Activity-guided purification and identification of endogenous bioactive peptides from barley sprouts (Hordeum vulgare L.) with diabetes treatment potential

Metabolic-associated disorders such as blood pressure and type 2 diabetes (T2D) are some of modern society's widespread problems. While there are many beneficial treatments, the quest for safe alternatives using natural products (e.g., cereals) is of great promise, especially plant-based peptides containing inherently endogenous bioactivities that can provide multiple health-promoting effects. Here, we aimed to purify and identify potential endogenous peptides of barley sprouts through an activity-guided process with a potential T2D therapeutical effect. Barley seeds were germinated, and sprouts were fractionated through ultrafiltration followed by RP-HPLC. All peptide fractions were examined for various bioactivities (alpha-glucosidase/DPP4 inhibition, antiglycation, antioxidant and metal chelation activities). LC-Q-TOF-MS/MS was employed for sequence identification of the fraction with the highest activity level. The data demonstrated that fractions with molecular weights lower than 3 kDa were the only ones with antiglycation activities. The RP-HPLC of the 3 kDa fraction resulted in 11 fractions, including 4 having significant IC50/EC50 levels. F11 demonstrated the highest potential as T2D treatment, and the sequence identification provided the sequences SQQENELTSLIVESNNRFNNASNT. Natural bioactive peptides from easy to procure and cheap sources are promising molecules for therapeutic applications. Further in vivo and clinical testing are necessary to validate the current findings.

Automated summary

This study aimed to purify and identify potential endogenous peptides of barley sprouts for potential type 2 diabetes (T2D) treatment. The findings showed that peptide fractions with molecular weights lower than 3 kDa were the only ones with antiglycation activities. Among them, F11 demonstrated the highest potential as a T2D treatment.