Synergistic Inhibition of Pro-Inflammatory Pathways by Ginger and Turmeric Extracts in RAW 264.7 Cells

Abstract

Synergy plays a prominent role in herbal medicines to increase potency and widen the therapeutic windows. The mechanism of synergy in herbal medicines is often associated with multi-targeted behavior and complex signaling pathways which are challenging to elucidate. This study aims to investigate the synergistic mechanism of a combination (GT) of ginger (G) and turmeric (T) extracts by exploring the modulatory activity in lipopolysaccharides (LPS)-induced inflammatory pathways and key molecular targets. A Bioplex ProTM mouse cytokine 23-plex assay was utilized to assess the broad anti-cytokine activity of GT in LPS and interferon (IFN)-ɣ (both at 50 ng/mL)-activated RAW 264.7 cells. The inhibitory effects of individual and combined G and T on major proinflammatory mediators including nitric oxide (NO), tumor necrosis factor (TNF) and interleukin (IL)-6 were tested using Griess reagents and ELISA assays, respectively. Immunofluorescent staining and Western blot were used to investigate the modulatory effect of GT on key proteins in the LPS/TLR4 signaling transduction. The regulation of murine microRNA miR-155-5p was tested using real-time PCR. The IC50 value and combination index (CI) values were used to demonstrate potency and synergistic interaction, respectively. GT synergistically attenuated a range of pro-inflammatory mediators including inducible NO, major cytokines (TNF and IL-6) and secondary inflammatory cytokines (GM-CSF and MCP-1). GT significantly inhibited LPS-induced NF-kB p65 translocation, the activation of TLR4, TRAF6, and phosphorylation of JNK and c-JUN. Moreover, the suppressive effect of GT on each of the protein targets in this axis was stronger than that of the individual components. Real-time PCR analysis showed that GT suppressed miR-155-5p to a greater extent than G or T alone in LPS-stimulated cells. Our study demonstrates the synergistic mechanism of GT in downregulating LPS-induced proinflammatory pathways at the miRNA and protein levels. Our results establish a scientific basis for the combined application of G and T as an advanced therapeutic candidate in inflammatory diseases with broad and synergistic anti-inflammatory activity and multi-targeted mechanisms.

Synergistic Anti-Inflammatory Activity of Ginger and Turmeric Extracts in Inhibiting Lipopolysaccharide and Interferon-γ-Induced Proinflammatory Mediators

“…In our previous study, the G and T combination in the specific ratio of 5:2 (w/w) was demonstrated to exhibit synergistic activity in LPS-induced proinflammatory pathways [43].…”

Tristaenone A: A New Anti-Inflammatory Compound Isolated from the Australian Indigenous Plant Tristaniopsis laurina

“…NF-kB translocation was determined as described in previous studies [ 23 ]. RAW 264.7 cells were plated in an 8-well Nunc™ Lab-Tek™ II Chamber Slide™ System (Thermo Fisher Scientific, Sydney, Australia) at 20,000 cells/well.…”

Immunomodulatory and anti-inflammatory therapeutic potential of gingerols and their nanoformulations

“…These results showed that the natural-origin compounds contained in ginger exhibit similar pharmacological efficacy to non-steroidal anti-inflammatory drugs ( Kumar et al, 2013 ; Aziz et al, 2015 ; Deng M. et al, 2022 ). It has also been explained that phosphatidylinositol-3-kinase (PI3K), Akt, and NF-κB light chain enhancer of activated B cells are prominent in the mechanism of the anti-inflammatory effect ( Mao et al, 2019 ; Zahoor et al, 2020 ; Zhang et al, 2021 ; Zhou et al, 2022 ).…”

“…). It has also been explained that phosphatidylinositol-3kinase (PI3K), Akt, and NF-κB light chain enhancer of activated B cells are prominent in the mechanism of the anti-inflammatory effect (Mao et al, 2019;Zahoor et al, 2020;Zhang et al, 2021;Zhou et al, 2022).…”