Topical application of porcine placenta extract inhibits the progression of experimental contact hypersensitivity.
OBJECTIVE
Placenta extract features as a composition of ointments used for skin beautification, dermatological diseases and skin dryness. However, little evidence has been cited about its underlying mechanisms of action by which it exerts a beneficial role in dermatological diseases in vivo. In this study, we intended to test the effect of topical application of porcine placenta extract in mouse model of contact hypersensitivity and elucidate its mechanism of action.


METHODS
To test the in vitro effect of porcine placenta extract, RAW 264.7 cells were cocultured with porcine placenta extract and stimulated with LPS (1 μg/ml) and the expression of inflammatory mediator TNF-α was estimated by RT-PCR at the mRNA level and by intracellular staining at the protein level. To further test in vivo efficacy, porcine placenta extract was topically applied to the mice with experimental skin hypersensitivity. For in vivo studies placenta extract in gel form was topically applied to ear of DNCB-induced contact hypersensitivity mouse model everyday for 2 weeks and progression of the disease was estimated by following criteria: (a) ear thickness, (b) serum IgE level by ELISA, (c) histological examination of ear tissue by H&E staining and (d) cytokine profile of total cells and CD4(+) T cells by real time PCR.


RESULTS
Topical application of porcine placenta extract on mouse ears with contact hypersensitivity decreased the severity and progression of the disease manifested by reducing ear swelling, inflammation and edema. Histological evaluation showed that placenta extract treatment reduced lymphocyte infiltration in the ear tissues. Protective effect of placenta extract is also associated with down-regulation of serum IgE level and inflammatory cytokine production (IL-1β, IFN-γ, TNF-α, IL-4, IL-12 and IL-17) in total lymph node cells and CD4(+) T cells.


CONCLUSIONS
Our data indicate that protective effect of porcine placenta extract in contact hypersensitivity is mediated by inhibition of the inflammatory responses and IgE production, suggesting a potential therapeutic application of porcine placenta extract to modulate skin inflammation.
School of Life Sciences and Immune Synapse Research Center, Gwangju Institute of Science and Technology, 1 Oryong-dong, Puk-ku, Gwangju 500-712, Republic of Korea.
Arijita
A
Jash
Ho-Keun
HK
Kwon
Anupama
A
Sahoo
Choong-Gu
CG
Lee
Jae-Seon
JS
So
Jungho
J
Kim
Yu-Kyoung
YK
Oh
Young Bong
YB
Kim
Sin-Hyeog
SH
Im
D000287:Administration, Topical; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D003877:Dermatitis, Contact / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D004195:Disease Models, Animal; D015536:Down-Regulation; D020834:Ethnopharmacology; D005260:Female; D007073:Immunoglobulin E / Q000097:blood; D018836:Inflammation Mediators / Q000378:metabolism; D008262:Macrophage Activation; D051379:Mice; D010920:Placenta / Q000737:chemistry*; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013552:Swine; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
D016207:Cytokines; D017931:DNA Primers; D018836:Inflammation Mediators; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D007073:Immunoglobulin E