Alkaloids from Plants with Antimalarial Activity: A Review of Recent Studies.

Philip F Uzor

doi:10.1155/2020/8749083

Abstract

Malaria is one of the major health problems in developing countries. The disease kills a large number of people every year and also affects financial status of many countries. Resistance of the plasmodium parasite, the causative agent, to the existing drugs, including chloroquine, mefloquine, and artemisinin based combination therapy (ACT), is a serious global issue in malaria treatment and control. This warrants an urgent quest for novel compounds, particularly from natural sources such as medicinal plants. Alkaloids have over the years been recognized as important phytoconstituents with interesting biological properties. In fact, the first successful antimalarial drug was quinine, an alkaloid, which was extracted from Cinchona tree. In the present review work, the alkaloids isolated and reported recently (2013 till 2019) to possess antimalarial activity are presented. Several classes of alkaloids, including terpenoidal, indole, bisindole, quinolone, and isoquinoline alkaloids, were identified with a promising antimalarial activity. It is hoped that the reports of the review work will spur further research into the structural modification and/or development of the interesting compounds as novel antimalarial drugs.

Highlights

Malaria is an extremely dangerous parasitic disease with ravaging effects in several parts of the world. e World Health Organization (WHO) estimate shows that approximately 3.3 billion people are living at risk places of malaria
Malaria has been treated with quinine, chloroquine, amodiaquine, mefloquine, and artemisinin derivatives (Figure 1), among other drugs. e alkaloidal drug, quinine, is the first antimalarial drug isolated from Cinchona bark. e drug is still quite useful in the treatment of multidrugresistant malaria
Artemisinin and its semisynthetic analogs artemether, artether, and artesunate are potent antimalarial agents especially used in the regions where the resistance has developed to other antimalarial agents. e WHO recommends the use of artemisinin analogs in combination with other drugs (ACT) for the treatment of malaria in order to control resistance

Summary

Introduction

Malaria is an extremely dangerous parasitic disease with ravaging effects in several parts of the world. e World Health Organization (WHO) estimate shows that approximately 3.3 billion people are living at risk places of malaria. Malaria has been treated with quinine, chloroquine, amodiaquine, mefloquine, and artemisinin derivatives (Figure 1), among other drugs. Chloroquine, a 4-aminoquinoline, was developed in the 1940s as a synthetic derivative from quinine. It was effective, cheap, and less toxic and was the drug of choice for malarial treatment for decades; its use has been restricted in modern malaria therapy due to parasite resistance to the drug [5, 6]. Mefloquine is structurally related to quinine and has been introduced to treat chloroquine-resistant malaria, though its use is limited because of resistance and neuropsychiatric side effects [7]. E WHO recommends the use of artemisinin analogs in combination with other drugs (ACT) for the treatment of malaria in order to control resistance. There have been reports of parasite resistance to the ACT [8]

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Findings

Conclusion