Effects of molecular weight fraction on antioxidation capacity of rice protein hydrolysates.

Rice protein was used as a starting material to provide rice protein hydrolysates (RPH) through enzyme-assisted extraction. RPH was further fractionated using ultrafiltration membrane (UF) and classified by molecular weight (MW; MW < 1 kDa, MW 1-10 kDa, and MW > 10 kDa). Peptides with MW < 1 kDa possessed superior antioxidant properties (p < 0.05). Therefore, UF demonstrated great efficacy in selectively separating antioxidant peptides. A Pearson correlation analysis revealed that the total phenolic concentration was correlated with oxygen radical absorbance capacity (ORAC; r = 0.999, p < 0.05). Amino acid contents had negative correlations with the scavenging activity (specifically, IC50) of 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radicals (r = - 0.986 to - 1.000). Reducing power was related to aromatic amino acid contents (r = 0.997, p < 0.05). In this study, enzymatic hydrolysis was discovered to be an effective method of extracting and isolating natural antioxidant proteins from broken rice, thus preserving the nutritional quality of rice and making those proteins more accessible in future applications.

Evaluating the Antioxidants, Whitening and Antiaging Properties of Rice Protein Hydrolysates.

Plant-derived protein hydrolysates have potential applications in nutrition. Rice protein hydrolysates (RPHs), an excellent source of proteins, have attracted attention for the development of cosmeceuticals. However, few studies have reported the potential application of RPH in analysis, and this study examined their antioxidant activities and the inhibitory activities of skin aging enzymes. The results indicated that the total phenolic and flavonoid concentrations were 2.06 ± 0.13 mg gallic acid equivalent/g RPHs and 25.96 ± 0.52 µg quercetin equivalent/g RPHs, respectively. RPHs demonstrated dose-dependent activity for scavenging free radicals from 1,1-diphenyl-2-picrylhydrazyl [half-maximal inhibitory concentration (IC50) = 42.58 ± 2.1 mg/g RPHs] and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (IC50 = 2.11 ± 0.88 mg/g RPHs), dose-dependent reduction capacity (6.95 ± 1.40 mg vitamin C equivalent/g RPHs) and oxygen radical absorbance capacity (473 µmol Trolox equivalent/g RPHs). The concentrations of the RPH solution required to achieve 50% inhibition of hyaluronidase and tyrosinase activities were determined to be 8.91 and 107.6 mg/mL, respectively. This study demonstrated that RPHs have antioxidant, antihyaluronidase, and antityrosinase activities for future cosmetic applications.

Effects of Hsian-tsao (Mesona procumbens Hemsl.) extracts and its polysaccharides on the promotion of wound healing under diabetes-like conditions.

The aim of the study was to evaluate the effects of Hsian-tsao (Mesona procumbens Hemsl.) and its polysaccharides on impaired wound healing in diabetes. The results indicate that ethanol extracts of Hsian-tsao (EE) and crude polysaccharides from water extracts of Hsian-tsao (WEP) had strong inhibitory effects on methylglyoxal (MG)-induced glycation and reactive oxygen species (ROS) production. EE and WEP also decreased MG-induced inflammation-related factors in RAW 264.7 macrophages and restored MG-impaired wound-healing factors in 3T3-L1 fibroblasts. Furthermore, EE and WEP were found to dose-dependently enhance the MG-impaired phagocytosis of Staphylococcus aureus and Pseudomonas aeruginosa by macrophages. Excitingly, EE and WEP significantly enhanced wound healing on the dorsal skin through regulation of macrophage inflammatory protein-2 (MIP-2), metalloproteinase-9 (MMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) protein expressions in diabetic mice, as evidenced by the percentage reduction in wound surface area and the results of histopathologic scoring analysis. In conclusion, these results suggest that Hsian-tsao extract and its polysaccharides might be utilized in alternative natural therapy to promote wound healing in diabetic individuals.