Protective effects of a mixed hot water extracts of Astragalus membranaceus (AWE) and Laminaria japonica (LWE), AWE: LWE 85:15 (g/g; AL mix), were investigated against
propylthiouracil (PTU)-induced
hypothyroidism in rats. Rats were challenged with PTU, resulting in, increased thyroid gland weight, decreased liver weight and
antioxidant activities, reduced serum tri-iodothyronine and
thyroxine levels with increased
thyroid stimulating hormone levels, and elevated serum
aspartate aminotransferase level. However, orally administered AL mix with 100, 200, and 400 mg kg-1 day-1 , significantly inhibited such abnormalities, dose-dependently. Moreover, PTU-induced abnormal histological architecture of the rat thyroid gland and liver were also significantly ameliorated by an AL mix. The results suggested that,
therapeutic use of AL mix for treating
hypothyroidism can be characterized by its diversified active ingredients particularly
iodine and
ferulic acid as confirmed by
phytochemical analyses. PRACTICAL APPLICATIONS: The AL mix has synergistic effects in modulating
thyroid hormone synthesis and preventing liver damages in PTU-induced hypothyroid rats. These effects of AL mix are mainly related to its richness specifically in
iodine and
ferulic acid. The growing interests of
iodine and
ferulic acid in AL mix are principally due to their beneficial effects in releasing sufficient
thyroid hormones in hypothyroid conditions and promoting liver-protective functions through its
antioxidant and anti-inflammatory potentials, respectively. Moreover, the results of AL mix are well-matched with the effects of standard
drug levothyroxine in the present study. Therefore, appropriate dosage of AL mix will be promising as new medicinal food for preventing thyroid dysfunctions and its related liver damages.