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.