Establishment of Psoriasis Rat Model with Spleen Deficiency and Dampness Obstruction Syndrome Induced by External Dampness Factors

Yating ZHANG; Haojie SU; Fanlu LIU; Panyu ZHOU; Qing WANG; Junhong ZHANG; Jingjing WU; Ling HAN

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Establishment of Psoriasis Rat Model with Spleen Deficiency and Dampness Obstruction Syndrome Induced by External Dampness Factors

VernacularTitle:外湿因素诱导下银屑病脾虚湿阻证病证结合大鼠模型的建立
Author: Yating ZHANG ¹ ; Haojie SU ² ; Fanlu LIU ² ; Panyu ZHOU ² ; Qing WANG ² ; Junhong ZHANG ³ ; Jingjing WU ³ ; Ling HAN ⁴
Author Information

1. Dongguan Hospital，Guangzhou University of Chinese Medicine，Dongguan，523000
2. The Second Clinical Medical College of Guangzhou University of Chinese Medicine
3. State Key laboratory of Dampness Syndrome of Chinese Medicine，The Second Affiliated Hospital of Guangzhou University of Chinese Medicine
4. Guangdong Provincial Laboratory of Traditional Chinese Medicine （Hengqin Laboratory）
Publication Type:Journal Article
Keywords: psoriasis; spleen deficiency and dampness obstruction syndrome; animal model combination of disease and syndrome; rat
From: Journal of Traditional Chinese Medicine 2025;66(13):1369-1377
CountryChina
Language:Chinese
Abstract: ObjectiveTo construct a rat model of psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type）， and evaluate the macroscopic manifestations and microscopic indicators of the model. MethodsTwenty-two SD rats were divided into normal group （n=3）， common psoriasis group （n=5）， spleen deficiency and dampness obstruction syndrome （external dampness type） group （n=7）， and psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type） group （n=7）. The spleen deficiency and dampness obstruction syndrome （external dampness type） rat model was established through 32-week exposure to an artificially simulated high-humidity environment， while the common psoriasis model was developed via 7-day topical application of imiquimod cream， and these two approaches were combined to construct a composite model of psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type）. Rats in the normal group were housed under normal humidity conditions. The general state， tongue manifestation of rats were observed to evaluate the macroscopic syndrome manifestations； the microscopic syndrome manifestations of rats were evaluated through adipose tissue and liver tissue changes； the severity of psoriasis in rats was evaluated through skin pathological changes， psoriasis area and severity index （PASI）， proliferating cell nuclear antigen （PCNA） expression and spleen tissue changes； changes in rat CD4⁺ interferon-γ⁺ cells （CD4⁺IFN-γ⁺ cells）， CD4⁺ tumour necrosis factor-α+ cells （CD4⁺ TNF-α⁺ cells）， and forkhead framing protein P3⁺ regulatory T cells （CD3⁺CD4⁺FoxP3⁺ Treg cells） were detected by flow cytometry. ResultsMacroscopically， both the spleen deficiency and dampness obstruction syndrome （external dampness type） group and psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type） group exhibited manifestations of spleen deficiency and dampness obstruction， including lethargy， huddling behavior， dull and disheveled fur， as well as soft or loose stools and perianal soiling in some individuals； both these two groups displayed enlarged tongue， swollen， and moist tongue texture， accompanied by slippery tongue surface. Microscopically， compared to the common psoriasis group， the psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type） group showed increased epididymal fat index （P＜0.05）； compared to the normal group and spleen deficiency and dampness obstruction syndrome （external dampness type） group， the psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type） group demonstrated significantly elevated spleen mass （P＜0.05）， while hepatic gross morphology and HE staining revealed no significant histopathological changes across all groups. Dorsal skin lesions were markedly exacerbated in the psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type） group when compared to those in common psoriasis group. Both the common psoriasis group and psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type） group exhibited significantly higher erythema scores， scaling scores， infiltration scores， PASI total scores， and proportions of CD3⁺CD4⁺FoxP3⁺Treg cells compared to the normal group and spleen deficiency and dampness obstruction syndrome （external dampness type） group （P＜0.05）， with pronounced PCNA-positive expression observed in the epidermal basal layer and dermis； the psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type） group displayed significantly increased proportions of CD4⁺TNF-α⁺cells compared to the spleen deficiency and dampness obstruction syndrome （external dampness type） group （P＜0.05）； whereas no significant differences were detected in CD4⁺IFN-γ⁺cell proportions among groups （P＞0.05）. ConclusionThe rat model of psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type） can be successfully constructed by artificially simulating a high-humidity environment combined with imiquimod induction.