Antiproliferative and antioxidant properties of protein-free and protein-bound phenolics isolated from purple Rice (Oryza sativa L.)

Sihui Xiong; Ming Chen; Xun Pei; Jinjing Yin; Hélder Oliveira; Nuno Mateus; Shuxin Ye; Muci Wu; Rui Zhang; Jingren He

doi:10.1016/j.ijbiomac.2024.139340

Antiproliferative and antioxidant properties of protein-free and protein-bound phenolics isolated from purple Rice (Oryza sativa L.)

Int J Biol Macromol. 2024 Dec 30:139340. doi: 10.1016/j.ijbiomac.2024.139340. Online ahead of print.

Authors

Sihui Xiong¹, Ming Chen¹, Xun Pei¹, Jinjing Yin¹, Hélder Oliveira², Nuno Mateus², Shuxin Ye³, Muci Wu¹, Rui Zhang⁴, Jingren He⁵

Affiliations

¹ National R&D Center for Se-rich Agricultural Products Processing, Hubei Engineering Research Center for Deep Processing of Green Se-rich Agricultural Products, School of Modern Industry for Selenium Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, China.
² REQUIMTE/LAQV, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, 4169-007, Porto, Portugal.
³ Yun-Hong Group Co. Ltd, Hubei Province 430206, PR China.
⁴ National R&D Center for Se-rich Agricultural Products Processing, Hubei Engineering Research Center for Deep Processing of Green Se-rich Agricultural Products, School of Modern Industry for Selenium Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, China; Key Laboratory for Deep Processing of Major Grain and Oil, Ministry of Education, Hubei Key Laboratory for Processing and Transformation of Agricultural Products, Wuhan Polytechnic University, Wuhan 430023, PR China. Electronic address: [email protected].
⁵ National R&D Center for Se-rich Agricultural Products Processing, Hubei Engineering Research Center for Deep Processing of Green Se-rich Agricultural Products, School of Modern Industry for Selenium Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, China; Key Laboratory for Deep Processing of Major Grain and Oil, Ministry of Education, Hubei Key Laboratory for Processing and Transformation of Agricultural Products, Wuhan Polytechnic University, Wuhan 430023, PR China. Electronic address: [email protected].

PMID: 39743086
DOI: 10.1016/j.ijbiomac.2024.139340

Abstract

Purple rice (Oryza sativa L.) is a rich in endogenous phenolics and proteins. The naturally occurring interactions between phenolic compounds and proteins have been shown to have beneficial effects on human health. In this study, four protein fractions of purple rice (albumin, prolamin, globulin, and glutelin) were extracted, and both protein-free and protein-bound phenolics (PFP and PBP) were isolated from each protein fraction. The major phenolics compounds identified in different protein fraction included protocatechuic acid, vanillic acid, and ferulic acid. Additionally, the PFP in the albumin fraction exhibited the highest number of anthocyanin glycosides (7 types) among all phenolic compounds, while the remaining compounds were identified only as cornflower-3-glucoside and paeoniflorin-3-glucoside. Moreover, the in vitro antioxidant activity and cancer cell inhibitory effects of PFP and PBP in various protein fraction were investigated using chemiluminescence and cellular assays. The results demonstrated that the inhibitory effect of H₂O₂ was more pronounced than that of other free radicals (O₂^- and OH^-), with albumin and prolamin exhibiting heightened antioxidant activities. Notably, the PBP in various protein fractions showed a higher antiproliferative capacity than their corresponding PFP, indicating a potential synergistic effect of protein-phenolic interactions that differed between the two cell lines, MKN-28 and HT-29.

Keywords: Antioxidant activity; Antiproliferative capacity; Phenolics; Protein; Purple rice (Oryza sativa L.).