Inhibitory Effects of Lamiaceae Plants on the Formation of Advanced Glycation Endproducts (AGEs) in Model Proteins

Protein glycation and oxidative stress caused by chronic hyperglycemia play vital role in diabetic complications. This study focused on the evaluation of the antiglycation effect of four Lamiaceae plants (Ocimum sanctum, O. basilicum, O. americanum and Metha cordifolia opiz.). Among the ethanolic extracts, O. sanctum extract exhibited high content of phenolic compounds and strong antioxidant activity. Chemical composition analyzed by HPLC revealing two major phenolic conpounds in O. sanctum extracts as rosmarinic acid (4.43 mg/g) and luteolin (0.96 mg/g). In the antiglycation assays, bovine serum albumin (BSA) and histone which were used as model proteins for investigation in the presence of methylglyoxal (MGO) with or without the extracts comparing with the authentic phenolic compounds. The results showed that O. sanctum extract possessed a potent antiglycation activity in both BSA and histone models with 23.4% and 43.0 % inhibition at the concentration of 500 and 250μg/mL, respectively. The results indicated that O. sanctum which contained high phenolic compounds has potential to prevent protein glycation caused by oxidative stress.