Valerian inhibits rat hepatocarcinogenesis by activating GABA(A) receptor-mediated signaling.

Valerian is widely used as a traditional medicine to improve the quality of sleep due to interaction of several active components with the γ-aminobutyric acid (GABA) A receptor (GABA(A)R) system. Recently, activation of GABA signaling in stem cells has been reported to suppress cell cycle progressio...

Full description

Bibliographic Details
Main Authors: Anna Kakehashi, Ayumi Kato, Naomi Ishii, Min Wei, Keiichirou Morimura, Shoji Fukushima, Hideki Wanibuchi
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2014-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC4242630?pdf=render
_version_ 1819168858818215936
author Anna Kakehashi
Ayumi Kato
Naomi Ishii
Min Wei
Keiichirou Morimura
Shoji Fukushima
Hideki Wanibuchi
author_facet Anna Kakehashi
Ayumi Kato
Naomi Ishii
Min Wei
Keiichirou Morimura
Shoji Fukushima
Hideki Wanibuchi
author_sort Anna Kakehashi
collection DOAJ
description Valerian is widely used as a traditional medicine to improve the quality of sleep due to interaction of several active components with the γ-aminobutyric acid (GABA) A receptor (GABA(A)R) system. Recently, activation of GABA signaling in stem cells has been reported to suppress cell cycle progression in vivo. Furthermore, possible inhibitory effects of GABA(A)R agonists on hepatocarcinogenesis have been reported. The present study was performed to investigate modulating effects of Valerian on hepatocarcinogenesis using a medium-term rat liver bioassay. Male F344 rats were treated with one of the most powerful Valerian species (Valeriana sitchensis) at doses of 0, 50, 500 and 5000 ppm in their drinking water after initiation of hepatocarcinogenesis with diethylnitrosamine (DEN). Formation of glutathione S-transferase placental form positive (GST-P(+)) foci was significantly inhibited by Valerian at all applied doses compared with DEN initiation control rats. Generation of 8-hydroxy-2'-deoxyguanosine in the rat liver was significantly suppressed by all doses of Valerian, likely due to suppression of Nrf2, CYP7A1 and induction of catalase expression. Cell proliferation was significantly inhibited, while apoptosis was induced in areas of GST-P(+) foci of Valerian groups associated with suppression of c-myc, Mafb, cyclin D1 and induction of p21(Waf1/Cip1), p53 and Bax mRNA expression. Interestingly, expression of the GABA(A)R alpha 1 subunit was observed in GST-P(+) foci of DEN control rats, with significant elevation associated with Valerian treatment. These results indicate that Valerian exhibits inhibitory effects on rat hepatocarcinogenesis by inhibiting oxidative DNA damage, suppressing cell proliferation and inducing apoptosis in GST-P(+) foci by activating GABA(A)R-mediated signaling.
first_indexed 2024-12-22T19:10:17Z
format Article
id doaj.art-893d5151bcfd4a78b42c17ccb10495b9
institution Directory Open Access Journal
issn 1932-6203
language English
last_indexed 2024-12-22T19:10:17Z
publishDate 2014-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj.art-893d5151bcfd4a78b42c17ccb10495b92022-12-21T18:15:41ZengPublic Library of Science (PLoS)PLoS ONE1932-62032014-01-01911e11361010.1371/journal.pone.0113610Valerian inhibits rat hepatocarcinogenesis by activating GABA(A) receptor-mediated signaling.Anna KakehashiAyumi KatoNaomi IshiiMin WeiKeiichirou MorimuraShoji FukushimaHideki WanibuchiValerian is widely used as a traditional medicine to improve the quality of sleep due to interaction of several active components with the γ-aminobutyric acid (GABA) A receptor (GABA(A)R) system. Recently, activation of GABA signaling in stem cells has been reported to suppress cell cycle progression in vivo. Furthermore, possible inhibitory effects of GABA(A)R agonists on hepatocarcinogenesis have been reported. The present study was performed to investigate modulating effects of Valerian on hepatocarcinogenesis using a medium-term rat liver bioassay. Male F344 rats were treated with one of the most powerful Valerian species (Valeriana sitchensis) at doses of 0, 50, 500 and 5000 ppm in their drinking water after initiation of hepatocarcinogenesis with diethylnitrosamine (DEN). Formation of glutathione S-transferase placental form positive (GST-P(+)) foci was significantly inhibited by Valerian at all applied doses compared with DEN initiation control rats. Generation of 8-hydroxy-2'-deoxyguanosine in the rat liver was significantly suppressed by all doses of Valerian, likely due to suppression of Nrf2, CYP7A1 and induction of catalase expression. Cell proliferation was significantly inhibited, while apoptosis was induced in areas of GST-P(+) foci of Valerian groups associated with suppression of c-myc, Mafb, cyclin D1 and induction of p21(Waf1/Cip1), p53 and Bax mRNA expression. Interestingly, expression of the GABA(A)R alpha 1 subunit was observed in GST-P(+) foci of DEN control rats, with significant elevation associated with Valerian treatment. These results indicate that Valerian exhibits inhibitory effects on rat hepatocarcinogenesis by inhibiting oxidative DNA damage, suppressing cell proliferation and inducing apoptosis in GST-P(+) foci by activating GABA(A)R-mediated signaling.http://europepmc.org/articles/PMC4242630?pdf=render
spellingShingle Anna Kakehashi
Ayumi Kato
Naomi Ishii
Min Wei
Keiichirou Morimura
Shoji Fukushima
Hideki Wanibuchi
Valerian inhibits rat hepatocarcinogenesis by activating GABA(A) receptor-mediated signaling.
PLoS ONE
title Valerian inhibits rat hepatocarcinogenesis by activating GABA(A) receptor-mediated signaling.
title_full Valerian inhibits rat hepatocarcinogenesis by activating GABA(A) receptor-mediated signaling.
title_fullStr Valerian inhibits rat hepatocarcinogenesis by activating GABA(A) receptor-mediated signaling.
title_full_unstemmed Valerian inhibits rat hepatocarcinogenesis by activating GABA(A) receptor-mediated signaling.
title_short Valerian inhibits rat hepatocarcinogenesis by activating GABA(A) receptor-mediated signaling.
title_sort valerian inhibits rat hepatocarcinogenesis by activating gaba a receptor mediated signaling
url http://europepmc.org/articles/PMC4242630?pdf=render
work_keys_str_mv AT annakakehashi valerianinhibitsrathepatocarcinogenesisbyactivatinggabaareceptormediatedsignaling
AT ayumikato valerianinhibitsrathepatocarcinogenesisbyactivatinggabaareceptormediatedsignaling
AT naomiishii valerianinhibitsrathepatocarcinogenesisbyactivatinggabaareceptormediatedsignaling
AT minwei valerianinhibitsrathepatocarcinogenesisbyactivatinggabaareceptormediatedsignaling
AT keiichiroumorimura valerianinhibitsrathepatocarcinogenesisbyactivatinggabaareceptormediatedsignaling
AT shojifukushima valerianinhibitsrathepatocarcinogenesisbyactivatinggabaareceptormediatedsignaling
AT hidekiwanibuchi valerianinhibitsrathepatocarcinogenesisbyactivatinggabaareceptormediatedsignaling