title: Effect of dehusked Garcinia kola seeds on the overall pharmacokinetics of quinine in healthy Nigerian volunteers.
abstract: We investigated the effect of concurrent ingestion of Garcinia kola seed on the pharmacokinetics of quinine. In a randomized crossover study, 24 healthy Nigerian volunteers were assigned into 2 groups (A and B; n = 12 per group) on the basis of G. kola dose orally ingested. Each subject received 600 mg quinine sulfate before and after ingesting 12.5 g of G. kola once daily for 7 days (group A) or 12.5 g twice daily for 6 days and once on the seventh day (group B). Blood samples were collected and analyzed for plasma quinine and its metabolite (3-hydroxyquinine) using a validated high performance liquid chromatography method. Concurrent administration of quinine with G. kola reduced quinine tmax by 48% (group A), mean Cmax by 19% and 26% in groups A and B, respectively, and slight reduction in mean AUC0- ∞ of quinine in both groups. 3-hydroxyquinine Cmax also reduced by 29% and 32%; AUC0-∞ by 13% and 9%, respectively. The point estimates of the T/R ratio of the geometric means for all Cmax obtained and only the AUC0-∞ at a higher dose of G. kola were outside the 80%-125% bioequivalence range. In conclusion, an herb-drug interaction was noted with concurrent quinine and G. kola administration.
authors.affiliation: Department of Clinical Pharmacy and Pharmacy Administration, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria.
authors.forename: Sharon I
authors.initials: SI
authors.lastname: Igbinoba
authors.affiliation: Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria.
authors.forename: Cyprian O
authors.initials: CO
authors.lastname: Onyeji
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria.
authors.forename: Moses A
authors.initials: MA
authors.lastname: Akanmu
authors.affiliation: Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria.
authors.forename: Julius O
authors.initials: JO
authors.lastname: Soyinka
authors.affiliation: Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA.
authors.forename: Srirama Sarma V V
authors.initials: SS
authors.lastname: Pullela
authors.affiliation: Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Cook
authors.affiliation: School of Medicine-Greenville, University of South Carolina, Greenville, SC, USA.
authors.forename: Thomas I
authors.initials: TI
authors.lastname: Nathaniel
mesh_terms: D000284:Administration, Oral; D000328:Adult; D019540:Area Under Curve; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid; D018592:Cross-Over Studies; D019587:Dietary Supplements / Q000009:adverse effects; D004347:Drug Interactions; D005260:Female; D029763:Garcinia kola; D006207:Half-Life; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D009549:Nigeria; D011802:Quinidine / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D011803:Quinine / Q000008:administration & dosage / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*; D012639:Seeds; D013810:Therapeutic Equivalency; D055815:Young Adult
chemical_list: C013569:3-hydroxyquinidine; D011803:Quinine; D011802:Quinidine
keywords: 3-hydroxyquinine; Garcinia kola; drug-herb interactions; pharmacokinetics; quinine