Antioxidant activity and DNA protective properties of rice grass juices

Abstract

Juice squeezed from cereal grasses harvested at the jointing stage, i.e., wheatgrass (Triticum aestivum), exhibits high antioxidant activity. Rice (Oryza sativa) may also exhibit antioxidant activity. We therefore examined the antioxidant activity of juices squeezed from grasses harvested at the jointing stage for seven coloured and seven white Thai rice cultivars. The antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl, ferric reducing antioxidant power, β-carotene bleaching, and thiobarbituric acid reactive substances assays. The total phenolic content (TPC) and total monomeric anthocyanin content (TMAC) were also determined. Coloured (purple) rice grass juices exhibited greater antioxidant potential than the grass juices from white rice and wheat. The coloured rice cultivar Kum Doisaket exhibited the highest antioxidant activity in all assays. Correlation analysis indicated that the TPC and TMAC could be responsible for the antioxidant activity. The DNA protective properties of the coloured rice cultivars Kum Doisaket and Kum Noi and wheat were also examined. Only the Kum Doisaket cultivar exhibited a dose-dependent DNA protective effect. The notable antioxidant efficacy for the Kum Doisaket cultivar may be influenced by the high level of anthocyanins present in its grass juice. This finding suggests the possibility of developing functional foods from coloured rice grass.

Variability of Hordeum vulgare L. Cultivars in Yield, Antioxidant Potential, and Cholinesterase Inhibitory Activity

“…Choe et al [28] demonstrated that the DPPH scavenging capacity of ethanol extracts of barley leaves was 80.3 ± 0.41% at 5 mg/mL and that of methanol extracts was 79.5 ± 0.54% at 5 mg/mL. Khanthapok et al [29] in their study indicated that the DPPH scavenging capacity of wheat grass was 0.81 ± 0.02 IC 50 mg/mL. Rattanapon et al [30] estimated that the DPPH scavenging capacity of rice grass was 89.32 ± 0.57 mmol TE/g.…”

Potential Protective Effects of Rice Seedling Extracts of a Malaysian Rice Variety, Biris, Against Doxorubicin-Induced Cytotoxicity

“…Even if rice grass juice gave less statistically ability on antioxidant activities, they still had comparable levels of antioxidant activities". A separate study (Khanthapoka et al 2015) has also demonstrated the antioxidant and DNA protection capacity of juice extracted from rice seedlings. Due to the differences in sample preparations, the results cannot be directly compared to the present study.…”

“…However, further investigations are needed for testing this hypothesis, as the protective effects might not be a direct, or only, result of the antioxidant capacity. Units expressed as *per 100 g of fresh rice seedlings in this work and wheatgrass (Kulkarni et al 2006) and **per 100 g of dried extracts of rice seedling (Khanthapoka et al 2015). 1 mean ± standard deviation of three biological replicates.…”

Applying nitrogen fertilizer increased anthocyanin in vegetative shoots but not in grain of purple rice genotypes

“…This has led to the development of a range of health foods and pharmaceutical products for health‐conscious consumers . More recently, the vegetative parts of purple rice plants have attracted attention as a source of antioxidants . Indeed, rice‐grass juice may contain more phenolic acids than the popular drink produced by macerating fresh wheat seedlings .…”

“…5 More recently, the vegetative parts of purple rice plants have attracted attention as a source of antioxidants. 6,7 Indeed, rice-grass juice may contain more phenolic acids than the popular drink produced by macerating fresh wheat seedlings. 8 Therefore, factors affecting the quality of antioxidants in staple and other foods should be taken into consideration when recommending agronomic practices to producers.…”