Background: Wedelolactone (WEL), a major coumestan ingredient in Wedelia chinensis, has been used to treat septic shock, hepatitis and venom poisoning in traditional Chinese medicines. The objective of the study was to elucidate the anti-inflammatory effects and mechanism of WEL with a cellular model of lipopolysaccharide (LPS)-induced RAW 264.7 cells. Results: To study the role of WEL in pro-inflammation, we measured key inflammation mediators and end products including nitric oxide (NO), prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and tumor necrosis factor-α (TNF-α) by using the Griess method, enzyme linked immunosorbent assay (ELISA) and Western blotting. Nuclear factor-kappaB (NF-κB) transcription activity was detected by luciferase reporter assay. The important pro-inflammatory transcription factors, NF-κB p65 and inhibitory kappaB alpha (IκB-α); and mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 MAPK (p38) were analyzed by Western blotting. Our study showed that WEL (0.1, 1, 10 μM) significantly inhibited the protein expression levels of iNOS and COX-2 in LPS-stimulated cells, as well as the downstream products, including NO, PGE2 and TNF-α. Moreover, WEL also inhibited LPS-induced NF-κB p65 activation via the degradation and phosphorylation of IκB-α and subsequent translocation of the NF-κB p65 subunit to the nucleus. Conclusions: Our results revealed that WEL has a potential to be a novel anti-inflammatory agent targeting on the NF-κB signaling pathway.

Hepatocellular carcinoma (HCC) is the fourth largest cause of cancer-related deaths worldwide with limited therapeutic interventions. Renewed interest in natural products as drug leads has resulted in a paradigm shift toward the rapid screening of medicinal plants for the discovery of new chemical entities. Rotundic acid (RA), a plant-derived triterpenoid, has been anecdotally reported to possess anti-inflammatory and cardio-protective abilities. The present study highlights the anti-cancer efficacy of RA on HCC in vitro and in vivo. The inhibitory effects of RA on HCC cell viability was determined by MTT. Soft agar colony formation and clonogenic assays also showed that RA inhibited HCC cell proliferation. Flow cytometry, confocal, and western blot results further indicated that RA induced cell cycle arrest, DNA damage, and apoptosis by modulating the AKT/mTOR and MAPK pathways. Besides the suppression of migration and invasion, tube formation and VEGF-ELISA revealed the anti-angiogenic abilities of RA on HCC. Moreover, RA also inhibited tumor growth in a HepG2 xenograft mouse model. To our best knowledge, this is the first extensive study of the anticancer activity of RA on HCC. The results demonstrate that RA could be a potential drug candidate for HCC treatment.