Piper cubebaL. Methanol Extract Has Anti-Inflammatory Activity Targeting Src/Syk via NF-κB Inhibition

Abstract

Piper cubeba L. is a plant in the Piperaceae family that is generally found in tropical countries and acts as an antioxidant and anti-inflammatory agent. Unfortunately, the molecular mechanism of the anti-inflammatory activity has not been fully investigated. In this study, we elucidated the anti-inflammatory mechanism by focusing on NF-κB signaling, which is considered a prototypical inflammatory signaling pathway in both innate and adaptive immune functions. Cellular activity and the molecular target of Pc-ME were identified in macrophage RAW264.7 cells and HEK293T cells by assessing NO production, cytokine expression by RT-PCR, luciferase gene reporter assay, and protein regulation in cytoplasm by Western blot upon NF-κB activation. Pc-ME reduced NO production without any cell toxicity; inhibited expression of proinflammatory cytokines such as iNOS and IL-6; downregulated NF-κB activation mediated by both MyD88 and TRIF; and diminished the phosphorylation of IκBα, IKKα/β, Akt, p85, Src, and Syk. Pc-ME inhibited Syk and Src autophosphorylation during overexpression in HEK cells, which confirmed our hypothesis that Syk and Src were signaling targets of Pc-ME. These findings indicate that Piper cubeba L. has anti-inflammatory activity by targeting Src/Syk in the NF-κB pathway.

Antimelanogenesis Effects of Theasinensin A

“…B16F10 cells (1 × 10 5 cells/well) were seeded for 24 h into a 12-well plate prior to transfection with plasmids (0.8 µg/mL per well), encoding a luciferase gene under a CREB promoter and β-galacosidase as a control by the lipofectamine method, as previously reported [ 32 ]. After 24 h of stabilization, the transfected cells were treated with TSA (12.5–25 µM) or arbutin (1 mM) concomitantly with α-MSH (100 nM) for the next 24 h. Luciferase activity was assessed using the Luciferase Assay System (Promega, Madison, WI, USA), as previously reported [ 64 , 65 ].…”

Trichosanthes tricuspidata Lour. Methanol Extract Exhibits Anti-Inflammatory Activity by Targeting Syk, Src, and IRAK1 Kinase Activity

“…LPS induced NF-κB activation, which phosphorylates the IκB kinase complex and simultaneously degrades IκBα, which results in translocation of p50/p65 NF-κB subunits in the nucleus [45,46]. Moreover, ERK1/2, JNK, and p38 have been identified as upstream subfamilies which activate AP-1 cascades [47,48].…”

Rottlerin Reduces cAMP/CREB-Mediated Melanogenesis via Regulation of Autophagy

“…The supernatants, containing protein from the melanin content, were analyzed by immunoblotting as previously reported [27,28]. The total and phosphorylated levels of LC3B (14,16), ATG5 (56), CREB (phospho-form 46; total form 40), PKA (42) and β-actin (45) were visualized with an ECL system (Amersham, Little Chalfont, Buckinghamshire, UK).…”