Dichondra repens (DR) is the main constituent in herbal beverages and consumed daily as a nutrition supplement for the liver in Taiwan. This study investigated the antioxidant and anti-inflammatory effects of D. repens ethanol extract (EDR) and its reference compounds ex vivo and in vivo. Fingerprint chromatograms (from HPLC) indicated that EDR contained vanillin, umbelliferone and scopoletin. EDR was evaluated for its antioxidant effects and LPS-induced NO production in RAW 264.7 cells. EDR decreased the LPS-induced NO production and expressions of iNOS and COX-2 in RAW 264.7 cells. In vivo anti-inflammatory activities of EDR were assessed in mouse paw oedema, induced by λ-carrageenan (Carr). We investigate the antioxidant mechanism of EDR via studies of the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) in the liver and the levels of malondialdehyde (MDA) and nitrite oxide (NO) in the oedematous paw. Serum NO and TNF-α were also measured. EDR exerts anti-inflammatory effects by suppressing TNF-α, NO, and might be related to the decrement of the level of MDA in the oedema paw via increasing the activities of CAT, SOD and GPx in the liver. The results show that EDR might be a natural antioxidant and anti-inflammatory agent.
