Characterization of element and mineral content in Artemisia annua and Camellia sinensis leaves by handheld X-ray fluorescence

Tea infusion is the most frequently worldwide consumed beverage next to water, with about 20 billion cups consumed daily. Artemisia annua leaves contain comparable levels of nutrients and mineral elements (dry matter basis) to many marketed tea (Camellia sinensis) leading us to suspect that this crop could also serve as an alternative source of nutrients for humans. Analyzer moveable X-ray fluorescence is used to evaluate the content of major, minor and toxic elements in A. annua from two different countries compared to six marketed tea in Senegal. To ensure qualified results, certified reference materials were used to perform the calibration. The very low and often negligible levels of inherent elements in the leaves, which are far below recommended toxic levels, establishes A. annua and selected marketed tea as a good reservoir of elements that might favour its use as a potential herbal tonic by humans. The mineral elements are present in different kinds of herbal leaves in various proportions depending on soil composition and the climate in which the plant grows.Keywords: X-ray fluorescence (XRF), Artemisia annua, Camellia sinensis, elements, leaves, medicinal plantAfrican Journal of Biotechnology Vol. 12(26), pp. 4179-418

Analysis of pfhrp2 genetic diversity in Senegal and implications for use of rapid diagnostic tests

Background: The Senegalese National Malaria Control Programme has recommended use of rapid diagnostic tests (RDTs) that target the histidine-rich protein 2 (HRP2), specific to Plasmodium falciparum, to diagnose malaria cases. The target antigen has been shown to be polymorphic, which may explain the variability in HRP2-based RDT results reported in field studies. The genetic diversity of the pfhrp2 gene has not been investigated in depth in many African countries. The goal of this study is to determine the extent of polymorphism in pfhrp2 among Senegal, Mali and Uganda parasite populations, and discuss the implications of these findings on the utility of RDTs that are based on HRP2 detection. Methods: Sequencing data from the pfhrp2 locus were used to analyze the genetic diversity of this gene among three populations, with different transmission dynamics and malaria parasite ecologies. Nucleotide diversity (π) and non-synonymous nucleotide diversity (πNS) were studied in the pfhrp2 gene from isolates obtained in Senegal. Amino acid repeat length polymorphisms in the PfHRP2 antigen were characterized and parameters of genetic diversity, such as frequency and correlation between repeats in these populations, were assessed. Results: The diversity survey of the pfhrp2 gene identified 29 SNPs as well as insertion and deletion polymorphisms within a 918 bp region. The Senegal pfhrp2 exhibited a substantial level of diversity [π = 0.00559 and πNS = 0.014111 (πS = 0.0291627)], similar to several polymorphic genes, such as msp1, involved in immune responses, and the gene encoding the SURFIN polymorphic antigen, which are surface exposed parasite proteins. Extensive repeat length polymorphisms in PfHRP2, as well as similar patterns in the number, organization and the type of predicted amino acid repeats were observed among the three populations, characterized by an occurrence of Type 2, Type 4 and Type 7 repeats. Conclusions: These results warrant deeper monitoring of the RDT target antigen diversity and emphasize that development of other essential genes as a target for diagnostic tools is critical