Therapeutic Effects of S-Petasin on Disease Models of Asthma and Peritonitis

To explore the anti-allergic and anti-inflammatory effects of extracts of Petasites genus, we studied the effects of s-petasin, a major sesquiterpene from Petasites formosanus (a butterbur species) on asthma and peritonitis models. In an ovalbumin-induced mouse asthma model, s-petasin significantly inhibited the accumulations of eosinophils, macrophages, and lymphocytes in bronchoalveolar fluids. S-petasin inhibited the antigen-induced degranulation of beta-hexosamidase but did not inhibit intracellular Ca2+ increase in RBL-2H3 mast cells. S-petasin inhibited the LPS induction of iNOS at the RNA and protein levels in mouse peritoneal macrophages. Furthermore, s-petasin inhibited the production of NO (the product of iNOS) in a concentration-dependent manner in the macrophages. Furthermore, in an LPS-induced mouse model of peritonitis, s-petasin significantly inhibited the accumulation of polymorpho nuclear and mononuclear leukocytes in peritoneal cavity. This study shows that s-petasin in Petasites genus has therapeutic effects on allergic and inflammatory diseases, such as, asthma and peritonitis through degranulation inhibition in mast cells, suppression of iNOS induction and production of NO in macrophages, and suppression of inflammatory cell accumulation.

Action and Signaling of Lysophosphatidylethanolamine in MDA-MB-231 Breast Cancer Cells

Previously, we reported that lysophosphatidylethanolamine (LPE), a lyso-type metabolite of phosphatidylethanolamine, can increase intracellular Ca2+ ([Ca2+]i) via type 1 lysophosphatidic acid (LPA) receptor (LPA1) and CD97, an adhesion G-protein-coupled receptor (GPCR), in MDA-MB-231 breast cancer cells. Furthermore, LPE signaling was suggested as like LPA1/CD97-Gi/o proteins-phospholipase C-IP3-Ca2+ increase in these cells. In the present study, we further investigated actions of LPE not only in the [Ca2+]i increasing effect but also in cell proliferation and migration in MDA-MB-231 breast cancer cells. We utilized chemically different LPEs and a specific inhibitor of LPA1, AM-095 in comparison with responses in SK-OV3 ovarian cancer cells. It was found that LPE-induced Ca2+ response in MDA-MB-231 cells was evoked in a different manner to that in SK-OV3 cells in terms of structural requirements. AM-095 inhibited LPE-induced Ca2+ response and cell proliferation in MDA-MB-231 cells, but not in SK-OV3 cells, supporting LPA1 involvement only in MDA-MB-231 cells. LPA had significant effects on cell proliferation and migration in MDA-MB-231 cells, whereas LPE had less or no significant effect. However, LPE modulations of MAPKs (ERK1/2, JNK and p38 MAPK) was not different to those by LPA in the cells. These data support the involvement of LPA1 in LPE-induced Ca2+ response and cell proliferation in breast MDA-MB-231 cells but unknown GPCRs (not LPA1) in LPE-induced responses in SK-OV3 cells. Furthermore, although LPE and LPA utilized LPA1, LPA utilized more signaling cascades than LPE, resulting in stronger responses by LPA in proliferation and migration than LPE in MDA-MB-231 cells.