD formation whereas LLC growth - by its decrease. Total NOD excretion with urine in EC-bearing mice during tumor development was in the range of 1.1x10(-7)-7.0x10(-6) mol/kg body weight that was 1.7-6.8 times higher than that in LLC-bearing mice. Treatment of EC-bearing animals with N(Ï)-nitro-L-arginine and aminoguanidine resulted in decreased NOD formation causing moderate tumor growth retardation. Effect of treatment with nitroprusside was shown to be dependent on the rout of its administration and dosage. Treatment of EC-bearing mice with picnogenol, tannic acid, spirulina and paprika enriched with selenium resulted in tumor growth inhibition at the early stage of EC growth accompanied by stimulation of endogenous NOD formation. CONCLUSION: Regulation of endogenous NOD formation towards normal physiological levels or hyperproduction of these compounds may result in tumor growth suppression.
Subject(s)
Antioxidants/pharmacology , Enzyme Inhibitors/pharmacology , Neoplasms/metabolism , Nitric Oxide Synthase/antagonists & inhibitors , Nitric Oxide/biosynthesis , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Humans , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Inbred CBA , Neoplasms/drug therapy , Nitric Oxide/analogs & derivatives , Xenograft Model Antitumor AssaysABSTRACT
Oral treatment with lycopene (per os) in doses of 10 or 50 mg/kg for 2 weeks led to accumulation of lycopene in the liver, liver microsomes, and blood plasma, increased total plasma antioxidant activity, inhibited LPO in the liver, and decreased solubilization of lysosomal enzymes. Lycopene had no effect on ex vivo resistance of liver microsomes to LPO and activities of antioxidant enzymes in the liver.
Subject(s)
Antioxidants/administration & dosage , Carotenoids/administration & dosage , Animals , Antioxidants/metabolism , Carotenoids/metabolism , Humans , Lipid Peroxidation , Liver/cytology , Liver/metabolism , Lycopene , Lysosomes/enzymology , Male , Microsomes, Liver/metabolism , Rats , Rats, Wistar , Vitamin E/metabolismABSTRACT
The inhibiting effect of organic Se (selen-enriched yeast Bioselen) on the endogenous synthesis of N-nitrosubstances was investigated in the Wistar rats, receiving 15 mg of sodium nitritis and 24 mg of diethylamin per 1 kg of bodyweight during 22 days. The level of nitrosoprolin synthesis and (NPro) and the level of nitrosodiethyl (NDie) in the stomach of rats served as the main indices. The highest level of NPro and NDie were revealed in the rats, without selen supplementation (581.2 +/- 113.3 mg per kg of bodyweight and 29.8 +/- 3.0 mg per kg of bodyweight). The highest inhibiting effect of Se was 54.5% for NPro and 54.7% for NDie and it was shown for the Se concentration of 1.5 mg per 1 kg of forage. The increase of Se dosage to 3.0 mg per 1 kg of forage was less effective and resulted in 25.5% of inhibiting of NPro u 47.0% - NDie.
