FUW Trends in Science & Technology Journal ftstjournal@gmail.com April, 2016 Vol. 1 No. 1 – e-ISSN: 24085162; p-ISSN: 20485170 pp 221-224 221 Supported by TOTAL ANTIOXIDANT CAPACITY, PHENOLIC AND FLAVONOIDS CONTENTS OF PARTIALLY PURIFIED AQUEOUS EXTRACT OF Vitex doniana LEAVES O.E. Yakubu 1* , E.P.K. Imarenezor 2 and S.M.C. Udeh 2 1 Department of Biochemistry, Federal University Wukari, Nigeria 2 Department of Biochemistry, University of Nigeria, Nsukka, Nigeria 3 Department of Microbiology, Federal University Wukari, Nigeria *Corresponding author: oj4real_2007@yahoo.co.uk. Abstract: In this study, the total antioxidant capacity (TAC), total polyphenolic content (TPC) and total flavonoids content (TFC) of aqueous extract fractions of Vitexdoniana leaves were determined. The results obtained from the study revealed that fraction 1 possessed the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (282 μg/ml TE). The decrease observed in the TAC of fractions is in the order; 1>3>2>4>5 and 6. Fractions 5 and 6 have the same TAC (76 μg/ml TE) being the fractions with the lowest TAC. Fraction 2 has the highest concentration of total flavonoids content (TFC) followed by fraction 1 and the lowest TFC was observed in fraction 5. Correlation between total antioxidant capacity and total flavonoids content of different fractions obtained from aqueous extract of V. doniana leaves showed moderate positive correlation (R 2 = 0.6549). similarly, total antioxidant capacity and total phenolic content of fractions showed positive correlation (R 2 = 0.6423) and correlation between total phenolic and total flavonoids contents of different fractions obtained from ethanol extract of V. doniana leaves showed the strong positive correlation (R 2 = 0.981). From the results, it can be deduced that the antioxidant activity of the fractions to a larger extent depends on the phenolic content, especially the flavonoids. Keywords: Total antioxidant, polyphenols, flavonoids, Vitexdoniana. Introduction Natural antioxidants from plant sources are potent and safe due to their harmless nature. A free radical in each molecule is determined as an unpaired electron that occupies an atomic or molecular orbital on its own. This reactive molecule is to another electron to pair, this in step an uncontrolled chain reaction that can damage the natural function of the living cell, resulting in different diseases (Zhishen et al., 1999). Many fruits and vegetables, herbs, cereals, seeds that contain natural antioxidants can abstract the lone electron from free-radical molecules and help humans to keep control on these harmful species. Most of these antioxidants in plants are highly colouredanthocyanines, proanthocyaninidins, flavans, flavonoids, and their glycosides, carotenoids, like β- carotene and lycopene (Matkowski et al., 2009). Isolation of anti- oxidants from plants depends on the polarity of these compounds. First distribution of antioxidants between a polar (aqueous, hydro ethanol) and a semi-polar solvent (n-butanol, ethyl acetate) can be used to determine the distribution factor of the compounds between phases (Matkowski et al., 2009). Vitexdoniana sweet, (family Verbanaceae) is a peren- nial shrub widely distributed in tropical West Africa, and some East African countries including Uganda, Kenya and Tanzania and high rainfall areas. It is found in the middle belt of Nigeria particularly Kogi, Benue, and parts of the savannah regions of Kaduna, Sokoto and Kano States (Etta, 1984). It is variously called vitex (English), dinya (Hausa), dinchi (Gbagyi), uchakoro (Igbo), oriri (Yoruba) ejiji (Igala) and olih (Etsako) (Burkill, 2000). V. doniana is employed in the treatment of a variety of diseases. Hot aqueous extracts of the leaves are used in the treatment of stomach and rheumatic pains, inflammatory disorders, diarrhoea dysentery and diabetes (Irvine, 1961; Etta, 1984). Yakubu et al. (2012; 2013) reported the antidiabetic properties of the leaves. The roots and leaves are used for nausea, colic and epilepsy (Bouquet et al., 1971; Iwu, 1993). In North-Central and eastern parts of Nigeria, the young leaves are used as vegetables or sauces and porridge for meals, especially for diabetic patients. Materials and Methods Collection and preparation of plant materials Fresh leaves of V. doniana were collected from its natural habitat in Ankpa, Kogi State. It was identified and authenticated by the Ethno- botanist in the Department of Medicinal Plant Research and Traditional Medicine of the National Institute for Pharmaceutical Research and Development (NIPRD) Abuja, Nigeria. A voucher specimen number NIPRD/H/6415 was deposited at the herbarium of the department. The plant material was dried in the laboratory at room temperature and pulverized using laboratory mortar and pestle. Aqueous extraction About 400 g of the pulverized sample was soaked in 2 L of distilled water (1:5 W/V) and was allowed to stand for 24 h at room temperature according to the study of Iwueke and Nwodo (2008). The extract was filtered and the filtrate was concentrated using rotary evaporator under reduced pressure. It was allowed to dry at room temperature and stored in refrigerator at 4 o C prior to usage. Fractionation The ethanol extract was subjected to column chromatograph to separate the extract into its component fractions. Silica gel was used in packing the column while varying solvent combinations of increasing polarity were used as the mobile phase. Packing of column This was done according to the method of Yakubu et al. (2014). The lower part of the glass column was stocked with glass wool with the aid of glass rod. 75 g of silica gel (G60-200 mesh size) was dissolved in 180 ml of absolute chloroform to make the slurry. The chromatographic column (30 mm diameter by 40 mm height) was packed with silica gel and was allowed free flow of the solvent into a conical flask. The set up was seen to be in order