抗色素過度沈著及紫外線保護活性之中草藥 第一報 旋覆花之活性成分

The Anti-hyperpigmentation and UV Protective Activity of Chinese Herbal Medicine I. The active compounds of Inula britannica

廖淑茹(Liao Shu-Ju)

指導教授 ： 顏焜熒 ； 楊玲玲

臺北醫學大學/藥學院/生藥學研究所/碩士(1999年)

摘要

Melanin生合成及UV (ultraviolet) 之照射與色素沉著過度有密切的關係。近來，天然成分於美妝產品之應用極受矚目，相關之研究開發也更顯重要。本論文以開發具抗色素過度沉著及UV保護活性之天然藥物資源為目的。 本研究從中醫藥古籍及民間常用藥材中選取面部用藥28種中藥材之50％EtOH萃取物，以體外試驗探討Melanin的生合成抑制及UV之吸收保護。紫外線會造成發炎反應進而誘導黑色素生成而堆積於表皮底層，並會損傷DNA造成老化。Melanin於Melanocyte生合成，tyrosinase催化dopa轉變為dopachrome，為Melanin生合成的速率限制步驟。而dopachrome再經自主氧化作用生成Melanin。實驗篩選出最具Tyrosinase抑制活性且具UV-A、UV-B吸收效用之藥材-旋覆花Inula britannica L.。以Tyrosinase抑制活性之追蹤進行成分之分離，並取活性劃分部進一步測試UV spectrum，證明旋覆花 旋覆花之50% EtOH經Diaion HP-20、Sephadex LH-20、LiChroprep RP-18之柱狀色層分析及精製，並經NMR、 Mass等儀器分析確定，可得由quinic acid及caffeic acid（亦為旋覆花含有之成分）鍵結而成之4,5-、1,4-、 3,5-di-o-caffeoylquinic acid。其中4,5- di-o-caffeoylquinic acid具Tyrosinase活性抑制； 1,4-、 3,5-di-o-caffeoylquinic acid具UV-A、UV-B吸收效用及Dopachrome經Autoxidation之Melanin生成抑制作用。 針對quinic acid、caffeic acid及旋覆花成分之chlorogenic acid、quercetin進行Melanin生合成之抑制試驗。其中quercetin最高之Tyrosinase活性抑制，但溶解度差。而以經修飾之quercetin pentaacetate進行相同之試驗，結果具有較好之溶解度且Tyrosinase之抑制效用及對dopachrome經autoxidation之Melanin生成抑制率，皆優於kojic acid。 綜合以上結果，旋覆花兼具抗黑色素過度沈著及紫外線之保護作用，為一極具開發潛力之天然藥物資源。

關鍵字

Melanin之生合成 ； Tyrosinase ； 色素沈著過度 ； UV-A

並列摘要

Melanin biosynthesis and UV (ultraviolet) irradiation are closely related to hyperpigmentation. Recently, much attention has been to the application of naturally occur crude drugs to cosmetics. The purpose of this investigation was to study the inhibitory effect of 50% EtOH from 28 crude drugs on melanin biosynthesis and UV protection in order to develop a skin-whitening agent from natural source. In this study, the 28 crude drugs selected from classics or folk cures were investigated in vitro for the action on a process involved in melanin biosynthesis and UV absorption. Solar UV irradiation causes various inflammatory skin conditions and DNA damage. Pigmentation on human skin followed by sunburn in thought to be due to overproduction of the dermal melanin. Melanin biosynthesis occurs in melanocytes and involves the production of dopachrome from dopa by tyrosinase, the rate limited step, and melanin Of the 28 extracts, the 50% EtOH extract from dried flower of Inula britannica L. had the best tyrosinase inhibition, and absorbed UV-A and -B. It was then separated by Diaion HP-20, Sephadex LH-20 and LiChroprep RP-18 column chromatography and got 4,5-, 1,4- and 3,5- di- o- caffeoylquinic acid by NMR, Mass and IR analysis. 4,5- di- o- caffeoylquinic acid inhibited tyrosinase. 1,4- and 3,5- di- o- caffeoylquinic acid absorbed UV-A and inhibitory autoxidation of dopachrome to melanin production. In the study, we also put chlorogenic acid, caffeic acid and quercetin, the components of Inula britannica L., to the test of melanin biosynthesis inhibitory. Quercetin had the best inhibition of tyrosinase activity, but was hard to dissolved. Quercetin pentaacetate was modified from quercetin and had better solubility. It had lower IC50 of tyrosinase and higher inhibition of autoxidation involved in melanin production than kojic acid. It can be concluded that the flower of Inula britannica L. is a potential crude drug of anti-hyperpigmentation and UV protection.

並列關鍵字

Melanin biosynthesis ； tyrosinase ； hyperpigmentation ； UV-A

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