Anti-glycation activity of the four types of herbs
- The anti-glycation activity was measured as follows: add human serum albumin (HSA), glucose, and each herbal extract (0. 006%); incubate at 60°C for 40 hours; and then measure the amount of 3-deoxyglucosone (3DG), pentosidine, and Ｎε-(carboxymethyl)lysine (CML) in the reaction solution as the products of the glycation reaction.
- The activities of the extracts of Roman chamomile, dokudami, hawthorn berry, and grape leaf to inhibit the production of 3DG, pentosidine, and CML varied among the plant species as well as with each of the glycation reaction products (figures below)11).
Constituents of the four herbs
The chamomile flowers contain at least 0.4% (V/W) of essential oils. The main constituents are α-bisabolol and bisabolol oxides A and B. In addition, matricin and flavones such as apigenin, and apigenin 7-glucoside are included. Specifically, chamaemeloside in Roman chamomile has been reported as one of the Maillard reaction inhibitors5)-9).
Dokudami leaves contain quercitrin, which is a flavonoid glycoside10).
Hawthorn berries contain flavonoid glycosides (rutin, vitexins, and hyperoside), pentacyclic triterpenes, saponins, oligomeric procyanidins, trimethylamine, condensed tannins, and vitamins B1, B2, and C1).
Grape leaves are rich in flavonoids such as quercetin1).
Anti-glycation activity of AG Herb MIX10)
The anti-glycation activity of AG Herb MIX from the mixed extract of dokudami, hawthorn berry, Roman chamomile, and grape leaf is compared with those of aminoguanidine and α-lipoic acid. (Aminoguanidine, which shows anti-glycation activity, is a therapeutic agent for diabetes complications. It is yet to be approved in Japan.)
- The anti-glycation activity was measured as follows: add human serum albumin (HSA), glucose, and each evaluated constituent (0. 006%); incubate at 60°C for 40 hours; and then measure the amount of 3-deoxyglucosone (3DG), pentosidine, and Ｎε-(carboxymethyl)lysine (CML) in the reaction solution as the products of the glycation reaction.
- As for the anti-glycation activity, the comparison based on the three kinds of glycation reaction products suggests that the result of AG Herb MIX is superior to those of aminoguanidine and α-lipoic acid.
- A concentration dependent activity against 3DG is indicated.
- For pentosidine and CML, it is confirmed that the anti-glycation activity is more marked than other anti-glycation substances.
- Since the anti-glycation activity of α-lipoic acid is an indirect one through promoting carbohydrate metabolism, no expectations can be made for it to directly inhibit the reaction products.
In a living human body, the generation of reactive oxygen species (e.g., superoxides, hydroxyl radicals) damage cells, causing cancer, inflammation, and accelerated aging. Especially for the skin, it is said to cause spots and wrinkles, etc.
Compared with other antioxidants, AG Herb MIX shows a higher antioxidant activity.
- DPPH radical scavenging activity
- Dissolve AG Herb MIX or a reference constituent in 50% ethanol to obtain a concentration of 10 mg/mL. Add DPPH and perform the ESR measurement.
- The DPPH radical scavenging ability of AG Herb MIX was about 4 times higher than vitamin E, about 40 times higher than astaxanthin, and about 70 times higher than coenzyme Q10 and α-lipoic acid.
- Superoxide scavenging activity
- Dissolve AG Herb MIX or a reference constituent to obtain a concentration of 10 mg/mL. Generate superoxides in the hypoxanthine-xanthine system and perform the complementary measurement of the superoxide scavenging activities with the spin trapping method using DMPO.
- The superoxide scavenging ability of AG Herb MIX as solid extract was about 20 times higher than α-lipoic acid, about 60 times higher than vitamin E and coenzyme Q10, and about 70 times higher than astaxanthin.