Inhibition of phorbol ester-induced COX-2 expression by some edible African plants
Inhibition of phorbol ester-induced COX-2 expression by some edible African plants
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DOI：
10.1002/biof.552210130
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发表时间：
2004-01-01
期刊：
影响因子：
6
通讯作者：
Surh, YJ
中科院分区：
文献类型：
--
作者：
Na, HK;Mossanda, KS;Surh, YJ
癌症布什（CB，Sutherlandia frutescens），魔鬼爪（DEV，Harpagophytum procumbens），Rooibos茶（RT，Aspalathus linearis）和Bambara花生（BB，Vignea地下）已被用于治疗非洲的一些恶性肿瘤和炎症性疾病。然而，这些药用植物的化学预防作用的生物化学基础仍不清楚。环氧合酶-2（考克斯-2）的异常高表达与肿瘤的发生、发展有关。在本研究中，我们发现CB，DEV，RT和BB的甲醇提取物抑制，在不同程度上，12-O-十四烷酰基佛波醇-13-乙酸酯（TPA）诱导的考克斯-2在人乳腺上皮细胞（MCF 10 A）和小鼠皮肤在体内的表达。为了确定上述药用植物抑制考克斯-2的分子机制，我们检测了它们对NF-κ B活化的影响，NF-κ B是负责调节考克斯-2表达的主要转录因子之一。CB和BB的甲醇提取物以剂量依赖性方式抑制MCF 10A细胞中TPA激活的NF-κ B的DNA结合。基于上述发现，CB和BB可能通过抑制NF-κ B的DNA结合来抑制TPA诱导的考克斯-2表达，这可能有助于这些非洲植物的化学预防或化学保护活性。
Cancer bush (CB, Sutherlandia frutescens), Devil's claw (DEV, Harpagophytum procumbens), Rooibos tea (RT, Aspalathus linearis), and Bambara groundnut (BB, Vignea subterranean) have been used to treat some malignancies and inflammatory disorders in Africa. However, biochemical basis for chemopreventive effects of these medicinal plants remains unclear. An abnormally elevated expression of cyclooxygenase-2 (COX-2) has been implicated in pathogenesis and progression of carcinogenesis. In the present study, we found that the methanol extracts of CB, DEV, RT, and BB inhibited, to a different extent, 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced COX-2 expression in human breast epithelial (MCF10A) cells and in mouse skin in vivo. To determine the molecular mechanism of COX-2 inhibition by the above medicinal plants, we examined their effects on activation of NF-kappaB which is one of the major transcription factors responsible for regulating COX-2 expression. Methanol extracts of both CB and BB inhibited the DNA binding of NF-kappaB activated by TPA in MCF10A cells in a dose-dependent manner. Based on above findings, CB and BB are likely to inhibit TPA-induced COX-2 expression through suppression of DNA binding of NF-kappaB, which may contribute to the chemopreventive or chemoprotective activity of these African plants.