Oleanolic acid attenuates renal fibrosis in mice with unilateral ureteral obstruction via facilitating nuclear translocation of Nrf2.

Abstract

BACKGROUND:

Renal interstitial fibrosis is a common final pathological process in the progression of kidney disease. This is primarily due to oxidative stress, which contributes to renal inflammation and fibrosis. Nuclear factor-erythroid-2-related factor 2 (Nrf2) is known to coordinate induction of genes that encode antioxidant enzymes. We investigated the effects of oleanolic acid, a known Nrf2 activator, on oxidative stress-induced renal inflammation and fibrosis.

METHODS:

One day before unilateral ureteral obstruction (UUO) performed in C57BL/6 mice, oleanolic acid treatment was initiated and was continued until 3 and 7 days after UUO. Renal inflammation and fibrosis, markers of oxidative stress, and changes in Nrf2 expression were subsequently evaluated.

RESULTS:

In the obstructed kidneys of UUO mice, oleanolic acid significantly attenuated UUO-induced collagen deposition and fibrosis on day 7. Additionally, significantly less inflammatory cell infiltration, a lower ratio of Bax to Bcl-2 expression, and fewer apoptotic cells on TUNEL staining were observed in the obstructed kidneys of oleanolic acid-treated mice. Oleanolic acid increased the expression of nuclear Nrf2, heme oxygenase-1, NAD(P)H:quinone oxidoreductase 1 and heat shock protein 70, and decreased lipid peroxidation in the obstructed kidney of UUO mice. There were no changes in the expression of total Nrf2 and Kelch-like ECH-associated protein 1, indicating that oleanolic acid enhanced nuclear translocation of Nrf2.

CONCLUSIONS:

These results suggest that oleanolic acid may exert beneficial effects on renal fibrosis by increasing nuclear translocation of Nrf2 and subsequently reducing renal oxidative stress.

• Authors: Sungjin Chung, Hye Eun Yoon, Soo Jeong Kim, Sung Jun Kim, Eun Sil Koh, Yu Ah Hong, Cheol Whee Park, Yoon Sik Chang, Seok Joon Shin
• Journal: Nutrition & metabolism (Nutr Metab (Lond)) Vol. 11 Issue 1 Pg. 2 (Jan 06 2014) ISSN: 1743-7075 [Print] England
• PMID: 24393202 (Publication Type: Journal Article)