title: Phytochemical screening, antioxidant, and antimicrobial activities of the crude leaves' extract from Ipomoea batatas (L.) Lam.
abstract: BACKGROUND
  Ipomoea batatas (L.) Lam., popularly known as sweet potato (SP), has played an important role as an energy and a phytochemical source in human nutrition and animal feeding. Ethnopharmacological data show that SP leaves have been effectively used in herbal medicine to treat inflammatory and/or infectious oral diseases in Brazil. The aim of this research was to evaluate the phytochemical, antioxidant, and antimicrobial activities of the crude leaves' extract of SP leaves.
  
  
  METHODS
  The screening was performed for triterpenes/steroids, alkaloids, anthraquinones, coumarins, flavonoids, saponins, tannins, and phenolic acids. The color intensity or the precipitate formation was used as analytical responses to these tests. The total antioxidant capacity was evaluated by the phosphomolybdenum complex method. Antimicrobial activity was made by agar disk and agar well diffusion tests.
  
  
  RESULTS
  The phytochemical screening showed positive results for triterpenes/steroids, alkaloids, anthraquinones, coumarins, flavonoids, saponins, tannins, and phenolic acids. Total contents of 345.65, 328.44, and 662.02 mg were respectively obtained for alkaloids, anthraquinones, and phenolic compounds in 100 g of the dry sample. The total antioxidant capacity was 42.94% as compared to ascorbic acid. For antimicrobial studies, no concentration of the SP freeze dried extract was able to inhibit the growth of Streptococcus mutans, S. mitis, Staphylococcus aureus, and Candida albicans in both agar disk and agar well diffusion tests.
  
  
  CONCLUSIONS
  SP leaves demonstrated the presence of secondary metabolites with potential biological activities. No antimicrobial activity was observed.
authors.affiliation: Department of Pharmacology, Anesthesiology and Therapeutics, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil.
authors.forename: Márcia Thaís
authors.initials: MT
authors.lastname: Pochapski
authors.forename: Eliana Cristina
authors.initials: EC
authors.lastname: Fosquiera
authors.forename: Luís Antônio
authors.initials: LA
authors.lastname: Esmerino
authors.forename: Elizabete Brasil
authors.initials: EB
authors.lastname: Dos Santos
authors.forename: Paulo Vitor
authors.initials: PV
authors.lastname: Farago
authors.forename: Fábio André
authors.initials: FA
authors.lastname: Santos
authors.forename: Francisco Carlos
authors.initials: FC
authors.lastname: Groppo