Human ARG1 peptide

As part of the search for new bioactive plants from the Colombian Caribbean, the dichloromethane fraction of the calyces of Physalis angulata L. (PADF) was selected for its anti-inflammatory activity. In this work, we investigated the immunomodulatory effect of PADF in activated macrophages and during dextran sulfate sodium (DSS)-induced colitis. PADF displayed a low content of withanolides or phenolic compounds, and a higher content of sucrose esters, representative anti-inflammatory metabolites of the Physalis genus. The PADF fraction at 12.5 mu g/mL prevented the induction of interleukin (IL)-1 beta, tumor necrosis factor (TNF-alpha), IL-6, IL-12, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) by lipopolysaccharide (LPS), while increased the levels of arginase (ARG1), IL-10, and mannose receptor C (MRC1). The polarization towards an anti-inflammatory profile was also observed in resting macrophages, without promoting the typical gene profile induced by IL-4, suggesting that PADF promotes a shift to a regulatory status rather than to an alternative one. In vivo, the administration of PADF to mice with chronic DSS-colitis reduced disease signs (i.e., body weight loss and colon shortening), and improved the histology score by diminishing the levels of pro-inflammatory cytokines and increasing the production of IL-10. Overall, results suggest that the regulatory effect on PADF towards macrophages might contribute to the therapeutic activity observed in the murine model of inflammatory bowel disease.

Pancreatic cancer is an aggressive malignancy that is unresponsive to conventional radiation and chemotherapy. Therefore, development of novel immune therapeutic strategies is urgently needed. L-4F, an Apolipoprotein A-I (ApoA-I) mimetic peptide, is engineered to mimic the anti-inflammatory and anti-oxidative functionalities of ApoA-I. In this work, H7 cells were orthotopically implanted in C57BL/6 mice and treated with L-4F. Then, pancreatic cancer progression and the inflammatory microenvironment were investigated in vivo. The cytotoxicity of L-4F toward H7 cells was assessed in vitro. Furthermore, we investigated the effects of L-4F on macrophage polarization by analyzing the polarization and genes of mouse bone marrow-derived macrophages in vitro. The results show that L-4F substantially reduced the tumorigenicity of H7 cells. L-4F inhibited inflammation by reducing the accumulation of inflammatory cells, such as IL-17A-, IL-4-, GM-CSF-, IL-1 beta-, and IL-6-producing cells and Th1 and Th17. Notably, L-4F also decreased the percentage of macrophages in tumor tissues, especially M2 macrophages (CD11b(+)F4/80(+)CD206(+)), which was also confirmed in vitro. Additionally, the expression of the M2 marker genes Arg1, MRC1, and CCL22 and the inflammatory genes IL-6, iNOS, and IL-12 was decreased by L-4F, indicating that L-4F prevents M2 type macrophage polarization. However, L-4F could not directly attenuate H7 cell invasion or proliferation and did not induce apoptosis. In addition, L-4F potently down-regulated STAT3, JNK and ERK signaling pathways but not affects the phosphorylation of p38 in RAW 264.7 cells. These results suggest that L-4F exhibits an effective therapeutic effect on pancreatic cancer progression by inhibiting tumor-associated macrophages and inflammation.