title: Effects of Tapinanthus globiferus and Zanthoxylum zanthoxyloides extracts on human leukocytes in vitro.
abstract: OBJECTIVE
  This study aimed at investigating the genotoxicity and cytotoxicity effect of Tapinanthus globiferus and Zanthoxylum zanthoxyloides to human leukocytes. In addition, the reductive potential and the chemical composition of the two plant extracts were also determined.
  
  
  METHODS
  Human leukocytes were obtained from healthy volunteer donors. The genotoxicity and cytotoxicity of T. globiferus and Z. zanthoxyloides were assessed using the comet assay and trypan blue exclusion, respectively. The antioxidant activity of the plant extracts was evaluated by the reducing power assay. Furthermore, high-performance liquid chromatography-diode array detector was used to characterize and quantify the constituents of these plants.
  
  
  RESULTS
  T. globiferus (10-150 µg/mL) was neither genotoxic nor cytotoxic at the concentrations tested, suggesting that it can be consumed safely at relatively high concentrations. However, Z. zanthoxyloides showed cytoxicity and genotoxicity to human leukocytes at the highest concentration tested (150 µg/mL). In addition, the total reducing power of T. globiferus was found higher than Z. zanthoxyloides in potassium ferricyanide reduction. Both plants extract contained flavonoids (rutin and quercetin) and phenolic acids (chlorogenic and caffeic).
  
  
  CONCLUSIONS
  The results obtained support the fact that some caution should be paid regarding the dosage and the frequency of use of Z. zanthoxyloides extract.
authors.affiliation: Department of Biochemistry, Federal University of Technology, PMB 704, Akure, Ondo, Nigeria.
authors.forename: Yetunde
authors.initials: Y
authors.lastname: Ogunbolude
authors.affiliation: Department of Chemistry, Abdul Wali Khan University, Mardan Pakistan.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ibrahim
authors.affiliation: epartment of Biochemistry, Adekunle Ajasin University, Akungba, Akoko, Ondo State, Nigeria.
authors.forename: Olusola Olalekan
authors.initials: OO
authors.lastname: Elekofehinti
authors.affiliation: Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria.
authors.forename: Adekunle
authors.initials: A
authors.lastname: Adeniran
authors.affiliation: Department of Biochemistry, Drug Metabolism and Molecular Toxicology Research Laboratories, Faculty of Basic Medical Sciences, College of Medicine, University of Ibadan, Ibadan, Nigeria.
authors.forename: Amos Olalekan
authors.initials: AO
authors.lastname: Abolaji
authors.affiliation: Department of Biochemistry and Molecular Biology, Post-Graduate Program in Biochemical Toxicology, Federal University of Santa Maria, Santa Maria-RS, CEP 97105-900, Brazil.
authors.forename: João Batista Teixeira
authors.initials: JB
authors.lastname: Rocha
authors.affiliation: Department of Biochemistry and Molecular Biology, Post-Graduate Program in Biochemical Toxicology, Federal University of Santa Maria, Santa Maria-RS, CEP 97105-900, Brazil ; Department of Biochemistry, Institute of Basic Health Science, Federal University of Rio Grande do Sul, Porto Alegre, CEP 90035-003, RS, Brazil.
authors.forename: Jean Paul
authors.initials: JP
authors.lastname: Kamdem
keywords: Cytoxicity; Tapinanthus globiferus; Zanthoxylum zanthoxyloides; genotoxicity; high performance liquid chromatography-diode array detector