Environmental Toxicology and Pharmacology 26 (2008) 92–95 Contents lists available at ScienceDirect Environmental Toxicology and Pharmacology journal homepage: www.elsevier.com/locate/etap Anti-inflammatory activity of four solvent fractions of ethanol extract of Mentha spicata L. investigated on acute and chronic inflammation induced rats P. Arumugam ∗ , N. Gayatri Priya, M. Subathra, A. Ramesh Department of Genetics, Dr. A.L.M. Post Graduate Institute of Basic Medical Sciences, University of Madras, Chennai 600113, India article info Article history: Received 11 August 2007 Received in revised form 14 February 2008 Accepted 18 February 2008 Available online 23 February 2008 Keywords: M. spicata Solvent fractions Acute and chronic toxicity Anti-inflammation abstract Anti-inflammatory effects of four solvent fractions of ethanol extract of Mentha spicata were evaluated in acute and chronic inflammation induced in Wistar albino rats. Lipid peroxidation (LPO) and some antioxi- dants produced during chronic inflammation were quantitated. Hexane (320 mg/kg of body weight in 25% DMSO), chloroform (320 mg/kg body weight in 25% DMSO), ethyl acetate (160 mg/kg body weight in 25% DMSO), aqueous (320 mg/kg of body weight in ddH 2 O) fractions, two negative control groups (25% DMSO and ddH 2 O) and two anti-inflammatory drugs (Diclofenac: 25 mg/kg of body weight; Indomethacin: 10mg/kg of body weight both in ddH 2 O) were administered by oral intubations to the eight groups of rats consisting six animals, each. In acute study, 1% carrageenan was injected subcutaneously in the sub- plantar region of the right hind paw after 1 h of administration of test doses. The increased paw edema was measured at 0.5, 1, 2, 4, 8, 16 and 24h intervals. In the chronic study, the oral administration was carried out for seven consecutive days. On eighth day, four sterile cotton pellets (50mg each) were implanted subcutaneously in the dorsal region of the rats. On the sixteenth day, the rats were sacrificed and the cotton pellets with granulomatous tissue were dissected out and weighed (fresh and dry). Both in chronic and acute inflammation, ethyl acetate (EAF) and aqueous fraction (AF) were effective. EAF is comparable with the positive standards in chronic inflammation. The results indicate that EAF’s anti-inflammatory activity is largely due to its ability to modulate in vivo antioxidants. © 2008 Elsevier B.V. All rights reserved. 1. Introduction Mentha spicata L., also known as spearmint belongs to the Lami- aceae (labiatae) family. The genus Mentha consists 25–30 species; and spearmint is the most common among them (Bhattacharjee, 1998). The plant is a glabrous perennial with creeping rhizomes and can grow up to 1 ft height. In India, it is commonly called as pudina and is widely used in culinary preparations to add flavor and aroma (Choudhury et al., 2006). Mint oil is of economic importance and is widely used in pharmaceutical, cosmetic, food, confec- tionary and beverage industries (Kanatt et al., 2007). Spearmint oil contains monoterpenoids like carvone, limonene, menthone, menthol, pulegone, dihydrocarveol and s-carvone. Some of them were found to possess high antioxidant activity than -tocopherol (Elmasta et al., 2006). The plant is also known for its ability to enhance memory (Adsersen et al., 2006). The boiled leaves extract is being used to relieve hiccup, flatulence, giddiness and as rem- edy for inflammation, bronchitis, and to control vomiting during pregnancy (Kumar and Chattopadhyay, 2007). Apart from being ∗ Corresponding author. Tel.: +91 44 2450 2430x5212; fax: +91 44 2450 2344. E-mail address: arumugamgenetics@yahoo.co.in (P. Arumugam). a stimulant and carminative, the mint plant is also known for its insecticidal, antimicrobial, antispasmodic and antiplatelet proper- ties (Papachristos and Stamopoulos, 2002; Samarth and Kumar, 2003; Ozgen et al., 2006; Tognolini et al., 2006). Many phe- nolic, flavonoid and terpenoid compounds have been identified from different extracts of spearmint. The major water-soluble phe- nolics include: eriocitrin, luteolin, glucoside, apigenin, acacetin, thymusin, thymonin, sideritoflavone and diosmetin (Yamamura et al., 1998). Two new monoterpenoids spicatoside, A and B, were found to possess anti-inflammatory, haemostatic and pain reliev- ing properties (Zheng et al., 2003). In this report we present in vivo anti-inflammatory effects of some solvent extracts of M. spicata assessed against carrageenan and cotton pellet-induced inflamma- tion in rats. 2. Materials and methods 2.1. Animals Healthy, Wistar albino rats of either sex (180–210 g) were purchased from King’s Institute, Chennai and were maintained at the departmental animal house under standard environmental conditions (temperature, 22 ± 2 ◦ C, and 12 h light/dark cycle). The animals had free access to standard pellet diet and water ad libitum; and were maintained in accordance with the Guidelines of the Committee for the Purpose of Control and Supervision of Experiments on Animals (CPCSEA), India. 1382-6689/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.etap.2008.02.008