Beneficial effects of trypsin inhibitors derived from a spider venom peptide in L-arginine-induced severe acute pancreatitis in mice

Albiflorin Alleviates Severe Acute Pancreatitis-Associated Liver Injury by Inactivating P38MAPK/NF-κB Signaling Pathway

Albiflorin (Alb) is a monoterpenoid component that is commonly found in Paeonia lactiflora Pall. or Paeonia veitchii Lynch. It is known for its impressive anti-oxidant and anti-inflammatory properties. However, the effect of Alb on severe acute pancreatitis (SAP)-associated liver injury has not been fully understood. To investigate this, we conducted a study using a rat model of SAP induced by administering two intraperitoneal injections of 20% L-arginine (3.3 g/kg) over a period of 2 h. Subsequently, the SAP-induced rats were randomly assigned into different groups with the treatment of gradient doses of Alb (5, 10, and 20 mg/kg), with the normal saline as the sham group. The pathological changes in rat livers were evaluated through hematoxylin-eosin staining. Furthermore, the levels of amylase (AMY), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were determined using specific enzyme-linked immunosorbent assay kits. Moreover, the serum levels of inflammatory factors, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β, were quantified. Finally, immunohistochemical and Western blot analyses were conducted to determine phosphorylation levels of nuclear factor kappa B (NF-κB) p65 and mitogen-associated protein kianse (MAPK) p38 in the liver tissues. TNF-α stimulated liver cells were used as a cell model to further confirm the involvement of NF-κB and p38 in the effect of Alb. Our study revealed that Alb effectively mitigated the hepatic pathological damage in a dose-dependent manner and reduced the levels of indicators associated with hepatic malfunction (AMY, AST, and ALT) in rats with SAP-induced liver injury. Additionally, Alb demonstrated its ability to suppress inflammation and oxidative stress markers in the liver tissues. Alb exerted dose-dependent inhibitory effects by modulating the P38MAPK/NF-κB signaling pathway. Overall, our findings strongly support the hepatoprotective effect of Alb in rats with SAP-induced liver injury, suggesting that Alb protects against SAP-induced liver injury through the suppression of inflammation and oxidative stress via the P38MAPK/NF-κB signaling pathway.

Animal venoms: a novel source of anti-Toxoplasma gondii drug candidates

Toxoplasma gondii (T. gondii) is a nucleated intracellular parasitic protozoan with a broad host selectivity. It causes toxoplasmosis in immunocompromised or immunodeficient patients. The currently available treatments for toxoplasmosis have significant side effects as well as certain limitations, and the development of vaccines remains to be explored. Animal venoms are considered to be an important source of novel antimicrobial agents. Some peptides from animal venoms have amphipathic alpha-helix structures. They inhibit the growth of pathogens by targeting membranes to produce lethal pores and cause membrane rupture. Venom molecules generally possess immunomodulatory properties and play key roles in the suppression of pathogenic organisms. Here, we summarized literatures of the last 15 years on the interaction of animal venom peptides with T. gondii and attempt to explore the mechanisms of their interaction with parasites that involve membrane and organelle damage, immune response regulation and ion homeostasis. Finally, we analyzed some limitations of venom peptides for drug therapy and some insights into their development in future studies. It is hoped that more research will be stimulated to turn attention to the medical value of animal venoms in toxoplasmosis.

Molecular cloning, bioinformatics analysis and functional characterization of HWTX-XI toxin superfamily from the spider Ornithoctonus huwena

Spider venom contains a very valuable repertoire of natural resources to discover novel components for molecular diversity analyses and therapeutic applications. In this study, HWTX-XI toxins from the spider venom glands of Ornithoctonus huwena which are Kunitz-type toxins (KTTs) and were directly cloned, analyzed and functionally characterized. To date, the HWTX-XI superfamily consists of 38 members deduced from 121 high-quality expressed sequence tags, which is the largest spider KTT superfamily with significant molecular diversity mainly resulted from cDNA tandem repeats as well as focal hypermutation. Among them, HW11c40 and HW11c50 may be intermediate variants between native Kunitz toxins and sub-Kunitz toxins based on evolutionary analyses. In order to elucidate their biological activities, recombinant HW11c4, HW11c24, HW11c27 and HW11c39 were successfully expressed, further purified and functionally characterized. Both HW11c4 and HW11c27 display inhibitory activities against trypsin, chymotrypsin and kallikrein. Moreover, HW11c4 is also an inhibitor relatively specific for Kv1.1 channels. HW11c24 and HW11c39 are found to be inactive on chymotrysin, trypsin, kallikrein, thrombin and ion channels. These findings provide molecular evidence for toxin diversification of the HWTX-XI superfamily and useful molecular templates of serine protease inhibitors and ion channel blockers for the development of potentially clinical applications.

Chloroquine relieves acute lung injury in rats with acute hemorrhagic necrotizing pancreatitis

This study preliminarily investigated the mechanism by which chloroquine (CQ) relieves acute lung injury (ALI) complicated in acute hemorrhagic necrotizing pancreatitis (AHNP). Sixty male Wistar rats were randomized into sham-operated group (group A, n=10), AHNP group (group B, n=10), L-arginine-treated group (group C, n=10), L-N-nitro-L-arginine methyl ester (NAME)-treated group (group D, n=10), CQ-treated group (group E, n=10) and CQ+L-NAME-treated group (group F, n=10). TLR4 expression was measured by using real time-PCR and Western blotting respectively. The results showed that, in the group B, the expression of TLR4 and the levels of TNF-α and IL-6 in the lungs were significantly increased, and the nitric oxide (NO) concentration was reduced, as compared with those in the group A (P<0.05 or P<0.01). Lung injury was aggravated with the increased expression of TLR4. When the inhibitor and stimulator of TLR4, namely L-Arg and L-NAME, were added respectively, lung injury was correspondingly relieved or aggravated (P<0.05 or P<0.01). In the group E, TLR4 expression was substantially lower and NO concentration higher than those in the group B (P<0.05 or P<0.01). However, in the group F, NO concentration was markedly decreased, and the inhibitory effect of CQ on TLR4 expression and the relief of lung injury were weakened when compared with those in the group E (P<0.05 or P<0.01). It was concluded that TLR4 may play an important role in the pathogenesis and development of ALI complicated in AHNP. CQ could relieve ALI by decreasing the TLR4 expression and increasing the NO release.