Non-steroid anti-inflammatory drugs: Combined assay for anti-edemic potency and gastric ulcerogenesis in the same animal

Simultaneous assessments of the anti-inflammatory and ulcerogenic activities of a test compound or new formulations of known anti-inflammatory drugs are conducted rapidly in starved rats, subjected to mild cold stress (?15°, 45 min) then challenged in a rear paw with carrageenan. Data are provided showing that some anti-ulcerant adjuncts may negate the anti-inflammatory activity of drugs such as aspirin, while other adjuncts do not and are therefore therapeutically beneficial (e.g. licorice extract, glucose with aspartic acid). Problems arising from drug esterification, use of suspending agents and alternative assays for gastrotoxicity, are clearly demonstrated by data generated in this bi-modal assay.     

The biochemical protective mechanisms against non-steroidal anti-inflammatory drug induced G-I mucosal damage

Conventional anti-ulcer agents give some protection against NSAID-induced GI injury, but they are by no means totally effective nor without some disadvantage for their side effects cost and for lack of efficacy. More selective protective effects may be achieved by use of agents which counteract the biochemical and cytological changes induced by the NSAIDs. The relative success of these approaches has yet to be fully evaluated but at least some of these procedures may prove cheaper and devoid of side effects encountered with traditional anti-ulcer therapies.     

Temporal pattern in swimming activity of two fish species (Danio rerio and Leucaspius delineatus) under chemical stress conditions

Circadian periodicity of swimming activity was investigated in two fish species, the zebrafish (Danio rerio) and the sunbleak (Leucaspius delineatus) under sublethal long-term exposure to the cyanobacteria toxin microcystin-LR (nominal concentrations of 0.5 μg l^- 1, 5 μg l^- 1, 15 μg l^- 1, 50 μg l^- 1) in 15-litre tanks. Swimming activity of fish was monitored continuously by using an automated video-monitoring and object-tracing system over a period of 17 days. Influenced by long-term exposure to microcystin-LR, Leucaspius delineatus reversed their significant diurnal swimming activity and the fish became statistically significant nocturnal. Danio rerio remained diurnal active, but a significant phase shift was registered. In both Danio rerio and Leucaspius delineatus analysis of time series by cosinor regression revealed microcystin-LR induced dose-dependent alterations of the mean of oscillation, amplitude, acrophase and period length in a different extent. For Danio rerio the periodogram analysis revealed a significant circadian component of swimming activity for control as well as exposure groups, whereby the spectral amplitude clearly decreased at microcystin-LR concentrations of 15 and 50 μg l^- 1. For Leucaspius delineatus the amplitude of circadian rhythm was decreased at all exposure concentrations of MC-LR. Furthermore the dominance of circadian rhythm was clearly reduced, whereas the rate of ultradian rhythms increased at elevated MC-LR concentrations of 5 μg l^- 1, 15 μg l^- 1 and 50 μg l^- 1. The studied temporal aspects of behaviour clearly indicated stress symptoms in both fish species, therefore it proved to be a relevant method to characterise the impact of toxic substances in the environment and for biomonitoring.