Search results for "Acute Toxicity"

An in vitro procedure for evaluation of early stage oxidative stress in an established fish cell line applied to investigation of PHAH and pesticide …

2004

Oxidative stress by increased production of reactive oxygen species such as superoxide has been implicated in the toxicity of PCB's and non-target toxicity of many pesticides. We report the development of a microplate-based method for determination of early stage oxidative stress using an established cell line (EPC) from a skin tumour of carp Cyprinus carpio L. and 2',7'-dichlorodihydrofluorescein diacetate (H(2)-DCFDA) as a fluorescent probe for detection of reactive oxygen species (ROS) formation. Sublethal concentrations of the herbicide Paraquat, an established redox cycling agent and a crude PCB mixture, Arochlor 1254 elicited a linear increase in ROS formation over 2 h exposure which …

Hypotensive Effect ofPistacia lentiscusL

1987

AbstractThe present studies were undertaken to confirm the hypotensive effect of Pistacia lentiscus L. in normotensive urethane anaesthetized Wistar rats. It was shown that lyophilized aqueous extract caused a dose-dependent decreased of the systemic arterial blood pressure. Acute toxicity was also determined. Phytochemical analysis revealed the presence of steroids-triterpenes, catechin tannins, flavonoids, sugars, resins and saponins.

INFLUENCE OF α-6-DEOXY-5-OXYTETRACYCLINE ON SOME PHARMA-COLOGICAL CHARACTERISTICS OF DAUNOMYCIN

1973

(1) Treatment with doxycyline substantially reduces the acute toxicity of daunomycin to the mouse. Treatment with doxycycline alters the distribution of daunomycin amongst the body tissues of the mouse. The ability of the isolated kidney to bind the daunomycin is enhanced by pretreatment with doxycycline. This observation is in agreement with the phenomenon noted in vivo with the same organ. (2) The antineoplastic activity of daunomycin, tested in vivo in mice bearing Sarcoma 180 is not modified by treatment with doxycyctine, nor does doxycycline modify the inhibition of DNA synthesis in isolated Sarcoma 180 cells by daunomycin. (3) The experiments carried out on isolated cell, namely: (a) …

An LD50model for predicting psychotropic drug toxicity using biopartitioning micellar chromatography

2001

The LD50 determination is the main way to measure the acute toxicity of all types of substances. At the present time, however, there is increasing opposition to the use of living animals in research and testing activities from animal rights groups as well as some scientists. Nevertheless, the need to have a tool for estimating the potential toxicity of new compounds for human consumption has encouraged the development of alternative methods. Under adequate conditions, the partitioning in micellar liquid chromatography can describe the drug biopartitioning. We have named this chromatographic system biopartitioning micellar chromatography (BMC). In this paper, an LD50 QRAR model developed for…

A3- and A2B-nitrocorroles: synthesis and antiviral activity evaluation against human cytomegalovirus infection

2020

Human cytomegalovirus (hCMV) is responsible for several pathologies impacting immunocompromised patients and can trigger life-threatening infection. Several antivirals are available and are used in the clinic, but hCMV resistant strains have appeared and patients have encountered therapeutic failure. Hence, there is a constant need for new best in class or first in class antiviral molecules. We have previously shown that nitrocorroles could be used as a potent anti-hCMV agent without acute toxicity in mice. They therefore represent an excellent platform to perform structure–activity relationship (SAR) studies and to increase efficiency or reduce toxicity. We have generated original A2B- and…

Pharmacological evaluation of the dichloromethanol extract fromInula crithmoides L.

1995

The pharmacological effect of the dichloromethanol extract of Inula crithmoides L. was analysed in in vitro and in vivo models. The extract dose-dependently decreased arterial blood pressure and furthermore it showed low acute toxicity, CNS depressor activity and analgesic and antiinflammatory effects. Preincubation of the guinea-pig ileum and rat duodenum (100 μg/mL) produced a significant reduction in the contractile effects of histamine and acetylcholine and a concentration-related inhibition of the effects of serotonin. Following further fractionation the methylene chloride/acetone (50/50) fraction caused a significant decrease in motor activity and significantly reduced the threshold o…

Prediction of Aquatic Toxicity of Benzene Derivatives to Tetrahymena pyriformis According to OECD Principles

2016

Background: Many QSAR studies have been developed to predict acute toxicity over several biomarkers like Pimephales promelas, Daphnia magna and Tetrahymena pyriformis. Regardless of the progress made in this field there are still some gaps to be resolved such as the prediction of aquatic toxicity over the protozoan T. pyriformis still lack a QSAR study focused in accomplish the OECD principles. Methods: Atom-based quadratic indices are used to obtain quantitative structure-activity relationship (QSAR) models for the prediction of aquatic toxicity. Our models agree with the principles required by the OECD for QSAR models to regulatory purposes. The database employed consists of 392 substitut…

Pharmacological Study of Santolina chamaecyparissus. I. Acute Toxicity, Antiinflammatory and Antiulcer Activity

1986

Analgesic and central depressor effects of the dichloromethanol extract fromSchinus molle L.

1997

The analgesic and central depressor effects of the dichloromethanol extract of Schinus molle L. were analysed in in vivo models. This extract showed low acute toxicity, CNS depressor activity and analgesic effect. Following further fractionation, the hexane/dichloromethane (75/25) fraction showed the most interesting results. Thus, this fraction caused a total inhibition of motor activity and significantly reduced the threshold of pain to chemical stimulus. © 1997 John Wiley & Sons, Ltd.

Pharmacological screening of the methanol and dichloromethanol extracts ofGenista patens

1995

The pharmacological effects of the dichloromethanol and methanol extracts obtained from leaves and stems of Genista patens DC were analysed in in vitro and in vivo models. Both extracts showed low acute toxicity (LD 50 >3 g/kg), CNS depressor and antiinflammatory activity, and similar analgesic effect in models of chemical and thermal stimulation. Furthermore, the dichloromethanol extract (1-20 mg/kg) induced a pronounced dose-dependent decrease on blood pressure. On isolated organs, the dichloromethanol extract (1, 10, 100 μg/mL) shifted the concentration-effect curve to the right for ACh and reduced the E max induced by histamine without modifying responses induced by noradrenaline and se…