Antioxidant, antioedema and analgesic activities of Andrographis paniculata extracts and their active constituent andrographolide

Andrographis paniculata (AP), a popular ingredient of Oriental folk medicine, is commonly used for treating infection, inflammation, fever and diarrhoea. In this study, extracts prepared from cultivated AP and their active constituent andrographolide were evaluated for antioxidant, antioedema and analgesic activities. The results showed that the aqueous AP extract (AP-H₂O) exhibited a greater antioxidant activity than the ethanol AP extract (AP-EtOH) in all model systems tested. At a concentration of 50 µg/mL, the free radical scavenging, xanthine oxidase inhibition and antilipid peroxidation activities for AP-H₂O were 66.8%, 57.3% and 65.3%, respectively, and for AP-EtOH were 57.8%, 52.6% and 34.2%, respectively. At a dosage of 100 mg/kg, AP-H₂O and andrographolide, but not AP-EtOH, showed antioedema and analgesic activities. In phytochemical analysis, AP-H₂O showed a higher concentration of total flavanoid but a lower phenol content than AP-EtOH. In conclusion, AP-H₂O was more potent than AP-EtOH in antioxidant activities. Furthermore, compared with andrographolide, AP-H₂O as an extract also appears to possess potent antioedema and analgesic activities. Copyright © 2009 John Wiley & Sons, Ltd.