*Article* **Antiglycation Effects of Adlay Seed and Its Active Polyphenol Compounds: An In Vitro Study**

**Cheng-Pei Chung 1,2,†, Shih-Min Hsia 3,4,5,6,†, Wen-Szu Chang 7, Din-Wen Huang 7,8, Wen-Chang Chiang 7, Mohamed Ali 9, Ming-Yi Lee 1,10 and Chi-Hao Wu 11,\***

	- Chang Gung University of Science and Technology, Taoyuan 333324, Taiwan
	- Taipei 110301, Taiwan

**Abstract:** This study aimed to evaluate the antiglycation effects of adlay on protein glycation using in vitro glycation assays. Adlay seed was divided into the following four parts: the hull (AH), testa (AT), bran (AB), and polished adlay (PA). A solvent extraction technique and column chromatography were utilized to investigate the active fractions and components of adlay. Based on a BSA-glucose assay, the ethanolic extracts of AT (ATE) and AB (ABE) revealed a greater capacity to inhibit protein glycation. ATE was further consecutively partitioned into four solvent fractions with *n*-hexane, ethyl acetate (ATE-Ea), 1-butanol (ATE-BuOH), and water. ATE-BuOH and -Ea show marked inhibition of glucose-mediated glycation. Medium–high polarity subfractions eluted from ATE-BuOH below 50% methanol with Diaion HP-20, ATE-BuOH-c to -f, exhibited superior antiglycation activity, with a maximum inhibitory percentage of 88%. Two phenolic compounds, chlorogenic acid and ferulic acid, identified in ATE-BuOH with HPLC, exhibited potent inhibition of the individual stage of protein glycation and its subsequent crosslinking, as evaluated by the BSA-glucose assay, BSmethylglyoxal (MGO) assay, and G.K. peptide-ribose assay. In conclusion, this study demonstrated the antiglycation properties of ATE in vitro that suggest a beneficial effect in targeting hyperglycemiamediated protein modification.

**Keywords:** adlay; adlay testa; antiglycation; phenolic acid
