Vessela Vitcheva

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The aim of the following study was to evaluate the effect of a purified saponin mixture (PSM), isolated from Astragalus corniculatus Bieb. (Fabaceae), on enzyme-induced and non-enzyme-induced lipid peroxidation (LPO), in liver microsomes from spontaneously hypertensive rats (SHRs) - strain Okamoto Aoki, as compared to normotensive Wistar rats (NTRs). The(More)
A purified saponin mixture (PSM) isolated from Astragalus corniculatus Bieb. (Fabaceae) was investigated for its protective effect in two models of toxicity, carbon tetrachloride (CCl4) and tert-butyl hydroperoxide (t-BuOOH), using isolated rat hepatocytes. CCl4 undergoes dehalogenation in the liver endoplasmic reticulum. This process leads to(More)
The antioxidant effect of saponarin, which is the main flavone isolated from Gypsophila trichotoma Wend., and its protection against cocaine hepatotoxicity were investigated in male Wistar rats. The animals were treated with cocaine (40 mg/kg i.p.) alone and also after 3 consecutive days of pretreatment with saponarin (80 mg/kg p.o.). After 18 hours the(More)
Five benzophenones and a xanthone, isolated from Hypericum annulatum Moris, were investigated for their protective effect against carbon tetrachloride toxicity in isolated rat hepatocytes. The benzophenones and the xanthone gentisein were administered alone (100 microM) and in combination with CCl4 (86 microM). CCl4 undergoes dehalogenation in the liver(More)
Numerous studies indicate that opioid tolerance involves a disruption in Ca2+ homeostasis. In vivo studies have indicated the involvement of dihydropyridine-sensitive (L-type) voltage-gated channels in morphine abuse. In this study, the effect of multiple administration of the dihydropyridine calcium channel blocker nifedipine (5 mg/kg/twice daily), given(More)
The hepatoprotective potential of saponarin, isolated from Gypsophila trichotoma, was evaluated in vitro/in vivo using a hepatotoxicity model of paracetamol-induced liver injury. In freshly isolated rat hepatocytes, paracetamol (100 μ mol) led to a significant decrease in cell viability, increased LDH leakage, decreased levels of cellular GSH, and elevated(More)
In this study, the in vivo effects of a purified saponin mixture (PSM), obtained from Astragalus corniculatus Bieb., were investigated using two in vivo hepatotoxicity models based on liver damage caused by paracetamol (PC) and carbon tetrachloride (CCl4 ). The effects of PSM were compared with silymarin. Male Wistar rats were challenged orally with 20%(More)
Cocaine belongs to the group of psychostimulants and together with amphetamines has been recognized as one of the most significant examples of drug abuse. Cocaine abuse is due to intense feelings of euphoria, friendliness, empathy, and hyperactivity, which result from its potent inhibitory effects on presynaptic dopamine and noradrenaline re-uptake. Misuse(More)
The objective of this study was to evaluate possible changes caused by multiple cocaine administration, alone and in combination with 1,4-dihydropiridine calcium channel blocker nifedipine, on cytochrome P450 levels both in the brain and liver. The experiment was done on male Wistar rats divided in four groups: control, treated with nifedipine (5 mg kg(-1)(More)
Myosmine [3-(1-pyrrolin-2-yl) pyridine] is an alkaloid structurally similar to nicotine, which is known to induce oxidative stress. In this study we investigated the effects of myosmine on enzymatic and non-enzymatic antioxidative defence in rat liver. Wistar rats received a single i.p. injection of 19 mg kg-1 of myosmine and an oral dose of 190 mg kg-1 by(More)