Anti-inflammatory activity of Ternstroemia gymnanthera stem bark extracts in bacterial lipopolysaccharide-stimulated RAW264.7 murine macrophage cells.

ABSTRACT

CONTEXT Ternstroemia gymnanthera Sprague (Theaceae) possesses various known pharmacological properties. However, its anti-inflammatory activity has not been reported. OBJECTIVE: The anti-inflammatory activity of Ternstroemia gymnanthera stem bark aqueous extract (TGSBE) was evaluated using LPS-stimulated RAW264.7 macrophages. MATERIALS AND METHODS: Cytotoxicity was assessed by MTT assay after 24 h with TGSBE (25-200 µg/mL). Further testing used TGSBE at 100 and 200 µg/mL. Griess and ELISA methods after 24 h with TGSBE determined NO and cytokine levels, respectively; then, mRNA levels (iNOS & cytokines) were analyzed by Quantitative-PCR after 12 h. NF-κB and MAPK were assessed by immunoblotting after TGSBE treatment for 12 h, followed by LPS for 30 min. Immunofluorescence assay was also performed for NF-κB. ROS and MMP, after 12 h with TGSBE, were determined by flow cytometry. The antioxidant potential of TGSBE was analyzed by ABTS assay. The Folin-Ciocalteu method determined the total phenolic content of TGSBE. LPS concentration was 0.5 µg/mL. RESULTS: TGSBE at 200 µg/mL showed about 96.2% viability while suppressing the production of NO (88.99%), TNFα (24.38%), IL-6 (61.70%) and IL-1ß (55.12%) and gene expression by 67.88, 45.24, 65.84, and 70.48%, respectively. TGSBE decreased ROS (79.26%) and improved MMP (48.01%); it inhibited translocation of NF-κB and MAPK activation. Radical scavenging activity was 50% at 402.17 µg/mL (ascorbic acid standard 88.8 µg/mL). Total phenolic content was 240.9 mg GAE/g. DISCUSSION AND CONCLUSION: TGSBE suppresses the inflammatory response by inhibiting the NF-κB and MAPK cascades exhibiting therapeutic potential to treat inflammatory diseases associated with increased activation of macrophages.