Extraction Optimization, UHPLC-Triple-TOF-MS/MS Analysis and Antioxidant Activity of Ceramides from Sea Red Rice Bran

Abstract

As a new type of salt-tolerant rice, sea red rice contains more minerals, proteins, and lipid compounds, and, in particular, its by-product rice bran may be used to replace other commercial rice brans as the main source of ceramides (Cers). However, the extraction rate of Cers is generally low, and it is crucial to seek an efficient extraction method. This study optimized the ultrasonic-assisted extraction of Cers from sea red rice bran using response surface methodology (RSM) and obtained a Cers yield of 12.54% under optimal conditions involving an extraction temperature of 46 °C, an extraction time of 46 min, and a material–to-liquid ratio of 5 g/mL. The Cers content in sea red rice bran was preliminarily analyzed using thin-layer chromatography, and the Cers content was determined via UHPLC-Triple-TOF-MS/MS after purification and separation using silica column chromatography. Forty-six different types of Cers were identified in sea red rice bran, of which Cer 18:0/24:0 (2OH), Cer 18:0/26:0, Cer 18:0/26:0 (2OH), and Cer 18:0/24:0 accounted for 23.66%, 17.54%, 14.91%, and 11.96%. Most of the Cers structures were mainly composed of sphingadienine. A biological activity assay indicated that Cers extracted from sea red rice bran had significant antioxidant and anti-aging properties. These findings indicate that the extracted Cers show great potential for applications in the cosmetic and pharmaceutical industries.

Ceramides from Sea Red Rice Bran Improve Health Indicators and Increase Stress Resistance of Caenorhabditis elegans through Insulin/IGF-1 Signaling (IIS) Pathway and JNK-1

“…The Cers with the highest component content in sea red rice bran were Cer 18:0/24:0 (2OH), Cer 18:0/26:0, Cer 18:0/26:0 (2OH), Cer 18:0/24:0, and Cer 18:0/25:0, which accounted for 23.66, 17.54, 14.91, 11.96, and 7.32, respectively. In vitro oxidation and antiaging experiments have confirmed that Cers from sea red rice bran show good biological activity . Thus, their combined antiaging effects in vivo and their molecular mechanisms are discussed below.…”

“…Based on our previous research, the Cer compounds in sea red rice bran were analyzed using UHPLC-Triple-TOF-MS/MS, and the data were integrated. We found that it contained 46 different Cer types . The sample was injected 1 μg at a time, and the internal standard method was used for quantitative analysis.…”

“…The results of our in vitro antioxidant and antiaging activity tests showed that Cers from sea red rice bran show high activity. Although Cers improved the free radical scavenging effect and inhibition rate of tyrosinase and elastase, the antiaging activity of Cers from sea red rice bran being effective in animals in vivo is yet to be reported. Therefore, the present study may be considered a continuation of our previous studies.…”

“…The column temperature was set at 55–60 °C, and the flow rate was limited to 0.4 mL/min. In short, the elution conditions remain unchanged according to the previous pattern . Finally, Applied Biosystems 1.6 software was used for data acquisition and pristine analysis.…”

“…Sea red rice grown in Zhanjiang City, Guangdong Province, China, was provided by Professor Hongkai Zhou of the Agricultural College of Guangdong Ocean University. Briefly, 50 g of sea red rice bran was weighed first, then the concentrate was separated from ethanol by extraction and evaporation according to the previous experimental methods and conditions, and finally the Cers extract was obtained.…”