Possible mechanisms mediating the protective effect of cilostazol in L-arginine induced acute pancreatitis in rats: role of cGMP, cAMP, and HO-1

Bicarbonated Ringer's solution improves L-arg-induced acute pancreatitis in rats via the NF-κB and Nrf2 pathways

OBJECTIVE

Bicarbonated Ringer's solution (BRS), as a new generation of crystalline fluid, has been widely used for intravenous fluid resuscitation in patients with shock diseases. The purpose of our study is to investigate the intervention effects and potential mechanisms of BRS on L-arg-induced AP in rats.

METHODS

The AP model was induced by intraperitoneal injection of 20% L-arg. BRS was infused immediately following the previous L-arg injection. The pancreatic tissue was harvested for histological examination. The serum levels of amylase and lipase activity, lactic acid, proinflammatory and anti-inflammatory cytokines were determined. The peroxide and antioxidant activities in the pancreatic tissue were measured. The protein and mRNA levels of nuclear factor-κB, TNF-α, nuclear factor erythroid 2-related Factor 2 and heme oxygenase-1 were determined by Western blot and quantitative reverse transcription PCR analysis.

RESULTS

Pancreatic tissue injuries were obviously alleviated, with a significant increase in normal acinar cells after BRS treatment. The serum levels of amylase, lipase, lactic acid, IL-1β and TNF-α were significantly decreased, while IL-10 was obviously increased by inhibiting the NF-κB pathway and TNF-α. Moreover, Nrf2 pathway and HO-1 were promoted by BRS treatment, which resulted in significantly reduced malondialdehyde and reactive oxygen species levels. In contrast, antioxidant activities, including glutathione peroxidase and so on, were markedly increased after BRS treatment.

CONCLUSIONS

Bicarbonated Ringer's solution improves L-arg-induced acute pancreatitis in rats through the NF-κB and Nrf2 pathways, indicating that BRS holds promise as a priority in fluid resuscitation to treat acute pancreatitis.

Combined carvacrol and cilostazol ameliorate ethanol-induced liver fibrosis in rats: Possible role of SIRT1/Nrf2/HO-1 pathway

Carvacrol is a natural phenolic monoterpenoid, and cilostazol is a selective phosphodiesterase-3 inhibitor with antioxidant, anti-inflammatory and antiapoptotic effects. This experiment aimed to explore the hepatoprotective effects of carvacrol and cilostazol alone and in combination against alcoholic liver fibrosis (ALF), and the underlying mechanisms, using silymarin as a reference anti-fibrotic product. ALF was induced by oral administration of ethanol (1 ml/100 g/day) thrice per week. Silymarin (100 mg/kg), carvacrol (70 mg/kg), cilostazol (50 mg/kg), or carvacrol + cilostazol combination were administered daily and concurrently with ethanol for six weeks. Hepatic changes were evaluated by quantifying serum biomarkers of liver injury, hepatic MDA, GSH and NOx as oxidative stress markers, interleukin (IL)-10 as an anti-inflammatory cytokine, 4-hydroxyproline (4-HYP) as a collagen synthesis indicator, transforming growth factor (TGF)-β1 as a profibrogenic cytokine, α-smooth muscle actin (α-SMA) as a marker of hepatic stellate cells (HSCs) activation, histopathological (necroinflammation and fibrosis) scores and hepatic sirtuin-1 (SIRT1), nuclear factor-erythroid 2-related factor 2 (Nrf2), and hemeoxygenase-1 (HO-1) mRNA levels. Our results showed that carvacrol, cilostazol, and their combination significantly ameliorated ethanol-induced hepatic fibrosis manifested as improving hepatic functions and histopathological features, attenuating α-SMA immunostaining, reducing TGF-β1 and 4-HYP levels, suppressing oxidativeinjury and elevating IL-10 contents. Such effects were accompanied by upregulating SIRT1, Nrf2 and HO-1 genes. This work disclosed for the first time the hepatoprotective effect of carvacrol against ALF and, to a greater extent, with carvacrol + cilostazol combination that could be partially accredited to SIRT1/Nrf2/HO-1 pathway with consequent antioxidant, anti-inflammatory, and anti-fibrotic features.

Effects of nitroglycerin combined with continuous regional arterial infusion on severe acute pancreatitis, triglyceride, inflammatory factors and prognosis

Background: To evaluate the effects of nitroglycerin combined with continuous regional arterial infusion (CRAI) on severe acute pancreatitis (SAP), triglyceride (TG), inflammatory factors and prognosis.

Methods: SAP patients were randomly divided into control and observation groups (n=169). The control group was treated with intravenous infusion of nitroglycerin once daily for 2 d, while the observation group was treated with nitroglycerin combined with CRAI for 7 d. Their hospitalization time, abdominal pain relief time, abdominal distension relief time and intestinal function recovery time were recorded. The levels of inflammatory factors, and TG were measured. Their liver and kidney functions, hemorheological indices, prognosis, and adverse reactions were evaluated.

Results: The observation group had significantly shorter hospitalization time, abdominal pain relief time, abdominal distension relief time, and intestinal function recovery time than those of the control group (P<0.05). After treatment, the levels of interleukin-6, tumor necrosis factor-alpha, endothelin, thromboxane A2 and TG significantly decreased in contrast with those before treatment in both groups, especially in the observation group (P<0.05). The hemorheological indices were significantly improved after treatment compared with those before treatment in both groups, and the observation group had better indices (P<0.05). The Acute Physiology and Chronic Health Evaluation-II score declined significantly in both groups after treatment, and the observation group had a more obvious decrease (P<0.05). During follow-up, similar incidence rates of adverse reactions were observed for both groups (P>0.05).

Conclusion: Nitroglycerin combined with CRAI is prominently effective for treating SAP, which can facilitate the health recovery and reduce the incidence of microcirculation disturbance-induced adverse events such as organ failure.

Reorienting of pramipexole as a promising therapy for acute pancreatitis in a rat model by suppressing TLR-4\NF-κB p65\NLRP3 inflammasome signaling

OBJECTIVE

Acute pancreatitis (AP), a disorder of global importance, has a growing incidence and prevalence, particularly in the western world. Its complications include pseudo-cysts and chronic pancreatitis. Pramipexole (PMX), a D2/3 receptor selecting agonist used in Parkinsonism, has reported anti-inflammatory effects lately.

PURPOSE

Exploring the potential curative role of PMX in an l-arginine-induced acute pancreatitis rat model besides a possible mechanistic pathway.

METHODS

Rats were divided randomly into three groups: control, l-arginine, and "l-arginine + PMX". 7 days after AP induction, rats decapitated and estimated for serum amylase, lipase, glucose, pancreatic inflammatory mediators "toll-like receptor-4, nuclear factor- kappa B p65 ,serum tumor necrosis factor-α, NLRP3 inflammasome, caspase-1, interleukin-1 beta, oxidative biomarkers "malondialdehyde, myeloperoxidase, nitrite/nitrate, reduced glutathione, and the apoptotic marker "caspase-3", with pancreatic histopathological changes.

RESULTS

L-arginine mediated AP proved by elevated serum lipase and amylase, pancreatic inflammatory, oxidative and apoptotic markers with infiltration of inflammatory cells using hematoxylin and eosin stain. PMX improved all these adverse signs of AP greatly.

CONCLUSION

PMX might be considered as an innovative therapy for AP due to its remarkable antioxidant, anti-apoptotic, and anti-inflammatory effects, which are attributed to the suppression of the NLRP3 inflammasome and its downstream inflammatory cytokines.

Salidroside alleviates taurolithocholic acid 3-sulfate-induced AR42J cell injury

OBJECTIVES

To investigate the protective effects of Salidroside (Sal) on AP cell model induced by taurolithocholic acid 3-sulfate (TLC-S) as well as its underlying mechanism.

METHODS

AR42J cells were divided into normal group (N group), AP cell model group (Mod group), Sal treated alone group (S+N group) and Sal treated AP cell model group (S+Mod group). The cell viability was examined by CCK-8 assay. Secretion of lipase and trypsin by AR42J cells, quantified using commercial assay kits, was used as the markers of TLC-S-induced pancreatitis. The levels of TNF-α, IL-1β, IL-8, IL-6 and IL-10 in the cell supernatant were measured by ELISA. The effect of Sal on molecules in the NF-κB signaling pathway and autophagy was investigated by qRT-PCR and western blot.

RESULTS

The decreased cell viability in Mod group was increased by Sal (P < 0.01). The upheaved activities of lipase and trypsin in AP cell model were declined by Sal (P < 0.01). The levels of TNF-α, IL-1β, IL-8 and IL-6 in the cell supernatant, Beclin-1 and LC3-Ⅱ mRNA and protein, p-p65/p65 protein, which were increased in AP cell model, were decreased by Sal; and IL-10 in the cell supernatant, LAMP2 mRNA and protein, p-IκBα/IκBα protein which was declined in AP cell model, was increased by Sal (P < 0.05 or 0.01). There were no significant differences in all indexes between the N and S+N groups (P > 0.05).

CONCLUSIONS

Sal alleviated AR42J cells injury induced by TLC-S, inhibited the inflammatory responses and modulated the autophagy, mainly through inhibiting the NF-κB signaling pathway.

Saikosaponin A-Induced Gut Microbiota Changes Attenuate Severe Acute Pancreatitis through the Activation of Keap1/Nrf2-ARE Antioxidant Signaling

Objective

Severe acute pancreatitis (SAP) is a serious and life-threatening disease associated with multiple organ failure and a high mortality rate and is accompanied by distinct oxidative stress and inflammatory responses. Saikosaponin A has strong antioxidant properties and can affect the composition of gut microbiota. We sought to determine the effects of Saikosaponin A interventions on SAP by investigating the changes of gut microbiota and related antioxidant signaling.

Methods

A SAP model was established in Sprague-Dawley (SD) rats through the injection of sodium taurocholate into the biliopancreatic duct and confirmed by elevated levels of serum lipase and amylase. The model was fed a standard diet either with saline solution or with Saikosaponin A. Fecal microbiota transplantation (FMT) from Saikosaponin A-induced rats into the rat model was performed to test the effects of gut microbiota. The composition of gut microbiota was analyzed by using 16S rRNA gene sequencing. We measured apoptotic status, inflammatory biomarkers, and Keap1-Nrf2-ARE ((Kelch-like ECH-associated protein 1) nuclear factor erythroid 2-related factor 2-antioxidant response element) antioxidant signaling.

Results

Saikosaponin A intervention attenuated SAP lesions and reduced the levels of serum amylase and lipase, oxidative stress, and inflammatory responses by reducing pathological scores and affecting the serum level of oxidative and inflammatory factors. Meanwhile, the expression of Keap1-Nrf2-ARE was increased. Saikosaponin A intervention improved microbiota composition by increasing the relative abundance of Lactobacillus and Prevotella species. FMT resulted in similar results as those caused by the Saikosaponin A intervention, suggesting Saikosaponin A may exert its function via the improvement of gut microbiota composition.

Conclusions

Saikosaponin A-induced gut microbiota changes attenuate SAP progression in the rat model and may be a potential natural drug for adjuvant treatment of SAP. Further work is needed to clear up the points.