Preventive Effects of Gardenia jasminoides on Cerulein-Induced Chronic Pancreatitis.

Our previous report revealed that Gardenia jasminoides (GJ) has protective effects against acute pancreatitis. So, we examined whether aqueous extract of GJ has anti-inflammation and antifibrotic effects even against cerulein-induced chronic pancreatitis (CP). CP was induced in mice by an intraperitoneal injection of a stable cholecystokinin (CCK) analogue, cerulein, six times a day, four days per week for three weeks. GJ extract (0.1 or 1[Formula: see text]g/kg) or saline (control group) were intraperitoneally injected 1[Formula: see text]h before first cerulein injection. After three weeks of stimulation, the pancreas was harvested for the examination of several fibrotic parameters. In addition, pancreatic stellate cells (PSCs) were isolated using gradient methods to examine the antifibrogenic effects of GJ. In the cerulein-induced CP mice, the histological features of the pancreas showed severe tissue damage such as enlarged interstitial spaces, inflammatory cell infiltrate and glandular atrophy, and tissue fibrosis. However, treatment of GJ reduced the severity of CP such as pancreatic edema and inflammatory cell infiltration. Furthermore, treatment of GJ increased pancreatic acinar cell survival, and reduced pancreatic fibrosis and activation of PSC in vivo and in vitro. In addition, GJ treatment inhibited the activation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated protein kinase (ERK) in the PSCs. These results suggest that GJ attenuated the severity of CP and the pancreatic fibrosis by inhibiting JNK and ERK activation during CP.

Saikosaponin d ameliorates pancreatic fibrosis by inhibiting autophagy of pancreatic stellate cells via PI3K/Akt/mTOR pathway.

Chronic pancreatitis is characterized by pancreatic fibrosis, associated with excessive activation of pancreatic stellate cells (PSCs) and increased expression of transforming growth factor-ß1 (TGF-ß1). Recently, our studies have shown that autophagy inhibitor could inhibit PSCs activation and reduce collagen secretion. Saikosaponin d (SSd), the major active component of bupleurum falcatum (a medicinal plant), has anti-fibrosis effects in liver. However, it is unclear whether SSd has a role in pancreatic fibrosis. This study aimed to investigate the effect of SSd on the autophagy and activation of PSCs in vivo and in vitro. In vivo, a rat chronic pancreatitis model was induced by intravenous injection of dibutyltin dichloride. SSd was administered at a dose of 2.0 mg/kg body weight per day by gavage. After 4 weeks, the pancreas was collected for histological and molecular analysis. In vitro, PSCs were isolated and cultured for treatment with different dosages of SSd. The results showed that SSd inhibited PSCs autophagy and activation while also reducing extracellular matrix (ECM) formation and pancreatic damage. SSd inhibited autophagy through activating the PI3K/Akt/mTOR pathway. SSd also promoted degradation of ECM with an increasing ratio of MMPs/TIMPs and suppressed the TGF-ß1/Smads pathway. From these results, we concluded that SSd prevents pancreatic fibrosis by reducing autophagy of PSCs through PI3K/Akt/mTOR pathway, which has crosstalk with the TGF-ß1/Smads pathway.

A small molecule inhibitor of NFκB blocks ER stress and the NLRP3 inflammasome and prevents progression of pancreatitis.

BACKGROUND: The underlying molecular mechanism that leads to development of chronic pancreatitis remains elusive. The aim of this study is to understand the downstream inflammatory signaling involved in progression of chronic pancreatitis, and to use withaferin A (WA), a small molecule inhibitor of nuclear factor κB (NFκB), to prevent progression of chronic pancreatitis. METHODS: Two different protocols were used to induce pancreatitis in mice: standard and stringent administration of cerulein. The severity of pancreatitis was assessed by means of pancreatic histology and serum amylase levels. Immunohistochemistry and flow-cytometric analysis was performed to visualize immune cell infiltration into the pancreas. Real-time PCR and Western blot were used to analyze the downstream signaling mechanism involved in the development of chronic pancreatitis. RESULTS: The severity of cerulein-induced pancreatitis was reduced significantly by WA, used as either preventive or curative treatment. Immune cell infiltration into the pancreas and acinar cell death were efficiently reduced by WA treatment. Expression of proinflammatory and proapoptotic genes regulated by NFκB activation was increased by cerulein treatment, and WA suppressed these genes significantly. Sustained endoplasmic reticulum stress activation by cerulein administration was reduced. NLRP3 inflammasome activation in cerulein-induced pancreatitis was identified, and this was also potently blocked by WA. The human pancreatitis tissue gene signature correlated with the mouse model. CONCLUSIONS: Our data provide evidence for the role of NFκB in the pathogenesis of chronic pancreatitis, and strongly suggest that WA could be used as a potential therapeutic drug to alleviate some forms of chronic pancreatitis.

Inhibition of chronic pancreatitis and pancreatic intraepithelial neoplasia (PanIN) by capsaicin in LSL-KrasG12D/Pdx1-Cre mice.

Capsaicin is a major biologically active ingredient of chili peppers. Extensive studies indicate that capsaicin is a cancer-suppressing agent via blocking the activities of several signal transduction pathways including nuclear factor-kappaB, activator protein-1 and signal transducer and activator of transcription 3. However, there is little study on the effect of capsaicin on pancreatic carcinogenesis. In the present study, the effect of capsaicin on pancreatitis and pancreatic intraepithelial neoplasia (PanIN) was determined in a mutant Kras-driven and caerulein-induced pancreatitis-associated carcinogenesis in LSL-Kras(G12D)/Pdx1-Cre mice. Forty-five LSL-Kras(G12D)/Pdx1-Cre mice and 10 wild-type mice were subjected to one dose of caerulein (250 µg/kg body wt, intraperitoneally) at age 4 weeks to induce and synchronize the development of chronic pancreatitis and PanIN lesions. One week after caerulein induction, animals were randomly distributed into three groups and fed with either AIN-76A diet, AIN-76A diet containing 10 p.p.m. capsaicin or 20 p.p.m. capsaicin for a total of 8 weeks. The results showed that capsaicin significantly reduced the severity of chronic pancreatitis, as determined by evaluating the loss of acini, inflammatory cell infiltration and stromal fibrosis. PanIN formation was frequently observed in the LSL-Kras(G12D)/Pdx1-Cre mice. The progression of PanIN-1 to high-grade PanIN-2 and -3 were significantly inhibited by capsaicin. Further immunochemical studies revealed that treatment with 10 and 20 p.p.m. capsaicin significantly reduced proliferating cell nuclear antigen-labeled cell proliferation and suppressed phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun as well blocked Hedgehog/GLI pathway activation. These results indicate that capsaicin could be a promising agent for the chemoprevention of pancreatic carcinogenesis, possibly via inhibiting pancreatitis and mutant Kras-led ERK activation.