Effects of known and potential antioxidants on animal models of pathological processes (diabetes, gastric lesions, allergic bronchospasm).

Highly reactive oxygen-free radicals are implicated in the pathogenic process of various diseases. Using an animal model of diabetes (alloxan-induced hyperglycaemia in mice), a model of gastric ulcer (indomethacin-induced gastric lesion in rats), and a model of bronchial asthma (ovalbumin-induced allergic bronchospasm in guinea pigs), a potential therapeutic effect was tested in known antioxidant drugs (alpha-tocopherol, ubiquinone), the thio-compound mesna, and drugs with a possible antioxidant effect (substances derived from the ergoline structure: 6-hydroxynicotinic acid and 4-hydroxypyridine). The pre-treatment with ubiquinone and 6-hydroxynicotinic acid almost completely prevented alloxan-induced hyperglycaemia (94 and 93% inhibition of hyperglycaemia, respectively). A weaker effect was shown by alpha-tocopherol and 4-hydroxypyridine (31 and 27% inhibition of hyperglycaemia, respectively). Mesna negligibly increased hyperglycaemia. 32% and 21% inhibitions of the number of gastric lesions were shown after administration of 6-hydroxynicotinic acid and alpha-tocopherol, respectively. Other drugs, most markedly mesna, aggravated gastric lesions. The most marked protective effect on ovalbumin-induced bronchospasm was exerted by 6-hydroxynicotinic acid (the pulmonary ventilation was increased by 84% in comparison with control group), while mesna and (alpha-tocopherol had a weaker effect (amelioration by 50 and 51 %, respectively). Ubiquinone and 4-hydroxypyridine aggravated pulmonary ventilation. The most marked protective effect in the animal models used was shown by 6-hydroxynicotinic acid.