TOTAL POLYPHENOL CONTENT AND ANTIOXIDANT AND CYTOTOXIC ACTIVITIES OF THE SRI LANKAN ENDEMIC PLANT GENUS SCHUMACHERIA Short Communication CHAMARA JANAKA BANDARA 1 , D. NEDRA KARUNARATNE 1 , ANURA WICKRAMASINGHE 1 , D. S. A. WIJESUNDARA 2 , B. M. RATNAYAKE BANDARA 1 , VERANJA KARUNARATNE 1,3* 1 Department of Chemistry, University of Peradeniya, Peradeniya, Sri Lanka, 2 Royal Botanic Gardens, Peradeniya, Sri Lanka, 3 Received: 12 Aug 2014 Revised and Accepted: 15 Sep 2014 Sri Lanka Institute of Nanotechnology, Homagama, Sri Lanka. Email: veranjak@slintec.lk ABSTRACT Objective: Schumacheriais a genus endemic to Sri Lanka distributed in lowland rain forests and mountain rain forests. The total polyphenol content and antioxidant and cytotoxic activities of hexane, dichloromethane and methanol extracts of stem-bark, root-bark, leaves and flowers of the three representative plant speciesS. castaneifolia, S. alnifolia and S. angustifolia belonging to the endemic genus Schumacheriaare reported. Methods: Antioxidant activity was determined using the DPPH (1,1-diphenyl-2-picrylhydrazine) radical scavenging assay. The total polyphenol content, expressed as the gallic acid equivalent, was determined using theFolin-Ciocaltue method and the cytotoxic activity was determined using the brine shrimp (Artemiasalina) assay. Results: The methanol extract of S. castaneifolia flowers (IC 50 = 6.8±0.1 ppm)and the methanol extracts of S. alnifolia stem-bark (IC 50 =7.1±0.4 ppm) and leaves (IC50 =8.3±0.3 ppm) showed antioxidant activity higher than that of α-tocopherol(IC 50 = 10.9±4.3 ppm). The methanol extracts of S. alnifolia stem-bark (69.3±6.9 mg g -1 ) and leaf (57.7±0.0 mg g -1 ) extracts showed the highest polyphenol content closely followed by the methanol extracts of S. castaneifolia flowers (71.2±0.6 mg g -1 ). The highest cytotoxic activity was exhibited by the methanol extract of S. castaneifolia flowers (LC 50 Conclusion: S. castaneifolia and S. alnifolia exhibit potent bioactivitiesvalidating the ethnomedical claims where the former has been used for oral aphthous. = 1.3±0.7 ppm), and all the other extracts showed comparatively less cytotoxic activity. Keywords: Schumacheria, Endemic genus, Total polyphenols, Antioxidant, Cytotoxic. In terms of the richness of its flora, Sri Lanka is a biodiversity hotspot. Out of the 3210 flowering plants recorded from the island, 916are endemic. As for the non-flowering plants such as lichens and mosses, whose accurate numbers are yet to be determined, new species continue to be reported [1, 2]. Considering the potential medicinal value of Sri Lankan plants, thus far there have been only a relatively few attempts at screening for biologically active compounds [3-6]. However, Sri Lankan plants have yielded alkaloids [7, 8], terpenoids [9, 10], iron chelating lichen hydroxybenzoic acids [11, 12],saponins [7], butenolides [13], and phenolic acids [14] all of which have shown potent biological activity. The genus Schumacheria belonging to the family Dilleniaceae is an endemic genus, comprising of three species, namely S. alnifolia Hook. f. & Thoms., S. angustifolia Hook. f. &Thoms., and S. castaneifolia Vahl. All three species of genus Schumacheriaare considered as relic plant species and their evolution probably started during the late Cretaceous and early territory period in the Gondwanaland about 100 to 120 million years ago [15]. They are erect or scrambling evergreen shrubs or small trees, [16] currently found in lowland-rainforest and mountain-rainforest of Sri Lanka. The two species S. alnifolia and S. angustifolia are extremely limited in their distribution and are endangered,while S. castaneifolia is common,but restricted to the lowland rainforest [17, 18]. As they have not been evaluated previously, it is important that proper systematic bioactivity studies of these three endangered species of Schumacheriaare carried out. We report herein, the antioxidant and cytotoxic activities and the total polyphenol content of the three representative species of the endemic genus Schumacheria. The plant material of the three species was collected in 2011;S. castaneifolia from Thummodara region in Rathnapura; S. alnifolia at Fishing-hut in Maskeliya andS. angustifolia from Haycock Hillin Hiniduma. The taxonomic identification of plant species was carried out by Dr. D. S. A. Wijesundara, Royal Botanic Gardens, Peradeniya. The specimens have been deposited in the National Herbarium of the Royal Botanical gardens, Peradeniya. Plant materials were separately cleaned, air dried, ground, sequentially extracted into hexane, dichloromethane and methanol using a bottle-shaker, and the solvent extracts were concentrated to provide the dry crude extract. The methanol extracts (0.5 g) of Schumacheria plant specimens were separately dissolved in 70 % methanol-water solution (25.0 ml) and were centrifuged at 1500 g for 10 min. The resulting supernatants were evaluated for the total polyphenol content. The total polyphenol content was determined by mixing a 10 fold diluted Folin-Ciocaltue reagent (1.0 ml) and the extract(200 µl); after 8 minutes, Na 2 CO3 The antioxidant activity of the plant extracts was determined using DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging method [19]. The final concentration of DPPH in the test mixture was maintained at 1× 10-4mol dm-3 in methanol, and α-tocopherol was used as a positive control. The IC50 values were determined in triplicate using solutions of 1, 5, 10, 15, 20, 40, 60, 80 and 100 ppm. The absorbance of the test solutions was measured at 517 nm after 30 min using a UV spectrophotometer (Shimadzu, UV-1800). The antioxidant activity was calculated using the formula: % antioxidant activity = [(Ai-Af) / Ai] × 100, where Ai is the initial absorbance of the test mixture following the addition of DPPH and Af is the absorbance after 30 min. [7.5 % (m/v)] aqueous solution (800 µl) was added, kept for 1 h and the UV absorbance measured at 765 nm. A calibration plot using standard gallic acid ranging in concentration from 1.0 to 20.0 ppm was obtained. The total polyphenol content of commercially available branded tea was determined and all data were represented equivalent to gallic acid (GAE). A commercially available tea extract (0.5 g) dissolved in 70% methanol-water (25 ml) was used as a positive control. Cytotoxic activity was determined using the brine shrimp assay [20]. From each dry plant extracts, a concentration series was prepared International Journal of Pharmacy and Pharmaceutical Sciences ISSN- 0975-1491 Vol 7, Issue 3, 2015 Innovare Academic Sciences