Inhibition of Protein Glycation by Extracts of Culinary Herbs and Spices

Abstract

We tested whether polyphenolic substances in extracts of commercial culinary herbs and spices would inhibit fructose-mediated protein glycation. Extracts of 24 herbs and spices from a local supermarket were tested for the ability to inhibit glycation of albumin. Dry samples were ground and extracted with 10 volumes of 50% ethanol, and total phenolic content and ferric reducing antioxidant potential (FRAP) were measured. Aliquots were incubated in triplicate at pH 7.4 with 0.25 M fructose and 10 mg/mL fatty acid-free bovine albumin. Fluorescence at 370 nm/440 nm was used as an index of albumin glycation. In general, spice extracts inhibited glycation more than herb extracts, but inhibition was correlated with total phenolic content (R(2) = 0.89). The most potent inhibitors included extracts of cloves, ground Jamaican allspice, and cinnamon. Potent herbs tested included sage, marjoram, tarragon, and rosemary. Total phenolics were highly correlated with FRAP values (R(2) = 0.93). The concentration of phenolics that inhibited glycation by 50% was typically 4-12 microg/mL. Relative to total phenolic concentration, extracts of powdered ginger and bay leaf were less effective than expected, and black pepper was more effective. Prevention of protein glycation is an example of the antidiabetic potential for bioactive compounds in culinary herbs and spices.

A Note Study on Antidiabetic Effect of Main Molecules Contained in Clove Using Molecular Modeling Interactions with DPP-4 Enzyme

“…The spices improved the biomarkers of oxidative stress in the tissues of fructose-fed insulin-resistant rats [21]. Culinary, herb and spice extracts also inhibited protein glycation in vitro and the most potent inhibitors were extracts of cloves, ground Jamaican allspice, and cinnamon [22]. Insulin-like biological activity of clove and other culinary or medicinal plant aqueous extracts were also proven in vitro [23].…”

Advanced Glycation End Products (Ages) in Food: Focusing on Mediterranean Pasta

“…For example, pre-treatment of meats with lemon, vinegar or with any acidic marinade before cooking has a significant effect in preventing the excessive increase of dAGE content. Dearlove and colleagues [19] demonstrated that polyphenols found in culinary herbs like sage, marjoram, tarragon, and rosemary are potent inhibitors of fructose-mediated protein glycation. Spice extracts, such as cloves, ground Jamaican allspice, and cinnamon, were also found to be glycation inhibitors, even stronger than herb extracts [19].…”

“…Dearlove and colleagues [19] demonstrated that polyphenols found in culinary herbs like sage, marjoram, tarragon, and rosemary are potent inhibitors of fructose-mediated protein glycation. Spice extracts, such as cloves, ground Jamaican allspice, and cinnamon, were also found to be glycation inhibitors, even stronger than herb extracts [19]. Since foods mainly composed of carbohydrates (e.g., starches, fruits, vegetables, and milk) contain the lowest AGE concentrations, another strategy to reduce dAGE intake consists in implementing the use of these healthy foods instead to eat full-fat cheeses, meats, and highly processed foods.…”

A novel in vitro method to detect inhibitors of protein glycation

“…Further, purifi ed phenolic compounds such as fl avones, proanthocyanidins, and other phenolics were found to have a strong inhibitory activity. 11 However, Povichit et al, found a strong antiglycating potential with some plant extracts having relatively low contents of total phenolic compounds. 12 A good correlation has been shown to exist between free radical scavenging capacity of the plant extract and AGE inhibitory activity in vitro.…”

“…12 A good correlation has been shown to exist between free radical scavenging capacity of the plant extract and AGE inhibitory activity in vitro. 11,13 Chen et al, suggested that the total saponin content too is correlated to AGE inhibitory potential. 13 In a recent review, anti-glycation properties of some foods, their active components, and their mechanisms of action were discussed.…”