Black Rice (Oryza sativa L. indica) Pigmented Fraction Suppresses both Reactive Oxygen Species and Nitric Oxide in Chemical and Biological Model Systems

Abstract

Anthocyanins, present in fruits and vegetables as natural colorants, have been well characterized to possess bioactive properties. Anthocyanin components extracted from black rice (Oryza sativa L. indica) separated by gel filtration and identified using LC-MS were cyanidin 3-glucoside and peonidin 3-glucoside. A standardized extract of black rice pigmented fraction (BRE) containing known proportions of cyanidin 3-glucoside and peonidin 3-glucoside exhibited marked antioxidant activities and free radical scavenging capacities in a battery of in vitro model systems. Significant (p < 0.05) prevention of supercoiled DNA strand scission induced by reactive oxygen species (specifically, peroxyl radical and hydroxyl radicals) and suppression of the oxidative modification of human low-density lipoprotein was obtained with BRE. In addition, BRE reduced (p < 0.05) the formation of nitric oxide by suppressing inducible nitric oxide synthase expression in murine macrophage RAW264.7 cells, without introducing cell toxicity. The results of this study show that black rice contains anthocyanin pigments with notable antioxidant and anti-inflammatory properties for potential use in nutraceutical or functional food formulations. Keywords: Black rice; anthocyanin; antioxidant; nitric oxide

Formulation and In-Vitro and In-Vivo Evaluation of a Mucoadhesive Gel Containing Freeze Dried Black Raspberries: Implications for Oral Cancer Chemoprevention

“…In addition to vitamin A derivatives, there are many additional chemopreventive compounds that have elicited a variety of cancer preventing effects including induction of apoptosis, stimulation of differentiation and suppression of cell proliferation in both in-vitro and in-vivo models (25)(26)(27)(28). Relevant to this current study, compounds which provide natural colors to fruits and vegetables such as the anthocyanins, have been shown to demonstrate a wealth of chemopreventive properties (15,(27)(28)(29)(30). While anthocyanins represent the primary flavinoids in FBR, black raspberries also contain additional chemopreventive compounds including ferulic acid, coumaric acid, quercetin, and phtyosterols.…”

Phenolic compounds and antioxidant activity of rice

“…This showed that the antioxidant compounds present in these grains might act in different ways to reduce the oxidative stress in the organism and, with that, help in the prevention of several diseases. The reduction of the oxidative stress by polyphenols in rice grains was observed in in vitro and ex vivo studies, indicated by the reduction in the production of nitric oxide (Hu et al, 2003) and in the concentration of reactive oxygen species (Hu et al, 2003;Chiang et al, 2006). Simultaneously to the reduction in the indicators of oxidation, an increase in the antioxidant capacity was observed, including higher total antioxidant capacity and increased activity of antioxidant enzymes, such as superoxide dismutase and catalase .…”

“…In rice grains with red and black pericarp, the main phenolics are the anthocyanins cyanidin-3-O-β-Dglucoside and peonidin-3-O-β-D-glucoside (Oki et al, 2002;Hu et al, 2003;Chen et al, 2006;Zhang et al, 2006;Yawadio et al, 2007). Other compounds identified include the anthocyanidins cyanidin and malvidin (Hyun and Chung, 2004;Zhang et al, 2006), the anthocyanins pelargonidin-3,5-diglucoside and cyanidin-3,5-diglucoside (Zhang et al, 2006) and phenolic acids, like ferulic, caffeic and protocatechuic acids (Morimitsu et al, 2002).…”

“…Polishing significantly reduces the concentration of phenolics since these compounds are localized mainly in the external layers of the grain. The bran contains between 70 and 90% of the phenolic acids in light brown pericarp rice grains (Zhou et al, 2004), and approximately 85% of the anthocyanins in the rice grains with black pericarp (Hu et al, 2003), with little variation depending on the cultivar and the compounds considered. According to Goffman and Bergman (2004), this high correlation between the content of phenolics in the grain and in the bran showed that it was possible to select for higher or lower phenolics content through the analysis of the grain without polishing, reducing the time of sample preparation.…”

“…Besides, grains with darker pericarp colour, such as red and black rice, contain higher amounts of polyphenols (Tian et al, 2004;Zhou et al, 2004). The concentration of total phenolics in the grain has been positively associated with the antioxidant activity (Itani et al, 2002;Goffman and Bergman, 2004;Zhang et al, 2006), with potential beneficial effects on health, such as reduction of oxidative stress (Ling et al, 2001;Hu et al, 2003), aid in the prevention of cancer (Hudson et al, 2000;Hu et al, 2003;Hyun and Chung, 2004;Chen et al, 2006), in the control of blood lipids and related diseases, which may help in the prevention of cardiovascular problems (Ling et al, 2001), and in the prevention of the complications of diabetes (Morimitsu et al, 2002;Yawadio et al, 2007). The aim of this article was to examine the phenolic compounds present in rice, their antioxidant activity and their potential beneficial effects on health.…”