Dihydrolipoic acid inhibits skin tumor promotion through anti-inflammation and anti-oxidation

Yuan Soon Ho, Ching Shu Lai, Hsin I. Liu, Sheng Yow Ho, Chein Tai, Min Hsiung Pan, Ying Jan Wang

研究成果: 雜誌貢獻文章同行評審

53 引文 斯高帕斯(Scopus)


α-Lipoic acid (LA) has been intensely investigated as a therapeutic agent for several diseases, including hepatic disorder and diabetic polyneuropathy. However, the effects of LA or its reduced form, dihydrolipoic acid (DHLA), on cancer chemoprevention has never been reported. In the present study, we examined the effects of DHLA/LA on the production of nitric oxide (NO) by inducible NO synthase (iNOS) and the formation of prostaglandin E2 (PGE2) by cyclooxygenase-2 (COX-2), two important mediators associated with inflammation. DHLA/LA significantly inhibited lipopolysaccharide (LPS)-induced NO and PGE2 formation in RAW 264.7 cells. Meanwhile, treatment with DHLA/LA suppressed the expression of iNOS protein but, unexpectedly, did not affect or increase the expression of COX-2 protein. The in vivo anti-inflammatory and antitumor-promoting activities were evaluated by a topical 12-O-tetradecanoylphorbol 13-acetate (TPA) application to mouse skin with measurement of edema formation, epidermal thickness and hydrogen peroxide production. DHLA significantly inhibited the priming and activation stages of skin inflammation induced by a double TPA application, by decreasing the inflammatory parameters. Furthermore, DHLA inhibited DMBA (0.3 μmol)/TPA (2.0 nmol)-induced skin tumor formation by reducing the tumor incidence and tumor multiplicity. When applied topically onto the shaven backs of mice prior to TPA, DHLA markedly inhibited the expression of iNOS protein. DHLA also strongly and directly inhibited COX-2 activity. These results suggest that DHLA can be a possible chemopreventive agent in inflammation-associated tumorigenesis.

頁(從 - 到)1786-1795
期刊Biochemical Pharmacology
出版狀態已發佈 - 6月 1 2007

ASJC Scopus subject areas

  • 生物化學
  • 藥理


深入研究「Dihydrolipoic acid inhibits skin tumor promotion through anti-inflammation and anti-oxidation」主題。共同形成了獨特的指紋。