The anti-angiogenic effect of tryptanthrin is mediated by the inhibition of apelin promoter activity and shortened mRNA half-life in human vascular endothelial cells.

BACKGROUND: Anti-angiogenesis is an important strategy of psoriasis treatment, but the side effects of systemic agents remain difficult to overcome. Topical use of indigo naturalis ointment has been proved to improve the skin lesion of psoriasis effectively and safely and one of its major components, tryptanthrin, has been demonstrated to have anti-angiogenic effect. Apelin, which has been reported to act as an angiogenic factor that could stimulate the proliferation and migration of vascular endothelial cells and proved to be elevated in psoriasis patients, is a potential target of anti-angiogenic therapy. PURPOSE: We aim to find out if tryptanthrin works on the apelin pathway and study its anti-angiogenic mechanism. STUDY DESIGN: Human umbilical vein endothelial cells (HUVECs) were used as the in vitro model. METHODS: The effect of tryptanthrin on the expression of apelin and its receptor, APJ, was examined. The mRNA stability, promoter activity, and bioactivity of apelin, were also investigated. Migration and tube formation assay were used to evaluate the relationship between tryptanthrin and apelin. PD98059 and wortmannin were used to study the role of ERK1/2 MAPK and PI3K in apelin signaling pathway. RESULTS: We demonstrated that tryptanthrin could inhibit the expression of apelin, attenuated the stability of apelin mRNA, and significantly inhibited the apelin promoter activity. The addition of apelin-13 restored the suppression of tube formation and migration by tryptanthrin. Both PD98059 and wortmannin could down-regulate the apelin mRNA expression suggesting the important signaling role of ERK1/2 MAPK and PI3K in the gene expression of apelin. CONCLUSION: The anti-angiogenic effect of tryptanthrin was mediated by down-regulating apelin gene expression through suppression of promoter activity and decrease of mRNA stability in human vascular endothelial cells.

Indigo naturalis and its component tryptanthrin exert anti-angiogenic effect by arresting cell cycle and inhibiting Akt and FAK signaling in human vascular endothelial cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Indigo naturalis has been used to treat inflammatory diseases and dermatosis, including psoriasis, since thousands of years in China. It has been proven effective in our previous clinical studies on treating psoriasis, but the active component and the mechanism of how indigo naturalis working still needs to be clarified. Since the dysregulated angiogenesis is known to play an important role in the pathogenesis of psoriasis, the anti-angiogenic effect of indigo naturalis and tryptanthrin, a pure component of indigo naturalis, was investigated. MATERIALS AND METHODS: The in vivo angiogenesis was studied by chick chorioallantoic membrane assay. The in vitro studies were performed using human vascular endothelial cells. Cell viability was determined by MTT assay. Cell cycle distribution was revealed by flow cytometry. The cellular messenger (m)RNA or protein expression level was analyzed by real-time RT-PCR or Western blot, respectively. Transwell filter migration assay and matrix gel-induced tube formation method were applied to examine the angiogenic potential. RESULTS: Indigo naturalis significantly inhibited the in vivo vascular endothelial growth factor (VEGF)-induced angiogenesis, as well as tryptanthrin. In vitro studies confirmed that indigo naturalis and tryptanthrin reduced the number of viable vascular endothelial cells. Tryptanthrin resulted in a cell cycle arrest and dose-dependently decreased the expressions of cyclin A, cyclin B, cyclin dependent kinase(CDK) 1 and 2, but not cyclin D and cyclin E, at both the mRNA and protein levels. The migration and tube formation of vascular endothelial cells were significantly inhibited by tryptanthrin in a dose-dependent manner. Result also showed that tryptanthrin could reduce the phosphorylated levels of both protein kinase B (PKB or Akt) and focal adhesion kinase (FAK). CONCLUSIONS: All together, these results demonstrated the anti-angiogenic effect of tryptanthrin, the acting component of indigo naturalis and revealed the underlying mechanism by inhibiting the cell cycle progression, cell migration and tube formation, likely mediated through blocking the Akt and FAK pathways.

Quality of life in patients with psoriasis in northern Taiwan.

BACKGROUND: Psoriasis has a significant negative impact on quality of life. The aim of this study was to identify factors associated with the quality of life of patients with psoriasis in Taiwan. METHODS: A retrospective study analyzing data from psoriasis patients who visited the outpatient clinics in the Department of Traditional Chinese Medicine, Chang Gung Memorial Hospital at Taipei, Taoyuan and Keelung from July 2009 to January 2010 was performed. RESULTS: A total of 480 patients who had completed the assessment of disease severity and the dermatology life quality index (DLQI) questionnaire were analyzed. Of these patients, 67.5% were men. The mean score on the DLQI was 9.16 ± 6.3 and 67% of all patients reported a moderate to extremely large impact on their quality of life (DLQI > 6). A higher psoriasis area and severity index (PASI), younger age and initial lesions on the nails significantly negatively impacted patients' quality of life. Smoking, alcohol intake and gender were also weakly correlated. CONCLUSION: The clinical severity, age and site of initial lesions are associated with negative impacts on the quality of life of patients with psoriasis. These findings provide significant new insights into factors that affect the life quality of patients with psoriasis in Taiwan.

Inhibitory effect of indigo naturalis on tumor necrosis factor-α-induced vascular cell adhesion molecule-1 expression in human umbilical vein endothelial cells.

The use of indigo naturalis to treat psoriasis has proved effective in our previous clinical studies. The present study was designed to examine the anti-inflammatory effect of indigo naturalis in primary cultured human umbilical vein endothelial cells (HUVECs). Pretreatment of cells with indigo naturalis extract attenuated TNF-α-induced increase in Jurkat T cell adhesion to HUVECs as well as decreased the protein and messenger (m)RNA expression levels of vascular cell adhesion molecule-1 (VCAM-1) on HUVECs. Indigo naturalis extract also inhibited the protein expression of activator protein-1 (AP-1)/c-Jun, a critical transcription factor for the activation of VCAM-1 gene expression. Since the reduction of lymphocyte adhesion to vascular cells by indigo naturalis extract could subsequently reduce the inflammatory reactions caused by lymphocyte infiltration in the epidermal layer and help to improve psoriasis, this study provides a potential mechanism for the anti-inflammatory therapeutic effect of indigo naturalis extract in psoriasis.