Bambusae Caulis in Taeniam modulates neuroprotective and anti-neuroinflammatory effects in hippocampal and microglial cells via HO-1- and Nrf-2-mediated pathways.

Recent evidence indicates that microglial activation and hippocampal damage may play important roles in neurodegenerative diseases, including Alzheimer's disease. Bambusae Caulis in Taeniam has been used as a folk remedy for the treatment of hypertension and cardiovascular disease in China and Korea. In this study, the mechanism responsible for the neuroprotective and anti-neuroinflammatory effects of Bambusae Caulis in Taeniam ethyl acetate fraction (BCE) was investigated. Heme oxygenase-1 (HO-1) is an inducible enzyme expressed in response to various inflammatory stimuli. Due to its role in the anti-inflammatory signaling pathway, the expression and modulation of HO-1 are important. In this study, the neuroprotective and anti-neuroinflammatory effects of BCE were examined using the murine microglial BV2 and hippocampal HT22 cells. We demonstrated that the administration of BCE provided neuroprotective effects against glutamate-induced cytotoxicity in HT22 cells through the HO-1 and nuclear erythroid-2 related factor 2 (Nrf-2) signaling pathways. We also reported that BCE inhibited lipopolysaccharide (LPS)-induced pro-inflammatory cytokines and that the presence of selective inhibitors of HO-1 (SnPP) resulted in the inhibition of BCE-mediated anti-inflammatory activity in BV2 microglial cells. BCE was shown to induce HO-1 expression as well as the nuclear translocation of Nrf-2 in both microglial and hippocampal cells. These findings revealed the potential therapeutic mechanisms of BCE in neurodegenerative diseases, suggesting that HO-1 and Nrf-2 signaling may play important roles in the mediation of its neuroprotective and anti-neuroinflammatory effects.

Anti-inflammatory activity of Bambusae Caulis in Taeniam through heme oxygenase-1 expression via Nrf-2 and p38 MAPK signaling in macrophages.

Recently, it has been reported that several natural extracts have anti-inflammatory effects through HO-1 induction. In this study, we used the ethyl acetate fraction of Bambusae Caulis in Taeniam (BCE) to investigate its anti-inflammatory effect on macrophages stimulated with LPS from Porphyromonas gingivalis. BCE inhibited the production of pro-inflammatory cytokines in P. gingivalis LPS-stimulated RAW264.7 cells. BCE also suppressed the nuclear translocation of NF-κB and AP-1. A selective inhibitor of HO-1 attenuated BCE's inhibitory effects on the production of pro-inflammatory cytokines. BCE also dose-dependently increased HO-1 expression at both the mRNA and the protein levels. BCE increased nuclear translocation of Nrf-2. Finally, a specific inhibitor of p38 reduced BCE-induced HO-1 expression and BCE-induced phosphorylation of p38 MAPK. BCE induced anti-inflammatory effects by activating Nrf-2-mediated HO-1 induction via p38 signaling in P. gingivalis LPS-stimulated macrophages. This result indicates that BCE is a promising therapeutic agent for combating periodontitis.

Inhibitory effects of Ginkgo biloba extract on inflammatory mediator production by Porphyromonas gingivalis lipopolysaccharide in murine macrophages via Nrf-2 mediated heme oxygenase-1 signaling pathways.

Periodontitis is an oral chronic inflammatory disease that influences systemic diseases. Heme oxygenase-1 has several beneficial abilities through Nrf-2 regulation. Ginkgo biloba has been reported to have anti-inflammatory effects associated with heme oxygenase-1 (HO-1) expression. In this study, we investigated whether the anti-inflammatory effects of G. biloba were involved with Nrf-2-mediated HO-1 expression in Porphyromonas gingivalis LPS-stimulated RAW264.7 macrophage cells. G. biloba was extracted with ethyl acetate (EGB). EGB exhibited anti-inflammatory activities, which suppressed the production of pro-inflammatory mediators, the activation of mitogen-activated protein kinases, and nuclear translocation of transcription factors. EGB also up-regulated the HO-1 expression, and the Nrf-2 level in the nucleus and its transactivity. Furthermore, reduced pro-inflammatory mediator levels by EGB were inverted in the presence of SnPP. The collective results suggest that the anti-inflammatory effects of EGB are due to the HO-1 expression via up-regulation of Nrf-2 in RAW 264.7 cells stimulated by P. gingivalis LPS.

Anti-inflammatory effect of heme oxygenase-1 toward Porphyromonas gingivalis lipopolysaccharide in macrophages exposed to gomisins A, G, and J.

Periodontitis, a chronic inflammatory periodontal disease that develops from gingivitis, is caused by periodontal pathogenic bacteria such as Porphyromonas gingivalis. Recent studies have focused on the antioxidant, anti-human immunodeficiency virus, anticarcinogenic, and anti-inflammatory properties of gomisins. However, the anti-inflammatory activities of gomisin plants through heme oxygenase-1 (HO-1) signals remain poorly defined. We found that gomisins' anti-inflammatory activity occurs via the induction of HO-1 expression. Gomisins G and J inhibit the production of the pro-inflammatory cytokines tumor necrosis factor-α, interleukin-1ß, and interleukin-6 and also block nuclear factor-κB activation in Raw264.7 cells stimulated with P. gingivalis lipopolysaccharide. Furthermore, pro-inflammatory cytokine production is inhibited through the induction of HO-1 expression. HO-1 expression is induced by all gomisins, but their anti-inflammatory activity via HO-1 signaling is observed with gomisins G and J, and not A. We found that gomisins G and J extracted from Schisandria chinensis can inhibit the P. gingivalis lipopolysaccharide induced-inflammatory responses in Raw264.7 cells.