Proanthocyanidins from the bark of Metasequoia glyptostroboides ameliorate allergic contact dermatitis through directly inhibiting T cells activation and Th1/Th17 responses.
OBJECTIVE
The leaves and bark of Metasequoia glyptostroboides are used as anti-microbic, analgesic and anti-inflammatory drug for dermatic diseases in Chinese folk medicine. However, the pharmacological effects and material basis responsible for the therapeutic use of this herb have not yet been well studied. The objectives of this study were to evaluate the anti-inflammatory effects of the proanthocyanidin fraction from the bark of M. glyptostroboides (MGEB) and to elucidate its immunological mechanisms.


METHODS
The anti-inflammatory activity of MGEB was evaluated using 2,4-dinitrofluorobenzene (DNFB)-induced allergic contact dermatitis (ACD) in mice. Its potential mechanisms were further investigated by determining its effects on Con A-induced T cell activation and Th1/Th17 responses in vitro.


RESULTS
Both intraperitoneal injection and oral administration of MGEB significantly reduced the ear swelling in DNFB-induced ACD mice. MGEB inhibited Con A-induced proliferation and the expression levels of cell surface molecules CD69 and CD25 of T cells in vitro. MGEB also significantly decreased the production of Th1/Th17 specific cytokines (IL-2, IFN-γ and IL-17) and down-regulated their mRNA expression levels in activated T-cells.


CONCLUSIONS
MGEB could ameliorate ACD, at least in part, through directly inhibiting T cells activation and Th1/Th17 responses.
Institute of Materia Medica, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China.
Fengyang
F
Chen
Institute of Materia Medica, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China.
Xiaodi
X
Ye
Institute of Bioengineering, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China.
Yadong
Y
Yang
Institute of Materia Medica, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China.
Tianli
T
Teng
Institute of Materia Medica, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China.
Xiaoyu
X
Li
Institute of Materia Medica, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China.
Shifang
S
Xu
Institute of Materia Medica, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China. Electronic address: yeyiping2005@163.com.
Yiping
Y
Ye
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D029779:Cupressaceae / Q000737:chemistry*; D016207:Cytokines / Q000276:immunology; D017449:Dermatitis, Allergic Contact / Q000188:drug therapy*; D005260:Female; D008213:Lymphocyte Activation / Q000187:drug effects*; D008807:Mice, Inbred BALB C; D008813:Mice, Inbred ICR; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000494:pharmacology*; D044945:Proanthocyanidins / Q000494:pharmacology*; D018417:Th1 Cells / Q000276:immunology; D058504:Th17 Cells / Q000276:immunology
D000893:Anti-Inflammatory Agents; D016207:Cytokines; D010936:Plant Extracts; D044945:Proanthocyanidins; C013221:proanthocyanidin
Allergic contact dermatitis; Metasequoia glyptostroboides; Proanthocyanidin; T cells activation; Th1/Th17 responses