Hypoglycemic Activity of Extracts and Compounds from the Leaves of Hintonia standleyana and H. latiflora: Potential Alternatives to the Use of the Stem Bark of These Species^,

Abstract

The CH(2)Cl(2)-MeOH (1:1) extract of the leaves of Hintonia standleyana and H. latiflora caused significant decrease in blood glucose levels in both normal and streptozotozin (STZ)-induced diabetic rats when compared with vehicle-treated groups (p < 0.05). These extracts were not toxic to mice according to the Lorke criteria. From the hypoglycemic extract of H. standleyana, two new 4-phenylcoumarins, namely, 6''-O-acetyl-5-O-beta-d-galactopyranosyl-7,4'-dihydroxy-4-phenylcoumarin (1) and 6''-O-acetyl-5-O-beta-d-galactopyranosyl-7,3',4'-trihydroxy-4-phenylcoumarin (2), were obtained. The analogous extract of H. latiflora yielded the new 5-O-[beta-d-xylopyranosyl-(1-->6)-beta-d-glucopyranosyl]-7,4'-dimethoxy-4-phenylcoumarin (3) along with several known compounds, including ursolic acid and desoxycordifolinic acid. Phenylcoumarins 1 and 2 showed hypoglycemic activity. HPLC profiles of the leaf extracts of both plants revealed the presence of known hypoglycemic phenylcoumarins as well as chlorogenic acid. The overall results have indicated that the leaves of H. standleyana and H. latiflora possess similar antidiabetic potential to their stem bark. Therefore, the leaves from these species could represent an alternative to the use of their stem bark, which, in turn, would contribute to the conservation of these Mexican medicinal plants.

Historia natural y cosecha de corteza de quina amarilla Hintonia latiflora (Rubiaceae)

“…El valor de la corteza de Hintonia latiflora se deriva de sus principios activos . La corteza contiene aceite fijo, caucho, resinas, materia colorante, taninos, principios amargos, alcaloides (ácido desoxicordifolínico), cucurbitacinas (cuatro derivados de dihidrocucurbitacina F), flavonoides, fenilcumarinas (4-fenilcumarinas y 4-fenil-5,2'-óxido-cumarinas) y glucocucurbitacinas (Camacho, 1990;Argotte-Ramos et al, 2006;Cristians et al, 2009). La fenilcumarina y glucocucurbitacina han sido ingredientes activos validados clínicamente contra el paludismo .…”

Development of a HPLC-DAD Method for the Simultaneous Quantification of 5-O-β-D-galactopyranosyl-7-methoxy-3’,4’-dihydroxy-4-phenylcoumarin and its Aglycone in Feces

“…Since the previous analytical methods for quantification of 4-phenylcoumarins [27][28][29] did not work in a biological matrix base analysis, different mobile phases (acetonitrile and TFA acidified water 50:50 Vol/Vol; 20:80 Vol/Vol; 24:76 Vol/Vol; 15:85 Vol/Vol; 10:90 Vol/Vol), flow rates (1 mL/min; 1.2 mL/min; 1.5 mL/min), columns (Symmetry C-18, Waters; Synergi C-18, Phenomenex; Eclipse C-8, Agilent; Zorbax C-18, Agilent) and column temperature were tested in order to obtain chromatographic resolution. The detection wavelength was set at 328nm in an HPLC-DAD 1100 (Agilent Technologies, Palo alto, CA, USA).…”

“…The method development and optimization were established empirically for the best solubilization conditions for both 4-PC and aglycone; also, the former analytical methods reported for 4-phenylcoumarins analysis [27][28][29] were considered for those goals ( Table 1). The development of this method was focused to the column, mobile phase and flow rate, in order to achieve the simultaneous detection and quantification of the bioactive compounds in feces in the less analytical time.…”

“…Several methods for the quantification of natural products were developed, mainly aimed to quality control of herbal drugs. The situation of 4-phenylcoumarins is no exception, the analytical methods generated were fixed on quantify these compounds as active markers of the stem-bark infusions of H. latiflora and H. standleyana crude drugs, using HPLC-UV detector [27], identify the 4-phenylcoumarins as chemical constituents of the leaves infusions of both Hintonia species by HPLC method [28]. Recently, the simultaneous quantification of both 4-phenylcoumarins and chlorogenic acid in Exostema caribaeum stem-bark aqueous extract by UPLC-PDA method has also been reported [29]; nevertheless, there is no records of analytical methods aimed to detect and quantify the 4-phenylcoumarins and their metabolites, the aglycones, in biological matrices as a part of pharmacokinetics studies.…”

“…Comparative chart between the published analytical methodologies for 4-phenylcoumarins Mata et al, 2008Cristians et al, 2009. Pérez-Vásquez et al, 2014 Current method…”