OBJECTIVE: Evaluate the relationship between the chemical composition of C. nutans and its anti-inflammatory properties using nuclear magnetic resonance (NMR) metabolomics approach.
METHODOLOGY: The anti-inflammatory effect of C. nutans air-dried leaves extracted using five different binary extraction solvent ratio and two extraction methods was determined based on their nitric oxide (NO) inhibition effect in lipopolysaccharide-interferon-gamma (LPS-IFN-γ) activated RAW 264.7 macrophages. The relationship between extract bioactivity and metabolite profiles and quantifications were established using 1 H-NMR metabolomics and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The possible metabolite biosynthesis pathway was constructed to further strengthen the findings.
RESULTS: Water and sonication prepared air-dried leaves possessed the highest NO inhibition activity (IC50 = 190.43 ± 12.26 μg/mL, P
OBJECTIVE: In this study, we aim to investigate the involvement of heme oxygenase-1 (HO-1) in the anti-inflammatory effects of ZnC in lipopolysaccharide (LPS)-induced RAW 264.7 murine macrophages.
MATERIALS AND METHODS: We used immunoblotting analysis to evaluate the involvement of HO-1 in the anti-inflammatory effects of ZnC and the signaling pathway involved was measured using Dual luciferase reporter assay.
RESULTS: Results from immunoblotting analysis demonstrated that pretreatment of cells with ZnC enhanced the expression of HO-1 in RAW 264.7 cells. Pretreatment of cells with HO-1 inhibitor (tin protoporphyrin IX dichloride) significantly attenuated the inhibitory effects of ZnC on nitric oxide (NO) production, inducible nitric oxide synthase (iNOS) expression and NF-κB activation in LPS-induced RAW 264.7 cells, suggesting that HO-1 play an important role in the suppression of inflammatory responses induced by ZnC. Furthermore, results from co-immunoprecipitation of Nrf2 and Keap1 and dual luciferase reporter assay showed that pretreatment of ZnC was able to activate the Nrf2 signaling pathway. Treatment of cells with p38 inhibitor (SB203580), c-Jun N-terminal kinase inhibitor (SP600125), and MEK 1/2 inhibitor (U0126) did not significantly suppress the induction of HO-1 by ZnC. Moreover, our present findings suggest that the effects of ZnC on NO production, HO-1 expression, and Nrf2 activation were attributed to its Zn subcomponent, but not l-carnosine.
CONCLUSION: Pretreatment with ZnC was able to activate Nrf2/HO-1 signaling pathway, thus suppressing the expression of inflammatory mediators, such as NO and iNOS in LPS-induced RAW 264.7 cells.