title: Phenological and geographical influence in the concentration of selected bioactive 4-phenylcoumarins and chlorogenic acid in Hintonia latiflora leaves.
abstract: BACKGROUND
  Hintonia latiflora is a Mexican medicinal plant with well-documented ethnomedical record comprising more than 400 years; in modern Mexico is used for treating several maladies such as diabetes and gastric ulcers. Although the pharmacological actions of the stem-bark and leaves have been demonstrated, the phenological and geographical effect on the concentration of active principles remains unexplored.
  
  
  OBJECTIVE
  The main goals of this study were to analyze the amount of selected 4-phenylcoumarins and chlorogenic acid in the leaves in order to assess the best harvesting period, and consequently their pharmacological efficacy. In addition, the preclinical antidiabetic efficacy of the infusion of the leaves was corroborated using standard pharmacological tests.
  
  
  METHODS
  The aqueous extracts from the leaves of Hintonia latiflora were prepared by infusion. For phenological and geographical comparison, leaves of Hintonia latiflora were collected in two different regions in Chihuahua and Michoacán. The material was analyzed by UPLC applying an analytical method that developed and validated for this purpose following the ICH guidelines. Investigation of the antidiabetic action was accomplished using an acute hypoglycemic test and oral glucose and sucrose tolerance tests.
  
  
  RESULTS
  The validated analytical method was successfully applied for quantifying chlorogenic acid (1) and 4-phenylcoumarins (2-5) in the leaves of 12 different batches (1-12) during one-year period, and seven different batches for each geographical region; the concentration of the metabolites at the phenological cycle was significantly different, their concentration increased during the pre-senescence phase whereas in the leaf renovation stage the highest concentration of 2-5 was reached. The overall analysis of the active compounds concentration between the two populations investigated seems to be less important than the phenological variations. The aqueous extract of the leaves of Hintonia latiflora exerted its antidiabetic effect by different mechanisms showing comparable effect to the organic extract.
  
  
  CONCLUSIONS
  The findings of the present investigation reveal that the best harvest season for the leaves of Hintonia latiflora is between the leaves renovation and senescence stages avoiding the flowering period. In addition, no significant differences were found among the two different geographical populations analyzed. The infusions of the leaves, rich in 4-phenylcoumarins and chlorogenic acid, showed comparable antidiabetic action than the organic extract.
authors.affiliation: Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Mexico City 04510, Mexico. Electronic address: scristians@ciencias.unam.mx.
authors.forename: S
authors.initials: S
authors.lastname: Cristians
authors.affiliation: Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Mexico City 04510, Mexico.
authors.forename: R
authors.initials: R
authors.lastname: Mata
authors.affiliation: Jardín Botánico, Instituto de Biología UNAM, Mexico City 04510, Mexico.
authors.forename: R
authors.initials: R
authors.lastname: Bye
mesh_terms: D000818:Animals; D002726:Chlorogenic Acid / Q000302:isolation & purification / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D003374:Coumarins / Q000302:isolation & purification / Q000494:pharmacology*; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy; D007004:Hypoglycemic Agents / Q000302:isolation & purification / Q000494:pharmacology; D008297:Male; D008519:Medicine, Traditional; D008800:Mexico; D051379:Mice; D008813:Mice, Inbred ICR; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves; D019666:Rubiaceae / Q000737:chemistry* / Q000254:growth & development
chemical_list: D003374:Coumarins; D007004:Hypoglycemic Agents; D010936:Plant Extracts; C094411:4-phenylcoumarin; D002726:Chlorogenic Acid
keywords: 4-phenylcoumarins; Antidiabetic activity; Chlorogenic acid; Hintonia latiflora; Phenology