Forsythiaside a

For analyzing HPLC fingerprint profiles, SAM (10mg/ml) or the marker glycyrrhizic acid, licorice, and forsythiaside A (10 μL) were injected directly into the Prominence UFLC instrument (Shimadzu LC-10A) with a C-18 reverse phase column. glycyrrhizic acid, licorice, and forsythiaside A were purchased from Sigma-Aldrich Chemical Co. (St. Louis, Mo, USA). Separation was conducted with a gradient elution of 0.6% phosphoric acid and acetonitrile (0-30 min, B 98%→70%; 30-60 min, B 70%→39%) at a flow rate of 0.8 mL/min. Chromatographic peaks were detected at 260 nm with a SPD-M20A DAD detector. Chromatographic data were collected and processed by an Empower™ chromatographic working station.

The LPS (E. coli 026:B6) and Griess reagent were obtained from Sigma (St. Louis, MO, USA). Glycyrrhizic acid, liquiritigenin, berberine, baicalin, baicalein, forsythiaside-A and poncirin were also purchased from Sigma. Enzyme-linked immunosorbent assay (ELISA) kits for tumour necrosis factor-alpha (TNF-α), interleukin (IL)-6 and IL-1β were acquired from Pierce Endogen (Thermo Scientific, Waltham, MA, USA). The PGE₂ ELISA kit was obtained from R&D Systems (Minneapolis, MN, USA). The primary antibodies for the phospho (p)-inhibitor of NF-κB α (I-κBα), p-ERK, p-jun NH₂-terminal kinase (JNK), p-p38, ERK, JNK and p38 antibodies were purchased from Cell Signaling (Danvers, MA, USA). COX-2 and iNOS antibodies were obtained from BD Biosciences (San Jose, CA, USA), while the NF-κB, IκBα, β-actin and lamin A/C antibodies were purchased from Santa Cruz Biotechnology (Dallas, TX, USA).