Antimalarial activity of traditional Kampo medicine Coptis Rhizome extract and its major active compounds

Abstract

Background: The herbal medicine has been an attractive source of new antimalarial drugs exemplified by quinine and artemisinin, thus we examined a variety of Japanese traditional herbal medicine (Kampo) for their potential antimalarial activities.Methods: We designed a comprehensive screening to identify novel antimalarial drugs from a library of Kampo crude drug extracts (n = 120). The antimalarial activity was initially evaluated in vitro against chloroquine/mefloquine-sensitive (3D7) and -resistant (Dd2) strains of Plasmodium falciparum. The cytotoxicity was also evaluated using primary Adult Mouse Brain cells. Subsequently, major active components of Kampo crude drug extracts showing high antimalarial activities and low cytotoxicity were further evaluated. Finally, the in vivo antimalarial activities of promising Kampo crude drug extract was investigated using P. yoelii infected mouse model in a seven-day suppressive test (treatment start two hours after challenge infection and continue for seven days).Results: Out of 120 extracts, Coptis Rhizome showed the highest antimalarial activity (IC50 1.9 µg/mL of 3D7 and 4.85 µg/mL of Dd2) with a high selectivity index (SI) > 263 (3D7) and > 103 (Dd2). Three major components in Coptis Rhizome also showed antimalarial activities with IC50 ranging from 1.1 to 6.0 µM (against 3D7) and from 3.1 to 11.8 µM (against Dd2). Among them, coptisine chloride exhibited the highest antimalarial activity (IC50 1.1 µM against 3D7 and 3.1 µM against Dd2) with SI of 37.8 and 13.2, respectively. Furthermore, Coptis Rhizome exhibited significant antimalarial activity in mice infected with P. yoelii 17X strain with respect to its activity on parasite suppression consistently throughout the entire test period (P < 0.05).Conclusion: Coptis Rhizome showed a significant in vivo antimalarial activity in mice infected with P. Yoelii, thus it is a potential natural resource for antimalarials and its component coptisine chloride is a promising antimalarial lead compound.

In vivo assessment of the antimalarial activity and acute oral toxicity of an ethanolic seed extract of Spondias pinnata (L.f.) Kurz

“…Currently, malaria remains a serious public health problem in several regions, especially tropical and subtropical zones [1][2][3], because it is a primary cause of morbidity and mortality. According to the World Health Organization (WHO) report in 2020 [4], there are approximately 229 million cases of malaria worldwide and 0.5 million deaths per year [5,6].…”