SUMMARY The root of Astragalus membranaceous (AM) has been used to treat edema and arthritis in thetraditional Korean medicine. To elucidate the anti-inflammatory and anti-nociceptive effects ofethanol extract of AM, the carrageenan-induced paw edema using a plethysmometer and thermalhypersensitivity using the plantar test were measured. Ibuprofen was used as a control drug.Pretreatment with AM (400 mg/kg p.o.) significantly reduced paw edema, compared to thecarrageenan-treated rats. In the plantar test, the thermal withdrawal latency in AM-treated groupwas significantly increased than the carrageenan-treated group. The results indicate that AMcould have be the anti-inflammatory and anti-nociceptive properties.Key words: Astragalus membranaceous; Inflammation; Nociception; Paw edema INTRODUCTION Recently, complementary and alternative medicineis increasingly used for the treatment of immunediseases and inflammation (Luo et al., 2007).Astragalus membranaceous (AM) is a traditionalmedicinal plant, and it has been widely used as atonic to enhance the body’s natural defensemechanisms such as the immune reaction andcirculation (Ryu et al., 2008). AM may exhibit theimmunomodulating and immunorestorative effectsboth in vitro and in vivo (Cho and Leung, 2007).Shen et al. (2008) also found that AM administrationduring 28 days significantly decreased inflammatoryinfiltration and mucus secretion in the lung tissueof allergic mice. AM has been shown to have anti-allergic, anti-inflammatory, and anti-nociceptiveproperties (Kosuge et al., 1985; Luo et al., 2007). Inaddition, it seems to have an anti-oxidantproperty (Boucheny and Brum-Bousquet, 1990)and inhibit the aggregation of platelets (Yun-Choi et al., 1985; Lu et al., 2005). Luo et al. (2007)reported that AM can reduce the small intestinemucosal damage after hemorrhage shockreperfusion. However, the mechanism of actionof AM is not fully defined.The present study was aimed to investigate theanti-inflammatory and anti-nociceptive propertiesof AM in carrageenan-induced paw edema model.For the anti-inflammatory effect, the volume ofedema was measured using a plethysmometer. Totest the anti-nociceptive effect, the thermal withdrawallatency by the plantar test was estimated.