Jung Ju Lee1, Kyun Ha Kim2, Eun Jeong Kim2, Jun-Yong Choi3, Sang-Jun Kim4, Seung-Il Jeong4, Jong-In Kim5, Myungsoo Joo6. 1. Department of Clinical Korean Medicine, Graduate School, Kyung Hee University, KHU Rd 23, Seoul 02447, Republic of Korea. 2. School of Korean Medicine, Pusan National University, PNU Rd 49, Yangsan 50612, Republic of Korea. 3. School of Korean Medicine, Pusan National University, PNU Rd 49, Yangsan 50612, Republic of Korea; Department of Internal Medicine, Korean Medicine Hospital of Pusan National University, Yangsan 50612, Republic of Korea. 4. Jeonju AgroBio-Materials Institute, Jeonju 57810, Republic of Korea. 5. Department of Clinical Korean Medicine, Graduate School, Kyung Hee University, KHU Rd 23, Seoul 02447, Republic of Korea. Electronic address: hann8400@hanmail.net. 6. School of Korean Medicine, Pusan National University, PNU Rd 49, Yangsan 50612, Republic of Korea. Electronic address: mjoo@pusan.ac.kr.
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE: The water extract of Forsythiae Fructus (WFF) is an herbal remedy that is prescribed to treat various inflammatory diseases in traditional Chinese medicine. Although the anti-inflammatory activity of WFF has been reported, the underlying mechanisms for the activity remain unclear. Here, we examined whether the anti-inflammatory activity of WFF is associated with Nrf2, an anti-inflammatory factor, and A20, an ubiquitin-regulator protein that inhibits signaling cascades of endotoxin or cytokines. MATERIALS AND METHODS: The water extract of Forsythia suspensa (Thunb.) Vahl was prepared and fingerprinted by HPLC. Cytotoxicity and intracellular ROS induced by WFF were determined by MTT and FACS analyses, respectively. Nuclear and cytoplasmic proteins were analyzed by immunoblot. Expression of mRNA was analyzed by a semi-quantitative RT-PCR. Expression of proteins or genes was quantitated by Image J. RESULTS: WFF activated Nrf2, inducing the expression of Nrf2-dependent genes, such as HO-1, NQO1, and GCLC in RAW 264.7 cells. On the other hand, WFF suppressed NF-κB induced by LPS or TNF-α, which was coincided with the expression of A20. Conversely, WFF failed to suppress NF-κB when A20 expression was silenced by siRNA. CONCLUSION: WFF activated Nrf2 and expressed A20. Given that Nrf2 suppresses inflammation and A20 broadly disrupts inflammatory signaling cascades, our results suggest that the anti-inflammatory activity of WFF is attributable to Nrf2 and A20.
ETHNOPHARMACOLOGICAL RELEVANCE: The water extract of Forsythiae Fructus (WFF) is an herbal remedy that is prescribed to treat various inflammatory diseases in traditional Chinese medicine. Although the anti-inflammatory activity of WFF has been reported, the underlying mechanisms for the activity remain unclear. Here, we examined whether the anti-inflammatory activity of WFF is associated with Nrf2, an anti-inflammatory factor, and A20, an ubiquitin-regulator protein that inhibits signaling cascades of endotoxin or cytokines. MATERIALS AND METHODS: The water extract of Forsythia suspensa (Thunb.) Vahl was prepared and fingerprinted by HPLC. Cytotoxicity and intracellular ROS induced by WFF were determined by MTT and FACS analyses, respectively. Nuclear and cytoplasmic proteins were analyzed by immunoblot. Expression of mRNA was analyzed by a semi-quantitative RT-PCR. Expression of proteins or genes was quantitated by Image J. RESULTS: WFF activated Nrf2, inducing the expression of Nrf2-dependent genes, such as HO-1, NQO1, and GCLC in RAW 264.7 cells. On the other hand, WFF suppressed NF-κB induced by LPS or TNF-α, which was coincided with the expression of A20. Conversely, WFF failed to suppress NF-κB when A20 expression was silenced by siRNA. CONCLUSION: WFF activated Nrf2 and expressed A20. Given that Nrf2 suppresses inflammation and A20 broadly disrupts inflammatory signaling cascades, our results suggest that the anti-inflammatory activity of WFF is attributable to Nrf2 and A20.