Protective effects of daphnetin on sodium taurocholate-induced severe acute pancreatitis in rats

Daphnetin ameliorates acute lung injury in mice with severe acute pancreatitis by inhibiting the JAK2-STAT3 pathway

Severe acute pancreatitis (SAP) is often associated with pulmonary inflammation leading to acute lung injury. Daphnetin, a natural coumarin derivative, has been reported to exert anti-inflammatory effects. Here, we explored the effect and possible mechanism of daphnetin in a mouse model of SAP-associated lung injury induced by an intraperitoneal injection of L-arginine. The severity of pancreatic and lung injury is determined by histology and its score. Immunostaining of inflammatory and apoptotic cells was used to demonstrate lung tissue inflammation and apoptosis; ELISA analysis of serum and tissue cytokine levels; and western blotting and immunohistochemical staining for the activated Janus kinase 2 (JAK2)-signal transducer and activator of transcription protein 3 (STAT3) signalling pathway in lung tissues. Daphnetin pretreatment significantly reduced SAP-induced pancreatic and lung tissue damage, reduced interleukin-6 and tumour necrosis factor-α concentrations in both serum and lung tissues, reduced serum amylase and myeloperoxidase activities, and reduced macrophage (CD11b) and neutrophil (Ly6G) infiltration and cell apoptosis in the lung tissue. Moreover, SAP-induced phosphorylation of JAK2 and STAT3 in the lung tissue was also significantly diminished by the daphnetin pretreatment. These results indicated that daphnetin reduces SAP-associated lung tissue damage, likely by inhibiting the activation of JAK2-STAT3 signalling.

Daphnetin suppresses experimental abdominal aortic aneurysms in mice via inhibition of aortic mural inflammation

Rupture of abdominal aortic aneurysm (AAA) is a devastating event that can be prevented by inhibiting the growth of small aneurysms. Therapeutic strategies targeting certain events that promote the development of AAA must be developed, in order to alter the course of AAA. Chronic inflammation of the aortic mural is a major characteristic of AAA and is related to AAA formation, development and rupture. Daphnetin (DAP) is a coumarin derivative with anti-inflammatory properties that is extracted from Daphne odora var. However, the effect of DAP on AAA development remains unclear. The present study investigated the effect of DAP on the formation and development of experimental AAAs and its potential underlying mechanisms. A mice AAA model was established by intra-aortic infusion of porcine pancreatic elastase (PPE), and mice were intraperitoneally injected with DAP immediately after PPE infusion. The maximum diameter of the abdominal aorta was measured by ultrasound system, and aortic mural changes were investigated by Elastica van Gieson (EVG) staining and immunohistochemical staining. The results demonstrated that DAP significantly suppressed PPE-induced AAA formation and attenuated the depletion of aortic medial elastin and smooth muscle cells in the media of the aorta. Furthermore, the density of mural macrophages, T cells and B cells were significantly attenuated in DAP-treated AAA mice. In addition, treatment with DAP resulted in a significant reduction in mural neovessels. These findings indicated that DAP may limit the formation and progression of experimental aneurysms by inhibiting mural inflammation and angiogenesis. These data confirmed the translational potential of DAP inclinical AAA inhibition strategies.

Daphne giraldii Nitsche (Thymelaeaceae): Phytochemistry, pharmacology and medicinal uses

Daphne giraldii Nitsche., a member of the genus Daphne (Thymelaeaceae), is a deciduous shrub with mild toxicity. Its rhizome bark, generally called 'Zushima' in Chinese, has many medicinal folkloric uses and good therapeutic effects. Previous studies investigating the chemical constituents and pharmacological activities of D. giraldii have focused on several major classes of compounds, such as coumarins, lignans and flavonoids, especially the interesting enantiomeric flavans. Extracts and pure compounds of D. giraldii were found to possess anti-inflammatory, anti-nociceptive, cytotoxicity, antimalarial, immunomodulating, sedative and hypnotic effects. They have also been reported to influence the cardiovascular functions and blood activities. This comprehensive review will describe the advances in the phytochemistry, pharmacology, medicinal uses and clinical applications of D. giraldii and its formulations covering the literature published from 1970 to 2018. Almost half of the reviewed studies were originally published in non-English languages (mainly in Chinese). Collectively, the aim of this article is to open new avenues for further in-depth pharmacological studies on D. giraldii.

Daphnetin Ameliorates Experimental Autoimmune Encephalomyelitis Through Regulating Heme Oxygenase-1

To assess the potential role of daphnetin, a clinically used anti-inflammatory agent, on the development of the inflammatory and neurodegenerative disease, we investigated its immune regulatory function in a murine model of experimental autoimmune encephalomyelitis (EAE). Significantly, lower levels of pro-inflammatory cytokines including interleukin (IL)-17, interferon-γ, Il6, Il12a, and Il23a were observed in brains of daphnetin-treated EAE mice, compared with those in control littermates. We also confirmed that daphnetin suppressed the production of IL-1β, IL-6, and tumor necrosis factor-α in lipopolysaccharide-stimulated mouse BV2 microglial cells. Mechanistically, heme oxygenase-1 (HO-1), a canonical anti-oxidant and anti-inflammatory factor, was found to be substantially induced by daphnetin treatment in BV2 cells. Also, a significantly higher level of HO-1, accompanied by a decreased level of malondialdehyde, was observed in daphnetin-treated EAE mice. More importantly, the deletion of HO-1 in BV2 microglia largely abrogated daphnetin-mediated inhibition of the inflammatory response. Together, our data demonstrate that daphnetin has an anti-inflammatory and neuroprotective role during the pathogenesis of EAE, which is partially at least, dependent on its regulation of HO-1.

The phytochemistry, pharmacokinetics, pharmacology and toxicity of Euphorbia semen

ETHNOPHARMACOLOGICAL RELEVANCE

Euphorbia semen, the dried and ripe seed of Euphorbia lathyris Linnaeus, is widely cultivated for traditional medicine use. This semen is used to expel water, help with phlegm retention, promote blood circulation, remove blood stasis, cure tinea and scabies, and treat amenorrhea, snakebites, terminal schistosomiasis, anuria and constipation.

AIM OF THE REVIEW

This review provides updated, comprehensive and categorized information on the local and traditional uses, phytochemistry, pharmacokinetics, pharmacological activities and toxicity of Euphorbia semen. Future research to deepen the recognition and utilization of Euphorbia semen is proposed.

MATERIALS AND METHODS

This article conducted a literature review on information about Euphorbia semen in multiple Internet databases, including PubMed, Web of Science, Wiley, Science Direct, Elsevier, ACS publications, SciFinder, Google Scholar and China National Knowledge Internet, until March of 2018. In this manuscript, a number of books, PhD and MSc dissertations, and Chinese Pharmacopeia were also used as references.

RESULTS

Approximately 240 chemical constituents have been isolated and identified from Euphorbia semen, namely, diterpenoids, coumarins, flavonoids, fatty acids, amino acids, and steroids. Pharmacokinetic study focused on investigating absorption, distribution, metabolism and excretion (ADME). The chemical constituents have extensive pharmacological effects, such as diuresis and anti-hyperuricaemia, anti-inflammation, antiviral, anticancer, antioxidant, antipigmentation, anti-platelet aggregation and anti-allergic activities, as well as hepatoprotection and neuroprotection. The toxicity of Euphorbia semen, including acute toxicity, target organ irritation and cocareinogenic effects, have been reported, and the detoxification methods are reviewed.

CONCLUSION

Euphorbia semen has extensive pharmacological activity and excellent clinical value, along with intense intestinal irritation. Although plenty of chemical constituents have been isolated and identified, the exact pharmacological and toxicological mechanisms still need to be explored.

Toll-Like Receptor 2 Signaling and Current Approaches for Therapeutic Modulation in Synucleinopathies

The innate immune response in the central nervous system (CNS) is implicated as both beneficial and detrimental to health. Integral to this process are microglia, the resident immune cells of the CNS. Microglia express a wide variety of pattern-recognition receptors, such as Toll-like receptors, that detect changes in the neural environment. The activation of microglia and the subsequent proinflammatory response has become increasingly relevant to synucleinopathies, including Parkinson's disease the second most prevalent neurodegenerative disease. Within these diseases there is evidence of the accumulation of endogenous α-synuclein that stimulates an inflammatory response from microglia via the Toll-like receptors. There have been recent developments in both new and old pharmacological agents designed to target microglia and curtail the inflammatory environment. This review will aim to delineate the process of microglia-mediated inflammation and new therapeutic avenues to manage the response.

Daphnetin Protects against Cerebral Ischemia/Reperfusion Injury in Mice via Inhibition of TLR4/NF-κB Signaling Pathway

Growing evidences indicate that immune-mediated mechanisms contribute to the development of cerebral ischemia/reperfusion (I/R) injury. Daphnetin (DAP) is a coumarin derivative extracted from Daphne odora var., which displays anti-inflammatory properties. However, the effect of DAP on cerebral I/R injury is not yet clear. Recent studies have demonstrated that TLR4/NF-κB signaling pathway takes part in the damaging inflammatory process of cerebral I/R injury. The present study aimed to investigate the effect of DAP on cerebral I/R injury in vivo and its possible mechanisms. DAP was administered before middle cerebral artery occlusion and reperfusion in mice. The neurological scores, cerebral infarct sizes, the levels of inflammatory cytokines, apoptotic neural cells, and the levels of TLR4, NF-κB p65, and IκBα were estimated. The results showed that an obvious improvement of neurological scores and infarct sizes was observed in DAP-treated mice after MCAO/R. DAP treatment decreased the overexpression of TNF-α, IL-1β, and IL-6 and attenuated neural cells apoptosis. Moreover, DAP treatment decreased the TLR4 expression, IκB-α degradation, and nuclear translocation of NF-κB. Taken together, our results suggested that DAP exerted neuroprotective and anti-inflammatory effects on cerebral I/R injury. The potential mechanism was involved in the inhibition of TLR4/NF-κB mediated inflammatory signaling pathway.

Role of Daphnetin in Rat Severe Acute Pancreatitis Through the Regulation of TLR4/NF-[Formula: see text]B Signaling Pathway Activation

Severe acute pancreatitis (SAP) often results in multiple-organ dysfunction syndrome with high mortality. There is no effective clinical therapy for SAP, yet daphnetin, a coumarin extracted from Dracaena marginata, has analgesic and anti-inflammatory effects, and has been used clinically in several diseases. The objective of this study was to investigate the role and underlying mechanisms of daphnetin in a rat SAP model. Male Wistar rats were pretreated with daphnetin via intraperitoneal injection, 30[Formula: see text]min before retrograde infusion of 5% sodium taurocholate into the biliopancreatic duct. Twelve hours after sodium taurocholate administration, rats were sacrificed and tissues and blood were harvested. Then, histological, chemical, and molecular analyses were performed. Daphnetin treatment reduced the levels of serum alanine transaminase and creatinine (CR), increased superoxide dismutase(SOD) activity, and decreased neutrophil infiltration and cell apoptosis of the pancreatic tissues in rat SAP. Daphnetin treatment significantly decreased expression of pro-inflammatory cytokines and increased expression of anti-inflammatory cytokines in rat SAP. Molecular analyses revealed that daphnetin reduced TLR4 expression and inhibited NF-[Formula: see text]B signaling pathway activation. These findings demonstrate that daphnetin attenuates acute pancreatic injury by regulating the TLR4/NF-[Formula: see text]B signaling pathway and inflammation in rat SAP model. Daphnetin may be a potential therapeutic agent for SAP.

Antioxidant Effect of Ukrain Versus N-Acetylcysteine Against Acute Biliary Pancreatitis in An Experimental Rat Model

Purpose/Aim: Oxidative stress plays an important role in the pathogenesis of acute pancreatitis (AP). We compared the therapeutic effects of Ukrain (NSC 631570) and N-acetylcysteine (NAC) in rats with AP.

MATERIALS AND METHODS

Forty male Sprague Dawley rats were divided into four groups: controls; AP; AP with NAC; and AP with Ukrain. AP was induced via the ligation of the bile-pancreatic duct; drugs were administered intraperitoneally (i.p.) 30 min and 12 h after AP induction. Twenty-four hours after AP induction, animals were sacrificed and the pancreas was excised. Levels of malondialdehyde (MDA) and nitric oxide (NO), and activity levels of tumor necrosis factor (TNF)-α, and myeloperoxidase (MPO) were measured in tissue samples. Total oxidant status (TOS), total antioxidant status (TAS), and total bilirubin, as well as activity levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), amylase and lipase were measured in serum samples. Pancreatic tissue histopathology was also evaluated.

RESULTS

Test drugs reduced levels of MDA, NO, TNF-α, total bilirubin, AST, ALT, TOS and MPO, amylase and lipase activities (P < 0.001), and increased TAS (P < 0.001). Rats treated with test drugs attenuated AP-induced morphologic changes and decreased pancreatic damage scores compared with the AP group (P < 0.05). Both test drugs attenuated pancreatic damage, but the therapeutic effect was more pronounced in rats that received Ukrain than in those receiving NAC.

CONCLUSIONS

These results suggest that treatment with Ukrain or NAC can reduce pancreatic damage via anti-inflammatory and antioxidant effects.

Ultrastructural changes in the pulmonary mechanical barriers in a rat model of severe acute pancreatitis-associated acute lung injury

This study examined the ultrastructural changes in the pulmonary mechanical barriers in a rat model of severe acute pancreatitis (SAP)-associated acute lung injury (ALI). Animals were randomized into the SAP group (n = 60) and the control group (n = 60). SAP was induced by retrograde injection of 5% taurocholic acid into the biliopancreatic duct. The morphological abnormalities assessed by histology and the lung wet/dry weight ratio and the ultrastructural abnormalities assessed by transmission electron microscope and scanning electron microscope examinations plus lanthanum nitrate tracing were compared between the two groups at 6, 12, and 24 h post-SAP induction (n = 10/group/time point). The SAP group had significantly greater extravascular effusion than the control group at each time point as assessed by the lung wet/dry weight ratio (p < .001). The severity of the tissue damage increased in the lung and pancreas over time in the SAP group (all p < .001). In the SAP group, ultrastructural damages to the endothelial, epithelial, and pleural barriers were apparent and the damages to the endothelial barrier were detected earlier than the other two barriers, suggesting its fundamental role in preventing the further development of SAP-associated ALI. Moreover, the ultrastructural abnormalities were detected earlier than symptoms and morphological changes. The ultrastructural damages in the endothelial, epithelial, and pleural barriers occurred in the early stage of SAP. The endothelial barrier is likely to be the first line to prevent the further development in this rat model of SAP-associated ALI.