Enhancement of Skin Anti-Inflammatory Activities of Eclipta prostrata L. from the Ultrasonic Extraction Process

This work first showed that the skin anti-inflammatory activities of Eclipta prostrata L. (E. prostrata L.)n be increased through an ultrasonic extraction process at a frequency of 120 kHz with 70% ethanol at 40 ◦C for 6 h. The extract from the ultrasound extraction (UE) contained 378.6 mg/100 g of wedelolactone (a major bioactive substance in E. prostrata L.), compared with the 172.9 mg/100 g from a conventional extraction process with 70% ethanol at 80 ◦C for 12 h (EE). The UE showed less than 10% of low cytotoxicity against normal fibroblast cells, and also exhibited much higher antioxidant activities than that from the EE when treating with 0.3 mg/mL of the extracts. It was proved that the high antioxidant activities of the UE were closely correlated with the enhancement of skin anti-inflammatory activities by effectively suppressing the production of tumor necrosis factor-alpha and interleukin-6 from macrophages. The production of prostaglandin E2 from human skin cells was also greatly reduced, compared with the EE for all ranges of the treatments. These results strongly indicate that the various biological activities of E. prostrata L. can be improved by a simple ultrasound extraction process because of the high elution of bioactive substances even at a low temperature.