IN VITRO ANTIOXIDANT ACTIVITY AND PHYTOCHEMICAL SCREENING OF LEAF EXTRACTS OF GREWIA HETEROTRICHA MAST Original Article B. USHA 1 *, K. C. PUSHPALATHA 2 1 Department of Biochemistry, Alva’s College, Vidyagiri, Moodbidri, D. K. 574227, Karnataka, India, 2 Received: 31 Jul 2016, Revised and Accepted: 06 Sep 2016 Department of Microbiology and Biochemistry, Mangalore University, P. G. Centre, Chikka Aluvara, Kushalnagar, Kodagu, Karnataka, India Email: usharao27@gmail.com ABSTRACT Objective: To investigate the presence of phytochemical components and to evaluate the in vitro antioxidant activity of pet. ether, chloroform, methanol and aqueous extracts of Grewia heterotricha mast leaves. Methods: The leaves of Grewia heterotricha mast were dried and extracts were prepared using a pet. ether, chloroform, methanol by soxhlet extraction method. The aqueous extract was prepared using distilled water by cold extraction method. The preliminary phytochemical analysis was carried out on aqueous, methanol, chloroform and pet. either leaf extracts of the plant using standard qualitative procedures. The total phenolic content (TPC) was estimated using modified Folin-Ciocalteau method, tannin content by Folin-Denis method and total flavonoids by aluminum chloride method. In vitro, antioxidant activities were evaluated by 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, H2 O2 Results: The preliminary phytochemical analysis revealed the presence of complex bioactive constituents like phenols, tannins, alkaloids, terpenoids, flavonoids, saponins, steroids, glycosides, coumarins, proteins and carbohydrates. Methanolic extract showed highest total phenolic content (87.58±2.52 mg CE/g) than aqueous extract (78.46±5.36 mg CE/g). Higher tannin content was found in the aqueous extract (148.0±8.96 mg TAE/g). Total flavonoids were highest in chloroform extract (314.9±25.06 mg QE/g) followed by aqueous (242.98±32.42 mg QE/g) and methanolic extract (217.0±18.32 mg QE/g) and lowest in a pet. ether extract (188.86±23.35 mg QE/g). The methanolic extract had shown very significant DPPH radical scavenging activity (IC scavenging activity and FRAP assay. 50 98.95 µg/ml) and H2 O2 scavenging activity (IC 50 Conclusion: The results obtained reveal that the leaves of Grewia heterotricha mast have potent antioxidant property. The observed activity may be associated with bioactive components like phenolics, flavonoids present in the leaf extracts and could have greater importance as therapeutic agents in oxidative stress-related degenerative diseases. Further studies are needed in order to purify bioactive compounds responsible for the antioxidant property. 110.1µg/ml) compared to the standard ascorbic acid. Higher reducing ability was observed in methanol extract (131.8±11.67 mg AE/g). Keywords: Grewia hetertricha mast, Antioxidant activity, Flavonoids, Phenolics, DPPH, Reducing power © 2016 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) DOI: http://dx.doi.org/10.22159/ijcpr.2016v8i4.15282 INTRODUCTION A number of plants have been used in traditional medicine over many years. These medicinal plants have been considered as sources for new drugs to treat numerous diseases. Therapeutic properties of medicinal plants are due to the presence of a wide variety of bioactive components in them. The most important bioactive components are phenolic compounds, flavonoids, alkaloids, and tannins. These phytochemicals are secondary metabolites synthesized by the plants [1, 2]. The secondary metabolites like flavonoids and phenolic compounds are considered as strong antioxidants which have the ability to scavenge free radicals, inhibit the activity of lipoxygenase and prevent tissue damage [3-5]. Natural antioxidants can reduce the risks of various oxidative stress related diseases such as cancer, neurodegenerative disorders, heart diseases and inflammation [6-8]. Grewia heterotricha mast belongs to the family Malvaceae, is a scandent shrub common in forests and along hedges in India. It is widely used as folk medicine in wound healing, fever, bronchitis, and to cure some skin and intestinal infections [9]. The pharmacological properties of this plant have not yet been evaluated. Hence, the present study was undertaken to identify the bioactive components and to evaluate antioxidant activity of leaves of Grewia heterotricha mast by in vitro methods. MATERIALS AND METHODS Collection of plant material Grewia heterotricha mast plants were collected from Udupi, during monsoon and post-monsoon seasons. The plant was authenticated by Dr. K. Gopalakrishna Bhat, Botanist, Udupi. A voucher specimen (20/11/2013) has been kept in our laboratory for future reference. The leaves were washed, shade dried and finely powdered and stored in air-tight container. Preparation of extract The powdered leaves (75g) were extracted successively with 350 ml each of petroleum ether (40-60˚C), chloroform, methanol using Soxhlet extractor for 24hr. The extracts were concentrated by evaporation using rotary vacuum evaporator to obtain dark viscous semi-solid. Similarly, water extract was also prepared by mixing leaf powder in distilled water and stirred continuously using magnetic stirrer for 48hr. The mixture was filtered and the filtrate was then concentrated. All the extracts were stored in a refrigerator and were used for further study. Phytochemical screening The leaf extracts were tested for the presence of bioactive compounds like flavonoids, terpenoids, alkaloids, glycosides, tannins, phenolics, saponins carbohydrates and proteins by using standard methods [10-12]. Quantitative analysis of antioxidant component Determination of total phenolic content The total phenolic content was estimated using the modified Folin- Ciocalteu method [13]. 0.5 ml of extract and 0.5 ml Folin-Ciocalteu’s reagent was mixed and the mixture was incubated at room temperature for 3 min. Then 2.0 ml 20% sodium carbonate solution International Journal of Current Pharmaceutical Research ISSN- 0975-7066 Vol 8, Issue 4, 2016