Identification of key components in water extracts of tea (Camellia Sinensis) using UPLC-PDA-ESiMS and evaluation of their possible antimalarial properties

Abstract

This study used a semi-quantitative approach to examine how water extracted green and black tea (Camellia Sinensis) inhibits the formation of β-hematin in-vitro. LC-PDA-ESi-MS analysis of the tea extracts revealed that they contain many active catechins. When compared to the positive control, chloroquine, the results demonstrated that black water extracts had a considerable anti-malarial potential even at significantly lower dosages, while the green tea water extracts showed no effect. However, when a bicarbonate solution was used to create the green tea infusion, the result was similarly effective to the positive control. Additionally, there was no difference in β-hematin formation when the black tea was prepared at various time points (freshly prepared vs. 24-48 hours of incubation). The absence of time-dependent effects suggests that the in-vitro assay is unaffected by oxidation or any other changes that may have occurred in the extracts and solely reacts to stable active compounds or minerals that prevent β-hematin formation. The diverse combined catechins present in the tea extracts were efficient in forming a favorable complex with free heme, thereby preventing β-hematin formation, which could irreversibly harm the plasmodium parasite during the intraerythrocytic stage.