Anemoside B4 protects against IgE-dependent allergic responses by suppressing the PLC/IP3 and JAK/STAT3 pathways

Crocetin inhibits mast cell-dependent immediate-type allergic reactions through Ca2+/PLC/IP3 and TNF pathway

Crocetin is a kind of glycocone naturally occurring in Crocus sativus L.. It is an active metabolite produced by biohydrolysis of Crocus sativus L.. Crocetin has anti-cardiovascular diseases and antioxidant effects, but its anti-allergic effect has not been reported. In this study, the inhibitory effect of crocetin on immunoglobulin E (IgE) - mediated allergic reaction and the mechanism of action were investigated. The passive cutaneous anaphylaxis (PCA) was used to elucidate the anti-allergic effects of crocetin in vivo. Degranulation assay, calcium imaging, and cytokine release assay were to evaluate the anti-allergic effect of crocetin in vitro. We found that crocetin IgE-mediated RBL-2H3 cell degranulation and allergy both in vitro and in vivo. The TNF pathway was inhibited by crocetin in our RNA-seq sequences, Furthermore, crocetin inhibits IgE-mediated calcium influx, and PLC / IP3 phosphorylation in RBL-2H3 cells. Our findings suggested that crocetin revealed prominent anti-allergy activity through TNF and Ca2+/PLC/IP3 pathway.

Anemoside B4 attenuates RANKL-induced osteoclastogenesis by upregulating Nrf2 and dampens ovariectomy-induced bone loss

Increased numbers and functional overactivity of osteoclasts are the pathological basis for bone loss diseases such as osteoporosis, which are characterized by cortical bone thinning, decreased trabecular bone quantity, and reduced bone mineral density. Effective inhibition of osteoclast formation and bone resorption are important means of treating such skeletal diseases. Anemoside B4 (AB4), the main active component of Pulsatilla chinensis, possesses a wide range of anti-inflammatory and immunoregulatory effects. However, its effect and mechanism in osteoclast differentiation remain unclear. In this study, we found through tartrate-resistant acidic phosphatase (TRAcP) staining and immunofluorescence staining that AB4 inhibited the differentiation, fusion, and bone-resorption functions of osteoclasts induced by receptor activator of nuclear factor κB ligand (RANKL) in vitro. Additionally, real time PCR (RT-qPCR) and western blot analysis showed AB4 downregulated the expression of osteoclast marker genes, including Nfatc1, Fos, and Ctsk, while upregulating Nrf2 expression. AB4 (5 mg/kg) alleviated bone loss in ovariectomized mice by inhibiting osteoclast formation. Furthermore, the knockout of Nrf2 weakened the inhibitory effects of AB4 on osteoclast formation and related gene expression. In summary, the results suggest AB4 can inhibit osteoclast differentiation and function by activating Nrf2 and indicate AB4 may be a candidate drug for osteoporosis.

Mast Cells as a Target-A Comprehensive Review of Recent Therapeutic Approaches

Mast cells (MCs) are the immune cells distributed throughout nearly all tissues, mainly in the skin, near blood vessels and lymph vessels, nerves, lungs, and the intestines. Although MCs are essential to the healthy immune response, their overactivity and pathological states can lead to numerous health hazards. The side effect of mast cell activity is usually caused by degranulation. It can be triggered by immunological factors, such as immunoglobulins, lymphocytes, or antigen-antibody complexes, and non-immune factors, such as radiation and pathogens. An intensive reaction of mast cells can even lead to anaphylaxis, one of the most life-threatening allergic reactions. What is more, mast cells play a role in the tumor microenvironment by modulating various events of tumor biology, such as cell proliferation and survival, angiogenesis, invasiveness, and metastasis. The mechanisms of the mast cell actions are still poorly understood, making it difficult to develop therapies for their pathological condition. This review focuses on the possible therapies targeting mast cell degranulation, anaphylaxis, and MC-derived tumors.