Cytochrome P450 single nucleotide polymorphisms in an indigenous Tanzanian population: a concern about the metabolism of artemisinin-based combinations.

BACKGROUND

Artemisinin-based combinations currently recommended for treatment of uncomplicated Plasmodium falciparum malaria in many countries of sub-Saharan Africa are substrates of CYP enzymes. The cytochrome enzyme system is responsible for metabolism of about 80-90% of clinically used drugs. It is, therefore, important to obtain the pharmacogenetics of the population in the region with respect to these combinations and thereby enable practitioners to predict treatment outcomes. The aim of this study was to detect and determine allelic frequencies of CYP2C82, CYP2C83, CYP3A41B, CYP3A53 and CYP2B6*6 variant alleles in a Tanzanian indigenous population.

METHODS

Genomic DNA extraction from blood obtained from 256 participants who escorted patients at Karume Health Centre in Mwanza Tanzania, was carried out using the Gene JET™ Genomic DNA purification kit (Thermo Scientific). Genotyping for the cytochrome P450 variant alleles was performed using predesigned primers. Amplification was done by PCR while differentiation between alleles was done by restriction fragment length polymorphism (PCR-RFLP) (for CYP2C82, CYP2C83) and sequencing (for CYP2B66, CYP3A53 and CYP3A4*1B).

RESULTS

CYP2C82, CYP2C83, CYP3A53, CYP3A41B and CYP2B6*6 variant allelic frequencies were found to be 19,10,16,78 and 36% respectively.

CONCLUSION

Prevalence of CYP2C82, CYP3A53, CYP3A41B and CYP2B66 mutations in a Tanzanian population/subjects are common. The impact of these point mutations on the metabolism of anti-malarial drugs, particularly artemisinin-based combinations, and their potential drug-drug interactions (DDIs) needs to be further evaluated.