Protective effects of 5,7,4 '-trihydroxy-6,3 ' dimethoxy-flavone 5-O-alpha-L-rhamnopyranoside, isolated from Annona squamosa leaves in thyrotoxicosis and in hepatic lipid peroxidation in rats

摘要

Hitherto unknown protective effects of 5,7,4'-trihydroxy-6,3'dimethoxy-flavone 5-O-alpha-L-rhamnopyranoside (THDMF-Rha); isolated from Annona squamosa leaves were evaluated in L-thyroxine (L-T-4)-induced thyrotoxicosis in rats. Administration of L-T-4 at 500 mu g/kg body weight for 12 days increased the levels of serum thyroid hormones, the activity of 5'-monodeiodinase-I (5'DI) and hepatic glucose-6-phosphatase (G-6Pase) as well as lipid peroxidation (LPO); with a parallel decrease in the levels of cellular antioxidants and serum lipids. However, administration of the isolated THDMF-Rha at a pre-standardized dose for 15 days ameliorated the L-T-4-induced alterations in the levels of thyroid hormones, hepatic LPO, G-6-Pase, 5'DI activity, and cellular levels of antioxidants and improved the status of different serum lipids, suggesting its antithyroidal and antioxidative potential. As compared to standard antithyroid drug, propylthiouracil, THDMF-Rha appeared to be more promising. (C) 2015 Elsevier Ltd. All rights reserved.