In this study antioxidant activity of methanol extract of rhizomes of Curculigo orchioides (MEC) was investigated using carbon tetrachloride (CCI4)-intoxicated rat liver asthe experimental model. The hepatotoxic rats were administered MEC for 90 days (daily, orally at the dose of 70 mg per kg body weight). Lipid peroxidation (LPO) in CCI4-intoxicated ratswas evidenced by a marked increment in the levels of thiobarbituric acid reactive substances (TBARS) and diene conjugates (CD), and also a distinct diminution in glutathione (GSH) content in the liver. In CCI 4 + MEC-treated rats these biochemical parameters attained an almost normal level. The decreased activity of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and glutathione reductase (GRD) in CCI4-intoxicated rats, and its retrieval towards near normalcy in CCI4+ MEC-administered rats revealed the efficacy of MEC in combating oxidative stress due to hepatic damage. Elevated level of glutathione transferase(GTS) observed in hepatotoxic rats too showed signs of returning towards normalcy in MEC co-administered animals, thus corroborating the antioxidant efficacy of MEC. The findings provide a rationale for further studies on isolation of active principles and its pharmacological evaluation. K E Y W O R D SAntioxidant enzymes, Carbon tetrachloride, Curcu/igo orchioides, Lipid peroxidation. I N T R O D U C T I O NCurculigo orchioides Gaertn. of Amaryllidaceae family is a herbaceous tuberous geophilous perennial with rootstock bearing several fleshy lateral roots (rhizomes). It is widely distributed in India. The rhizomes of this plant possess medicinal properties and are sweet, cooling, diuretic, aphrodisiac, viriligenic and tonic which can be used against hemorrhoids, leucorrhoea, pruritis, skin diseases, asthma, bronchitis and jaundice etc. (1) Curculigo saponin G, isolated from rhizomes of the plant has been reported to increase weight of thymus gland in vivo in mice. (2) Ethanolic extract of Corchio/deshas been reported to have sedative, anticonvulsant and androgen-like effect, and also Biochemistry, 2002 adaptive effects, such as enhancing tolerance towards hypoxia and hyperthermia (3). Our previous study (unpublished data) revealed hepatoprotective potential of methanol extract of C. orchioides. Therefore in the present work attempt has been made to study the antioxidant effect of Corch/o/des in CCI4-intoxicated experimental rats.It has been hypothesized that one of the principal causes of CCI4-induced liver injury is LPO by free radical derivatives of CCI 4 . Thus the antioxidant activity or the inhibition of the generation offree radicals is important in the protection against CCI 4 -induced hepatopathy. (4) Antioxidant action has been reported to play a crucial role in the hepatoprotective capacity of many plants, such as Curcuma /onga, Ganoderma formosanum, So/anum n/grum, Boehmer/a n/yea andSpiru//na maxima. (5-9) Ayurveda, an indigenous system of medicine in India, has a long tradition of tre...