Preventive and therapeutic potential of placental extract in contact hypersensitivity

Abstract

Immunoregulatory effects of placental extract and placenta-derived factors have been demonstrated in various conditions. Accordingly, placental extract has been used as certain types of medical intervention in Asian countries, whereas experimental evidence supporting its therapeutic effects and mechanisms has yet to be fully demonstrated. In this study, we investigate preventive and therapeutic effects of placental extract in contact hypersensitivity (CHS), a mouse model of allergic contact dermatitis. Administration of placental extract prior to the sensitization of allergic antigen (Ag) significantly inhibited the severity of CHS induced by Ag challenge. This effect was associated with reduced numbers of CD4+ T cells in peripheral blood, decrease of tissue-infiltrating lymphocytes, and preferential production of Th2-type cytokines in Ag-challenged sites. In addition, CHS caused by repetitive challenges of allergic Ag was also prevented and treated by administration of placental extract. Finally, administration of cyclo-trans-4-Lhydroxyprolyl-L-serine, a dipeptide derived from placental extract, also alleviated CHS, suggesting its potential role in the effects of placental extract in CHS. Taken together, our findings demonstrated experimental evidence supporting immunoregulatory effects of placental extract in allergic skin diseases and elucidated its potential mechanisms.

Putative Prophylaxes Updated of Placenta Extract and Aloe vera as Biogenic Stimulants

“…Finally, administration of cyclo-trans-4-L-hydroxy-prolyl-L-serine (JBP485), a dipeptide derived from PE, also alleviated CHS, suggesting its potential role in the effects of PE in CHS. Taken together, these findings demonstrated experimental evidence supporting immunoregulatory effects of PE in allergic skin diseases and elucidated its potential mechanisms [35] .…”

Human placental extract reduces allergic inflammation in a murine allergic rhinitis model

“…Previous studies have demonstrated the immune inhibitory effect of HPE in allergic dermatitis and arthritis . We hypothesize that HPE might impair the distribution of CD4+ T lymphocytes, thereby inhibiting the allergic response.…”

Topical application of porcine placenta extract inhibits the progression of experimental contact hypersensitivity

“…Hence this can partly explain the reason as to why we did not detect significant change in IL-6 level in our study. Report by Kim et al, showed that placenta extract prevents the development of CHS by decreasing IFN-␥ while increasing IL-4 and IL-10 levels (Kim et al, 2010). They performed subcutaneous implantation of placenta extract 3 days before sensitization which resulted in a significant inhibition of CHS response.…”

“…1). Recent work by Kim et al, also showed that treatment of placenta extract significantly decreased CD4 + T cells in the PBMC (Kim et al, 2010). However the role of CD4 + T helper (Th) cells versus CD8 + cytotoxic T (Tc) cells in CHS is still unclear.…”

“…Recent report showed that the compound cyclo-trans-4-l-hydrocypyrolyl-l-serine, isolated from PE, has beneficiary effect to ameliorate CHS (Kim et al, 2010). However, the efficacy of this compound is apparent in the later stage of the disease whereas PE is effective from the early stage of the disease.…”