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Abstract

This study was designed to determine the anthocyanin cyanidin-3-glucoside content and antioxidant activity of rice varieties under salinity stress. Two classes of Thai rice lines: cyanic (Riceberry, Kham, and Khamdoisaket) and acyanic (KDML 105, Sinlek, were hydroponically grown. Seedlings were grown for 16 days and were supplied with salinity nutrient solution with 0 (control) and 60 mM NaCl for 11 days. The total phenolic content and the antioxidant activity, including 2,2-diphenyl-1-picrylhydrazyl free radical-scavenging, ferric reducing antioxidant power, and lipid peroxidation were also determined by colorimetric assay. Anthocyanin pigment cyanidin-3-glucoside was quantified by high performance liquid chromatography. The results show that salinity stress in Khamdoisaket and KDML 105 cultivars significantly (p < 0.05) increased the total phenolic content, antioxidant activity, and cyanidin-3-glucoside content. Riceberry, Kham, and Sinlek cultivars, showed a moderate increase. The salt tolerant variety, BC2F7#62-56, showed only a slight but not significant increase in antioxidant activity and virtually unchanged lipid peroxidation, total phenolic content, and anthocyanin cyanidin-3-glucoside content under salinity stress. These results suggest that the increased total phenolic content, antioxidant activity, and anthocyanin cyanidin-3-glucoside content in rice seedling might be a protection mechanism against salinity stress. BC2F7#62-56 seems to have potential tolerance to salinity stress. This capability could be related to unchanged antioxidant activities, lipid peroxidation, total phenolic content, and anthocyanin cyanidin-3-glucoside content.

Optimization of conditions to achieve high content of gamma amino butyric acid in germinated black rice, and changes in bioactivities

“…Likewise, The α-glucosidase inhibiting property of phenolics, anthocyanins, GABA, and tocols was increased from 64.28 ± 2.51, 64.42 ± 2.70, 63.10 ± 1.71, and 63.62 ± 1.35 to 81.44 ± 2.05, 80.84 ± 2.23, 76.40 ± 2.01, and 76.59 ± 1.33% of inhibition/mg of extracts, respectively ( Figure 3A (b)). The germination improved the free radical scavenging ability of several Thai rice varieties (Daiponmak et al, 2010;Chutipaijit et al, 2009Chutipaijit et al, , 2011Ghosh et al, 2011;Umnajkitikorn et al, 2013;Yodpitak et al, 2013). The study results also clearly indicated that germination procedure increased the bioactivities of BR phytochemicals ( Figure 3A).…”

“…Umnajkitikorn et al (2013) reported that the presence of salt (150 mM NaCl) enhanced the free radical scavenging ability of rice (cultivar Kum Doi Saket). Several studies reported the improvement of total phenolic, anthocyanins, and flavonoids content in Thai rice varieties during germination under the salinity (60-200 mM NaCl) (Chutipaijit et al, 2009(Chutipaijit et al, , 2011Daiponmak et al, 2010;Ghosh et al, 2011). The germination of cold sensitive rice seeds at 17 °C improved the antioxidant property of rice seedlings, especially lipid peroxidation, and superoxide dismutase activity, and further facilitated the accumulation of plant hormone gibberellic acid, which diminished the impact of cold stress (Grohs et al, 2016).…”

A comparative proteomic study of white and black glutinous rice leaves

“…19 was found to contain cyaniding 3-glucoside, as suggested by OD 535 . It has been reported that the majority of black rice plants contain anthocyanidin-3-glucosides as the major anthocyanin, which functions as the major antioxidant compound [6,38,42,43] and strong superoxide radical scavenging activity [44,45,46]. Since Br no.…”

Correlation of Phytochemical, Metal Contents and Antioxidant Activities of Black Glutinous Rice Bran and Potential Chemoprevention

“…The bioactive components in the rice bran extract were diff erent due to several factors, including cultivation techniques, ripening environments and growing conditions (11,12). All rice bran extracts had signifi cantly lower (p≤0.05) antioxidant activities than the corresponding positive controls.…”

“…It was found in an in vitro study that Mn contributes to the antioxidant activity of rice (10). Concentrations of phenolics, fl avonoids, anthocyanins and minerals are diff erent depending on variety, growing conditions and soil components (11,12). Various cultivars of black glutinous rice are grown in the northern region of Thailand and they may have diff erent antioxidant components that need to be investigated.…”