Inhibition of Advanced Glycation End-Product Formation and Antioxidant Activity by Extracts and Polyphenols from Scutellaria alpina L. and S. altissima L.
Methanolic extracts from the aerial parts and roots of two Scutellaria species, S. alpina and S. altissima, and five polyphenols from these plants demonstrated a significant ability to inhibit the formation of advanced glycation end-products (AGE) in vitro. S. alpina, which is richer in polyphenolic compounds, had strong antiglycation properties. These extracts demonstrated also high activity in the FRAP (ferric-reducing antioxidant power), antiradical (DPPH) and lipid peroxidation inhibition assays. Among the pure compounds, baicalin was the strongest glycation inhibitor (90.4% inhibition at 100 μg/mL), followed by luteolin (85.4%). Two other flavone glycosides had about half of this activity. Verbascoside was similar to the reference drug aminoguanidine (71.2% and 75.9%, respectively). The strong correlation observed between AGE inhibition and total flavonoid content indicated that flavonoids contribute significantly to antiglycation properties. A positive correlation was also observed between antiglycative and antioxidant activities. The studied skullcap species can be considered as a potential source of therapeutic agents for hyperglycemia-related disorders.
Department of Biology and Pharmaceutical Botany, Medical University of Lodz, ul. Muszynskiego 1, Lodz 90-151, Poland. izabela.grzegorczyk@umed.lodz.pl.
Izabela
I
Grzegorczyk-Karolak
Department of Pharmaceutical Biochemistry, Wroclaw Medical University, ul. Borowska 211A, Wroclaw 50-556, Poland. krzysztof.golab@umed.wroc.pl.
Krzysztof
K
Gołąb
Department of Pharmaceutical Biochemistry, Wroclaw Medical University, ul. Borowska 211A, Wroclaw 50-556, Poland. jakub.gburek@umed.wroc.pl.
Jakub
J
Gburek
Department of Biology and Pharmaceutical Botany, Medical University of Lodz, ul. Muszynskiego 1, Lodz 90-151, Poland. halina.wysokinska@umed.lodz.pl.
Halina
H
Wysokińska
Department of Biology and Pharmaceutical Botany, Wroclaw Medical University, ul. Borowska 211, Wroclaw 50-556, Poland. bbsekret@umed.wroc.pl.
Adam
A
Matkowski
D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000627:therapeutic use; D002417:Cattle; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology; D017127:Glycation End Products, Advanced / Q000037:antagonists & inhibitors*; D006943:Hyperglycemia / Q000188:drug therapy*; D015227:Lipid Peroxidation / Q000187:drug effects; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry; D059808:Polyphenols / Q000737:chemistry* / Q000494:pharmacology; D031363:Scutellaria / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry
D000975:Antioxidants; D005419:Flavonoids; D017127:Glycation End Products, Advanced; D010936:Plant Extracts; D059808:Polyphenols; D012710:Serum Albumin, Bovine; C038044:baicalin
Scutellaria alpina; Scutellaria altissima; advanced glycation end products; antioxidants; flavonoids