Research Article IN VITRO EVALUATION OF ANTIOXIDANT ACTIVITY OF AERIAL PART OF MAERUA APETALA. ROTH (JACOBS) (CAPPARACEAE) M.PACKIA LINCY 1 , V.R. MOHAN 1 *, S.JEEVA 2 1 Ethnopharmacology Unit, Research Department of Botany, V.O.Chidambaram College, Tuticorin 628 008, Tamil Nadu, India. 2 PG & Research Department of Botany, Scott Christian College, Nagercoil, Tamil Nadu Email: vrmohanvoc@gmail.com Received: 14 March 2014, Revised and Accepted: 8 March 2014 ABSTRACT Objective: To determine the total phenolics, flavonoids and in vitro antioxidant activity of petroleum ether, benzene, ethyl acetate, methanol and ethanol extracts of whole plant of Maerua apetala using various antioxidant model system viz, DPPH, hydroxyl, superoxide, ABTS and reducing power. Methods: Total phenolic content was estimated by folin-ciocalteau method. Flavonoids were determined by Aluminium chloride method. In vitro antioxidant activity of petroleum ether, benzene, ethyl acetate, methanol and ethanol extracts was evaluated by studying 1,1-diphenyl-2- picrylhydrazyl (DPPH) radical scavenging activity, hydroxyl radical scavenging activity, superoxide radical scavenging activity, ABTS radical cation scavenging activity and reducing power using standard procedure. Result: The total phenolics and flavonoids in methanol extract were found to be 1.25g100g -1 and 2.44g100g -1 respectively. Among the solvent tested, methanol and ethanol extracts of whole plant of M. apetala showed potent in vitro antioxidant activities. Conclusion: This investigation explored immense free radical scavenging potential of whole plant of M. apetala which can be used for the treatment of various free radical mediated ailments. Keywords: anti oxidant, Maerua apetala, ethanol, DPPH, ABTS, reducing power. INTRODUCTION Antioxidants help the organisms in dealing with oxidative stress, caused by free radical damage. Free radicals are chemical species, which contains one or more unpaired electrons due to which they are highly unstable and cause damage to other molecules by extracting electrons from them in order to attain stability. Reactive oxygen species (ROS) readily combine and oxidize biomolecules such as carbohydrates, proteins and lipids and thus making them inactive with subsequent damage to cells, tissues and organs [1,2]. It is possible to reduce the risks of chronic diseases and prevent disease progression by either enhancing the body’s natural antioxidant defences or by supplementing with proven dietary antioxidants [3]. This is one of the reasons why discovery and synthesis of novel antioxidants is a major active area. In recent years, the use of natural antioxidants present in food and other biological materials has attracted considerable interest due to their presumed safety, nutritional and therapeutic value [4]. Antioxidants derived from fruits, vegetables, spices and cereals are very effective and have reduced interference with the body’s ability to use free radicals constructively [5,6]. Natural antioxidants mainly come from plants in the form of phenolic compounds (flavonoids, phenolic acids and alcohols, stilbenes, tocopherols, tocotrienols) ascorbic acid and carotenoids. The quest for natural antioxidants for dietary, cosmetic and pharmaceutical uses has become a major industrial and scientific research challenge over the last two decades. Efforts to gain extensive knowledge regarding the power of antioxidants from plants and to tap their potential are therefore on the increase. Many medicinal plants have been investigated for their beneficial use as antioxidants or source of antioxidants using presently available experimental techniques. Maerua is an important ayurvedic drug used as one of the ingredients in many Ayurvedic preparations. Ethnomedical survey reveals that Maerua is used to cure various diseases such as fever, stomach ache, skin infections, urinary calculii, diabetes mellitus, epilepsy, pruritis, rigidity in lower limbs, and abdominal colic [7]. Maerua is an important controversial drug used in diseases like anaemia, fever, diabetes, stomach disorders, typhoid, urinary infection and cough [8]. Maerua apetala (Capparaceae) is one of the botanical sources of the Ayurvedic drug. So far, no attempts have been made to evaluate the antioxidant properties of Maerua apetala. Hence the present study was performed to investigate the in vitro antioxidant activity of different extracts of Maerua apetala aerial part using different models viz: DPPH, hydroxyl, superoxide and ABTS radical cation scavenging activity. MATERIALS AND METHODS The aerial part of Maerua apetala Roth (Jacobs) were collected from Vattakottai, Kanyakumari District, Tamil Nadu. The collected samples were cut into small fragments and shade dried until the fracture is uniform and smooth. The dried plant material was granulated or powdered by using a blender and sieved to get uniform particles by using sieve No. 60. The final uniform powder was used for the extraction of active constituents of the plant material. Preparation of plant extract The coarse powder (100g) of aerial part of Maerua apetala was extracted successively with petroleum ether, benzene, ethyl acetate, methanol and ethanol, each 250mL in a Soxhlet apparatus for 24 hrs. All the extracts were filtered through Whatman No.41 filter paper. All the extracts were concentrated in a rotary evaporator. The concentrated extracts were used for in vitro antioxidant activity. The methanol extract was used for the estimation of total phenolics and flavonoids. Estimation of total phenolic content Vol 7, Suppl 2, 2014 ISSN - 0974-2441