OBJECTIVES: To elucidate the anti-inflammatory activity of S. ferruginea parasitising on three different hosts of Vitex negundo L., Micromelum minutum (G. Forst.) Wight & Arn. and Tecoma stans (L.) Juss ex HBK., as well as, to determine the metabolite differences related to their anti-inflammatory properties.
MATERIALS AND METHODS: Two plant parts of S. ferruginea, stems and leaves, were extracted in water. The freeze-dried stem of S. ferruginea grown on T. stans was liquid-liquid partitioned into several solvents. Their potential anti-inflammatory activity was assessed via inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS) and interferon-γ (IFN-γ)-induced RAW 264.7 macrophage cells. The metabolite variation was examined using proton nuclear magnetic resonance (1 H-NMR) combined with multivariate data analysis (MVDA).
RESULTS: Scurrula ferruginea stems parasitising on T. stans and V. negundo which were freeze dried exhibited higher anti-inflammatory activity with IC50 values of 114.47 ± 2.96 and 118.87 ± 2.31 μg/mL, respectively. The mid-polar ethyl acetate fraction of S. ferruginea hosted on T. stans displayed the highest NO inhibition with 84.80 ± 0.45% at 200 μg/mL. Principal component analysis (PCA) indicated notable and clear discriminations among the different plant parts and host plants based on the identified metabolites. Furthermore, partial least squares (PLS) regression model suggested the anti-inflammatory bioactivity might be associated with the presence of choline, isoleucine, catechin, leucine and chlorogenic acid.
CONCLUSION: This study suggests S. ferruginea could serve as a potential anti-inflammatory agent, highlighting the importance of T. stans as the host plant.
AIM OF THE STUDY: To evaluate the anti-inflammatory activity as well as the preliminary mechanism of S. ferruginea parasitizing on Tecoma stans.
MATERIALS AND METHODS: The anti-inflammatory capability of freeze-dried stem aqueous extract was assessed via inhibition of inflammatory cytokines interleukin- (IL-) 1β, IL-6, IL-10, and tumor necrosis factor-alpha (TNF-α) production in lipopolysaccharide (LPS) and interferon-γ (IFN-γ) stimulated RAW 264.7 macrophages. The underlying anti-inflammatory mechanism was deciphered through reverse transcriptase and real time quantitative polymerase chain reactions (RT-PCR and qPCR) for inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), IL-1β, and TNF-α mRNA expression.
RESULTS: The results exhibited that aqueous extract of freeze-dried S. ferruginea stem sample concentration-dependently inhibited IL-1β protein production along with the down regulation of iNOS and IL-1β mRNA expression. Moreover, it significantly suppressed the protein release of IL-6 and IL-10 in a concentration-dependent manner. However, it slightly reduced TNF-α at higher sample concentration (250 μg/mL) without affecting the mRNA expression levels of COX-2 and TNF-α.
CONCLUSIONS: This study suggests that S. ferruginea parasitizing on Tecoma stans exerted anti-inflammatory capability attributed to inhibition of iNOS and IL-1β mRNA expression, NO creation, IL-1β, IL-6, IL-10, and TNF-α protein production, indicating this plant might be a useful plant-derived candidate against inflammation.