Plant-derived antimalarial agents: new leads and efficient phythomedicines. Part I. Alkaloids

Abstract

Malaria remains one of the most serious world health problem and the major cause of mortality and morbidity in the endemic regions. Brazil is among the 30 high-burden countries and most of the cases occur in the Legal Amazonian Region. New chemotherapeutical agents are needed for the treatment of malaria. Many plant species are used in traditional medicines of malarious countries and a relatively few number of these have been investigated for evaluation of their antimalarial effect. Still lower is the number of those that have had the active natural compounds isolated and the toxicity determined. This area is, then, of great research interest. A discovery project of antimalarial natural products from plants traditionally used to treat malaria must include in vitro and in vivo assays as well as bioguided isolation of active compounds. The final products would be antimalarial chemical entities, potential new drugs or templates for new drugs development, and/or standardized antimalarial extracts which are required for pre-clinical and clinical studies when the aim is the development of effective and safe phythomedicines. This review discusses these two approaches, presents briefly the screening methodologies for evaluation of antimalarial activity and focuses the activity of alkaloids belonging to different structural classes as well as its importance as new antimalarial drugs or leads and chemical markers for phytomedicines.

In-Vivo Screening of Antiplasmodial Activity of Methanolic Leaf Extract of Albizia chevalieri against Plasmodium Berghei Model

“…The result of the current study revealed that the leaf extract of Albizia chevalieri prolong the survival time of an infected rat in the four day suppressive test. Plant materials that can prolong the survival time of infected experimental animals compared to the negative control are considered active agents against malaria (Oliveira et al, 2009). Which is in line with the current study.…”

Therapeutic Potentials of Ethanolic Extract of Leaves of Holarrhena Floribunda (G. Don) Dur. And Schinz (Apocynaceae)

“…Mean survival time is another parameter evaluates the antimalarial activity of plant extracts. Accordingly, a plant material that can prolong the survival time of infected experimental animals compared to the negative control is considered as active agent against malaria (Oliveira et al, 2009). In this study, statistically, the mice treated with 500 mg/kg of extract had significantly lived longer than negative control and this could be attributed to parasitemia suppression effect of the extract.…”

In vitro antiplasmodial effect of ethanolic extracts of coastal medicinal plants along Palk Strait against Plasmodium falciparum

“…Among the tested extracts, the stem extracts of A. indica and J. glandulifera showed IC 50 value (43.81 毺 g/mL, 49.14 毺 g/mL respectively) at 2.3 fold and 2.6 fold concentration of positive control chloroquine respectively. This might be due to the presence of glycosides, alkaloids, flavonoids, phenol and tannins [3,[25][26][27] . According to Rasoanaivo et al 14%, 57% and 29% of extracts from medicinal plants were classified as active, weakly active and inactive respectively [22] .…”