Secondary Topic: Basic Science
Effects of Aloe on the regulation of thyroxine release in FRTL-5 thyroid cells
Byoung-Seob Ko, Ph.D.; Hiroe Go, Ph.D.; Jin Ah Ryuk, PH.D., Korea Institute of Oriental Medicine, Daejeon, Korea, Republic Of
Late Breaker: Yes
We investigated the effects of aloe on thyroxine production in FRTL-5 cells.
To clarify the possible role of aloe in the regulation of thyroid function in maintaining endocrinal homeostasis, we measured the amount of thyroxine release using a T4 ELISA kit with or without thyrotropin (TSH).
In the 6H group (with TSH), thyroxine release was decreased compared with the control group. Moreover, mRNA and protein expression of thyroid peroxidase (TPO) which is one of the important factors of thyroxine synthesis, were decreased significantly. Conversely, in the 5H group (without TSH), thyroxine release and protein expression of TPO were increased compared with the control group. To know the mechanism of regulatory effects of aloe on thyroxine release, we investigated protein expression of upstream key factors of thyroid hormone synthesis such as phospho-ERK, phospho-CREB, phospho-AKT and PKA. Although protein expression of phospho-ERK, phospho-CREB and PKA were decreased in 6H group, those of 5H group were increase. Protein expression of phosphor-AKT were not changed in both 6H and 5H group.
These results suggest that aloe could be candidate for TSH-like substances and paly a regulatory role in thyroxin release via PKA-CREB or PKA-ERK pathway.