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Compounds from rosemary and Mexican oregano are natural inhibitors of dipeptidyl peptidase‐IV, a target for type‐2 diabetes management (1045.20)
Author(s) -
Bower Allyson,
RealHernandez Luis,
Berhow Mark,
Mejia Elvira
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.1045.20
Subject(s) - naringenin , origanum , chemistry , polyphenol , traditional medicine , herb , food science , flavonoid , biochemistry , essential oil , antioxidant , medicinal herbs , medicine
Herbs are a concentrated source of polyphenols. Emerging research shows polyphenols can inhibit the diabetic drug target dipeptidyl peptidase‐IV (DPPiv). The aim was to identify compounds from culinary herbs that may be used in the management of type‐2 diabetes (T2DM). Total polyphenol (TP) and total flavonoid (TF) concentrations as well as DPPiv inhibition were measured and bioassay guided fractionation was used to identify compounds from oregano (OV, Origanum vulgare ), marjoram (MO, Origanum majorana ), rosemary (RO, Rosmarinus officinalis ) and Mexican oregano (LG, Lippia graveolens ) that inhibit DPPiv. OV had the highest concentration of TP (430 ± 17 μg gallic acid equiv/mg dry weight, DW) while RO of TF (661 ± 25 μg rutin equiv/mg DW, P<0.01). The herb extracts and their fractions with the lowest IC 50 for DPPiv were RO (16 ± 5 μM), LG (31 ± 3 μM), RO fractions (range 0.37‐20.27 μM) and LG fractions (range 1.1‐17.4 μM). LC/MS identified flavonoids in fractions from RO and LG; of these compounds, computational modeling identified hispidulin (‐9.4), eriodictyol (‐8.9) and naringenin (‐8.6) as having the lowest binding affinities (kcal/mol). The IC 50 of these compounds were 0.5, 11.2 and 2.8 μM, respectively, and formed H‐bonds to Thr565 and Arg560; hispidulin and naringenin to Lys512, while only hispidulin formed H‐bonds to Asn562. These amino acids may be important sites of DPPiv inhibition by flavonoids. Overall, these data suggest that hispidulin, naringenin and herbs containing these flavonoids are potent inhibitors of DPPiv and should be investigated further in the management of T2DM. Grant Funding Source : Jonathan Baldwin Turner Fellowship, Division of Nutritional Sciences, University of Il