RESUMEN
Sweet potato leaves contain the highest levels of functional polyphenols. In this study the effects of the sweet potato leaf extract and its contents, such as mono (3, 4, and 5)-caffeoylquinic acid (CQA), di-CQA (4,5-diCQA, 3,5-diCQA, and 3,4-diCQA) and caffeic acid (CA), were evaluated on the ß-catenin/Tcf-4 signaling in human colorectal cancer HCT116 cells. The extract and the CQA derivatives inhibited the ß-catenin/Tcf-4 signaling, and the inhibition of the di-CQA (with two caffeoyl groups) was higher than that of the mono-CQA (one-caffeoyl group) and CA, suggesting that the caffeoyl structure in the presence of a catechol group plays a significant role in interfering with the ß-catenin/Tcf-4 signaling. In addition, the CQA derivatives had no effect on the ß-catenin protein expression, but all test compounds inhibited the expression of the Tcf-4 transcription, and the inhibition of the di-CQA derivatives was stronger than those of the mono-CQA derivatives as well as the ß-catenin/Tcf-4 transcriptional activity. These compounds can modulate the downstream Wnt signaling pathway, suggesting that sweet potato leaves can be a protective food for colorectal cancer.
Asunto(s)
Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Regulación hacia Abajo/efectos de los fármacos , Ipomoea batatas/química , Extractos Vegetales/farmacología , Ácido Quínico/análogos & derivados , Factores de Transcripción/genética , beta Catenina/metabolismo , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Células HCT116 , Humanos , Hojas de la Planta/química , Ácido Quínico/farmacología , Transducción de Señal/efectos de los fármacos , Factor de Transcripción 4 , Factores de Transcripción/metabolismoRESUMEN
A novel catechin, pilosanol N (1), was isolated from Agrimonia pilosa Ledeb and its structure was determined by (1)H, (13)C NMR and HRESI-MS analyses. Compound 1 inhibited nitric oxide (NO) production in LPS/IFN-γ -induced RAW264.7 macrophages, and then the iNOS gene expression and its protein production with LPS/IFN-γ treatment cells were also suppressed in the presence of 1. In addition, compound 1 scavenged NO or nitrogen radicals generated from NOR3 (4-ethyl-2-hydroxyamino-5-nitro-3-hexenamide) as an NO donor. These results indicated that pilosanol N can decrease the level of NO through a mechanism that involved both a decrease in the NO production and NO scavenging.
