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Background:Protein glycation and glycotoxicity belong to the main oxidative-stress related complications in diabetes. Perovskia species are used in Asian folk medicine as antidiabetic herbs.Objective:The aim of this study was to verify the ability of the methanolic extract from Perovskia atriplicifolia Benth. roots to diminish glycation of albumin and to prevent cell damage in vitro. Furthermore, we tested the extract for in vitro antioxidant activity and inhibition of elastase and collagenase.Material and Methods:The aqueous methanol extract was analyzed by UHPLC-MS for the content of polyphenols and terpenoids. The prevention of glycated albumin-induced cell damage was tested in four mammalian cell lines (peripheral blood mononuclear cells, human embryonic kidney cells – HEK293, normal human fibroblasts, and Chinese hamster ovary cells) with the 5-(3-carboxymethoxyphenyl)-2-(4,5-dimethylthiazoly)-3-(4-sulfophenyl) tetrazolium assay.Results:Glycated albumin is significantly more toxic than native human serum albumin (LC50 from 35.00 to 48.34 μg/mL vs. 5.47–9.10 μg/mL, respectively). The extract, rich in rosmarinic acid (344.27 mg/g dry mass), mitigated the glycated albumin toxicity, and increased glycated albumin-treated cell survival by more than 50%. The inhibition of advanced glycation endproduct formation was confirmed by monitoring conformational changes. The free radical scavenging activity was higher than Trolox and metal reducing power was one-third to half that of ascorbic acid. The activity of elastase and collagenase was inhibited by 54.75% ± 6.87% and 60.03% ± 7.22%, respectively.Conclusions:The results confirm antiglycative and antiglycotoxic potential of Perovskia root and its traditional antidiabetic use. The high activity can be attributed to rosmarinic acid abundance.SUMMARY Perovskia is a small genus of aromatic shrubby plants growing in arid regions of Central and South Asia. Different parts are used in folk medicine as antiparasitic, anti-infectious and antidiabetic remedy. Here, we have studied the extract from roots for inhibition of: glycation-induced cytotoxicity, human serum albumin glycation, inflammation-related enzymes, as well as for antioxidant activity. Result: the extract from P. atriplicifolia roots inhibited protein glycation and AGE-induced toxicity in cell cultures. The mechanism is likely to rely on the antioxidant activity of high content of rosmarinic acid. Abbreviations used: AGE: advanced glycation end-products; DPPH: 2,2-diphenyl-1-picrylhydrazyl; HSA: human serum albumin.

The present communication reports on changes in the secondary and tertiary structures of Hemoglobin (Hb) upon fructation. The presence of Lemon balm (LB) provided significant protection toward the formation of early (HbA1c) and advanced glycation end products (Hb-AGEs), as evident from circular dichroism (CD) and fluorescence studies. The degree of AGE modification and its inhibition were characterized with intrinsic fluorescence, the fibrillar state, and the exposure of hydrophobic clusters. An increased signal of intrinsic fluorescence was observed upon glycation, particularly in the later stage of fructation. Glycation mediated fibril formation and its inhibition were assessed by Thioflavin T (ThT) assay. These sequence of events were parallel with an increase in β-sheet content from ~2 to 13% for Hb-AGE, as evidenced by Congo red binding and CD. Furthermore, the late stage of glycation was also marked by an increase loss of heme moiety, confirming the relatively high affinity of ANS toward glycated-globin which was mitigated by applying the balm extract. However, the activity of balm can be attributed to inhibition of oxidative stress and free radicals derived from Hb-AGE, or chelation of metal ions producing in Fenton reaction. Overall, the presence of LB provided significant protection against AGE-induced deleterious processes, can qualify the herb as an effective AGE-inhibitor with potential prevention toward diabetic complications arising from Hb glycation.