Abstract

Garcinia kola seed is a commonly used social masticatory agent in Africa and is believed to possess many useful medicinal properties. The effect of the seed of G. kola Heckel on the salivary pharmacokinetics of ofloxacin was studied in healthy human volunteers. In a 2-way crossover design, ten healthy human volunteer received oral dose of 200 mg ofloxacin and saliva samples were collected and analyzed (previous studies have established good correlation between the saliva and serum pharmacokinetics of ofloxacin). After a 2-week washout period, the volunteers again received 200 mg ofloxacin in addition to G. kolaseeds, and saliva samples were collected and analyzed. The pharmacokinetic studies showed that ingestion of G. kola altered ofloxacin pharmacokinetics since it caused significant reductions in C_max (6.85 to 5.14 μg/ml), AUC (64.65 to 50.02 μg/h/ml) and K_a(2.53 to 1.58/h) while there was a significant increase in CL_T (69.29 to 86.35 ml/min). A non-significant reduction and increment was recorded for T_1/2 (1.21 to 0.98 h) and T_max(1.2 to 1.7 h) respectively. These data show that G. kola impairs the bioavailability of ofloxacin by a possible chelate formation between ofloxacin and flavonoid constituents ofG. kola seed and by a reduction in the gastric emptying rate.

Key words: Garcinia kola seed, ofloxacin bioavailability, pharmacokinetic, humans, adaptogen.