Aims: 

Increased oxidative stress have been described previously in models of hyperthyroidism and in human subjects with Basedow disease. In this study, the influence of a diet enriched in soy and sea buckthorne on reactive oxygen and nitrogen species and antioxidant defence was explored. Soy products are attractive because of their beneficial effects on chronic diseases such as cardiovascular diseases, atherosclerosis, and type II diabetes. Also, polyunsaturated fatty acids, having an antioxidant effect, were found in high concentration in Hippophaea rhamnoides (sea buckthorne).

Methods: 

Hyperthyroidism was elicited by intraperitoneally L-Thyroxin administration in white, male, Wistar rats. Animals' diet was enriched in Hippophaea rhamnoides and soy. Oxidative stress markers (lipid peroxides, carbonyl proteins), nitrites and antioxidant defence (thiols groups, hydrogen donor ability) were assessed from blood and from some target tissues of the thyroid hormones: thyroid gland, hepatic tissue and myocardium.

Results: 

The diet enriched in Hippophaea rhamnoides and soy led to a significant decrease in oxidative stress markers and nitrites and to an increase in antioxidant defence of the analysed tissues, soy being more efficiently. The most relevant results were noticed in hepatic tissue showing its involvement in reactive oxygen and nitrogen species production when is subjected to an excess in thyroid hormones. Biochemical markers are correlated with histological studies of the analysed tissues.

Conclusion: 

Present data suggest thatHippophaea rhamnoides and soy decrease tissue susceptibility to oxidative insult generated through an excess in thyroid hormones. A new approach regarding fytotherapeutical alternatives in thyroid gland dysfunction has to be considered.