INTRODUCTION Cassia occidentalis is an annual herb commonly known as Senna occidentalis belongs to genus Cassia family leguminosae. Its vernacular names are Kasondi, Kasmard and Coffee senna. It is usually an erect plant but also a little bit branched, smooth, semi-woody, fetid herb or shrub. It varies in length from 0.8 to 1.5 m. Therapeutically it was used for sore eyes, constipation, fever, cancer and venereal diseases 1 . Different pharmacological activities like antimicrobial activity have been reported from different parts of the plant like leaves, seeds and roots 2,3 . The leaves of this plant have hepatoprotective effect 4 , anticancer effect 5 , antimalarial effect 6 , antioxidant effect 7 , antiinflammatory effect 8,9 and a potent antidiabetic, laxative and anthelmentic agent 10-12 . Plants synthesize a variety of bioactive metabolites that have been studied to some extent. The physiology and biochemistry of secondary metabolism gives an opportunity to breed plants with a better protection against microbes. Understanding of their molecular pharmaco- logy is a key to exploit bioactive plant chemicals in a rational way in medicine and agriculture (biorational pesticides). Some natural products are also involved in defense against a-biotic stress, e.g. UV-B exposure. Many of the secondary metabolites have interesting biological properties and a number are of medicinal importance. Because the production of the valuable natural products, such as benzylisoquinoline, monoterpene indole and diterpene alkaloids 13 . Phytochemical Evaluation and Bioactive Properties of Different Parts of Cassia occidentalis Plant Extracts IRSHAD AHMAD, KAMRAN BASHIR, IMRAN SHAIR MOHAMMAD * , MUHAMMAD WAJID and MUHAMMAD MAJID AZIZ Department of Pharmacy, The Islamia University of Bahawalpur, Bahawalpur, Pakistan *Corresponding author: Tel: +92 3458012087; E-mail: imranshairmohammad@gmail.com (Received: 23 April 2013; Accepted: 29 October 2013) AJC-14311 The aim of this study is to investigate the secondary metabolites (bioactive constituents), antioxidant and enzyme inhibitory activities of the dichloromethane and methanolic extract of roots and aerial parts of the plant Cassia occidentalis which belongs to the family leguminosae. The extraction of coarse powder of dried roots and aerial parts of plant material was performed with dichloromethane and successively with methanol at room temperature. The filtrate was concentrated on rotary evaporator at 35 ºC. Then different phytochemical tests were performed for the identification of secondary metabolites, which revealed the presence of saponins, flavonoids, tannins, resins, anthraquinones and cardiac glycosides. The dichloromethane and methanolic extracts of Cassia occidentalis have bioactive secondary metabolites, significant free radical scavenging (antioxidant) and enzyme inhibitory activities such as chymotrypsin and lipoxygenase. Key Words: Secondary metabolites, Dichloromethane and methanolic extracts, Chymotrypsin and lipoxygenase enzyme inhibition. O OH OH OH O OH HO O OH OH O OH HO Quercetin Kaempferol Chemical structures of quercetin and kaempferol Oxygen is an indication of life. It produces energy by oxidation of the food. The oxidation of food produces energy and free radicals which can be harmful for the body. These free radicals may cause degenerative issues like skin depig- mentation and aging as well as chronic disorders like athero- sclerosis, cancer and diabetes. Antioxidants are the chemical compounds that delay or inhibit oxidative damage to a target Asian Journal of Chemistry; Vol. 25, No. 17 (2013), 9945-9948 http://dx.doi.org/10.14233/ajchem.2013.15676