Astragalus saponins Inhibits Lipopolysaccharide-Induced Inflammation in Mouse Macrophages.

Excessive nitric oxide (NO) and pro-inflammatory cytokines are produced during the pathogenesis of inflammatory diseases and cancer. It has been demonstrated that anti-inflammation contributes Astragalus membranaceus saponins (AST)'s beneficial effects in combination of conventional anticancer drugs. However, the immunomodulating property of AST has not been well characterized. In this study, we found that AST suppressed lipopolysaccharide (LPS)-induced generation of NO without causing cytotoxicity in the mouse macrophage RAW264.7. The gene and protein overexpression of inducible NO synthase (iNOS) as well as the production of tumor necrosis factor-[Formula: see text], evoked by LPS, was consistently down-regulated by AST. AST also inhibited the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and suppressed nuclear factor (NF)-[Formula: see text]B activation and the associated I[Formula: see text]B[Formula: see text] degradation during LPS insult. Furthermore, AST induced growth inhibition in promyelocytic leukemic HL-60 cells and T-lymphocyte leukemic Jurkat cells, but exerted no cytotoxic effects in normal human peripheral blood mononuclear cells (PBMC). It is known that the chemotherapeutic drug 5-FU can suppress the immune system, which can be identified by a reduced white blood cell count and decreased hematocrit, while the combination of AST and 5-FU can reverse the above hematologic toxicities. To summarize, non-cytotoxic concentrations of AST suppress LPS-induced inflammatory responses via the modulation of p38 MAPK signaling and the inhibition of NO and cytokine release. Importantly, AST can alleviate the hematologic side effects of current chemotherapeutic agents. These findings can facilitate the establishment of AST in the treatment of inflammatory diseases and inflammation-mediated tumor development.

Anti-fibrotic effects of phenolic compounds on pancreatic stellate cells.

BACKGROUND: Pancreatic fibrosis is a prominent histopathological characteristic of chronic pancreatitis and plausibly a dynamic process of transition to the development of pancreatic ductal adenocarcinoma. Conversely, the activation of pancreatic stellate cells (PSCs) has been recently suggested as the key initiating step in pancreatic fibrosis. As natural polyphenols had been largely applied in complementary therapies in the past decade, in this study, we aimed to investigate which groups of phenolic compounds exert promising inhibitory actions on fibrogenesis as there are few effective strategies for the treatment of pancreatic fibrosis to date. METHODS: We examined the anti-fibrotic effects of a variety of herbal constituents using a cellular platform, the LTC-14 cells, which retained essential characteristics and morphologies of primary PSCs, by means of various biochemical assays including cell viability test, real-time polymerase chain reaction and Western blotting analysis. RESULTS: Among a number of commonly used herbal constituents, we found that the application of rhein, emodin, curcumin and resveratrol significantly suppressed the mRNA and protein levels of several fibrotic mediators namely alpha-smooth muscle actin, type I collagen and fibronectin in LTC-14 cells against transforming growth factor-beta stimulation. Though the values of cytotoxicity varied, the mechanism of the anti-fibrotic action of these four phenolic compounds was principally associated with a decrease in the activation of the nuclear factor-kappaB signaling pathway. CONCLUSIONS: Our findings suggest that the mentioned phenolic compounds may serve as anti-fibrotic agents in PSC-relating disorders and pathologies, particularly pancreatic fibrosis.