Identification of 3- deoxyanthocyanins from red sorghum (Sorghum bicolor) bran and its biological properties

Abstract

Anthocyanins known as potent antioxidant provides attractive colours and used as an ingredient in food systems. This study aims to evaluate a potential anthocyanin extraction method from red sorghum bran and to investigate its antioxidant and cytotoxic properties. The anthocyanin content was found to be higher in acidified methanol and on separation was identified as apigeninidin and leuteolinidin, which obviously could attribute to its antioxidant properties and cytotoxic activity. Anthocyanins are natural pigments used as food additives and known for its potent antioxidant and antiproliferative property. In addition to their potential as food colorants, anthocyanins are nowadays regarded as an important nutraceuticals mainly due to their possible antioxidant effects and they have been given a potential therapeutic role related to some cardiovascular diseases, cancer treatment, inhibition of certain types of virus including Human Immunodeficiency Virus type 1 (HIV-1) and improvement of visual acuity (Stintzing et al., 2002; Talavera et al., 2006; Sandvik et al., 2004; Beattie et al., 2005; Jang et al., 2005; Cooke et al., 2005; Andersen et al., 1997; Nakaishi et al., 2000). This study aims to evaluate anthocyanin content, to analyze antioxidant and antipropliferative activity from red sorghum bran. When acidified methanol was used as a solvent for extraction, maximum amount of anthocyanin was obtained as compared to methanol alone. On separation by Thin Layer Chromatography and High Pressure Liquid Chromatography, the compounds were identified as apigenindin and luteolindin. The antioxidant activity was found to be higher in red sorghum bran. Anthocyanin from red sorghum bran also showed moderate cytotoxic activity against HT 29 and HEP G2 cell lines. Is assumed that the antioxidant and antiproliferative activity of the extract from red sorghum bran was due to apigenindin and luteolindin. So the anthocyanins extracted from easily available red sorghum bran would be a valuable source for antioxidant and antiproliferative activity in food industry. Key words: Bran, sorghum, anthocyanins, antioxidant activity, high pressure liquid chromatography, DPPH, HT 29 cancer cell line, HEP G2 cancer cell line.