Involvement of heme oxygenase-1 induction in inhibitory effect of ethyl gallate isolated from Galla Rhois on nitric oxide production in RAW 264.7 macrophages

Abstract

In the present study, we investigated an anti-inflammatory effect of ethyl gallate (EG) isolated from Galla Rhois as evaluated by inhibition of nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression, and a potential role of heme oxygenase-1 (HO-1) in the inhibition of NO production elicited by EG. Treatment of RAW264.7 macrophages with EG significantly inhibited the production of NO and iNOS expression stimulated by lipopolysaccharide (LPS). We also demonstrated that EG treatment increased HO-1 mRNA and protein expression, as assessed by quantitative RT-PCR and Western blot analysis. EG treatment also increased the levels of nuclear factor-erythroid 2-related factor 2, which is critical for transcriptional induction of HO-1. In addition, treatment with SnPP (tin protoporphyrin IX), a selective HO-1 inhibitor, counteracted the inhibitory effect of EG on nitrite production, suggesting that HO-1 is, at least in part, implicated in the inhibition of NO production induced by EG treatment. Taken together, these results indicate that EG isolated from Galla Rhois suppresses NO production in LPS-stimulated RAW 264.7 macrophages via HO-1 induction.

Time-Dependent Effects of Systemic Lipopolysaccharide Injection on Regulators of Antioxidant Defence Nrf2 and PGC-1α in the Neonatal Rat Brain

“…We observed previously that inhibition of ERK1/2, Akt and JNK reduced Nrf2 mediated transcription in astrocytes [17,21]. This is in accord with a recent report showing that LPS stimulated expression of HO-1, a down-stream product of Nrf2 transcription, involved Akt and ERK1/2 activation [23]. In the present study the levels of phosphorylated/activated Akt were increased 24 h after LPS exposure (JNK was below detection limit and ERK1/2 too variable).…”

Constituents ofTalisia nervosawith Potential Utility against Metabolic Syndrome

“…Furthermore, compounds 2 and 3 decreased the nitric oxide (NO) production in macrophages with IC 50 values of 7.0 and 7.5 μg/mL, respectively (Table 2). These data are consistent with the previous studies, which reported that methyl gallate and ethyl gallate inhibited NO production and iNOS expression in macrophages stimulated by LPS [22][23]. On the other hand, these two compounds (2,3) did not show any inhibition of NF-κB in PMA induced chondrocytes, as shown in Table 2.…”

Hepatoprotective effect of gallotannin-enriched extract isolated from gall on hydrogen peroxide-induced cytotoxicity in HepG2 cells

“…[ 6 7 8 9 10 11 ] Methyl gallate and ethyl gallate isolated from GR were also found to exert significant anti-inflammatory activity in lipopolysaccharide-stimulated RAW264.7 macrophages through the induction of heme oxygenase-1 and the suppression of inducible nitric oxide synthase/cyclooxygenase-2 (COX-2). [ 12 13 ] Moreover, galloylglucose (GG6-10) isolated from GR inhibited the invasion of metastatic HT-1080 cells into a reconstituted basement membrane through inhibition of gelationolysis mediated by matrix metallopeptidase (MMP-2) and MMP -9, whereas the ellagic acid extracted from GR showed anticancer activity against nasopharyngeal carcinoma cells through downregulated expression of COX-2 and stathmin. [ 14 15 ] Furthermore, oral administration of GR 85% methanol extract reduced brain infarct volume by 37.5% and lipid peroxidation in middle cerebral artery occlusion, while also improving sensory motor function in a transient focal cerebral ischemia rat model.…”